mixed crop-livestock farming systems … crop-livestock farming systems for the inland northwest ......
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MIXED CROP-LIVESTOCK FARMING SYSTEMS FOR THE INLAND NORTHWEST, US
By
STEPHEN GEORGE BRAMWELL
A thesis submitted in partial fulfillment of the requirements for the degree of
MASTER OF SCIENCE IN SOIL SCIENCE
WASHINGTON STATE UNIVERSITY Department of Crop and Soil Science
DECEMBER 2008
To the Faculty of Washington State University:
The members of the Committee appointed to examine the thesis of STEPHEN GEORGE BRAMWELL find it satisfactory and recommend that it be accepted.
___________________________________ Chair ___________________________________ ___________________________________
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ACKNOWLEDGMENT
I would like to acknowledge my mother, father and sister, who have provided a loving,
supportive and engaging family environment throughout my life. Their support has given me the
security to branch out, keep exploring, and eventually find my calling in sustainable agriculture.
At the same time, their questions, perspectives and jesting challenges to my thinking and
decisions have inspired me to truly understand my path and perspectives.
Special thanks goes to my wonderful partner, Katrina Prime, whose pragmatism and
common sense help bring wandering and overly-complicated thoughts back to solid ground. Her
support and love has been essential throughout the last five years of our life together. I would
think it utterly impossible to maintain the high quality of life and undertake the work that I have,
without her.
My deep gratitude also goes to my committee. Lynne Carpenter-Boggs was daring
enough to coax a rangy organic farmer into a graduate program at WSU, and then patient enough
to let me pursue an uncommon and complicated line of research. Her editing craft with a #2
pencil, deftness in making key organizational decisions, and cool head when projects went awry,
will continue to be a model for me. Thank you to Dave Huggins for putting in critical editing
time. Only with his help have I truly come to understand the critical line between what we know
and don’t know—and perhaps more importantly, how and why to honor that line. John Reganold
provided key insight on how to bring this thesis to satisfactory and proper wholeness. I hope to
carry forward his wisdom in not mistaking fascinating details for the story that needs, and
actually can, be told.
My thanks also goes to Sean Wetterau, Dave Uberuaga, Derek Appel and numerous other
research technicians who maintain a critical research continuity at WSU. Managing
unpredictable livestock, hauling equipment around the state, and connecting technical research
dots would have been impossible without their help.
iii
MIXED CROP-LIVESTOCK FARMING SYSTEMS FOR THE INLAND NORTHWEST, US
Abstract
by Stephen George Bramwell M.S.
Washington State University December 2008
Chair: Lynne Carpenter-Boggs
Challenges to agricultural resource management and maintenance of farm profitability
confront Palouse agriculture. Mixed crop-livestock farming systems have been viewed as
alternative production models that may improve agriculture’s impacts on soil, water, energy and
other resources, as well as to improve economic performance. Almost no current regional data on
mixed crop-livestock systems for the Palouse region exists, however, and up-to-date research is
needed to gain a sense of their potential.
In chapter 1 of this thesis, I identify the potential for mixed cropping systems in the
Palouse region, briefly review the benefits and challenges for mixed systems in other regions,
present regional research relevant to mixed systems in the Palouse, and identify research
opportunities for crop-livestock systems. Research data from the mid-1900s in the Palouse, and
recent scientific literature from other regions, were used to identify advantages and
disadvantages, research and development needs, and strategies with respect to development and
application of mixed crop-livestock systems. Many Washington State University research
bulletins from the 1930s to the 1960s are relevant to both identifying and addressing current
needs. Researchers documented increased forage carrying capacity using rotational grazing
management and grass-alfalfa pasture mixes, changes in farmland acreage used for grazing and
iv
forage crops, and a cattle production system for the region including a pasturing period and
feeding strategies. Extra-regional literature was used to identify strengths, weaknesses and
research opportunities of mixed systems with respect to potential benefits and drawbacks,
climatic determinants in optimizing mixed systems, optimizing potential grazing resources in the
Palouse, economic outlooks, organic methods, no-till systems, and climate change.
In chapter 2 of this thesis, agronomic and economic questions regarding adaptation of
mixed crop-livestock farming systems to the Palouse region are addressed. In a farm system that
rotates annual crops with perennial forage on the same field, perennials must be effectively
terminated to prepare for annual crops. In an organic system on erodible soil, both herbicides
and intensive tillage would be eschewed. Little is known about the profitability of these
integrated systems, how to terminate persistent pastures without chemicals or a moldboard plow,
and the effect of tillage methods on N availability for subsequent annual crops. The objective of
this research was to assess the performance of a Triticale (× Triticosecale) grain crop following
grazed alfalfa terminated with different methods of tillage. Treatments were moldboard plowing
or low soil disturbance under-cutting sweeps. Intact alfalfa served as control. Soil inorganic
nitrogen (N), grain yield, tillage effectiveness, and profitability were assessed. Soil NO3-N
accumulated in low disturbance treatments. Organic unfertilized Triticale grain yield was
positively correlated to degree of disturbance, ranging from 1630 to 4200 kg ha-1, and yield was
negatively correlated with alfalfa re-growth. Returns over total costs of a grazed alfalfa-wheat
rotation (GGR: $168 ac-1) were roughly half those of a hayed alfalfa-wheat rotation (HGR: $341
ac-1). The profitability of the hayed alfalfa-grain rotation responded sharply to changes in prices
paid for organic alfalfa hay. The addition of wheat production to continuously grazed alfalfa
(CG) increased returns over total cost considerably. Potential to improve soil quality through
v
grazed forages in crop-pasture rotations appears to compete with the profitability of hayed
systems, and low-disturbance tillage methods still need refining to ensure soil conservation
during perennial to annual transition.
vi
TABLE OF CONTENTS Page ACKNOWLEDGEMENTS................................................................................................ iii ABSTRACT.........................................................................................................................iv LIST OF TABLES............................................................................................................ viii LIST OF FIGURES .............................................................................................................ix GENERAL INTRODUCTION.............................................................................................1 RESEARCH AND DEVELOPMENT NEEDS FOR MIXED CROP-LIVESTOCK FARMING SYSTEMS IN THE INLAND NORTHWEST, U.S. Abstract ........................................................................................................................9 Introduction................................................................................................................10 The need for alternative systems in the Palouse region.............................................12 Mixed systems in other regions of the world.............................................................14 Regional research relevant to mixed systems in the Palouse.....................................20 Research opportunities for mixed systems ................................................................24 Conclusions................................................................................................................33 References..................................................................................................................36 TILLAGE AND INTEGRATION EFFECTS ON NITROGEN AND PROFIT OF CROP AND LIVESTOCK AGRICULTURE ON THE COLUMBIA PLATEAU Abstract ......................................................................................................................52 Introduction................................................................................................................53 Materials and methods ...............................................................................................57 Results .......................................................................................................................67 Discussion..................................................................................................................79 Acknowledgements....................................................................................................86 References..................................................................................................................87 GENERAL CONCLUSION ...............................................................................................90 APPENDIX I. Distribution of crop-livestock papers by year and world region ................96 APPENDIX II. Enterprise budgets and supporting material for cost-benefit analysis.......97 APPENDIX III. SAS code and explanations......................................................................98
vii
LIST OF TABLES
1.1. Typical nitrogen fertilizer application for a New Zealand ley-wheat cropping
system compared to a Palouse wheat-pea rotation .................................................16
1.2. Rates of infiltration, erosion and runoff on land in winter wheat under different
cropping systems during the December 1945 storm...............................................17
1.3. Average yields per ha of companion crops and Spanish sweetclover ....................22
1.4. Productivity of grass and grass-alfalfa pastures......................................................23
1.5. Proportionate distribution of land use acres in Washington, 1936 .........................23
2.1. Tillage and seeding operations................................................................................58
2.2. Budget assumptions ................................................................................................65
2.3. Seasonal soil inorganic N fluctuation at 0-150 cm depth following different
methods of tillage to terminate alfalfa ....................................................................68
2.4. Triticale grain yield, aboveground biomass, number of surviving alfalfa crowns,
and weed index at grain harvest on July 12, 2007 ..................................................69
2.5. Summarized costs and returns of rotation components for organic grazed alfalfa-
wheat, hayed alfalfa-wheat and continuously grazed alfalfa ..................................73
2.6. Summarized costs and returns for organic grazed alfalfa-wheat, hayed alfalfa-
wheat and continuously grazed alfalfa....................................................................74
2.7. Average annual variable costs, ownership costs and returns for organic grazed
alfalfa-wheat, hayed alfalfa-wheat and continuously grazed alfalfa ......................77
2.8. Effects of price variation on alfalfa, wheat and beef on net returns of organic
grazed alfalfa-wheat, hayed alfalfa-wheat and continuously grazed alfalfa...........78
viii
LIST OF FIGURES
1.1. Palouse River basin watershed with land use designations. ...................................12
1.2. Annual numbers of published crop-livestock studies in 2000 - 2007.....................15
1.3. Monthly mean, maximum and minimum temperatures in Pullman, WA...............25
1.4. Monthly mean precipitation at the WSU/USDA-ARS field station .......................25
2.1. Baseline fall soil NO3-N and PMN under alfalfa....................................................70
2.2. Non-incubated NO3-N in top 150 cm soil from fall 2006 to fall 2007...................70
2.3. Fall 2007 soil PMN by depth and treatment ...........................................................70
2.4. Fall 2007 soil NO3-N by depth and treatment ........................................................70
2.5. Spring 2007 soil PMN by depth and treatment.......................................................71
2.6. Spring 2007 soil NO3-N by depth and treatment ....................................................71
2.7. Summer 2007 soil PMN by depth and treatment....................................................71
2.8. Summer 2007 soil NO3-N by depth and treatment .................................................71
2.9. Spring 2007 soil moisture by depth and treatment .................................................72
2.10. Summer 2007 soil moisture by depth and treatment ..............................................72
2.11. Fall 2007 soil moisture by depth and treatment......................................................72
2.12. Aboveground biomass at grain harvest...................................................................72
2.13. Annual variable costs of different rotation components .........................................74
2.14. Annual returns over total costs for rotation components ........................................76
2.15. Budget summary for organic a grazed alfalfa-grain rotation, a hayed alfalfa-grain rotation
and a continuously grazed rotation .........................................................................77
2.16. Sensitivity analysis of different crop rotations in response to changing prices for alfalfa,
wheat and beef ........................................................................................................84
ix
GENERAL INTRODUCTION
Mixed crop livestock farming systems—used interchangeably here with integrated
systems—consist of crops and livestock incorporated in spatially and/or temporally overlapping
ways on individual farms, or between nearby farms. The integration of these two production
systems is very old, and is thought to have arisen between 8 and 10 millennia ago (Russelle et
al., 2007). There are, and have been, many reasons why farmers adopt mixed systems.
Traditionally, livestock have been used to take advantage of land not suitable for arable crop
production, provide traction for primary soil tillage, store wealth and represent prestige, turn
inedible cellulosic plant matter into food or other products useful to humans, transfer fertility
from extensive grazing areas to concentrated cropping areas, and speed the cycling of nutrients
between crops and forage resources.
Mixed farming systems are highly diverse, and include cattle-coconut integration in Sri
Lanka (Anonymous, 2001), rice/wheat/cattle/sheep/goat rotations in India, combinations of rice,
vegetables, pigs, ducks and fish in Thailand (Devendra, 2002), peanut-bahiagrass systems in the
southeast, U.S. (Katsvairo, 2006), the four-course Norfolk rotation in England (Schiere, 2002),
and the sheep-wheat farming systems of Australia and New Zealand, to name a few. Those
systems drawn upon most extensively in this thesis are the Australian and New Zealand models.
Rotations practiced in these countries include (i) single-year alternations between grain and
grazed legumes on the same field, (ii) longer rotations of 3-12 or more years of perennial grasses,
legumes, or mixes followed by an equal or lesser duration of annual crops (phase systems), and
(iii) grazing and resource-sharing collaborations between separate crop and livestock producers
in close proximity, though these are more common in European variations on these systems
(Groot, 2003).
1
Today, mixed systems fulfill many of the functions they traditionally have in developing
countries, particularly when access to off-farm resources is limited (Thomas, 2002; Devendra,
2002, Schiere, 1999). Crop-livestock integration has been useful under these circumstances by
making efficient use of on-site natural resources to produce multiple farm products, providing
biological options for weed and pest control, and recycling nutrients for continued soil fertility
(Franzluebbers et al., 2007).
In European countries, the U.S., Canada, Australia and New Zealand, there appears to be
a general increase in interest in mixed crop-livestock systems evidenced in the increasing
number of studies on the topic in these regions (Chapter 1, Fig 1.2). This may be the result of
concerns over the sustainability of conventional agriculture worldwide. Crop-livestock
integration has been common since mid-century in Australia and New Zealand (Puckridge and
French, 1983), and is considered to be one of the more sustainable models for farming in the
world (Loi, 2005). By contrast, in the U.S. production of crops and livestock has become more
specialized since the 1950s, and more reliant on off-farm inputs for fertility, weed control, and
animal feeds (Kirschenman, 2007). Concerns that U.S. agriculture is unsustainable emerge from
increased fertilizer and fuel costs (Hinman, 2005; USDA, 2008), energy-dependence of the US
food system in light of constricting petroleum supply (Pimentel et al., 2008), effects of
agriculture on biodiversity both globally (Cassman and Wood, 2005) and locally (Noss et al.,
1995), interactions between agricultural chemical use and human health (Benbrook et al., 2008),
contribution of soil organic matter oxidation to global climate change (Lal, 2007), and impacts of
agricultural chemicals on freshwater and marine ecosystems (Mitsch et al., 2001; Tilman et al.,
2002) and groundwater (Barbash et al., 2001)
2
Farming systems and management options that have emerged to address aspects of
agricultural sustainability/unsustainability in the US include organic agriculture (Delate et al.,
2003), biodynamic agriculture (Carpenter-Boggs et al., 2000), conservation tillage (Huggins and
Reganold, 2008), localized agriculture (Edwards-Jones et al., 2008), and many others.
In recent years, reintegration of crop and livestock farming systems has been considered
to address some problems with specialized, input-intensive agriculture in the US, Canada and
elsewhere (Russelle et al., 2007). Particularly with respect to off-farm inputs, it has been
suggested that mixed systems may provide a useful alternative to specialized systems if access to
these off-farm resources becomes restricted (Schiere et al., 2002). Specifically, problems with
the disposal of livestock ‘wastes’ may preference reintegration of specialized crop and livestock
systems (Naylor et al, 2005). And mixed systems may be called upon for their potential to reduce
agricultural energy use (Hoeppner et al., 2007), provide biological options for pest control
(Goosey et al., 2005; Langer, 2001), provide an alternative source of on-farm soil fertility (Allen
et al., 2008), and improve various parameters of soil quality (Fliessbach et al., 2007; Riley et al.,
2008).
The functions, strengths, weaknesses and future research opportunities concerning mixed
systems have been studied considerably in many regions of the world, and research attention is
increasing. However, it has been noted that more research is needed on crop-livestock systems
under the economic, policy, climatic and edaphic conditions in which they may be developed and
utilized (Entz et al., 2002). In the approximately 2 million acre Palouse River basin region of the
inland Northwest, US, a valuable body of research exists from the mid 1900s that is relevant to
current mixed crop-livestock research. Still, given the relative absence of these systems from
3
modern Palouse farming systems (Hardesty and Tiedeman, 1996), considerable basic research is
needed to assess the potential viability of these farming systems for the region today.
The goals of this graduate research project were to (1) review available research and
farmer experience on crop-livestock systems around the world, review regionally available
literature potentially relevant to this field, and identify areas of potential future research activity,
and (2) undertake basic research concerning N cycling, use of conservation tillage and economic
assessments for mixed systems in the Palouse. This thesis is separated into two chapters that
address these general goals.
In chapter one of this paper, I (i) identify the potential for mixed cropping systems in the
Palouse region, (ii) briefly review the benefits and challenges for mixed systems in other regions,
(iii) present regional research relevant to mixed systems in the Palouse, and (iv) identify research
opportunities for crop-livestock systems.
In chapter two I take up an important management challenge of mixed crop-livestock
farming and compare economic alternatives for integrated or non-integrated management
systems in the Palouse region. One critical management challenge is converting persistent
perennial pastures to annual crops without chemical controls, excessive N loss, or excessive
tillage. Given the hilly, erosion-prone topography of the Palouse, conservation tillage approaches
to perennial-annual conversion are preferable in Palouse crop-livestock systems seeking to
eliminate or reduce herbicide applications. The impact of tillage methods on N mineralization
following pasture break-up has been examined for crop-livestock systems. This is an area where
considerable disagreement exists as to whether tillage increases, decreases, or does not impact
subsequent plant available N, and how these dynamics over a full growing season (Lloyd, 1992;
Mohr et al., 1999; Weil et al., 1993). The potential of crop-livestock systems to lose N through
4
leaching and volatilization has been observed elsewhere (Berntsen et al., 2006; Huggins et al.,
2001; Lloyd, 1992), and is an important consideration in the environmental sustainability of such
a system. In chapter two we begin to address some of these questions with respect to N cycling,
and the impact of different methods of tillage on soil inorganic N and pasture eradication.
Then I examine the economic potential of three organic production systems involving
forages (grazed and hayed) in crop rotations because economic viability influences efforts to use
resources sustainably. I assess the financial performance of a grazed alfalfa-wheat rotation, a
hayed alfalfa-wheat rotation, and grassfed beef production with no integration of crop
production.
In chapter two, my objectives are to (i) monitor N dynamics (leaching and availability)
following the termination of long-term alfalfa forage using different methods of tillage, (ii)
quantify grain yield potential following terminated alfalfa, and assess the impact of tillage
method on yield, (iii) assess the viability of a conservation tillage method to terminate alfalfa in
comparison with moldboard plow, and (iv) investigate the economic performance of three
organic cropping systems: (a) wheat integrated into continuously grazed alfalfa pasture, (b)
wheat integrated with a alfalfa hay enterprise, and (c) continuously grazed alfalfa production
with no grain component.
This study is organized by the potential benefit of crop-livestock farming systems, an
apparent need to improve the sustainability of agriculture in the Palouse region, and the
numerous obstacles and opportunities for diversifying wheat-based production systems in the
Palouse with grazed forages. A focus on research needs followed by an on-farm trial targeting
specific problems was adopted to inspire continued interest in this field, provide a research
example to build on, and identify the most pressing and promising topics for future work.
5
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RESEARCH AND DEVELOPMENT NEEDS FOR MIXED CROP-LIVESTOCK FARMING SYSTEMS IN THE INLAND NORTHWEST, US
Bramwell, S.G.1, L.Carpenter-Boggs2, D.R. Huggins3, J.P. Reganold4
(to be submitted to Agronomy Journal) 1 Washington State University, Dept. of Crop and Soil Sciences, PO Box 646420, Pullman, WA. 99164-6420, USA, E-Mail: [email protected].
2 Washington State University, Center for Sustaining Agriculture and Natural Resources, PO Box 646420, Pullman, WA. 99164-6420, USA, Email: [email protected].
3 U.S. Department of Agriculture, Agricultural Research Services, PO Box 646420, Pullman, WA. 99164-6420, USA, Email: [email protected].
4 Washington State University, Dept of Crop and Soil Sciences. PO Box 646420, Pullman, WA. 99164-6420. USA. E-mail: [email protected].
ABSTRACT
Challenges to agricultural resource management and maintenance of farm profitability
confront Palouse agriculture. Mixed crop-livestock farming systems have been viewed as
alternative production models that may improve agriculture’s impacts on soil, water, energy and
other resources, as well as to improve economic performance. Almost no current regional data on
mixed crop-livestock systems for the Palouse region exists, however, and up-to-date research is
needed to gain a sense of their potential. Research data from the mid-1900s in the Palouse, and
recent scientific literature from other regions, were used to identify advantages and
disadvantages, research and development needs, and strategies with respect to development and
application of mixed crop-livestock systems. Many Washington State University research
bulletins from the 1930s to the 1960s are relevant to both identifying and addressing current
needs. Researchers documented increased forage carrying capacity using rotational grazing
management and grass-alfalfa pasture mixes, changes in farmland acreage used for grazing and
forage crops, and a cattle production system for the region including a pasturing period and
feeding strategies. Extra-regional literature was used to identify strengths, weaknesses and
- 9 -
research opportunities of mixed systems with respect to potential benefits and drawbacks,
climatic determinants in optimizing mixed systems, optimizing potential grazing resources in the
Palouse, economic outlooks, organic methods, no-till systems, and climate change.
INTRODUCTION
Mixed systems—used here interchangeably with integrated systems—strive to
incorporate crops and livestock in mutually beneficial and spatially and/or temporally
overlapping ways on individual farms, or between proximate farms. Typical cereal-livestock
rotations include (i) single-year alternations between grain and grazed legumes on the same field
(ley systems), (ii) longer rotations of 3-12 or more years of perennial grass, legume, or mixes
followed by an equal or lesser duration of annual crops (phase systems), and (iii) grazing and
resource-sharing collaborations between separate crop and livestock producers in close
proximity, though the latter have been considered to be less true to the ecological concept of
diversification (Sulc and Tracy, 2007).
Globally, mixed crop-livestock farming systems are practiced in nearly every agro-
ecological zone (FAO 1999). They account for 6 billion acres of farmland (de Hann et al., 1997)
and produce 92 percent of the world’s milk supply, 70 percent of small ruminant meat, and 54
percent of the world’s overall meat supply (de Hann et al., 1997; Thomas et al., 2002).
In recent years, mixed farming systems have been viewed as a positive alternative to
agricultural practices that negatively impact water quality (Barbash et al., 2001) and availability
(Allen et al., 2007), soil organic matter and greenhouse gas emissions (Lal, 2007), and soil
structural and chemical characteristics (Fliessbach et al., 2007; Riley et al., 2008).
- 10 -
Research in crop-livestock agriculture is sufficiently developed to generally assess the
promise of this alternative system under a range of conditions; it has been noted, however, that
more research is needed on crop-livestock systems under the economic, policy, climatic and
edaphic conditions in which they may be developed and utilized (Entz et al., 2002).
In the 2 million acre Palouse River basin of the inland Northwest United States, roughly
60 percent of the land is devoted to dryland annual crop production and 30 percent to extensive
range (Fig 1.1) (Hall et al., 1999). Livestock production is confined to feedlots, range, gullies,
lightly wooded areas, and some pasture (Hardesty and Tiedeman, 1996). No current data exists
to quantify the extent of crop-livestock integration, if it does exist, in the Palouse; however, it is
not considered to be practiced to any considerable extent, and livestock are rarely observed on
agricultural fields (Hardesty and Tiedeman, 1996).
Concern over soil erosion in the Palouse in the first half of the 20th century resulted, by
one estimate, in grass-legume rotations practiced by half of the farmers in the Palouse by 1955
(Kaiser, 1961). This researcher notes that use of perennials in crop rotations declined
subsequently due to price supports for annual grain crops, introduction of the clover weevil
(Hypera punctata F.), increasing herbicide damage to legumes reducing yields, greater economic
returns for annual grain as compared to livestock production, and technological innovation that
improved residue management and provided options to reduce soil erosion in annual systems.
Other factors that influenced land use decisions were the increasing use of nitrogen fertilizers in
the 1950s, and the comparative price advantage of raising wheat (Kreizinger and Law, 1945).
Nevertheless, researchers in the Palouse have maintained that more sod and green-
manure crops may be needed to control soil erosion and increase organic matter (Papendick et
al., 1985). At the same time, there is insufficient research specific to the Palouse to come to a
- 11 -
widely accepted conclusion on this point. To address this research gap, we (i) identify the
potential for mixed cropping systems in the Palouse region, (ii) briefly review the benefits and
challenges for mixed systems in other regions, (iii) present regional research relevant to mixed
systems in the Palouse, and (iv) identify research opportunities for crop-livestock systems.
Figure 1.1. Palouse River basin watershed with land use designations (Washington Dept. of Ecology, 2008).
THE NEED FOR ALTERNATIVE SYSTEMS IN THE PALOUSE REGION
Alternative farm practices are of increasing interest in the Palouse region due to apparent
shortcomings of current practices. Impacts of agriculture on natural resources and farm economic
viability have been studied considerably in the Palouse. Soil erosion has received attention due to
the one million acres of Palouse farmland situated on slopes between 8 and 30 percent (Hall et
al., 1999), precipitation that falls predominantly (80 percent) between October and May on bare
- 12 -
soil impacted by freeze-thaw cycles (Greer et al., 2006), and tillage and residue management
practices that largely do not protect soil surfaces (Montgomery et al., 1999; Guy et al., 2002).
Soil organic matter of Palouse farmland declined 35 to 40 percent within 60 years of agriculture
settlement in the late 1800s (Rasmussen et al., 1989), one-fourth to three-fourths of topsoil has
been lost from 60 percent of the cropland (USDA, 1978), and tillage-induced soil translocation
has removed the topsoil from most ridge tops (Papendick et al., 1985).
Fertilizer and fuel costs have compromised farm financial viability in the Palouse region,
as elsewhere (Hinman, 2005). The annual average change in the price of anhydrous ammonia
between 2005 and the price spike in 2008 ($1,470 tonnes-1) was $305.67, as compared to $5.03
between 1975 and 2005 (USDA, NASS; Wilbur-Ellis Co, 2008). Soil pH is also declining to
levels that can reduce yields for crops traditionally grown in the Palouse: lentils (Lens cularis)
(5.65), wheat (Triticum aestivum) (5.19), and spring peas (5.3) (Mahler and Mcdole, 1987).
Declines in pH have resulted from nitrification of NH4-based fertilizers prior to plant uptake of
soil inorganic NO3-N. Over 91 million kg of anhydrous ammonia were applied to Washington
wheat in 2005 (USDA, 2008). Comprising roughly 55 percent of Washington wheat production,
the five-county Palouse River basin region applied approximately 50 million kg. Other concerns
for Palouse agriculture common to other regions include the prospect of herbicide-resistant
weeds (Gorddard et al., 1996), expectations of increasing production to meet the expanding
world food demand (Tilman et al., 2002), and mounting environmental costs of agricultural
production (Pretty et al., 2000). More sustainable alternative systems for the Palouse would
minimize erosion potential, build soil organic matter to restore soils closer to their production
potential, reduce needed rates of N fertilizer application, and provide a more diverse array of
farm products.
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MIXED SYSTEMS IN OTHER REGIONS OF THE WORLD
Mixed crop-livestock farming systems have been increasingly studied in relation to many
of the challenge areas as discussed above, but not in the Palouse region. A simple measure of
research attention is a review of relevant journal articles. The search engine Web of Science was
used with two different sets of search terms: ‘crop livestock integration’, and ‘mixed farming
crop livestock’. Papers were selected on the basis of explicit reference to crop-livestock systems;
relevant studies only indirectly relating to crop-livestock systems were excluded. This search
revealed a 230 percent increase in publications between 2000 and 2007, with an increasing share
originating in developed countries (Fig 1.2). Fifty-seven papers originated in the ‘developed
world’, including Australia, Canada, European countries, New Zealand and the US. Eighty-three
papers originated in the ‘developing world’. A table of these papers organized by last name of
first author is in Appendix I, and references for all of the papers are found under Chapter 1
references. This study utilizes but does not limit itself to these papers due to the value of papers
beyond this narrow time frame, as well as papers that are relevant to though do not explicitly
deal with mixed systems.
Papers in the crop-livestock literature deal with potential benefits and associated
challenges for mixed systems with respect to erosion control, SOM, water management, legume
breeding, basic agronomy in mixed systems, soil fertility, and biological pest control. Benefits
commonly include reduced erosion, increased soil C and N, and I improved soil structure. In
Uruguay, Garcia-Prechac (2004) reported the use of no-till in crop-livestock rotations to reduce
erosion during the arable phase so that the erosion rate over the entire rotation matched levels
measured for native prairie. Grasses in arable crop rotations in Norway lowered bulk density,
improved soil structure, and increased plant available water and aggregate stability compared to
- 14 -
19
22
30
10
4 4 4
14
35
13
66
9
16
12
7
15
12
16
19
1312
9
0
5
10
15
20
25
30
35
2000 2001 2002 2003 2004 2005 2006 2007
US, Europe, Australia, NZ Developing World Total
Figure 1.2. Annual numbers of published crop-livestock studies in 2000 - 2007. Inlaid pie charts show relative share of studies carried out in developing vs. developed countries in 2002-2003 versus 2006-2007.
45%55%25%75%
2002‐2003 2006‐2007
conventional, stockless rotations (Riley et al., 2008). In Switzerland, soil microbial C and N were
respectively 30 and 35 percent higher in an organic system with simulated grazing and manure
application compared to a conventional system receiving synthetic fertilizers and pest controls
(Fliessbach et al., 2007).
Mapfumo et al. (2002), in trials in Alberta, Canada, reported that perennials (smooth
bromegrass, Bromus inermis L.; and meadow bromegrass, Bromus riparius Rhem.) accumulated
2.7 times more total C than winter triticale (X Triticosecale Wittmack) through litter and root
mass contributions to soil C pools. Mixed cropping systems on the Canterbury Plains of New
Zealand balanced losses of SOM and organic N in arable phases of crop rotations (2-4 yrs.) with
accumulations of these components of soil fertility during grass-legume pasture phases (also 2-4
yrs) (Haynes and Francis, 1990). These researchers found that soil C equilibrated at roughly 2.5
to 2.7 percent compared to 3 percent in adjacent, never-plowed grassland soils. Fertilizer N use
was also low in the New Zealand systems. Nitrogen fertilizer was eliminated for three years of
- 15 -
cereal cropping following grass-legume pasture, in which no fertilizer N was used. After three or
four years of arable cropping, 100 to 150 kg N ha-1 was required to maintain yields. Annual N
use, as well as a 6-yr total for N use in this system can be compared to a 6-yr continuous wheat
cropping system in the Palouse region. Annual average fertilizer N application in the New
Zealand system was roughly 22 percent of the Palouse continuous wheat system, or 24 kg N ha-1
as compared to 110 kg N ha-1 (Haynes and Francis, 1990; Young et al., 2006) (Table 1.1).
Table 1.1. Typical nitrogen fertilizer application for a New Zealand mixed cropping system compared to a Palouse continuous wheat rotation N fertilizer application (lb N ac-1) Year 1 2 3 4 5 6 6-yr total Ley-wheat (3-yr, 3-yr) 0 0 0 0 0 150 150 Continuous wheat 78 174 112.1 78 151 151 745
(Adapted from Haynes and Frances, 1990; Young et al., 2006)
In cotton-pasture rotations in Texas, Allen et al. (2008) reported 40 and 23 percent
reductions in N fertilizer use and irrigation, respectively. Goosey et al. (2005) report that stubble
grazing during a fallow year in dryland grain production in Montana controlled weeds and pest
larvae. Mechanical and chemical control strategies otherwise constituted the largest variable cost
in this cropping system.
Notable management challenges remain for mixed cropping systems as well. Grass-
clover pasture termination on sandy soils in Denmark resulted in up to 235 kg ha-1 inorganic N
losses via leaching in the second and third years after conversion to spring barley (Hordeum
vulgare L.) (Berntsen et al., 2006). In lower rainfall areas where leaching loss is not expected,
such as southern Australia, N volatilization has resulted in losses of roughly 22 kg ha-1, with up
to 60 percent of sheep urinary N lost via this pathway (Puckridge and French, 1983). Soil water
depletion resulted in decreased yields of winter wheat following perennial legumes in trials in
- 16 -
Pendleton, Oregon (16.75 in. annual rainfall) (Rasmussen et al., 1989). An identical experiment
by this research group in Weston, Oregon (17.56 in. annual rainfall) showed increased yields at
this slightly higher rainfall, leading these researchers to conclude that depletion of soil moisture
contributed to yield declines.
Little contemporary regional research literature is available with respect to crop-livestock
systems in the Palouse. A period of increased research activity targeting perennial legumes in
crop rotations, as reviewed below, occurred in the mid 1900s. One analysis of four crop rotations
in the Palouse at that time showed that an alfalfa/grass-wheat rotation compared to a wheat-pea
rotation resulted in a 360 percent increase in rate of water infiltration, a 67 percent reduction in
runoff and a 75 percent reduction in soil loss (Table 1.2) (R.L. Kent, 1957).
Fuentes et al. (2004) reported more recently on hydraulic conductivity of soils under
native prairie and no-till management in the Palouse. Native Palouse prairie exhibited ten times
the hydraulic conductivity of a 27-yer old no-till treatment. Purakayashtha et al. (2008) found
that neither no-till nor perennial grasses would restore SOC to levels found under native Palouse
prairie over the 10 to 30-year period.
Table 1.2. Rates of infiltration, erosion and runoff on land in winter wheat under different cropping systems during the December 1945 storm, Pullman, Washington. Rotation Rate of infilt.
(mm hr-1) Runoff percent
Soil loss (tones ha-1)
Alfalfa-grass, wh. wh. p. wh. 9.1 9 12.3 Sweet-clover-grass, wh. p. wh. 4.3 16 26.7 Wheat-peas 2.54 27 49.0 Wheat-fallow 1.5 44 74.0
(Kent, 1957)
- 17 -
Energy and Economics
Mixed systems have impacted farm economic performance primarily through variation in
energy use and input costs. A stockless alfalfa-wheat compared to a wheat-flax rotation reduced
energy use by 40 percent in research trials near Winnipeg, Canada (Hoeppner et al., 2007).
Organic and conventional management were compared in rotations with and without alfalfa by
these researchers. Energy savings in the organic compared to conventional systems with alfalfa
resulted from reduced eliminated pesticide and fertilizer use, and reduced use of machinery and
fuel. The long-term Swiss DOK trials reported 45 percent lower energy use in an organic
treatment that included clipped forage receiving animal manure compared to a conventional
treatment receiving mineral fertilizers (Maeder et al., 2002). Lack of livestock in these rotations
limits their usefulness to appraising economic impacts of crop-livestock integration in the
Palouse.
An integrated cotton-livestock rotation compared to a cotton monoculture in the southern
US increased profitability by between 46 to 90 percent, increasing with the depth of the irrigation
well (Allen et al., 2005). In a southern US trial of grazed versus ungrazed annual forages, net
return over variable costs for the grazed and ungrazed treatments, respectively, were $302 and -
$63 ha-1 (Franzluebbers and Stuedemann, 2007). In Nebraska (30 in annual rainfall), net returns
for cattle grazing Big Bluestem (Andropogon gerardii) ($291 ha-1) were 2.5 times higher per
year than annual dryland corn (Zea mays) ($121 ha-1) (Mitchell et al., 2005). Within and
between-farm mixing of potato (Solanum tuberosum) and dairy production in Maine increased
profitability after two years of coupling these enterprises (Hoshide et al., 2006).
- 18 -
Model regions of crop-livestock integration for the Palouse
Examples of viable crop-livestock farming systems exist as potential models for mixed
systems across the three primary rainfall zones in the Palouse region (<380 mm, 380-450 mm.,
and 450-660 in.) (Beus et al., 1990). Ley-farming in Western Australia is practiced in regions
receiving between 250 and 380 mm annual rainfall, and ley and phase farming are practiced in
south and southeast Australian regions receiving between 250 to over 500 mm total annual
rainfall (Squires and Tow, 1991). This belt of crop-livestock production from southwest to
southeastern Australian is known as the sheep-wheat zone. A rainfall distribution pattern is also
common to the Palouse and the sheep-wheat zone, as precipitation in both regions occurs
primarily during winter months separated by dry summers. An important difference between the
regions is mean annual winter temperature in the Palouse of 0º C compared to 18º C in Victoria,
Australia. In this respect, efforts to develop mixed systems in the Palouse would relate to
ongoing work in the US and Canadian northern Great Plains (NGP) (Carr et al., 2005a; Entz et
al., 2002), with -3º C average winter temperatures.
With respect to climatic conditions, Australian sheep-wheat rotations with the least
modification are suitable to areas of Argentina, Chile, North Africa, the Near East, Portugal,
South Africa, Spain and Uruguay, and Oregon and California in the US (Puckridge and French,
1983). This researcher notes that livestock integration in southern Australia in the 1930s
“improved soil fertility [that] led to increased cereal yields and greater sheep and cattle
production”. Use of subterranean clover in pastures in an area receiving 533 mm average annual
rainfall increased soil inorganic N levels at a rate of 30 kg N ha-1 yr-1 over a 30-year period
(Cocks, 1977). Share of yield increase after 1950 that derived from improved soil fertility as
compared to breeding and other factors was estimated at 60 to 70 percent (Donald, 1963).
- 19 -
In the NGP, Entz et al. (2002) estimated that forages are rotated on 5 to 15 percent of
arable cropland; alfalfa was sown on 61 percent of 1.3 million ha of total forage cropland in the
region. Reviewing prior forage research in the NGP, these researchers reported benefits
including 50 percent yield gains for wheat following 3-years of alfalfa (Medicago sativa),
accumulation of soil inorganic N of 137 kg ha-1 after 3-years of alfalfa hay crops, non-N related
yield increases, increased microbial N, increased hydraulic conductivity, and reduced weed
pressure. Drawbacks included forage-induced drought in lower-rainfall areas (Brandt and Keys,
1982), which could be particularly salient to mixed systems in the Palouse, and depletion of soil
nutrients through intensive mineral uptake of hayed forages (though less removal occurs in
grazed forages).
REGIONAL RESEARCH RELEVANT TO MIXED
SYSTEMS IN THE PALOUSE
Settlement in the Palouse region of the inland Northwest, U.S. occurred later (1860s –
1910) than did Eastern and Midwestern settlement (1600s – 1700s). By 1895, almost all of the
tillable land area was under cultivation in the Palouse (Jennings et al., 1990). Very little land use
data is available for the region early in the 1900s (and what is available tends to be incomparable
over time due to varying data collection methods). Data that is available suggests a small role for
soil building perennials in Palouse agriculture before 1940. Pubols et al. (1937) report no more
than 6 percent of total cropland acreage was sown to grass-legume mixes in 1936. In 1939, the
same researchers estimated that land use consisted of dryland annuals in rotation with peas and
fallow (88 percent), legumes or perennial grasses in rotation (1 percent), native pasture (7
percent), and idle or abandoned land (4 percent) (Pubols et al., 1939).
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After the establishment of the Pacific Northwest Erosion Control Experiment Station near
Pullman, WA in July 1930, concerns over wheat-dominated annual cropping systems originated
the first research projects that would be closely relevant to mixed cropping systems in the region.
All of these are available in archived Experiment Station Bulletins at both the University of
Idaho and Washington State University (WSU). Most are now available through an online,
searchable, 100-yr literature review of northwest US agricultural publications (CSANR, 2004).
Areas of study carried out from the 1920s into the 1960s included variety trials for alfalfa,
sweetclover (Melilotus alba) and other soil building perennials; perennial establishment
methods; biomass productivity, carrying capacity and soil conservation performance for legume
and grass-legume mixes; grazing management and forage nutrient content; a patchwork of land-
use surveys and interviews to assess the adoption and use of perennials; and weed and pest
management in these crops.
Examples include higher carrying capacity for sweetclover compared to ladino clover
(Trifolium repens) or mixed grasses, and establishment methods for a sweetclover nursery
(Singleton, 1931). Hodgeson et al. (1931) found an 8.45 percent increase in milk production per
acre of cows on rotational pasture compared to continuous grazing. They noted that live weight
of rotationally grazed cattle was 33.9 percent greater than continuously grazed cattle even though
available dry matter per head per day was 28.3 percent lower, likely resulting from differences in
utilization.
Grass-legume mixes for the Palouse were studied considerably. Kreizinger (1943)
reported hay yields (tonnes. ha-1) of smooth bromegrass (Bromus inermis Leyss) (1.8), crested
wheatgrass (Agropyron cristatum L. )(1.1), smooth bromegrass and alfalfa (5.2), crested
wheatgrass and alfalfa (6.9), and smooth bromegrass, crested wheatgrass and alfalfa (7.4). The
- 21 -
study concluded that grass-alfalfa mixes carried five steer ha-1 for a roughly 90 d grazing season
(twice the carrying capacity of solid grass swards). Mixed pastures of alfalfa, smooth
bromegrass and crested wheatgrass were considered the best option for eastern Washington, and
the researchers were testing Sudan grass (Sorghum vulgare var. sudanense) as a late summer
forage.
Grazing trials complemented the agronomy work, determining live weight gain and
grazing period for the grass-alfalfa mixes used by Kreizinger and Law (Table 1.3) (Ensminger et
al., 1944). The short (90 d) grazing period was managed by purchasing weaned, 230 kg calves in
the fall, winter feeding on roughages that were inexpensively available at the time, and grazing
once spring pasture stands reached 15 cm in height (end of April). Average weight at the onset of
spring grazing was 302 kg head-1. After the pasture period, either grain was supplemented with
the pasture to extend the season to the beginning of October, or the cattle were finished on grain
and hay in a dry-lot. Average cattle weights at the end of the grazing only and supplementation
period were 382 and 491 kg respectively. Total weight gain over the autumn to autumn
production system was roughly 263 kg head-1, of which roughly 80 kg head-1, (or 30 percent)
was obtained through pasture resources.
Kreizinger and Law (1945) studied barley, spring wheat and oats (Avena sativa) as nurse
crops for pasture establishment. They concluded that nurse crop during establishment reduced
Table 1.3. Productivity of grass and grass-alfalfa pastures as measured by beef production of yearling steers (2.47 steer per ha) at Pullman, Washington. All grazing began April 26, 1941. Pasture type Smooth
brome (SB) Crested
wheatgrass (CW) SB +
alfalfa CW + alfalfa SB + CW +
alfalfa Grazing period (days) 33 33 94 94 94 Grazing weight gain (kg) 42 40 109 97 104
(Ensminger et al., 1944)
- 22 -
Table 1.4. Average yield per ha of first year companion crops and Spanish Sweetclover-Bromar Mountain Bromegrass top-growth the second year as affected by establishment method Treatment Comp.
crop (kg) Sweetcl.
(kg) Grass (kg) Total (kg) Percent
grass (%) Clover and grass in alternate rows; no companion crop
-- 8,003 1,939 9,943 20
Clover and grass in 6-in. alternating rows over-seeded in peas
1,379 6,358 1,489 7,847 19
Clover and grass seeded together in alternating rows with spring barley
2,164 6,087 830 6,917 12
(Schwendiman and Kaiser, 1960)
subsequent alfalfa yields irreparably. Schwendiman and Kaiser (1960) presented similar findings
after considering peas or spring barley as companion crops (Table 1.4).
Recurrent studies compared soil erosion in annual field crops and perennials in the wind
and water-erosion prone Palouse (1932; Taylor and Baker, 1947). These researchers as well as
Pubols et al. (1939) surveyed land use and erosion (Table 1.5). The latter researcher’s work
involved 225 farms and 580 thousand ha. They recommended an increased use of perennial
plants and the potential use of livestock to offset loss in income due to less wheat acreage.
Decline in the use of grass-legume mixes in the 1950s, and in particular sweetclover,
resulted from increased use of N fertilizers, legume intolerance to herbicides, and the clover
Table 1.5. Proportionate distribution of land use acres and associated erosion and runoff, wheat region of Washington, 1936
Land Use Annual row crops,
w/o stubble Soil building perennials
Native pasture Idle or abandoned land
Percent sample area
88 1 7 4
Averge erosion losses (m.t. ha-1)
33.8 – 74.1 0.51 – 1.0 N/A N/A
Run-off (mm) 15.5 – 36.8 0.51 – 1.0 N/A N/A (adapted from Taylor and Baker, 1947; Pubols et al., 1939)
- 23 -
weevil. Schwendiman and Kaiser (1960) documented a 60 percent yield loss for sweetclover-
grass mixes at the onset of the use of 2,4-D in the Palouse in 1945, a 25 percent decline in green
manure yield of grass-clover mixes receiving 90 kg ha-1 N, and a 10.3 percent increase with 54
kg S ha-1 and no N.
RESEARCH OPPORTUNITIES FOR MIXED SYSTEMS
Forage development for a low rainfall, cold-winter climate
Temperature and precipitation dynamics limit the crops Palouse farmers can grow
economically (Figs 1.3 & 1.4). The region receives 280 to 580 mm annual precipitation, and
roughly two times the precipitation during the winter months compared to the summer months
(USDA-ARS, 2008). Cool mean winter temperatures (-2.1º C in January) have resulted in the
predominance of cool season crops such as winter wheat, Austrian field peas and spring wheat or
peas as cash crops. Insufficient summer precipitation restricts the use of annual green manure
crops between these winter annuals, and the opportunity cost of growing soil building crops as
opposed to a winter or spring annual have been considered too high to justify economically
(Painter, 1991).
Forage cultivars and management practices suitable to Palouse rainfall characteristics are
still needed. Krall et al. (2007) and Carr et al. (Carr et al., 2005a; 2005b) provide good examples
of developing locally viable forages by breeding cold-hardy self-reseeding medic varieties
(Medicago sativa, var. Laramie—[Wyoming]) from their non-cold-hardy Australian
counterparts. Other key research areas in forage/cropping systems that will be informed by
climatic patterns in the Palouse are selection of methods and nurse crops for pasture
- 24 -
0.0
1.0
2.0
3.0
4.0
5.0
Jan Feb Mar Apr May Jun Jul Aug Sep Nov Dec
Precipitation (inche
s)
17‐year average 2007
0
10
20
30
40
50
60
70
80
90
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Tempe
rature (F)
Average Average max. Average min.
Figure 1.4. Monthly mean precipitation at the Washington State University, USDA-ARS Palouse Conserveration Field Station, 5 mi. from Pullman, WA (USDA-ARS, 2008).
Figure 1.3. Monthly mean, maximum and minimum temperatures in Pullman, WA (USDA-ARS, 2008).
establishment (Sulc and Tracy, 2007), seeding different forage crops by different landscape
position based on adaptability to microclimates, (Guretzky et al., 2007; Sanderson et al., 2007),
and more persistent legumes in grass-legume pastures such as birdsfoot trefoil (Lotus
corniculatus L.) or alfalfa (Carr et al., 2005b).
Forage chains for year-round grazing are increasingly used by grassfed livestock
producers (Huesby, pers. comm., 2007). Annual forage crops in rotation with pastures may help
Palouse graziers reduce hay purchases during cold, wet winter grazing and hot, droughty
summers. Large-seeded legumes, millet (Pennisetum americanum), winter rye (Lolium
multiflorum Lam.), and irrigated crops such as turnips (Brassica rapa var. rapa) and corn have
been forage chain candidates elsewhere (Alford et al., 2003; Contreras-Govea and Albrecht,
2005; Maloney et al., 1999; Strydhorst et al., 2008).
Labor and Economics
Farm diversification can improve agricultural sustainability (Brummer, 1998), but
generally increases the complexity, labor and in some cases total input costs. Long-term trials at
the Neely-Kinyon research site in Iowa compared a conventional crop rotation (corn-soybean)
- 25 -
with organic annual crop rotation (corn-soybean-oat), and an organic annual-perennial mix
(corn-soybean-oat-alfalfa) (Delate et al., 2003). Production costs were 42 and 13 percent higher
for the conventional and annual organic rotations compared to the organic annual-perennial
rotation, respectively, but labor costs were 112 and 14 percent higher in the latter compared to
the two respective former rotations. This trial did not include grazed alfalfa, though it is likely
that labor costs of maintaining livestock would exceed those for haying equipment. A Palouse
survey carried out in the 1940s found 18 percent higher labor costs for farms utilizing soil
conservation practices, which were correlated with keeping livestock and larger acreages in
pasture (Taylor and Baker, 1947).
Management choices, such as method of livestock integration (on-farm versus between-
farm), will influence farm complexity and labor costs. Between-farm integration as described by
Hoshide (2006), or contract grazing may decrease labor costs. Management and labor
investments in mixed cropping systems should perhaps focus initially on between-farm
integration, particularly because land use in the Palouse is currently specialized with 58 percent
in cropland and 28 percent in rangeland (Fig 2.1). The practice of transhumance (circulating
sheep herds between summer and winter range) was adopted by early range sheep operations and
is embedded culturally in the Palouse (McGregor, 1982).
Crop-livestock mixing will impact the economic viability of diversification in the
Palouse. Painter et al. (1991) found that a long-term organic farmer in the Palouse absorbed
additional costs over returns when growing soil-building crops as opposed to cash grains. She
concluded that, in combination with farm policy that rewards production over conservation, soil
conservation crops do not pay because the choice to grow a soil building crop competes directly
with cash grain production. Grazing soil building crops may provide an economic benefit to
- 26 -
rotation with a soil-building crop in the Palouse (Clark, 2004), but choices will still be
constrained by low summer rainfall, marginal total precipitation and cool winters.
Research in other regions has demonstrated economic competitiveness of livestock
integration (Delate et al., 2003; Fontaneli et al., 2000; Franzluebbers and Stuedemann, 2007;
Hoshide et al., 2006; Mitchell et al., 2005), but few farmers in the Palouse will be willing to
invest before region-specific economic data is available. Local research by Ensminger et al.
(1944) provided a good starting place to judge the potential of these systems and create
enterprise budgets based on current market conditions. Needed information includes amount and
cost of labor, production potential for multiple crops and livestock species within the mixed
system, processing and marketing options and costs, pricing for livestock product (valuing
potential premiums for local, grassfed and organic), seasonal feed costs and/or transportation
costs to alternative feed sources, and price points for contract grazing.
Soil and C management
Soil C monitoring work has been carried out regionally for no-till systems (Purakayastha
et al., 2008) and in other regions for grazing systems (Bosch et al., 2008), but no regional work is
available to appraise C sequestration and erosion-reduction potential of mixed systems in the
Palouse. Future work on mixed systems could build on past work assessing the ability of grazed
perennials to reduce erosion (Garcı́a-Préchac et al., 2004) and accumulate soil C (Lal, 2007;
Mapfumo et al., 2002). No studies are available that document or model C and organic N
fluctuations under extended grazing of grasses, legumes and mixes followed by a phase of
annual crop production. Work should also determine whether the private costs and societal
benefits of soil C management in mixed systems are adequately balanced. Pendell et al. (2006)
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quantified potential additional costs of no-till practices that would hypothetically require societal
compensation to compel farmers to practice these methods. These balances need to be quantified
for mixed systems if we want to harmonize market signals with cropping systems that provide
public goods.
Work is needed as well in developing alternatives for farmland that will soon expire from
Conservation Reserve Program contracts in the Palouse. Returning the 1 million CRP acres in
Washington State to annual row crops threatens undoing twenty years of erosion control and
converting this acreage from C sink to source (Gebhart et al., 1994). If those accrued benefits are
to be retained, studies are needed that compare the impacts of various CRP take-out options such
as annual crops, grazed perennial pasture, or mixed systems.
Conservation tillage and crop-pasture rotations have made significant contributions to
sustainable management of soil resources in other regions, and may do so as well in the Palouse.
Numerous studies have shown that perennials result in improved soil microbial biomass, water
storage capacity, soil organic nitrogen, reduced leaching, and other benefits (Cox et al., 2006;
Fuentes et al., 2004; Mapfumo et al., 2002; McGill et al., 1986). No-till crop-pasture rotations
(CPR) in Uruguay lowered soil erosion to levels found under Prairie (Garcı́a-Préchac et al.,
2004). Interestingly, erosion was higher in CPR with conventional tillage than annual cropping
with no-till.
Organic agriculture
Mixed crop-livestock systems may provide opportunities to adopt organic or low-input
farming practices in the Palouse region through biological weed control, and improving the
profitability of green manures in crop rotation. The potential benefits of organic agriculture have
- 28 -
included increased profitability (Delate et al., 2003), improved soil quality (Fliessbach et al.,
2007), and reduced pesticide levels in humans {{450 Lu,C.S. 2006}}. In the Palouse region, the
potential to reduce reliance on expensive off-farm inputs may be important to wheat growers
whether organic certification is desirable or not.
Some challenges to exploiting potential benefits of organic or otherwise low-input
systems were identified in a survey of Washington wheat growers. Low yield, lack of affordable
organic N fertilizer, and weed control issues were cited as deterrents (Dawson et al., 2007).
Another issue is that the Palouse is an erosion prone environment not suitable to intensive tillage
practices sometimes used in organic systems. That these barriers and others prevent the use of
low external input practices is suggested by the slow adoption of organic agriculture by
Washington wheat growers between 2000 and 2006. Organic wheat acreage in the state increased
by 13 percent compared to a 135 percent increase in organic apple acreage (Granatstein and
Kirby, 2007). Approximately doubled prices for organic as compared to conventional wheat
resulted in only 3,819 acres of certified organic wheat out of roughly 2.2 million wheat acres in
Washington State in 2006.
Two primary potential benefits of using mixed systems for organic production would be
biological pest control and reduced reliance on off-farm fertilizers. Grazing may enable adoption
of low input alternative pest control methods in the Palouse. This option has received increased
attention by the USDA Agricultural Research Service (Hatfield et al., 2006), and shows promise
with respect to grazing control of Wheat Stem Sawfly larvae in dryland grain systems in
Montana (Hatfield et al., 1999); alfalfa suppression of grass in corn rotations (Clay and Aguilar,
1998); high-density rotational grazing to control Canada Thistle ((De Bruijn and Bork, 2006);
and pasture phases in rotation to stay weed herbicide resistance (Gorddard et al., 1996).
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Lack of alternatives to conventional N fertilizers in the Palouse could be addressed by
lower N-input requirements of mixed systems. Nitrogen fertilizer inputs have been reduced in
mixed systems by inclusion of grass-legume pastures that accumulate organic N, supply all or
some portion of the N needs of subsequent crops, and reduce the number of years in crop
rotations that require N fertilizer application (Allen et al., 2005; Gregory et al., 2005; Williams,
1967). Grazing grass-legume green manures is also more profitable than incorporating them
because it contributes to farm income through animal product (Franzluebbers and Stuedemann,
2007). Lack of grazed grass-legume mixes may account for the slow adoption of low-input
farming practices in the Palouse. Organic cropping in regions lacking nearby off-farm N fertility
sources (such as livestock facilities or municipal waste) may require on-farm nutrient sources
that simultaneously provide income.
This grazed pasture strategy, however, also raises the challenge of terminating perennial
leguminous forages with minimal or no chemicals without erosive tillage methods. Strategies to
convert from perennials to annual fields crops have been assessed widely in the crop-livestock
literature (Davies and Peoples, 2003; Delate et al., 2002; Halvorson et al., 2000), but few studies
have addressed organic or reduced-till methods (Garcı́a-Préchac et al., 2004). Initial work on this
problem by the authors indicated inadequate alfalfa termination by soil conserving under-cutting
sweeps (Chapter 2); however, similar alfalfa-barley trials that use a larger and heavier sweep
implement terminate alfalfa while still minimizing erosion (Dave Huggins, pers. comm., 2008).
More research is needed in this area.
- 30 -
Example research projects
Crop-livestock farming systems involve complex interactions between the soil, plants,
livestock, the climate, management and other environmental incursions. An improved
understanding of the potential advantages and disadvantages of mixed systems for the Palouse
will require varied investigations. Key needs include region-specific assessments of productivity
of both crop and livestock options within mixed systems, profitability, cultivars adapted to
different links in a year-round forage chain, and management practices to use livestock and
forages strategically. Other informational needs include winter grazing impacts on soil structure,
soil water dynamics and weed communities. Based on prior research, hypotheses that should be
tested in the Palouse include:
• Grazed perennials deplete water reserves through deep root systems and long growing seasons (Bullied and Entz, 1999); or grazed perennials increase the effective precipitation for agriculture through improved water use efficiency, infiltration and hydraulic conductivity (Allen et al., 2007; Fuentes et al., 2004).
• Grazing provides biological weed management of common Palouse weeds such as Canada Thistle (Circium arvense), bindweed (Convolvulus arvensis), Prickly lettuce (Lactuca serriola), Lambsquarter (Chenopodium album) and Skeletonweed (Chondrilla juncea) (Bellinder et al., 2004; De Bruijn and Bork, 2006; Goosey et al., 2005; Hatfield et al., 2006).
• Livestock grazing in Palouse mixed systems negatively impacts soil physical attributes due to limited overwintering options; or livestock grazing improves soil physical structure due to manure contributions to SOM and undisturbed periods of perennial cover, (Flores et al., 2007; Franzluebbers and Stuedemann, 2006; Riley et al., 2008)
• Integration of livestock boosts rural economic activity through increased purchase of regional products (Sontag, 2008).
• Efficiency of mixed systems in fuel and fertilizer use improves economic performance (Delate et al., 2003); or labor costs and declining livestock markets reduces the economic performance of mixed systems relative to arable field crops (Fontaneli et al., 2000; Franzluebbers and Stuedemann, 2007; Mitchell et al., 2005).
- 31 -
• Mixed systems provide profitable strategies to utilize biological N fixation, but N leaching potential and volatilization of urinary N increase (Adams and Jan, 1999; Askegaard et al., 2005; Thompson and Fillery, 1998).
• Alfalfa-grass mixes provide the most profitable and productive option for longer, phase farming crop-livestock systems in the Palouse, but winter-hardy, self-reseeding medics are useful for short-duration crop-livestock rotations (Carr et al., 2005a; Krall et al., 2007).
• Soil organic N accumulated under long-term grass-legume pastures is sufficient to produce yields equal to county averages in the first two years following pasture termination, but supplementation with fertilizer N is required to sustain grain yields in subsequent crops (Haynes and Francis, 1990).
Regional crop-livestock production systems
How livestock would specifically be integrated into Palouse cropping systems is an
important question. Cow-calf, stocker and finishing are the three primary phases of livestock
production in the U.S. In the grazing trial described by Ensminger et al. (1944), 230 kg weaned
calves were purchased in the fall of one year, and sold into a feedlot for finishing the next fall. In
between, Palouse pasture and hay resources were used in what would be considered a stocker
phase. In this system, pasture resources contributed a relatively small share to livestock gain
(roughly 30 percent) compared to grain and hay resources (70 percent). With respect to mixed
systems today, this raises the question of whether livestock integration in the Palouse is
economically viable because it required such intensive use of grain and hay inputs in the past. If
not viable, this would require that future livestock integration rely more heavily on grazing
resources in the cow-calf and finishing phases of livestock production.
To answer the first question, future research could develop a financial assessment of the
system proposed by Ensminger et al using current costs and prices. This assessment would
provide a basis to modify the system for improved financial and agronomic performance.
Development strategies to improve the system could focus on testing early and late season
- 32 -
annual forage options (Twidwell et al., 1992), use of high quality pasturage such as bottomland,
irrigated pasture (of which there is little in the Palouse), and/or higher rainfall zones in the
eastern Palouse for finishing cattle, overwintering cow-calf pairs on scab-rock in the western
Palouse range for later stocker grazing elsewhere on Palouse pasture during the summer, testing
different cattle breeds for performance on pasture, and assessing regional collaborations for
Palouse farmers to develop a regional production chains from calf to market. Examples of
regional specialization-collaboration exist. One farmer in the western Palouse (roughly 380 mm
rainfall) is using post-CRP dryland pasture to raise organic stocker cattle for eventual sale to an
irrigated pasture-finishing cattle operation in Walla Walla, Wash (WSFFN, 2008).
This type of between-farm crop-livestock integration may initially, or ultimately, be more
suitable in the Palouse. Sheep herding in the past in this region was based on herding sheep
between summer and winter ranges to obtain sufficient forage (McGregor, 1982). This suggests
linking year-round forage chains has historically been a significant challenge in the region.
CONCLUSION
Integration of crops and livestock has potential to address environmental and economic
challenges of agriculture. There has been a widespread, increasing interest in mixed systems as
observed in an increasing number of research papers published since 2002. In other regions,
research findings indicate that mixed systems may provide adaptable models for Palouse
agriculture, but results are naturally difficult to translate without direct regional research. The
promise of these systems is that, elsewhere, they have performed well with respect to key
resource conservation needs for the Palouse. They were adaptable to no-till, improved soil
structure, increased plant water availability in arid climates, and at least the perennial phases of
- 33 -
rotations accumulated soil C at a faster rate than annuals. Importantly, N application has been
reduced substantially and could provide alternative, more locally available and secure sources of
N fertility for Palouse agriculture.
Mixed systems were also not without problems, and noting these can help to identify
future research needs. The potential for substantial N leaching following pasture termination, N
volatilization of manure and urinary N in hotter climates, and soil water depletion following
deep-rooted perennials could all be studied.
Economic assessments from other regions have investigated aspects of mixed systems,
yet specific treatment choices and environmental conditions make these economic studies only
partially applicable to the Palouse. In the Palouse region, for instance, long winters and distance
from compost or manure sources limits the economic information-value of studies that substitute
clipped forages and manure application for maintaining livestock year-round. Also, trials using
irrigation, and those in regions with higher rainfall zones, impact all-important determinants of
economic performance for livestock production: average daily gain of grazing livestock, length
of grazing season, and over-wintering costs. Such studies, then, cannot add much to the question
of the viability of grazing livestock in the region.
An intensified period of research directly relevant to mixed systems today occurred in the
Palouse from the 1920s to the 1960s. One study described a full production system to introduce
grazing livestock in the Palouse; however, the system relied heavily on grain and hay inputs to
provide feed on either end of a short grazing season. As a result, a particular vision for a grazing-
intensive crop-livestock system in the region, as well as the economic viability of such a system,
is not at all clear. This research did suggest promising grass-alfalfa mixtures of crested
wheatgrass, smooth bromegrass and alfalfa, but the short grazing period illustrated the
- 34 -
challenged situation for grazing in the region: dry summers and cold winters that support cool-
season crops constrain summer pasture productivity. Grazing results from earlier studies may
not, however, reflect current production potential using rotational grazing, improved forage
varieties, annual forages, and bottomland pastures to extend grazing options.
A number of research opportunities with respect to mixed systems in the Palouse exist in
increasing sustainable production and profit, soil water management, biological weed control,
regional economic impacts of increased livestock production, impacts of grazing on soil physical
parameters, N accounting, and economic feasibility analyses that balance the cost of alternative
practices with the value of, for instance, C credits.
A review of the mixed systems in other regions, past regional research, and potential
future work reveals considerable existing knowledge on crop-livestock systems. The complexity
of these systems, however, makes it difficult to extrapolate findings across time or space. Future
regional research and on-farm trials can draw on this knowledge, and develop on-the-ground
assessments of mixed systems for the Palouse region.
- 35 -
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EFFECTS OF MIXED CROP-LIVESTOCK FARMING SYSTEMS ON NITROGEN AND PROFIT
Bramwell, S.G.1, L.Carpenter-Boggs2, D.R. Huggins3, J.P. Reganold4, K. Painter5
1 Washington State University, Dept. of Crop and Soil Sciences, PO Box 646420, Pullman, WA. 99164-6420, USA, E-Mail: [email protected].
2 Washington State University, CTR for Sustaining Ag and Nat Res (CSANR), PO Box 646420, Pullman, WA. 99164-6420, USA, Email: [email protected].
3 U.S. Department of Agriculture, Agricultural Research Services, PO Box 646420, Pullman, WA. 99164-6420, USA, Email: [email protected].
4 Washington State University, Dept of Crop and Soil Sciences. PO Box 646420, Pullman, WA. 99164-6420. USA. E-mail: [email protected].
5Washington State University, CTR for Sustaining Ag & Nat Res (CSANR), 207a Hulbert Pullman, WA 99164-6210 509-335-5807. Email: [email protected].
ABSTRACT
In a farm system that rotates annual crops with perennial forage on the same field,
perennials must be effectively terminated to prepare for annual crops. In an organic system on
erodible soil, both herbicides and intensive tillage would be eschewed. Little is known about the
profitability of these integrated systems, how to terminate persistent pastures without chemicals
or a moldboard plow, and the effect of tillage methods on N availability for subsequent annual
crops. The objective of this research was to assess the performance of a Triticale (×
Triticosecale) grain crop following grazed alfalfa terminated with different methods of tillage.
Treatments were moldboard plowing or low soil disturbance under-cutting sweeps. Intact alfalfa
served as control. Soil inorganic nitrogen (N), grain yield, tillage effectiveness, and profitability
were assessed. Soil NO3-N accumulated in low disturbance treatments. Organic unfertilized
Triticale grain yield was positively correlated to degree of disturbance, ranging from 1630 to
4200 kg ha-1, and yield was negatively correlated with alfalfa re-growth. Returns over total costs
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of a grazed alfalfa-wheat rotation (GGR: $168 ac-1) were roughly half those of a hayed alfalfa-
wheat rotation (HGR: $341 ac-1). The profitability of the hayed alfalfa-grain rotation responded
sharply to changes in prices paid for organic alfalfa hay. The addition of wheat production to
continuously grazed alfalfa (CG) increased returns over total cost considerably. Potential to
improve soil quality through grazed forages in crop-pasture rotations appears to compete with
profitability, and low-disturbance tillage methods still need refining to ensure soil conservation
during perennial to annual transitions.
INTRODUCTION
Mixed crop-livestock farming systems typically employ annual pasture legumes in
rotation with annual grain crops, or longer periods of perennial grasses, legumes or mixes
followed by a period of annual cropping. Dryland sheep-wheat systems developed in southern
Australia in the 1950s that integrated clover (Medicago) and medic (Medicago) forages with
wheat (Triticum aestivum) (Puckridge and French, 1983). Livestock grazing legume-based
annual or perennial pastures increased wheat yields and livestock carrying capacity in southern
and West Australia, and boosted the organic matter levels of naturally infertile soils in the
following decades (Donald, 1963; Cocks, 1977). The prospect, or imperative, of developing
farming systems capable of improving facets of resource-use efficiency or quality, while
sustaining profitability, has inspired research on mixed systems worldwide. This has included,
among numerous other projects, challenged attempts to transplant Australian-style mixed
systems to Syria and North African countries (Christiansen et al., 2000), work on no-till crop-
pasture rotations in Uruguay based on New Zealand crop-livestock models (Garcı ́a-Préchac et
al., 2004), efforts to expand the use of grazed forages in crop rotations in the northern Great
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Plains of the USA and Canada (Entz et al., 2001), development of methods in Holland to assess
the role of livestock in relation to agricultural sustainability in developed and developing
countries (Schiere et al., 2002), and efforts to breed self-reseeding, winter-hardy forage legumes
in Montana and Wyoming from Australian varieties (Carr et al., 2005; Krall et al., 2007).
The Columbia Plateau (CP) region of the inland Northwest U.S. is roughly 15 million
acres, of which about 60 percent is in dryland cropping systems, and 31 percent in extensive
range cattle operations (Schillinger and Papendick, 2008). Integration of these two specialized
production systems has been suggested in this region to increase total productivity. For instance,
land enrolled in the Conservation Reserve Program (CRP) could, through controlled grazing,
utilize animals for vegetation control, and make better use of underutilized forage resources
(Hardesty and Tiedeman, 1996). Interest in exploring greater use of livestock in CP cropping
systems has been expressed at listening sessions and field days coordinated by the Biologically
Intensive and Organic Agriculture (BIOAg) program at Washington State University (WSU). In
November 2006, a small crop-livestock working group conference was held in Pullman, Wash.
made up of farmers and WSU researchers. Primary obstacles to mixed systems were articulated,
and generally encompassed a lack of basic economic and agronomic knowledge.
This research project was conceived as an attempt to address some specific, elementary
knowledge gaps regarding mixed systems for the CP. One challenge identified by farmers and
researchers was conversion from perennial cover to an annual crop without the aid of herbicides
or overly-erosive mechanical termination. In trials of this sort, a 5-yr old bromegrass-alfalfa sod
was mechanically terminated in Iowa using moldboard plowing, a Kverneland plow and Howard
rotavator as potential strategies to transition to organic grain production in post-CRP land
(Delate et al., 2002). Yields exceeding county averages in these trials indicated intensive tillage
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may enable farmers to make this transition and retain organic certification. Such tillage,
however, would be a problem on sloping, erosion-prone land on the CP.
Degree of tillage disturbance, tillage timing, grazing and herbicide applications may also
impact N cycling following conversion from perennial crops to annual grain. This could have
implications for resource-use efficiency, grain productivity, and environmental impacts. In one
study, leaching loss was 216-235 kg N ha-1 following conversion from grass-legume pasture to
barley (Berntsen et al., 2006). Primary drivers of N mineralization, however, are unclear. In one
study, higher plant-available N resulted from tillage as compared to low-disturbance herbicide
treatments in 3 out of 4 trials, suggesting the importance of soil aeration in N mineralization for
subsequent crops (Mohr et al., 1999). Alternatively, Weil et al. (1993) reported higher N
mineralization rates under minimum tillage treatments compared to rotary tillage of legumes in
preparation for annual grains. In other work, no differences have been observed in N leaching
between plowed and minimum cultivated plots of tilled grassland; in this case, soil texture was
considered a more important determinant of potential N losses (Lloyd, 1992). Given high
variability, region-specific research on N dynamics following perennial-annual conversion would
be useful for farmers to assess impacts of tillage method for N fertility planning, and to minimize
leaching risk.
Effective perennial termination and N fertility dynamics during perennial-annual
transitions will both impact the economic performance of mixed systems. Multiple management
pathways are also available for the farmer whose management options include grazing, haying,
and grain production. Grazing livestock may improve the profitability of cover crops in annual-
based crop rotations by providing saleable animal product (Clark, 2004), and has increased
profitability as compared to plowing cover crops under (Franzluebbers and Stuedemann, 2007).
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However, economic thresholds for haying versus grazing management of perennial crops are
difficult to predict until such systems are field tested under a range of price potentials.
Essentially no research data is available in this region to assess economic tipping points between
different cropping system combinations including annual grains, perennial cover crops, and hay
and livestock options for forage biomass utilization and resource management.
This research begins to address the above uncertainties over what method of tillage
would be most appropriate for perennial-annual conversion for mixed systems on the CP, the
impact of tillage methods on soil N dynamics and potential for associated N leaching during this
transition, and the economic performance of annual grains integrated into a grazed and hayed
alfalfa-based crop rotation. We assess the performance of an integrated alfalfa-Triticale grain
crop rotation in terms of: (1) utilization of biological N; (2) grain yield; (3) adaptability to
conservation tillage, and (4) the economic performance of different rotation combinations as
above using different market prices. With respect to N management, we hypothesize: (i)
potential N leaching following the breakup of long-term perennial alfalfa as observed by other
researchers (Lloyd, 1992); (ii) greater tillage disturbance would mineralize more N, either
aggravating leaching or improving grain yield, and (iii) biological N supply by mineralization
would be sufficient to produce grain yield comparable to regional averages. We also hypothesize
that conservation tillage could be applied to perennial-annual transitions in these systems, and
that the complementarity of grazed alfalfa-grain farming systems provide economic benefits as
compared to hayed alfalfa-grain systems and purely grazed alfalfa systems.
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MATERIALS AND METHODS
In September 2006, trials were initiated at Thundering Hooves (TH) farm in the western
region of the CP (40.422º N latitude, 16.932º W longitude). Plots were established on an
Ellisforde silt-loam soil (coarse-silty, mixed, superactive, mesic Calcidic Haploxeroll, 0-7
percent slope). Diagnostic soil horizons include mollic epipedon up to 20 cm thick, a subsoil
cambic horizon of very fine loamy sand between 20 and 60 cm, and carbonate accumulation
between 30 and 60 cm (NRCS, 2008). Soils tend to be fairly well-drained, though irrigation
created saturated subsoil horizons that became sticky and massive. Average annual precipitation
between Touchet and Walla Walla, WA, at the research site, is approximately 355 mm. Average
annual growing degree days are 2,650 (5.5º C base temperature). Dryland wheat, asparagus,
spinach, potatoes, green peas, alfalfa hay, barley, corn, grapes, string and lima beans, and Walla
Walla Sweet Onions are the primary crops grown commercially in the area. Bluebunch
wheatgrass, Sandberg bluegrass, big sagebrush, rabbitbrush, common yarrow, silky lupine, and
threetip sagebrush constitute the native vegetation (NRCS, 2008).
The primary enterprise at TH farm since 1998 has been organically managed, pasture
finished beef (Bos Taurus) on irrigated alfalfa (Medicago sativa) and grass pasture. Farm
operations minimize soil disturbance; the only annual grown in the last ten years has been turnip
(Brassica rapa) to extend the summer grazing season. Conversion of alfalfa to annual crops, if
they are grown, is done using a moldboard plow to roughly 13 cm.
In this research project, conversion of perennial alfalfa to Triticale was accomplished
through treatments consisting of two primary tillage operations following 10 years of alfalfa
pasture. These were moldboard plowing (MP) to a depth of 10 cm, and low soil disturbance
under-cutting sweeps operated at 7 cm depth with 100 (SW100) and 80 percent surface coverage
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(SW80). Data on this latter treatment is not presented as its ineffectiveness at controlling alfalfa
regrowth rendered it agronomically and logistically moot. A forth treatment was managed as
grazed alfalfa (ALF), which received simulated grazing three times during the growing season.
The MP treatment was established using a 110 hp tractor (JD 4240) and two-way
moldboard plow (JD 4200: 3 sheers, 40 cm centers). Sweep treatment SW100 utilized the same
tractor with a sweep (JD 1600: 38 cm duckfeet, 31 cm centers). Disk operation subsequent to
plow employed a 3-point offset finishing disk (JD V: 1.83 m wide, 51 cm disk). Triticale (x
Triticosecale) was sown with a 1998 hoe-type air drill (specially manufactured for WSU, similar
to Concord drills of the time) equipped with Ron Kyle openers (2.44 m wide, 31 cm rows).
Each replicate plot was 4.5 by 8 m, arranged in a randomized complete block design with
four treatments and four blocks. Primary tillage operations were imposed in the fall of 2006 and
spring of 2007 (Table 2.1). Organically certified triticale grain (var. 37812, Progene Plant
Research, Othello, WA) was sown at a rate of 111 kg ha-1 on March 7th, 2007.
Table 2.1. Tillage and seeding operations Treatment Date and operation
25 October 2006 7 March 2007 7 March 2007 Plow Moldboard plow Disk Seed Triticale
SW100 100% sweep 100% sweep Seed Triticale SW80 80% sweep 80% sweep Seed Triticale Alfalfa No cultivation No cultivation No seeding
Soil measurements
Soil cores were collected from each plot at spring seeding (March 7), grain harvest (July
12) and fall (Nov. 21) using a Giddings hydraulic probe (Giddings Machine Co., Windsor, CO).
Aluminum sleeves were used to extract the soil from each sampling location. Fall soil samples
were collected to 2.4 m by 30 cm depth increments, with the top 30 cm split at 0-15 and 15-30
cm. Spring and summer soil cores were collected to 1.5 m by 30 cm depth increments. At the
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time of sampling, extracted soil cores were extruded horizontally onto a 1.5 m section of angle
iron and evenly bisected lengthwise, resulting in two representatives samples for each depth
increment. Half of each bisected sample was placed in a numbered drying can for gravimetric
soil water analysis. The other half was deposited in a pre-labeled plastic bag, placed on ice and
returned to the laboratory, where samples were refrigerated. Immediately subsequent to field
work, samples for gravimetric soil water analysis were dried for 24 h at 105º C. Soil weight (g)
was recorded before and after drying, as well as the weight of each can. Percent gravimetric soil
water (θg) was calculated as:
100)())((
))(())((x
gweightcancangsoilcangsoilcangsoil
dry
drywetg −+
+−+=θ
Soil water content was calculated for subsequent investigation of possible interaction with soil
inorganic N dynamics throughout the growing season, and was expressed as (g H2O g soil-1) x
100, or percent.
For soluble N and PMN analysis, four approximately 5 g sub-samples were weighed out
of each refrigerated sample into 35 ml centrifuge tubes. Their exact oven dry weight was
calculated as:
Oven dry weight, (OD) (g) = soilwet (g)1+θg (%)
After weighing soil into centrifuge tubes, 12.5 ml distilled H2O was dispensed in two tubes, and
25 ml 1 M KCl into the other two. The former were incubated in anaerobic conditions for 14 d at
35º C for subsequent calculation of potentially mineralizable nitrogen (PMN) as described below
(Drinkwater et al., 1996). The other two samples were shaken 30 min, filtered (#1 Whatman),
and the extractant frozen until N analysis. At the end of 14 days, 12.5 ml 2 M KCl was dispensed
into each incubated sample for extraction identical to that performed on non-incubated samples.
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These were then frozen as well. Subsequently, approximately 2 ml of each replicate extractant
for incubated and non-incubated sub-samples was dispensed into a sample cup and analyzed for
NO3-N and NH4-N using an ALPKEM RFA™ 300 auto-analyzer. Nitrogen concentration results
obtained from the auto-analyzer were expressed as mg N L-1 of extractant. These concentrations
were converted to mg kg-1 as:
mg N kg-1 soil = N (mg / l) x 0.025 (l)OD (kg)
.
Incubated and non-incubated NH4-N concentrations were used to calculate PMN, and non-
incubated NO3-N concentrations were used as a metric of plant available N.
Calculations of soil inorganic N concentration provided values (mg N kg-1) by depth
increment (as described) to 240 cm for fall 2006 and 2007 samples, and to 150 cm for spring and
summer 2007 sampling. These values were used for statistical analyses of treatment means by
depth and treatment, interactions between depth and treatment, and interactions between soil
inorganic N and gravimetric water content. A repeated measures statistical model was used for
these analyses as described below. Soil inorganic N content on a concentration basis (mg N kg-1)
by treatment and depth was converted to an estimation of field availability (kg N ha-1) by
treatment using an estimated soil bulk density of 1.25 g cm-3, and the following calculation:
kg N ha-1 1612831 101501000125.0 −−−− ÷×××= kgmgcmhacmcmkgkgNmg
Nitrogen content expressed on this field availability basis was used to summarize soil inorganic
N data over the entire growing season as in Table 3.
Plant measurements
Plant measurements included an index for surviving weeds, number of surviving alfalfa
crowns, aboveground biomass and grain yield. All plant samples were collected at harvest on
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July 12th, 2007. At that time, each treatment was assessed a weed index rating from 0 to 5 based
on visually estimated percent cover; ratings were 0 = no weeds, 1 = 1-20 percent, 2 = 21-40
percent, 3 = 41-60 percent, 4 = 61-80 percent, and 5 = 81-100 percent weeds. Weeds included
surviving alfalfa, and those most conspicuous in the plots, including perennial rye (Lolium
perenne, L.), cheatgrass (Bromus tectorum, L.), lambsquarter (Chenopodium album), and
pigweed (Amaranthus sp.). Alfalfa crowns were counted in one, 1 m2 quadrat per plot. Alfalfa
aboveground biomass was determined by cutting one, 1 m2 quadrat per treatment at 50 mm, a
height approximate to simulated grazing, and weighed. Aboveground biomass samples included
all vegetation within the sampled area, including triticale straw, alfalfa and weeds. Alfalfa
samples were dried at 50° C for 48 hr, and weighed (g). Alfalfa aboveground biomass sampling,
followed by haying, occurred on May 17th, July 10th, and August 28th, 2007. Triticale grain
aboveground biomass, including straw and seed heads, was estimated from one, 1 m2 quadrat per
plot seeded to grain. Samples were threshed using a Wintersteiger plot combine (Wintersteiger
Inc., Salt Lake City, UT) and the grain samples weighed (g). Yield in g m-2 was multiplied by 10
to convert to kg ha-1. After grain harvest on July 12th, 2007 biomass was harvested off all plots.
Alfalfa was harvested one additional time as above. Triticale grain was selected for agronomy
and soils portion of this project due to interest of the farmer-cooperator at TH in using Triticale
grain as organic turkey feed.
Financial assessments
The economic performance of three organically managed crop rotations was assessed,
including continuously grazed alfalfa, a grazed alfalfa-wheat rotation, and a hayed alfalfa-wheat
rotation. Soft white spring white (var. Louise) was used in the financial assessments instead of
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Triticale grain (as used for agronomy-soils work) because TH management seeded 40 ha of this
crop in spring 2008. Triticale had been selected initially since TH management desired all crop
production to cycle through livestock for soil fertility reasons. As a result of a field-scale sowing
of wheat following plow-terminated alfalfa in 2008, however, this crop was used in financial
assessments as it is a more likely candidate for crop-livestock rotations on the wheat dominated
CP.
Long-term, continuously grazed organic alfalfa was the baseline, extant production
system in operation at the outset of these trials at TH farm in 2007. The farm breeds, raises,
finishes and markets its own organically-certified grassfed beef with an approximately 250-cow
herd. TH owns and operates a cut-and-wrap business in Walla Walla, Washington, and in 2007
completed construction on a USDA-certified mobile slaughter unit. The farm utilizes retail,
wholesale and direct sales marketing channels. As a whole, the operation is vertically integrated
to a considerable extent.
Financial assessments for this research project built upon the baseline, grassfed grazing
production system at TH by adding organic grain production. Triticale grain was added in 2007
via the tillage-trials as described above. In 2008, TH farm managers converted the remainder of
the roughly 40 ha alfalfa field in which the 2007 tillage trials had been located to organic soft
white wheat. Being the same field, this land had been managed as grazed alfalfa continuously
from 1997 through 2007 in an identical manner to the prior management of the land used for
tillage research plots in 2007.
Alfalfa to wheat conversion was accomplished by TH management using an
International, 6-bottom plow operating to roughly 13 cm in early February 2008 followed by a
disk-harrow operation. The field was seeded February 7th using triple-ganged JD model B van
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Brundt drills with double-disk openers. Wheat grain yield was estimated by cutting four, 1 m2
quadrats randomly located in the wheat field on the periphery of the tillage plots from 2007.
Samples were cut manually on July 21st, 2008 and subsequently threshed using a parked
Wintersteiger plot combine (Wintersteiger Inc., Salt Lake City, UT). Grain samples were
weighed (g) and yield in g m-2 was multiplied by 10 to convert to kg ha-1.
Setup and assumptions
Due to the complexity of the existing TH grassfed cattle operation, including over-
wintering cattle, processing and marketing strategies, we limited this work to cost-benefit
analyses of:
1. Expanding existing beef production at TH to include an organic grain enterprise,
2. Alfalfa production for beef versus organic hay, and
3. A hypothetical situation whereby a nearby grain producer entered into a contract grazing relationship with TH on a seasonal basis.
Expansion to organic grains: This analysis estimated costs and returns of adding wheat
production to an existing grazed alfalfa operation. Costs including machinery operations, fertility
management, weed management, and marketing were obtained directly from the experiment and
actual management decisions at TH.
Hayed versus grazed alfalfa in rotation with grain: This analysis estimated the costs and returns
for raising grain in rotation with grazed alfalfa. Data concerning grazing production costs,
benefits and management were directly available from TH interviews and records. These were
combined with grain production data to assess a grazed alfalfa-grain rotation. Processing,
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overwintering and marketing costs however were excluded and instead replaced with a flat price
paid per pound gain offered to graziers that TH contracts with. This approach assumed contract
graziers operated on a seasonal basis and were exempted from beef processing and marketing
costs. Building a USDA-certified mobile slaughter unit, purchasing a cut and wrap operation and
developing multiple retail, wholesale and direct marketing channels are not tasks every farmer
interested in combining crop and livestock enterprises would need to undertake. As such, we
treated livestock production as a contract operation embedded into an existing production chain.
We used TH as the model production chain since this farm already has established this network.
Grain production figures for the hayed alfalfa-grain rotation chain required more assumptions
than the grazed rotation as TH grazes and does not hay alfalfa. Fertility and weed management
assumptions were made as described in Table 2.2.
Contract grazing venture: It was assumed that contract grazing may be desirable to grain
farmers near TH by providing weed management, income during a cover crop phase, and/or soil
fertility through recycling a cover crop back onto cropland. The potential value of grazing in pre-
existing crop-based farms was unknown. This analysis estimated figures on per acre returns to
dedicating 500 acres to a grazing contract at TH prices per pound gain. In this scenario, the
farmer was responsible for infrastructure (including fencing, machinery, etc), management, and
labor for a summer grazing period only. Soil fertility and weed management benefits for an
otherwise crop-based farming system (nor the value of possible organic certification of
subsequent crops) were not given values, though they presumably would have value.
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*Alfalfa production in the haying enterprise the same as in the grazing enterprise
Table 2.2. Budget assumptions
General Labor cost ($/hr) $20.00 Field/pasture size (acres) 500 Manure ($/ton) $50.00 Weed management in grazed alfalfa-grain rotation Cattle Weed management in hayed alfalfa-grain rotation Rotary hoe
Grazing enterprise Price paid for livestock gain ($/lb) $1.00 Cow initial weight (kg) 350 Calf initial weight (kg) 150 Alfalfa hay production yr-1 (tons/acre) 5 Alfalfa production yrs 2-6 (tons/acre) 8.61†
Alfalfa NEg (Mcal/kg) 0.61 Cow average daily gain (lbs) 2.2 Calf average dailiy gain (lbs) 1.3 Cow-calf days of grazing (per acre) 160 Manure amendment for alfalfa establishment in grazed system (tons/acre)
0
Weed management none Grain enterprise
Wheat yield (bushel/acre) 70.0 Wheat bushel weight (lbs) 60 Price for organic alfalfa hay ($/ton) $200.00 Price of organic wheat ($/bushel) $15.00 Wheat seed cost ($/lb) $0.28 Wheat seeding rate (lb/ac) 100
Hay enterprise* Manure amendment for alfalfa establishment in grazed system (tons/acre)
8
Price of organic alfalfa hay ($/ton) $200.00
† Biomass productivity from alfalfa sampling in 2007, and comparable to TH estimations
Enterprise budgeting
The economic performance of each rotation was assessed using a Washington State
University enterprise budget format (Painter 2007). These budgets consist of budget
assumptions, enterprise budgets for establishment and production components for each phase of
the rotation, supplemental information (such as machine cost calculations, cattle weight gain and
capital infrastructure calculations), and a summary page to compile and present data on each
rotation as a whole.
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The continuously grazed rotation consisted of 1 yr alfalfa establishment and 9 yrs of
grazing. The grazed-alfalfa and hayed alfalfa-grain rotations consisted of 1 yr of alfalfa
establishment, 6 yrs of grazing/haying, and 3 yrs of grain crop production. The economic
performance of each complete cropping system was determined by developing enterprise
budgets for each phase of all rotations. These Excel-based budgets are intended to enable
growers to modify particular cost and return figures in relation to their own conditions and
operations. Excel sheets are in Appendix II, and in an included CD.
Expense data for seed, amendments and pest/weed management were obtained from
estimated current market rates. Data on operating expenses such as labor, irrigation, electricity,
marketing, ownership costs and supplies was obtained from interviews with the TH farm
manager. Pasture productivity data was obtained from aboveground biomass cuttings. Number of
cow-calf grazing days was calculated from biomass productivity, and average daily (AVD) gains
were calculated (see Budgets, Appendix II) from daily dry matter intake at 2% of body weight,
National Resource Council (NRC) figures for net energy for gain (NEg) in fresh alfalfa, and an
NRC table value for AVD given a specified level of NEg in the ration (Kellems and Church,
2001). Prices paid per pound cattle weight gain on pasture was based on an active offer by the
farm manager for contract grazing in the region (Neibergs, 2008). Wheat grain yield estimates
were obtained from the wheat field planted by TH as above.
Machine operating costs for all rotations were estimated using a Machine Cost program
(MCP) developed by the Agricultural Economics and Rural Sociology department at the
University of Idaho, Moscow, ID (UI AERS, 2008). This program was used to calculate
machinery labor costs, fuel and lubrication use, depreciation, interest, and machinery taxes,
housing and insurance from provided data on machinery purchase price, current value, hours of
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use, width of implement, age when purchased, years of life, fuel type and cost of fuel (data on all
of these assumptions is included in Excel worksheets on the CD). The MCP was used to
calculate these values for each implement and each operation for every phase of each rotation in
the cropping system.
Statistical Analysis
Four replicate blocks with four treatments each were arranged in a randomized complete
block design. A standard RCBD statistical model and Tukey pairwise comparisons (McIntire,
1990) were used to compare treatment means of weediness, surviving alfalfa crowns,
aboveground biomass, and soil inorganic N content on a field availability basis (kg N ha-1),
(Tables 3 & 4). The effect of tillage, depth and tillage by depth interactions with respect to soil
inorganic N concentrations (mg kg-1) (Figs 1-5) were analyzed using a Repeated Measures
model, Tukey pairwise comparisons and orthogonal contrast estimate statements. Probability
levels of P ≤ 0.05 were considered significant. The SAS code used for these analyses is in
Appendix III.
RESULTS
Tillage and soil moisture effects on soil nitrogen
Method of alfalfa take-out significantly affected soil NH4-N and NO3-N concentrations
(Table 2.3, Fig 2.2). Baseline data collected October 26th, 2006 indicated a significant
accumulation of NO3-N at 150 cm (Fig 2.1). This accumulation was detectable in the November
21st, 2007 soil sampling period as well (Fig 2.4). Primary tillage treatments imposed fall 2006
did not result in significantly different soil NO3-N, PMN or soil water by spring 2007 (Figs 2.5,
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2.6 and 2.9). By summer 2007, potential mineralizable soil N (PMN) to 150 cm was 5.31 and
2.34 times greater in SW100 than MP and ALF, respectively (Table 2.3, Fig 2.7). Analysis of
covariance, using percent soil moisture recorded at the time of soil sampling as the covariate,
could not be used due to depth x moisture interaction. Gravimetric water content showed a
correlation between soil moisture and PMN in summer 2007. SW100 had the lowest soil
moisture and highest PMN value at this time (Figs 2.7 and 2.9). No clear relationship was
observed between PMN and aboveground biomass at summer grain harvest in 2007 (Fig 2.12).
Alfalfa had the least biomass due to an earlier cutting on May 17th, 2007.
By fall 2007, SW100 soil to 150 cm had 1.57 and 1.76 times greater NO3-N than MP and
ALF (Table 2.3, Fig 2.4). No significant differences in soil inorganic N were observed between
MP and ALF treatments at any time.
Table 2.3. Seasonal soil inorganic N fluctuation at 0-150* cm depth following different methods of tillage to terminate alfalfa.
7 March 2007 12 July 2007 21 November 2007 NO3-N†
(kg ha-1)
Water content
(%)
NO3-N (kg ha-1)
PMN (kg ha-1)
Water content
(%)
NO3-N (kg ha-1)
Water content
(%) MP‡ 177.7 a± 21.3 a 37.2 a 17.1 a 16.9 a 81.0 a 27.8 a
SW100 165.9 a 21.0 a 35.1 a 90.9 b 14.4 b 127.6 b 25.4 a
ALF 130.1 a 20.9 a 48.9 a 38.8 a 16.0 a 72.3 a 24.7 b*Soil inorganic N data from 150 to 240 cm as collected in fall 2006 and 2007 not shown † Soil NO3-N and potentially mineralizable nitrogen (PMN) calculated as a sum to 150 cm. ‡ Treatment abbreviations: MP = moldboard plow; SW100 = undercutting sweep with 100 percent coverage; ALF = alfalfa control ±Different letters within a column indicate significant differences at P ≤ 0.05.
Gravimetric water content was significantly affected by treatments, with summer SW100
water content 17.4 and 11.1 percent lower than MP and ALF, respectively. By fall, ALF water
content was 12.6 and 2.8 percent lower than MP and SW100, respectively (Table 2.3). Lower
water content was associated with elevated PMN in the summer; however, comparisons across
- 68 -
depths indicate that the elevated PMN values were located in surface soil, whereas soil moisture
differences in PMN are only observed between 30 and 150 cm (Figs 2.7 and 2.10).
Tillage effects on grain yield and weeds
A positive correlation was observed between the number of surviving alfalfa crowns and
total aboveground biomass, while a negative correlation was observed between surviving alfalfa
crowns and Triticale grain yield (Table 2.4). Grain yield was significantly affected by method of
tillage, with yield after MP 2.6 times that of conservation tillage method SW100. Weed index
was also significantly affected by method of tillage, with MP reducing weed pressure
significantly better than SW100. A considerable number of alfalfa crowns (5.5 m-2) survived
even the most disruptive method of tillage (MP), and significantly more survived SW100.
Table 4. Triticale grain yield, aboveground biomass, number of surviving alfalfa crowns, and weed index at grain harvest on July 12, 2007.
Triticale grain yield (kg ha-2)
Biomass±
(g m-2) Alfalfa crowns
(no. m-2) Weed Index
(0-5)† Plow 4200a* 383a 5.5a 0.38a
Sweep 1630b 601b 8.25b 1.13b
Alfalfa - 668c 11c 3.81c
* Different letters within a column indicate significant differences at P ≤ 0.05. † 0-5 scale based on qualitative observations of percent weed cover. Ratings were attributed as: 0 = no weeds; 1 = 1-20% weeds; 2 = 21-40% weeds; 3 = 41-60% weeds; 4 = 61-80% weeds; 5 = 81-100% weeds ±Biomass = total aboveground biomass (alfalfa, triticale straw, weeds)
- 69 -
0
30
60
90
120
150
180
210
240
0 10 20 30 40
N (mg kg‐1)
Dep
th (cm)
NO3‐N PMN
Figure 2.1. Baseline fall 2006 soil NO3-N and PMN under alfalfa. Significant effects of depth at P ≤ 0.05 shown by different letters.
b
a
c
c
c
b
c
c
c
0
30
60
90
120
150
180
210
240
0 10 20
NO3‐N (mg kg‐1)
Depth (cm)
30
MP SW100 ALF
Figure 2.4. Fall 2007 soil NO3-N by depth and treatment. Significant depth effect shown by letters and tillage effect by (T) at P ≤ 0.05.
ba
b
b
b
c
c
c
c
Figure 2.2. Non-incubated soil NO3-N in top 150 cm from fall 2006 to fall 2007. Significant effect of treatment observed only in fall 2007 at P ≤ 0.05.
T
0
30
60
90
120
150
180
210
240
0 10 20 30
PMN (mg kg‐1)
Dep
th (cm)
MP SW100 ALF
Figure 2.3. Fall 2007 soil PMN by depth and treatment. Significant treatment effect observed at P ≤ 0.05.
81
128
49
72
178
37 35
166
130
102
0
20
40
60
80
100
120
140
160
180
200
Fall 06 Spring 07 Summer 07 Fall 07
NO3‐N (k
g ha
‐1)
MP SW100 ALF
- 70 -
Figure 2.6. Spring 2007 soil NO3-N by depth and treatment.
0
30
60
90
120
150
0 10 20
NO3‐N (mg kg‐1)
Dep
th (cm)
30
MP SW100 ALF
0
30
60
90
120
150
0 10 20
NO3‐N (mg kg‐1)
Dep
th (cm)
30
MP SW100 ALF
Figure 2.8. Summer 2007 soil NO3-N by depth and treatment.
0
30
60
90
120
150
0 10 20 30
PMN (mg kg‐1)
Dep
th (cm)
MP SW100 ALF
Figure 2.7. Summer 2007 PMN by depth and treatment. Significant effect of treatment for whole soilcolumn at P ≤ 0.05 indicated by different letters.
b ab
1
2
3
4
5
6
0 10 20 30
PMN (mg kg‐1)
Dep
th (cm)
MP SW100 ALF
Figure 2.5. Spring 2007 soil PMN by depth and treatment.
- 71 -
0
30
60
90
120
150
0 10 20 3
Soil moisture (%)
Dep
th (c
m)
0
MP SW100 ALF
0
30
60
90
120
150
180
210
240
0 10 20 30 40
Soil moisture (%)
Dep
th (cm)
MP SW100 ALF
0
30
60
90
120
150
0 10 20 30
Soil moisture (%)Dep
th (cm)
MP SW100 ALF
Figure 2.11. Fall 2007 soil moisture by depth and treatment. Significant effect of treatment in whole soil column at P ≤ 0.05 indicated with letters.
abb
Figure 2.10. Summer 2007 soil moisture by depth and treatment. Significant effect of treatment in whole soil column at P ≤ 0.05 indicated by different letters.
Figure 2.9. Spring 2007 soil moisture by depth and treatment.
aab
1094 1138
796
0
200
400
600
800
1000
1200
1400
Abo
vegrou
nd bim
oass (g)
MP SW100 ALF
Figure 2.12. Aboveground biomass at grain harvest.
- 72 -
Economic performance
Tables and figures presented
Current organic wheat prices of $15 bu-1 and yield data, organic hay valued at $200 ton-1,
and beef valued at $1 lb-1 were used to calculate costs and returns for each rotation component
(Table 2.5), and costs and returns for three rotation options including continuous grazing, grazed
alfalfa-wheat, and hayed alfalfa-wheat (Table 2.6). Some differences in these rotation
components and full rotations are reported graphically as total variable costs for each rotation
component (Fig 2.13), returns over total costs (net returns) for each rotation component (Fig
2.14), and a full summary of costs and benefits of each of the three full rotations (Fig 2.15).
Prices received for beef (three prices of $0.75, $1 and $2 lb-1) were varied to construct a
sensitivity analysis of the impact of different prices on profitability (returns over total costs) of
the three crop rotation options (Fig 2.16). A similar sensitivity analysis was carried out to assess
the impact of prices received for organic alfalfa hay ($150, $200 and $250 ton-1) and wheat
($11.25, $15 and $18.75 bushel-1) on the profitability of each of the three rotations (Table 2.8).
Table 5. Summarized annual costs and returns of rotation components of three rotations: grazed alfalfa-wheat (GGR), hayed alfalfa-wheat (HGR), and continuously grazed alfalfa (CG).
Rotation component
Total Cost of
Operation
Revenue per acre ($/acre)
Returns over TC ($/acre)
Total VC
($/acre)
Returns over VC ($/acre)
Fixed Costs
($/acre)
Labor ($/acre)
Land Payment ($/acre)
GAE $543 $464 -$79 $367 $98 $176 $41 $41 HAE $1,014 $1,000 -$14 $814 $186 $199 $45 $80 GA $505 $558 $53 $344 $214 $161 $98 $79 HA $1,329 $1,722 $393 $985 $737 $344 $400 $268 GG $570 $1,050 $480 $221 $829 $349 $28 $280 GH $695 $1,050 $355 $350 $700 $345 $33 $240
GAE: Grazed alfalfa establishment, HAE: Ungrazed alfalfa establishment, GA: Cattle grazing alfalfa, HA: Alfalfa hay, GG: Grain in grazed rotation, GH: Grain in ungrazed rotation. TC: total costs; VC: variable costs.
- 73 -
Table 6. Summarized costs and returns for a forage-grain rotation with grazing, with haying, and a continuously grazed rotation with no grain.
Rotation Total Cost
GGR: Grazed alfalfa-grain rotation; HGR: hayed alfalfa-grain rotation; CG: continuous grazing. TC: total costs; VC: variable costs.
($/ac/yr)
Revenue ($/ac/yr)
Returns over TC
Variable
Costs
Returns over VC
Fixed Costs
Labor
Land Payment ($/ac/yr)
GGR $528 $696 $168 $310 $387 $219 $71 $136 HGR $1,107 $1,448 $341 $777 $671 $330 $254 $241 CG $509 $549 $40 $347 $202 $162 $92 $75
Variable costs for rotation components
Total variable costs for each component of the hayed alfalfa-wheat rotation (HAE, HA,
GH) were considerably higher than for the grazed alfalfa-wheat rotation components (GAE, GA,
GG) (Fig 2.11). Variable costs for grazed versus hayed alfalfa establishment, alfalfa management
(grazing or haying), and wheat production were respectively 55, 65 and 27 percent lower (Table
2.5, Fig 2.13). During alfalfa establishment, higher amendment costs resulted in higher variable
costs for the hayed rotation. Haying alfalfa resulted in higher variable costs due to higher costs
for labor and other expenses, which included crop insurance, tarping and machinery repairs.
$‐
$100
$200
$300
$400
$500
$600
$700
$800
$900
$1,000
GAE HAE GA HA GG GH
Cost ($
acre‐1)
Other
Labor
Irrigation
Pest/weedcontrolAmendment
Seed
Figure 2.13. Annual variable costs of different rotation components (GAE: grazed alfalfa establishment, HAE: hayed alfalfa establishment, GA: cattle grazing alfalfa, HA: hayed alfalfa GG: grain in grazed rotation, GH: grain in hayed rotation).
- 74 -
Variable costs during the wheat phase were higher in the hayed system due to amendment costs
(manure application), and slightly higher costs for fuel use, machinery labor (an added rotary
hoeing operation) and machinery repairs. Labor costs for hayed alfalfa ($400 ac-1) were roughly
4 times as high as for grazed alfalfa ($98 ac-1).
Returns over total costs for rotation components
At $200 ton-1, haying alfalfa generated higher costs yet higher revenue and total returns
than the grazed system. Returns over total cost for alfalfa establishment were negative for yr 1 of
the grazed-alfalfa grain rotation (GGR), hayed-alfalfa rotation (HGR) and the continuously
grazed rotation (CG). CG rotation was composed only of alfalfa establishment (GAE) and grazed
alfalfa (GA), for which returns over total costs were comparatively lowest (Fig 2.14). Losses
under alfalfa establishment were slightly less for hayed alfalfa establishment (HAE) than grazed
(GAE). Comparing grazing versus haying rotation components, returns over total costs for
grazed alfalfa (GA: $53 ac-1) were 13.5 percent of those for hayed alfalfa (HA: $393 ac-1).
During the grain rotation component, returns over total costs for wheat production in the grazed
system (GG: $480 ac-1) were 1.4 times higher than in the hayed system (GH: $355 ac-1). This
owed to variable costs being 1.58 higher for wheat production in the hayed system as compared
to the grazed system (Table 2.5), with manure amendments and labor comprising most of the
difference (Fig 2.13).
- 75 -
$393
$480
$355
‐$79 ‐$14 $53
‐$200
‐$100
$0
$100
$200
$300
$400
$500
$600
GAE HAE GA HA GG GH
Figure 14. Annual returns over total costs for rotation components. (GAE: Grazed alfalfa establishment, HAE: Hayed alfalfa establishment, GA: Cattle grazing alfalfa, HA: Alfalfa hay, GG: Grain in grazed rotation, GH: Grain in hayed rotation).
Full rotation cost-benefit comparisons
Economic performance of all three rotation options was analyzed on the basis of annual
average per acre costs and returns, with 10-yrs being required to complete a full cycle for each
rotation. Averaged over this 10-yr period, returns over total costs for hayed alfalfa-wheat (HGR:
$341 ac-1) were 2 and 8.5 times higher than the grazed alfalfa-wheat (GGR: $168 ac-1) and
continuously grazed alfalfa (CG: $40 ac-1) rotations, respectively (Fig 2.13). Both variable costs
and fixed costs were considerably higher for HGR than in GGR and CG, owing to higher costs
for manure amendments, machinery, labor and fuel (Table 2.6). Considerably higher revenue for
HGR ($1,448 ac-1) compared to GGR ($668 ac-1) and ($549 ac-1) resulted from higher prices for
organic alfalfa hay in relation to per acre productivity compared to organic grassfed beef.
- 76 -
40
777
347
71 92136
696
1,448
549
341
168
310202
671
387
162219
330254 241
75
0
200
400
600
800
1,000
1,200
1,400
1,600
GGR HGR CG
($ acre‐
1 )Revenue
Returns overtotal costs
Total variablecosts
Returns overvariable costs
Fixed costs
Labor
Landpayment
Figure 2.15. Budget summary of annual average costs and benefits for a grazed alfalfa-grain rotation (GGR), a hayed alfalfa-grain rotation (HGR), and continuously grazed alfalfa (CG).
Table 2.7. Average annual variable costs, fixed costs and returns for three organic crop rotation options. GGR HGR CG Revenue $ 696.20 $ 1,448.20 $ 548.60 Seed $ 13.99 $ 13.99 $ 5.50 Amendments $ - $ 70.00 $ - Pest/weed control $ - $ - $ - Irrigation $ 157.00 $ 160.30 $ 175.00 Labor $ 71.29 $ 254.35 $ 92.18 Other: $ 46.22 $ 225.64 $ 50.28 Overhead $ 14.43 $ 36.21 $ 16.15 Operating Interest $ 6.72 $ 16.88 $ 7.53 Ownership Costs $ 218.61 $ 329.74 $ 162.24 Net return $ 167.94 $ 341.08 $ 39.72 GGR: grazed alfalfa-wheat rotation; HGR: hayed alfalfa-wheat rotation; CG: continuous alfalfa grazing rotation.
- 77 -
Sensitivity analysis for grain and alfalfa prices
Returns over total costs for each rotation component were analyzed in relation to
changing prices received for organic wheat, organic alfalfa hay, and organic grassfed beef (Table
2.8). The length (in yrs) of each production component in each rotation was held constant and the
total rotation cycle remained 10-yrs for all rotations. GGR and HGR reacted similarly to
changing prices for wheat as the ratio of forage crops to grain crops were the same in both
rotations. Returns over total costs for GGR would decline to below those for CG at higher wheat
prices than for the HGR rotation. Sensitivity analysis of changing alfalfa prices showed sharp
reaction of returns over total costs for HGR in response to increasing and decreasing prices.
Haying alfalfa reduced returns over total costs to levels below those obtained in the grazed
alfalfa-wheat rotation at alfalfa prices roughly below $160 ton-1. Increase in the price paid per
pound gain significantly increased returns over total costs for both the grazed alfalfa-grain
rotation and the continuously grazed alfalfa.
Table 2.8. Effect of price variation for alfalfa, wheat and beef on net returns for three organic crop rotation options
Base prices Alfalfa: $200 ton-1 Wheat: $15 bu-1 Beef: $1 lb-1
Alfalfa price sensitivity $150 $200 $250 GGR $ 167.94 $ 167.94 $ 167.94 HGR $ 57.78 $ 341.08 $ 624.38 CG $ 39.72 $ 39.72 $ 39.72 Wheat price sensitivity $11.25 $15 $18.75 GGR $ 89.19 $ 167.94 $ 246.69 HGR $ 262.33 $ 341.08 $ 419.83 CG $ 39.72 $ 39.72 $ 39.72 Beef price sensitivity $0.75 $1.00 $2.00 GGR $ 156.34 $ 167.94 $ 214.34 HGR $ 341.08 $ 341.08 $ 341.08 CG $ (97.43) $ 39.72 $ 588.32
GGR: grazed alfalfa-wheat rotation; HGR: hayed alfalfa-wheat rotation; CG: continuously grazed alfalfa
- 78 -
DISCUSSION
Alfalfa termination, effect on grain yield
Integrating forages, either grazed or hayed, into farming systems may help increase on-
farm biological N fixation and perhaps profit; however, viable use of perennial forage crops
requires adequate control in relation to management goals and limitations concerning tillage
intensity and use of agricultural chemicals. Conservation tillage treatments resulted in
subsequent grain yields well below optimum or acceptable levels. By contrast, a similar alfalfa-
barley trial in south central Idaho is indicating a more aggressive under-cutting sweep could be
effective at mechanically terminating alfalfa (Dave Huggins, pers. comm., 2008). More work is
needed to refine these minimum-disturbance tillage methods for use in organic crop-livestock
systems, and to set reasonable goals for “sufficient” control. Settling on acceptable weed
tolerances in relation to yield penalties, and maximum tillage intensity in relation to controlling
soil erosion, will be important in determining these thresholds.
Soil nitrogen leaching
A small accumulation of subsoil NO3-N as observed in fall 2006 and 2007 under alfalfa
agreed with documented concerns of potential N leaching following conversion of perennials to
annual row crops (Askegaard et al., 2005; Huggins et al., 2001; Lloyd, 1992). In this experiment,
cumulative soil NO3-N concentrations under alfalfa amounted to approximately 20.14 kg N ha-1
between 120 and 150 cm in fall 2006, and 14.33 kg ha-1 between 90 and 120 cm in fall 2007—
significant though not high concentrations. Since this experiment did not incorporate continuous
monitoring, as with tile drainage monitoring, porous cups or lysimeters, leaching loss of these
pockets of soil NO3-N cannot be confirmed. In a similar conversion of perennials to row crops,
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Huggins et al. (2001) reported low tile NO3-N drainage under CRP and alfalfa, followed by an
increase in drainage losses under subsequent corn-soybean rotations to levels found under
continuous corn-soybean. These results would agree with claims made by Haynes and Francis
(1990) concerning New Zealand mixed cropping systems. They found that SOM and soil organic
N accumulate under perennial forages, and are either utilized or lost under subsequent arable
crops.
Specific N loss pathways and proportions depend substantially on management practices
and soil type. Huggins et al. (2001) report negligible drain losses under ungrazed CRP and
alfalfa, whereas Russelle (1996) report high potential for N losses under grazing management
due to volatilization from concentrated urine and manure patches. Berntsen et al. (2006) report
moderately low N losses from coarse-textured soils under grazed pasture followed by substantial
leaching losses during the first two years of conversion to spring barley, pointing to the critical
conversion period from perennials to annuals.
That perennial-annual rotations will be more N-efficient than purely annual rotations
seems apparent due simply to substitution of more N-efficient perennial crops for less N-
inefficient annual row crops in some years of the rotation. This hypothesis is supported by
research showing reduced N requirements of row crops following perennial legumes and reduced
N inputs into grazed and ungrazed perennial-annual rotations (Allen et al., 2008; Lory et al.,
1995; Rasmussen et al., 1989). Whether grazed perennial-annual rotations are self-provisioning
with respect to N, and still N-inefficient in terms of volatilization and leaching, is not yet clear.
Entz et al. (Entz et al., 2001) observed the lowest concentrations of subsoil NO3-N in a 4 year
alfalfa/2 year wheat rotation, suggesting that mixed cropping systems, properly managed, might
both reduce fertilizer N needs throughout rotations as well as exhibit higher N-use efficiency.
- 80 -
Tillage effects on PMN and soil NO3-N
No significant differences in fall 2007 soil NO3-N were observed between the tillage-
intensive MP treatment and the undisturbed ALF control; low subsoil NO3-N was observed in
both plots (Figure 2.4). These findings are contrary to results reported by Mohr et al. (Mohr et
al., 1999). These researchers investigated the effects of tillage versus herbicide termination of
perennial alfalfa on soil NO3-N beneath a subsequent wheat crop. They reported elevated NO3-N
levels for tillage in three out of four experiments, suggesting the higher degree of disturbance
facilitated mineralization from labile organic N pools, perhaps through increased soil aeration.
Alternatively, Weil et al. (1993) reported elevated fall soil NO3-N in reduced tillage treatments,
arguing that minimum tillage enhanced biological N fixation.
Higher summer 2007 PMN and fall 2007 NO3-N concentrations in the low-disturbance
SW100 in this research trial agree with the results obtained by Weil et al. (1993), but disagree
with our original hypothesis that increased tillage would increase soil NO3-N concentrations.
Correlation of significantly lower percent soil moisture with PMN in SW100 in summer 2007
could suggest the importance of a balance between soil moisture and soil pore air to N
accumulation in this labile pool. In this scenario, improved soil aeration would have been
maintained not in MP but in SW100. By this logic, however, PMN would have been highest in
ALF, which it was not. Regardless, elevated PMN in SW100 during the summer translated to
higher PMN and soil NO3-N by fall 2007.
Plant community and root composition might help explain distribution of PMN and NO3-
N concentrations between the treatments. At July sampling, the ALF treatment consisted of
mature alfalfa plants with undisturbed, large-crowned root systems. Aboveground biomass in
MP consisted largely of Triticale. Belowground biomass would have consisted of growing
- 81 -
Triticale roots and terminated alfalfa roots exhibiting the least regrowth due to greatest tillage
disturbance. In SW100, aboveground biomass was an alfalfa-Triticale mix. Belowground, partial
alfalfa termination would have exhibited significant alfalfa root regrowth mixed with lesser
developed, though established Triticale root systems. Distribution and quantities of fine root
hairs in these three different systems, particularly alfalfa fine-root regrowth, may have resulted in
elevated summer PMN and fall NO3-N levels in SW100. Bolger et al. (2003) report higher post-
termination N mineralization for subterranean clover (Trifolium subterraneum) compared to
alfalfa due to coarser root structure in the latter. This would help explain the lowest soil N levels
under alfalfa. Whether soil physical (compaction, moisture, aeration) or biological (root
composition, root hair distribution) characteristics determine the size of the labile N pool after
alfalfa-to-row crop conversion remains undetermined.
Clearer relationships between soil moisture, tillage, plant community, root structure and
soil N may have been further confounded by uneven soil nutrient redistribution by ruminant
herbivory, which is common to pasture systems (Heady and Child, 1994). Future work, and
perhaps larger sampling areas, is needed to more fully understand soil N dynamics in grazed
mixed cropping systems.
Economic performance
Expanding existing beef production at TH to include an organic grain enterprise
Over a 10-yr period, integrating wheat into the ongoing grassfed beef operation at TH
farm increased net returns from $40 ac-1 yr-1 to $168 ac-1 yr-1. One problem with this assessment
is that the price paid for beef in this budget is lower than the market price obtained by TH. This
farm manages a complex combination of production, processing and marketing tasks in order to
- 82 -
raise and sell certified-organic grassfed beef. A cut and wrapped, quarter-head of organically-
certified grassfed beef is priced by TH at roughly $6 lb-1 marketed direct to the consumer. The
price paid per pound gain in this economic analysis was $1 lb-1. The difference between these
two prices represents the costs to TH of creating and maintaining the complicated production and
marketing chain this farm depends on. For every increment from $1 lb-1 to $6 lb-1 in added
return, added production, processing and marketing costs accrue which are difficult to quantity
since they are not replicated anywhere in the United States. TH farm was the first farm in the US
to privately design and build a USDA-certified mobile processing unit. Substituting a flat price
paid per pound gain likely undervalues livestock gain on pasture within the TH production chain.
High returns over total costs in a grazed alfalfa-grain rotation ($168 ac-1) are thus difficult to
compare to relatively low returns over total costs for a continuously grazed rotation ($40 ac-1).
Unknown values also complicate this comparison, such as the potential reduction in leaching
potential of annual grains in rotation with N rich alfalfa forages (Mohr et al., 1999). The value of
fertility accrued under grazed alfalfa compared to hayed alfalfa for subsequent grain crops were
reflected in reduced amendment costs for the former; however, the precise fertility credit of a
grazed versus hayed rotation will require field research involving controlled nutrient response
estimations.
Increasing the price paid per pound gain for organic grassfed beef substantially increased
the profitability of the two rotations with grazing components. Returns over total costs for both
grazed alfalfa-grain and continuously grazed alfalfa exceeded those for hayed alfalfa-grain at
roughly $1.50 pound-1 beef, and net returns for a grazed-only rotation exceeded those for a
grazed alfalfa-grain rotation before the price of beef reach $2 lb-1 (Figure 2.16). Given TH put
100-acres into wheat in 2007 in response to $15 bu-1 prices, while at the same time marketed
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beef for $6 lb-1 suggests the cut-off for not growing gain at $15 bu-1 is higher than beef prices of
$2 lb-1. The degree of the response (Table 2.8) suggests that other management factors might be
further constraining variations in profitability. The simple cost-benefit framework used here,
however, does suggest fairly narrow tolerances in profitability between these farming systems.
Further developing this model, and conducting fields tests to verify it, might prove to be useful in
optimizing management choices on diversified farms, particularly in light of changing prices and
costs. Additional optimization analyses could be included to account for different combinations
of years spent in each rotation component, and variations in selected input costs.
‐$200
‐$100
$0
$100
$200
$300
$400
$500
$600
$0.75 $1.00 $2.00
Price of beef ($ lb‐1)
Returns over total costs ($
ac‐1 )
GGR
HGR
CG
Figure 16. Sensitivity analysis showing the change in returns over total cost for different crop rotations in response to changes in the price of organic grassfed beef.
Alfalfa production for beef versus hay
Total costs as well as revenue and returns over total costs were roughly twice as high in
the hayed alfalfa-grain rotation as compared to the grazed alfalfa-grain rotation. Hayed alfalfa in
rotation with organic wheat is apparently a high input, high return cropping system option at
- 84 -
$200 ton-1 alfalfa, $15 bushel-1 wheat, and $1 pound-1 beef. One important qualification is that a
long-term hayed alfalfa-wheat rotation was not directly trialed in this research project, and as
such weed and fertility management should receive field testing to more truly understand
management opportunities and costs. Sensitivity analysis for both alfalfa prices and beef prices
revealed considerable opportunity for shifts in relative economic performance of the three
rotation options investigated. High production costs for hayed systems required alfalfa prices
greater than $160 ton-1. The range in the producer market value for organic grassfed beef from
$1 lb-1 to $6 lb-1 reflected the established state of uncertainty concerning processing and
marketing costs of this value-added product. The threshold at which the profitability of grazed
alfalfa in rotation with grain exceeded the profitability of hayed alfalfa in this analysis was
roughly $1.60 pound-1 beef. Unquantified processing and marketing costs, however, make it
difficult to pinpoint a precise threshold at which the price of beef adequately covers expenses
and facilitates competition with a hayed alfalfa rotation.
Contract grazing option for a crop farmer
Returns over total costs for contract grazing cattle on a 500-acre pasture were $40 ac-1.
Potential profitability of this management option in relation to haying is not governed by the
same uncertainty over unknown processing and marketing costs in this situation, because the
value of beef is set and processing and marketing costs can be ignored. Increases in the price
paid per pound gain therefore contribute directly to net returns. At $200 ton-1 alfalfa and $1
pound-1 beef, annual net returns were considerably higher for the hayed alfalfa-wheat rotation
($341 ac-1, Table 2.5) compared to continuously grazed alfalfa ($39 ac-1, Table 2.7). However,
raising the price of beef to roughly $2 pound-1 increased net returns for continuously grazed
alfalfa to $588 ac-1 (Table 2.8), suggesting here as well a narrow economic threshold governing
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the profitability of haying versus grazing. Notable in these two management options was that
labor costs for hayed alfalfa were approximately 4 times higher than grazed alfalfa due primarily
to four haying operations (Table 2.7). Also, in grazed alfalfa, fencing costs represented only
about 2 percent of total costs. This suggests labor and ownership costs may not be the most
significant financial barriers to using grazing in crop rotations, particularly in situations where
grazing is contracted at a flat price, and is not a year-round endeavor. Undeveloped processing
and marketing infrastructure appear to most significantly limit a clear understanding of the
economic balances between the different management options examined.
ACKNOWLEDGEMENTS
The research was made possible through the funding of the U.S. Dept. of Agriculture
Sustainable Agriculture Research and Education (SARE) program. Significant contributions of
labor, equipment and expertise came from the USDA-ARS research station and technicians in
Pullman, WA. Special thanks to farms like Thundering Hooves and S&S Homestead that spur
innovation in sustainable agricultur
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REFERENCES
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Carr, P.M., W.W. Poland and L.J. Tisor. 2005. Forage legume regeneration from the soil seed bank in western north dakota. Agron. J. 97:505.
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Franzluebbers, A.J. and J.A. Stuedemann. 2007. Crop and cattle responses to tillage systems for integrated crop-livestock production in the southern piedmont, USA. Renewable Agriculture and Food Systems 22:168-180.
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GENERAL CONCLUSION
Challenges to agricultural sustainability have been studied considerably in the Palouse
region. Some areas of particular concern include increasing costs of agricultural chemical inputs,
loss and/or redistribution of roughly half of the region’s SOC from its original values/landscape
positions, soil acidification from NH4-based fertilizers, concerns over the human and ecological
impacts of fertilizers and pest control chemicals lost to surface and groundwater, and broad
challenges of herbicide resistance and demands to increase or sustain world agricultural output.
Questions as to the economic and environmental sustainability of conventional
agriculture have prompted interest in and development of numerous alternatives. These include
organic agriculture, biodynamic agriculture, conservation tillage practices, agroecology, local
agriculture and more diversified farming systems. The integration of crops and livestock in
mixed farming systems has been investigated for its potential to reduce off-farm inputs, make
efficient use of on-site natural resources to produce multiple farm products, provide biological
options for weed and pest control, and recycle nutrients for continued soil fertility. An increasing
number of research studies in recent years have revealed an exciting, though complicated and
challenging mode of agricultural production.
This research project was inspired by the perspective in biodynamic agriculture, and to
varying degrees in the literature on mixed systems, that crop and livestock production should be
integrated as a general principle of agro-ecological integrity. The actual execution of this project
was organized around a similar hypothesis that mixed systems can address challenges to
agricultural sustainability in the Palouse. The first chapter of this thesis addressed this hypothesis
theoretically by reviewing the benefits and obstacles to mixed systems in other regions, and
identifying needed information (in the form of research and development knowledge) to
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critically analyze the potential of these systems in the Palouse today. The objectives of this
chapter were to (i) identify the potential for mixed cropping systems in the Palouse region, (ii)
briefly review the benefits and challenges for mixed systems in other regions, (iii) present
regional research relevant to mixed systems in the Palouse, and (iv) identify research
opportunities for crop-livestock systems.
The second chapter of this thesis addressed the hypothesis (that mixed systems can
contribute to agricultural sustainability) from an applied perspective. In this chapter I assessed a
mixed crop-livestock system in Walla Walla, Wash. in terms of adaptability to other
conservation practices (conservation tillage), nitrogen dynamics, production potential, and
economic performance. The objectives this chapter were to (i) monitor N dynamics (leaching and
availability) following the termination of long-term alfalfa forage using different methods of
tillage, (ii) quantify grain yield potential following terminated alfalfa, and assess the impact of
tillage method on yield, (iii) assess the viability of a conservation tillage method to terminate
alfalfa in comparison with moldboard plow, and (iv) investigate the economic performance of
three organic cropping systems: (a) wheat integrated into continuously grazed alfalfa pasture, (b)
wheat integrated with a alfalfa hay enterprise, and (c) continuously grazed alfalfa production
with no grain component.
A review of mixed systems in other regions of the world suggested that crop-livestock
integration may indeed provide models to improve agricultural sustainability in the Palouse.
Crop-pasture rotations were adapted to no-till practices, improved soil structure and increased
plant water availability (an important consideration for a potentially drier future Palouse region).
Perennials accumulated soil C at a faster rate than annuals, and N application has been reduced
through greater use of biological N fixation.
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Research work in other regions showed promising results; however, these needed to be
carefully qualified due to inherent environmental, edaphic, policy and cultural differences
between regions. Also, mixed systems were not without explicit problems. Substantial N
leaching following grass-legume pasture termination was widely observed when moisture is
sufficient for leaching. In hotter, drier climates, N loss via volatilization loosened the generally
tight N cycling capacities of perennial groundcover by redistribution of soil organic N into
concentrated urine and manure patches on the soil surface. Water management complicated
annual-perennial systems as well through draw-down of soil water reserves by deep-rooted
perennials prior to annual cropping.
Economic assessments from other regions investigated aspects of mixed systems, yet
specific treatment choices and environmental conditions made these economic studies only
partially applicable to the Palouse. In the Palouse region, for instance, long winters and distance
from compost or manure sources limits the economic information-value of studies that substitute
clipped forages and manure application for maintaining livestock year-round. Also, trials using
irrigation, and those in regions with higher rainfall zones, impacted all-important determinants of
economic performance for livestock production: average daily gain of grazing livestock, length
of grazing season, and over-wintering costs. Such studies, then, cannot add much to the question
of the viability of grazing livestock in the region.
Regional research in the Palouse from the 1920s to the 1960s did highlight promising
research work relevant to mixed systems that is worth redoing under present conditions, and/or
building on, today. One study described a full production system to introduce grazing livestock
in the Palouse. Heavy emphasis on grains revealed our lack of understanding, even today, of
what a grazing-intensive mixed system in the Palouse would actually look like. Areas of research
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where the viability of such a system should be assessed and/or improved include testing annual
forages for shoulder-season grazing, use of new perennial grass-legume varieties, and regional
farmer-grazier collaborations. Other research areas include impacts of mixed systems on soil
water management, farm-level economic performance and regional economic activity, use of
grazing for pest control, impacts of livestock on soil quality, and fluctuations in SOC and organic
N between grazed perennial and annual crop phases in rotations.
Current work should not shy away from uncertainty, however, because both innovative
regional grazing collaborations and untested forage strategies will likely go some distance
towards addressing limited spring, fall and winter grazing options. This is a very exciting area
for research activity today.
In chapter two, on-farm research trials in Walla Walla, Wash. provided initial insight into
the effects of mixed systems on nitrogen and profit. Potential for N leaching was observed, with
accumulation of subsoil NO3-N in fall 2006 and 2007 under alfalfa of 20.14 kg N ha-1 and 14.33
kg ha-1 respectively. Low-disturbance SW100 resulted in a significantly higher accumulation of
subsoil NO3-N, but no significant differences in fall 2007 soil NO3-N were observed between the
tillage-intensive MP treatment and the undisturbed ALF control. This disagreed both with our
hypothesis and with the findings of other researchers. Low-disturbance undercutting sweep,
however, did result in a 62 percent lower triticale grain yields than MP in the 2007 trials. In the
field scale soft white spring wheat trials in 2008, wheat grain yields between 5380 and 6055 mg
ha-1 were obtained with no added fertilizers or pesticides. This was from 100 to 108 percent of
county averages, suggesting the potential of these systems to improve agricultural resource-use
efficiency and sustain yields. Possible improvements to SW100 tillage methods would have been
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a heavier implement outfitted with coulters to keep the cutting edge below the soil surface, and
to prevent side slipping that allowed strips of alfalfa to survive.
Comparing grazing versus an integrated livestock-wheat rotation over a 10-yr model
period, integrating wheat into the ongoing grassfed beef operation at Thundering Hooves farm
increased net returns from $40 ac-1 yr-1 to $168 ac-1 yr-1. A sensitivity analysis showed that net
returns for both grazed alfalfa-grain and continuously grazed alfalfa exceeded those for hayed
alfalfa-grain as the price per pound beef was increased to $1.50 pound-1. Net returns for a grazed-
only rotation exceeded those for a grazed alfalfa-grain rotation before the price of beef reach $2
lb-1 (Figure 16). The degree of the response depicted by our economic model suggests
unaccounted for production costs that likely constrain profitability. Further developed and field
tested, this model might be a useful framework to optimize management choices on diversified
farms, particularly in light of rapidly changing prices and costs.
Comparing a hayed versus grazed alfalfa-wheat rotation, net returns were roughly twice
as high in the hayed alfalfa-grain rotation as compared to the grazed alfalfa-grain rotation. The
threshold at which the profitability of grazed alfalfa-wheat exceeded the profitability of hayed
alfalfa-wheat in this analysis was roughly $1.60 pound-1 beef. The profitability of hayed alfalfa-
wheat exceeded the profitability of grazed alfalfa-wheat at roughly $160 ton-1 for alfalfa. With
respect to contract grazing, net returns on a 500-acre pasture were $40 ac-1 yr-1. The profitability
of rotations with grazing was highly sensitive to increases in prices paid lb-1 gain on pasture.
As observed in this thesis, mixed crop-livestock systems do exhibit exciting potential to
improve agricultural sustainability in the Palouse region. This field of inquiry, however, is
clearly in its infancy in the Palouse region, and much uncertainty remains. The successes of
mixed systems in other regions provide grounds for optimism, while conceptual, agronomic and
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logistic challenges both in this region and elsewhere can spur continued work. Ultimately, the
potential of crop-livestock agriculture will only be adequately appraised by developing,
implementing and investigating these systems through regional field trials.
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Appendix I. Distribution of crop-livestock papers by year and world region 2000 2001 2002 2003 2004 2005 2006 2007
Australia, Canada, Europe, New Zealand, U.S. Fontaneli Entz Entz Alford Acosta-Martinez Allen Berntsen Franzluebbers
Karunatilake Eriksen Karunatilake Carr Blodgett Carr Hatfield Franzluebbers Weston Langer Preston Davies Clark Carr Krall Hoeppner
Peoples Schiere Krall Dear Contreras-Govea Pretty Russelle Ledgard Davies Katsvairo Sulc Goosey Franzluebbers Liebig Gregory Hoshide Allen Loi Humphries Schmutz McGechan O'Connell Nichols Naylor Kellerbach Dolling Entz Sleutel Watson Russelle Whitbread Fliessbach Maraseni
2000 2001 2002 2003 2004 2005 2006 2007 Developing countries
Oba Mulatu Devendra Hedlund Garcia-Prechac Wong Rao Komwihangilo Dos Santos Thornton Devendra Gebremedhin Devendra Campillo Duncan Avasthe
Fisher Tanner Okumu Romney Desta Annicchiarico Yiridoe Tanrivermis Ndubuisf Madani Thorne Sumberg Lamanda Bouwman Lenne Siegmund Conelly Delve Thomas Michalk Chianu Abunyewa Spera Minh
Christiansen Singh Devendra Andom Powell Rao Tiffen Haileslassie Ali Devendra Rao Rischkowsky van Zyl Rufino Nhan Salako Samarajeewa Spera Zeng Hassen Harris Sanginga Semwal Manyong Ravisankar Sumberg Manlay Lenne Devendra Larbi Rischkowsky Pineiro Herrero Devendra Meaux Vall Dar Sangare Augusseau da Silva Flores Ikpe Desta Tipraqsa Omotayo Chianu Mapiye
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APPENDIX II.
Enterprise budgets and supporting material for cost-benefit analysis of a grazed alfalfa-wheat rotation, hayed alfalfa-wheat rotation, and a continuously grazed alfalfa rotation.
Table A.1. Production costs for establishing irrigated organic alfalfa pasture in a grazed alfalfa-wheat system Quantity Price or Value or Item Per Acre Unit Cost Cost/Acre Gross Returns Alfalfa hay for winter feed 5 ton $0.00 $0.00 Saleable cow-calf weight gain 464.1 lbs $1.00 $464.10 Operating Inputs Seed: $55.00 Barley nurse crop 20 lb $0.15 $3.00 Alfalfa Seed 20 lb $2.00 $40.00 Alfalfa Seed for re-seeding 4 lb $3.00 $12.00 (assume 20% of the time) Amendments $0.00 Manure 0 ton $50.00 $0.00 Compost $0.00 Pest/weed control $0.00 Irrigation $175.00 Water charge 4 irrigations $30.00 $120.00 Electrical 1 $ $55.00 $55.00 Labor $41.01 Irrigation labor 4 irrigations $6.00 $24.00 Machinery Labor 0.85 acre $20.00 $17.01 Other: $70.53 Soil Test 1 acre $0.30 $0.30 Crop insurance 5 ton $2.00 $10.00 Gopher control 1 acre $2.00 $2.00 Haul and stack hay 1 acre $9.00 $9.00 Tarping 5 acre $4.00 $20.00 Fuel 5.07 gal $3.50 $17.73 Lubricants 1 acre $2.66 $2.66 Machinery Repairs 1.00 acre $8.84 $8.84 Overhead $17.08 Operating Interest .
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Table A.1 (cont). Production costs for establishing irrigated organic alfalfa pasture in a grazed alfalfa-wheat system Total Operating Costs $366.58 Operating Costs per Unit $73.32 Net Returns Above Operating Expenses $97.52 Ownership Costs: Machinery depreciation $54.65 Machinery interest $36.01 Machinery insurance, taxes housing, licence $8.73 Organic certification Farm $1,000.00 $10.00 Side-roll irrigation (1/3 cost share w/ other rotation phases) $15.40 Land costs (33% income and 33% cost share) $40.85 Side-roll irrigation $5.13 Land Taxes $5.50 Total Ownership Costs $176.28 Ownership Costs per Unit $35.26 Total Costs per Acre $542.86 Total Cost per Unit $108.57 Returns to Risk -$78.76
Table A.2. Production costs for establishing irrigated organic alfalfa pasture in a hayed alfalfa-wheat system Quantity Price or Value or Item Per Acre Unit Cost Cost/Acre Gross Returns Alfalfa hay for winter feed 5 ton $200.00 $1,000.00 Saleable cow-calf weight gain 0 lbs $1.00 $0.00 Operating Inputs Seed: $55.00 Barley nurse crop 20 lb $0.15 $3.00 Alfalfa Seed 20 lb $2.00 $40.00 Alfalfa Seed for re-seeding 4 lb $3.00 $12.00 (assume 20% of the time) Amendments $400.00 Manure 8 ton $50.00 $400.00 Compost $0.00 Pest/weed control $0.00 Irrigation $175.00
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Table A.2 (cont). Production costs for establishing irrigated organic alfalfa pasture in a hayed alfalfa-wheat system Water charge 4 irrigations $30.00 $120.00 Electrical 1 $ $55.00 $55.00 Labor $44.71 Irrigation labor 4 irrigations $6.00 $24.00 Machinery Labor 1.04 acre $20.00 $20.71 Other: $83.96 Soil Test 1 acre $0.30 $0.30 Crop insurance 5 ton $2.00 $10.00 Gopher control 1 acre $2.00 $2.00 Haul and stack hay 1 acre $9.00 $9.00 Tarping 5 acre $4.00 $20.00 Fuel 5.55 gal $3.50 $19.41 Lubricants 1 acre $2.91 $2.91 Machinery Repairs 1 acre $20.34 $20.34 Overhead $37.93 Operating Interest $17.68 Total Operating Costs $814.29 Operating Costs per Unit $162.86 Net Returns Above Operating Expenses $185.71 Ownership Costs: Machinery depreciation $45.74 Machinery interest $30.84 Machinery insurance, taxes housing, licence $6.33 Organic certification Farm $1,000.00 $10.00 Side-roll irrigation (1/3 cost share w/ other rotation phases) $15.40 Land costs (33% income and 33% cost share) $80.44 Side-roll irrigation $5.13 Land Taxes $5.50 Total Ownership Costs $199.39 Ownership Costs per Unit $39.88 Total Costs per Acre $1,013.68 Total Cost per Unit $202.74 Returns to Risk -$13.68
Table A.3. Production costs for grazing cattle on organic alfalfa Quantity Price or Value or Item Per Acre Unit Cost Cost/Acre Gross Returns Alfalfa hay 0 ton $250.00 $0.00 Saleable cow/calf weight gain 558 lb $1.00 $558.20
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Table A.3 (cont). Production costs for grazing cattle on organic alfalfa Operating Inputs Seed: $0.00 Alfalfa pasture 0 lb $4.60 $0.00 - $0.00 Amendments $0.00 Manure 0 ton $50.00 $0.00 Compost g $0.00 Pest/weed control $0.00 Irrigation $175.00 Water charge 4.00 irrigations $30.00 $120.00 Electrical (irrigation) 1 $55.00 $55.00 Labor $97.87 Irrigation labor 4 irrigations $6.00 $24.00 Livestock labor 3.3 hrs $20.00 $66.00 Machinery Labor 0.39 hrs $20.00 $7.87 Custom hay Other: $48.03 Hauling mile Butcher 0 lb $0.45 $0.00 Livestock insurance 1 head $9.00 $9.00 Marketing (10% of sale) 0 head $55.82 $0.00 Salt and minerals 1 lbs $1.00 $1.00 Veterinary medicine 1 head $15.00 $15.00 Kill 0 head $65.00 $0.00 Fuel 3.88 gal $3.50 $13.58 Lubricants 0 gal $2.04 $2.04 Machinery Repairs . 7.41 $7.41 Overhead $16.05 Operating Interest $7.48 Total Operating Costs $344.43 Operating Costs per Unit $0.62 Net Returns Above Operating Expenses $213.77 Ownership Costs: Fencing $9.69 Machinery depreciation $22.07 Machinery interest $13.91 Machinery THI $6.35 Organic certification Farm $1,000.00 $10.00 Side-roll irrigation (1/3 cost share w/ other rotation phases) $15.40
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Table A.3 (cont). Production costs for grazing cattle on organic alfalfa Land costs (33% income and 33% cost share) $79.10 Land taxes $4.16 Total Ownership Costs $160.68 Ownership Costs per Unit $0.29 Total Costs per Acre $505.10 Total Cost per Unit $0.90 Returns to Risk $53.10
Table A.4. Production costs for haying organic alfalfa Quantity Price or Value or Item Per Acre Unit Cost Cost/Acre Gross Returns Alfalfa hay 8.61 ton $200.00 $1,722.00 Saleable cow/calf weight gain 0 lb $1.00 $0.00 Operating Inputs Seed: $0.00 Alfalfa pasture 0 lb $4.60 $0.00 Amendments $0.00 Manure 0 ton $50.00 $0.00 Compost g $0.00 Pest/weed control $0.00 Irrigation $175.00 Water charge 4 irrigations $30.00 $120.00 Electrical (irrigation) 1 service $55.00 $55.00 Labor $399.88 Irrigation labor 4 irrigations $6.00 $24.00 Livestock labor 0 hrs $20.00 $0.00 Machinery Labor 1.57 hrs $20.00 $31.48 Custom hay 8.61 ton $40.00 $344.40 Other: $342.71 Hauling 100 mile $0.50 $50.00 Crop insurance 1.5 ton $2.00 $3.00 Gopher control 1 acre $2.00 $2.00 Haul and stack hay 1 acre $9.00 $9.00 Marketing (10% of sale) 0.861 ton $200.00 $172.20
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Table A.4 (cont). Production costs for haying organic alfalfa Tarping 1.5 acre $4.00 $6.00 Fuel 8.02 gal $4.00 $32.08 Lubricants 0 gal $4.23 $4.23 Machinery Repairs . $ 64.20 $64.20 Overhead $45.88 Operating Interest $21.39 Total Operating Costs $984.86 Operating Costs per Unit $114.39 Net Returns Above Operating Expenses -$984.86 Ownership Costs: Machinery depreciation $24.24 Machinery interest $15.10 Machinery THI $6.74 Organic certification Farm $1,000.00 $10.00 Side-roll irrigation (1/3 cost share w/ other rotation phases) $15.40 Land costs (33% income and 33% cost share) $268.14 Land taxes $4.16 Total Ownership Costs $343.78 Ownership Costs per Unit $39.93 Total Costs per Acre $1,328.64 Total Cost per Unit $154.31 Returns to Risk $393.36
Table A.5. Production costs for irrigated organic wheat following grazed alfalfa Quantity Price or Value or Item Per Acre Unit Cost Cost/Acre Gross Returns Organic spring wheat 70 bu $15.00 $1,050.00 Operating Inputs Seed: $28.30 Spring wheat (var. Louise) 100 lb $0.28 $28.30 $0.00 Amendments $0.00 Rock phosphate 0 lb $4.50 $0.00 Kelp meal 0 lb $0.53 $0.00 Manure 0 ton $50.00 $0.00 Lime 0 ton $17.00 $0.00
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Table A.5 (cont). Production costs for irrigated organic wheat following grazed alfalfa Pest/weed control $0.00 0 $0.00 Irrigation $115.00 Water charge 2 irrigations $30.00 $60.00 Electricity 1 fee $55.00 $55.00 Labor $28.22 Irrigation labor 2 irrigations $6.00 $12.00 Machinery Labor 0.811 hrs $20.00 $16.22 Other $34.50 Crop insurance 1 acre $9.00 $9.00 Fuel 5.37 gal $3.50 $18.79 Lubrication 0 $2.82 $2.82 Machinery Repairs . 3.89 $3.89 Overhead $10.30 Operating Interest $4.80 Total Operating Costs $221.12 Operating Costs per Unit $3.16 Net Returns Above Operating Expenses $828.88 Ownership Costs: Machinery depreciation $25.50 Machinery interest $15.18 Machinery THIL $5.09 Organic certification Farm $1,000.00 $3.33 Side-roll irrigation (1/3 cost share w/ other rotation phases) $15.40 Land costs (33% income and cost share) $279.94 Land taxes $4.16 Total Ownership Costs $348.60 Ownership Costs per Unit $4.98 Total Costs per Acre $569.72 Total Cost per Unit $8.14 Returns to Risk $480.28
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Table A.6. Production Costs for irrigated organic wheat following hayed alfalfa Quantity Price or Value or Item Per Acre Unit Cost Cost/Acre Gross Returns Organic spring wheat 70 bu $15.00 $1,050.00 Operating Inputs Seed: $28.30 Spring wheat (var. Louise) 100 lb $0.28 $28.30 $0.00 Amendments $100.00 Rock phosphate 0 lb $4.50 $0.00 Kelp meal 0 lb $0.53 $0.00 Manure 2 ton $50.00 $100.00 Lime 0 ton $17.00 $0.00 Pest/weed control $0.00 0 $0.00 Irrigation $126.00 Water charge 2 irrigations $30.00 $60.00 Electricity 1 fee $66.00 $66.00 Labor $33.18 Irrigation labor 2 irrigations $6.00 $12.00 Machinery Labor 1.059 hrs $20.00 $21.18 Other: $38.73 Crop insurance 1 acre $9.00 $9.00 Fuel 6.01 gal $3.50 $21.04 Lubrication 0 $3.16 $3.16 Machinery Repairs . 5.53 $5.53 Storage Facility & Equip. Repairs Overhead $16.31 Operating Interest $7.60 Total Operating Costs $350.12 Operating Costs per Unit $5.00 Net Returns Above Operating Expenses $699.88 Ownership Costs: Machinery depreciation $31.36 Machinery interest $18.20
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Table A.6 (cont). Production Costs for irrigated organic wheat following hayed alfalfa Machinery THIL $5.28 Side-roll irrigation (full payment w/o other phases) $46.25 Land costs (33% income and cost share) $239.88 Land taxes $4.16 Total Ownership Costs $345.13 Ownership Costs per Unit $4.93 Total Costs per Acre $695.25 Total Cost per Unit $9.93 Returns to Risk $354.75
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Table A.7. Summer cow-calf weight gain on fresh alfalfa 350 kg medium
frame heifer 150 kg medium
frame steer calf
Alfalfa production (t/ac) 8.61 Forage used 0.85 % DM alfalfa, fresh 0.24 Total feed available (tons) 1.76 Total feed (lbs) 3512.88 Animal weight (kg) 350.00 150.00 Animal weight (lbs) 770.93 330.40 DMI intake (lbs, 2% body weight)
15.42 6.61
Cow-calf DMI (lbs/day) 22.03 Cow-calf days 159.48 Alfalfa, fresh NEg content (Mcal/lb)
0.28 0.28
Animal NEg intake (Mcal/d) 4.32 1.85 Cow-calf weight gain (lbs/day) (Table 8, NRC)
2.20 1.30
Combined cow-calf AVD (lbs) 3.50 Total gain over grazing season (lbs/grazing period/ac)
558.20
Table A.8. Winter weight gain on alfalfa hay produced during establishment year 350 kg medium
frame heifer
Alfalfa tons per acre 5.00 Cattle wasteage 0.85 % DM alfalfa hay, early 0.90 Total feed available 3.83 Total feed (lbs) 7650.00 Feeding period (days) 210.00 Daily feed available (lbs) 36.43 Animal weight (lbs) 773.00 DMI (% body weight) 0.02 Daily DMI (lbs) 15.46 Cattle per acre 2.36 Alfalfa NEg (Mcal/lb) 0.26 Cattle NEg intake 4.02 Cattle weight gain (lb/d) Table 8 2.21 Total gain (lbs) 464.10
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Table A.9. Fencing costs for a square 100 ac pasture unit unit cost Energizer 1 409 409 T-posts 300 4 1200 Polywire 4 90 360 Reels 5 65 325 Porcelain bullnose insulators 4 23 92 T-post insulators 41 13 533 Pigtail tread-ins 2 160 320 High-tensile wire 2 109 218 Voltmeter 1 60 60 Wire bend tool 2 8 16 Misc supplies 1 200 200 Corner posts 25 10 250 Post pounder rental 2 150 300 Labor to build fence $193.72 Total 4476.724 Estimate used for this budget 6000
- 107 -
- 108 -
Table A.10. Summary of machine operation for a grazed alfalfa-wheat rotation Summary Rotation hours of
use Annual ave. hrs of use
As previous w/ 5% margin
1 Tractor (Ford TW20)
993.27 99.33 104.29
2 Plow 215.83 21.58 22.66 3 Disk harrow 287.77 28.78 30.22 4 Packer 17.97 1.80 1.89 5 Disk drill 471.70 47.17 49.53 6 Combine 294.70 29.47 30.94 7 Swather 288.78 28.88 30.32 8 Bale wagon 859.95 86.00 90.29 Total 3429.96 343.00 360.15 Table A.11. Summary of machine operation for a hayed alfalfa-wheat rotation Summary Rotation hours of
use Annual ave. hrs of use
As previous w/ 5% margin
1 Tractor (Ford TW20)
1415.93 141.59 148.67
2 Plow 215.83 21.58 22.66 3 Disk harrow 287.77 28.78 30.22 4 Packer 17.97 1.80 1.89 5 Disk drill 471.70 47.17 49.53 6 Rotary hoe 85.96 8.60 9.03 7 Manure spreader 336.70 33.67 35.35 8 Combine 294.70 29.47 30.94 9 Swather 1031.35 103.14 108.29 10 Bale wagon 3071.25 307.13 322.48 Total 7229.16 722.92 759.06 Table A.12. Summary of machine operation for a continuously grazed alfalfa rotation Summary Rotation hours of
use Annual ave. hrs of use
As previous w/ 5% margin
1 Tractor (Ford TW20)
207.84 20.78 21.82
3 Disk harrow 71.94 7.19 7.55 4 Packer 17.97 1.80 1.89 5 Disk drill 117.92 11.79 12.38 6 Swather 412.54 41.25 43.32 7 Bale wagon 1228.50 122.85 128.99 Total 2056.72 205.67 215.96
Table A.13. Machine complement for grazed alfalfa-wheat rotation Taxes, Housing, Annual Annual Insurance, Repairs Current Hours Age When Years of Labor Licenses (Materials Salvage Acres Fuel Fuel
Type of Machine
Value of Use Purchased Life Multiplier (% of avg value)
& Labor) Value per Hour
Type Type
Manager's Pickup 30,000 18,000 new 10 years 6.80 600 15,000 18.0 Gasoline 12.0 Labor's Pickup 15,000 6,000 7 years 10 years 6.80 600 3,500 12.0 Gasoline 12.0 1 1982 Ford TW20 20,000 104.29 26 years 10 years 1.20 96 676 Diesel 11.0 2 1981 Int'l 720 Plow 2,000 22.66 27 years 10 years 1.10 0.60 75 52 7.0 3 16' Disk-harrow 5,995 30.22 5 years 15 years 1.10 0.60 26 353 7.0 4 45' JD 200 Roller packer 17,000 1.89 4 years 15 years 1.10 0.60 2 1,001 27.8 5 15' JD 450 Disk Drill 22,000 49.53 5 years 12 years 1.20 0.60 191 820 4.2 6 1981 JD 6622 Combine 8,000 30.94 27 years 10 years 3.00 19 56 5.09 7 2002 MacDon 25' Swather 15,000 30.32 12 years 10 years 1.10 3.20 16 1,536 12.1 Diesel 4.8 8 Bale Wagon, self-propelled,
lg bales 60,000 90.29 5 years 10 years 1.20 3.10 2,041 6,144 4.1 Diesel 4.0
- 109 - Per Acre Machine Cost: Depreciation Interest THI&L Fixed
Costs Repairs Fuel Lube Total Labor Acre
Manager's Pickup 1.87 1.86 1.4 5.13 0.6 5.25 0.79 6.64 0.00 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.2 3.50 0.52 5.22 0.00 10.33 1 Ford TW20, Plow 3.87 1.85 0.21 5.93 0.60 1.44 0.22 2.26 3.16 11.35 2 Ford TW20, Disk-harrow 4.45 2.64 0.26 7.35 0.25 1.44 0.22 1.91 3.16 12.42 3 Ford TW20, Roller-packer 19.83 14.88 1.01 35.72 0.07 0.36 0.05 0.48 0.79 36.99 4 Ford TW20, Disk Drill 8.30 4.58 1.11 13.99 1.11 2.35 0.35 3.81 5.19 22.99 5 1981 JD 6622 Combine 5.20 2.37 0.69 8.26 0.13 4.81 0.72 5.66 4.71 18.63 6 2002 MacDon 25' Swather 3.70 2.05 0.73 6.48 0.04 1.39 0.21 1.64 1.98 10.10 7 Bale Wagon, lg bales (self-
propelled) 14.69 8.12 2.80 25.61 5.57 3.44 0.52 9.53 5.89 41.03
Table A.14. Machine complement for hayed alfalfa-wheat rotation Taxes, Housing, Annual Annual Insurance, Repairs Current Hours Age When Years of Labor Licenses (Materials Salvage Acres Fuel Fuel
Type of Machine
Value of Use Purchased Life Multiplier (% of avg value)
& Labor) Value per Hour
Type Type
Manager's Pickup 30,000 18,000 new 10 years 6.80 600 15,000 18.0 Gasoline 12.0 Labor's Pickup 15,000 6,000 7 years 10 years 6.80 600 3,500 12.0 Gasoline 12.0 1 1982 Ford TW20 20,000 148.67 26 years 10 years 1.20 195 676 Diesel 11.0 2 1981 Int'l 720 Plow 2,000 22.66 27 years 10 years 1.10 0.60 75 52 7.0 3 16' Disk-harrow 5,995 30.22 5 years 15 years 1.10 0.60 26 353 7.0 4 45' JD 200 Roller packer 17,000 1.89 4 years 15 years 1.10 0.60 2 1,001 27.8 5 15' JD 450 Disk Drill 22,000 49.53 5 years 12 years 1.20 0.60 191 820 4.2 7 Case IH 181MT Rotary Hoe 2,700 9.03 5 years 10 years 1.10 0.60 3 259 17.45 8 Case IH 595 Manure
spreader 9,800 35.35 10 years 10 years 1.10 0.60 231 511 5.94
6 1981 JD 6622 Combine 8,000 30.94 27 years 10 years 3.00 21 56 5.09 9 2002 MacDon 25' Swather 15,000 108.29 12 years 10 years 1.10
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3.20 210 1,536 12.1 Diesel 4.8 10 Bale Wagon, self-propelled,
lg bales 60,000 322.48 5 years 10 years 1.20 3.10 20,243 6,144 4.1 Diesel 4.0
Per Acre Machine Cost: Depreciation Interest THI&L Fixed
Costs Repairs Fuel Lube Total Labor Acre
Manager's Pickup 1.87 1.86 1.4 5.13 0.6 5.25 0.79 6.64 0.00 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.2 3.50 0.52 5.22 0.00 10.33 1 Ford TW20, Plow 3.07 1.47 0.16 4.70 0.66 1.44 0.22 2.32 3.16 10.18 2 Ford TW20, Disk-harrow 3.65 2.26 0.21 6.12 0.31 1.44 0.22 1.97 3.16 11.25 3 Ford TW20, Roller-packer 19.63 14.78 1.00 35.41 0.09 0.36 0.05 0.50 0.79 36.70 4 Ford TW20, Disk Drill 7.00 3.95 1.03 11.98 1.21 2.35 0.35 3.91 5.19 21.08 6 Ford TW20, Rotary Hoe 2.29 1.21 0.11 3.61 0.09 0.57 0.09 0.75 1.26 5.62 7 Ford TW20, Manure
spreader 6.64 3.27 0.29 10.20 1.33 1.68 0.25 3.26 3.70 17.16
5 1981 JD 6622 Combine 5.03 2.30 0.66 7.99 0.13 4.81 0.72 5.66 4.71 18.36 8 2002 MacDon 25' Swather 1.03 0.57 0.20 1.80 0.16 1.39 0.21 1.76 1.98 5.54 9 Bale Wagon, lg bales (self-
propelled) 4.11 2.27 0.78 7.16 15.44 3.44 0.52 19.40 5.89 32.45
Table A.15. Machine complement for continuously grazed alfalfa rotation Taxes, Housing, Annual Annual Insurance, Repairs Current Hours Age When Years of Labor Licenses (Materials Salvage Acres Fuel Fuel
Type of Machine
Value of Use Purchased Life Multiplier (% of avg value)
& Labor) Value per Hour
Type Type
Manager's Pickup 30,000
18,000 new 10 years 6.80 600 15,000 18.0 Gasoline 12.0
Labor's Pickup 15,000 6,000 7 years 10 years 6.80 600 3,500 12.0 Gasoline 12.0 1 1982 Ford TW20 20,000 21.82 26 years 10 years 1.20 4 676 Diesel 11.0 2 16' Disk-harrow 5,995 7.55 5 years 15 years 1.10 0.60 3 353 7.0 3 45' JD 200 Roller packer 17,000 1.89 4 years 15 years 1.10 0.60 2 1,001 27.8 4 15' JD 450 Disk Drill 22,000 12.38 5 years 12 years 1.20 0.60 10 820 4.2 5 2002 MacDon 25' Swather 15,000 43.32 12 years 10 years 1.10 3.20 33 1,536 12.1 Diesel 4.8 6 Bale Wagon, self-propelled,
lg bales 60,000 128.99 5 years 10 years 1.20 3.10 3,901 6,144 4.1 Diesel 4.0
- 111 - Per Acre Machine Cost:
Depreciation Interest THI&L Fixed
Costs Repairs Fuel Lube Total Labor Acre
Manager's Pickup 1.87 1.86 1.4 5.13 0.6 5.25 0.79 6.64 0.00 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.2 3.50 0.52 5.22 0.00 10.33 1 Ford TW20, Disk-harrow 19.39 11.21 1.15 31.75 0.08 1.44 0.22 1.74 3.16 36.65 2 Ford TW20, Roller-packer 22.33 16.08 1.17 39.58 0.05 0.36 0.05 0.46 0.79 40.83 3 Ford TW20, Disk Drill 37.21 20.33 4.78 62.32 0.24 2.35 0.35 2.94 5.19 70.45 4 2002 MacDon 25' Swather 2.58 1.43 0.51 4.52 0.06 1.39 0.21 1.66 1.98 8.16 5 Bale Wagon, lg bales (self-
propelled) 10.25 5.66 1.95 17.86 7.43 3.44 0.52 11.39 5.89 35.14
Table A.16. Machine per acre cost for alfalfa establishment in a grazed system
(Calculated using the MachCost Calculator from the University of Idaho) Ownership Costs ($/acre): Operating Costs ($/acre): Operation Depreciation Interest THI Total Ownership
Costs Repairs
Fuel Lube
Total Labor ($/ac)
Total Cost ($/ac)
Manager's Pickup 1.87 1.86 1.40 5.13 0.60 5.25 0.79 6.64 - 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.20 3.50 0.52 5.22 - 10.33 Ford TW20, Disk-harrow 4.45 2.64 0.26 7.35 0.25 1.44 0.22 1.91 3.16 12.42 Ford TW20, Roller-packer 19.83 14.88 1.01 35.72 0.07 0.36 0.05 0.48 0.79 36.99 Ford TW20, Disk Drill 8.30 4.58 1.11 13.99 1.11 2.35 0.35 3.81 5.19 22.99 2002 MacDon 25' Swather 3.70 2.05 0.73 6.48 0.04 1.39 0.21 1.64 1.98 10.10 Bale Wagon, lg bales (self-propelled)
14.69 8.12 2.80 25.61 5.57 3.44 0.52 9.53 5.89 41.03
Total Cost $/Acre 54.65 36.01 8.73 99.39 8.84 17.73 2.66 29.23 17.01 145.63 Gal/acre 5.07 Hours/ac 0.85 Table A.17. Machine per acre cost for alfalfa establishment in a hayed system 112 (Calculated using the MachCost Calculator from the University of Idaho) Ownership Costs ($/acre): Operating Costs ($/acre): Operation Depreciation Interest THI Total Ownership Costs Repairs
Fuel Lube
Total Labor ($/ac)
Total Cost ($/ac)
Manager's Pickup 1.87 1.86 1.40 5.13 0.60 5.25 0.79 6.64 - 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.20 3.50 0.52 5.22 - 10.33 Ford TW20, Disk-harrow 3.65 2.26 0.21 6.12 0.31 1.44 0.22 1.97 3.16 11.25 Ford TW20, Roller-packer 19.63 14.78 1.00 35.41 0.09 0.36 0.05 0.50 0.79 36.70 Ford TW20, Disk Drill 7.00 3.95 1.03 11.98 1.21 2.35 0.35 3.91 5.19 21.08 Ford TW20, Manure spreader 6.64 3.27 0.29 10.20 1.33 1.68 0.25 3.26 3.70 17.16 2002 MacDon 25' Swather 1.03 0.57 0.20 1.80 0.16 1.39 0.21 1.76 1.98 5.54 Bale Wagon, lg bales (self-propelled)
4.11 2.27 0.78 7.16 15.44 3.44 0.52 19.40 5.89 32.45
Total Cost $/Acre 45.74 30.84 6.33 82.91 20.34 19.41 2.91 42.66 20.71 146.28 Gal/acre 5.55 Hours/ac 1.04
Table A.18. Machine per acre cost for cattle on alfalfa (Calculated using the MachCost Calculator from the University of Idaho) Ownership Costs ($/acre): Operating Costs ($/acre): Operation Depreciation Interest THI Total Ownership Costs Repairs Fuel Lube Total Labor Total Cost Manager's Pickup 1.87 1.86 1.40 5.13 0.60 5.25 0.79 6.64 - 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.20 3.50 0.52 5.22 - 10.33 2002 MacDon 25' Swather 3.70 2.05 0.73 6.48 0.04 1.39 0.21 1.64 1.98 10.10 Bale Wagon (self-propelled) 14.69 8.12 2.80 25.61 5.57 3.44 0.52 9.53 5.89 41.03 Total Cost $/Acre 22.07 13.91 6.35 42.33 7.41 13.58 2.04 23.03 7.87 73.23 Gal/acre 3.88 Hours/acre 0.39 Table A.19. Machine per acre cost for hayed alfalfa (4 cuttings) (Calculated using the MachCost Calculator from the University of Idaho) Ownership Costs ($/acre): Operating Costs ($/acre): Operation Depreciation Interest THI Total Ownership Costs Repairs Fuel Lube Total Labor Total Cost Manager's Pickup 1.87 1.86 1.40 5.13 0.60 5.25 0.79 6.64 - 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.20 3.50 0.52 5.22 - 10.33 2002 MacDon 25' Swather 4.12 2.28
113 0.80 7.20 0.64 5.56 0.84 7.04 7.92 22.16 Bale Wagon (self-propelled) 16.44 9.08 3.12 28.64 61.76 13.76 2.08 77.60 23.56 129.80 Total Cost $/Acre 24.24 15.10 6.74 46.08 64.20 28.07 4.23 96.50 31.48 174.06 Gal/acre 8.02 Hours/acre 1.57 Table A.20. Machine Per Acre Cost for wheat in a grazed system (Calculated using the MachCost Calculator from the University of Idaho) Ownership Costs ($/acre): Operating Costs ($/acre): Operation Depreciation Interest THI Total Ownership Costs Repairs Fuel Lube Total Labor Total cost Manager's Pickup 1.87 1.86 1.40 5.13 0.60 5.25 0.79 6.64 0.00 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.20 3.50 0.52 5.22 0.00 10.33 Ford TW20, Plow 3.87 1.85 0.21 5.93 0.60 1.44 0.22 2.26 3.16 11.35 Ford TW20, Disk-harrow 4.45 2.64 0.26 7.35 0.25 1.44 0.22 1.91 3.16 12.42 Ford TW20, Disk Drill 8.30 4.58 1.11 13.99 1.11 2.35 0.35 3.81 5.19 22.99 1981 JD 6622 Combine 5.20 2.37 0.69 8.26 0.13 4.81 0.72 5.66 4.71 18.63 Total Cost $/Acre 25.50 15.18 5.09 45.77 3.89 18.79 2.82 25.50 16.22 87.49 Gal/acre 5.37 Hours/acre 0.81
TableA.21. Machine per acre cost for wheat in a hayed system (Calculated using the MachCost Calculator from the University of Idaho) Ownership Costs ($/acre): Operating Costs ($/acre): Operation Depreciation Interest THI Total Ownership Costs Repairs Fuel
Lube Total Labor
($/ac) Total $/Acre
Manager's Pickup 1.87 1.86 1.40 5.13 0.60 5.25 0.79 6.64 0.00 11.77 Labor's Pickup 1.81 1.88 1.42 5.11 1.20 3.50 0.52 5.22 0.00 10.33 Ford TW20, Plow 3.07 1.47 0.16 4.70 0.66 1.44 0.22 2.32 3.16 10.18 Ford TW20, Disk-harrow 3.65 2.26 0.21 6.12 0.31 1.44 0.22 1.97 3.16 11.25 Ford TW20, Disk Drill 7.00 3.95 1.03 11.98 1.21 2.35 0.35 3.91 5.19 21.08 Ford TW20, Rotary Hoe 2.29 1.21 0.11 3.61 0.09 0.57 0.09 0.75 1.26 5.62 Ford TW20, Manure spreader 6.64 3.27 0.29 10.20 1.33 1.68 0.25 3.26 3.70 17.16 1981 JD 6622 Combine 5.03 2.30 0.66 7.99 0.13 4.81 0.72 5.66 4.71 18.36 Total Cost $/Acre 31.36 18.20 5.28 54.84 5.53 21.04 3.16 29.73 21.18 105.75 1.06 Hours/ac 6.01 Gal/acre
114
APPENDIX III. SAS CODE AND EXPLANATIONS
Randomized Complete Block Design (RCBD)
RCBD code used to analyze soil inorganic N without taking account of depth as a
repeated measure or soil moisture as a covariate. Treatment was used as a fixed effect, and block
as a random effect. Analyses carried out using this code included soil inorganic N concentration
at any single depth increment, as an average of the entire column, and the total column soil
inorganic N availability as calculated on a field basis (kg ha-1) as in the materials and methods
section. The values shown here are averaged soil column concentrations for March incubated
NO3-N, but was used on all comparisons amenable to this setup: totals, net differences, averages,
depth-by-depth analysis etc. for which neither multiple depth increments nor a covariate was not
considered.
data nitrogen; Input trt $ block N @@; title 'Treatment and block effects on incubated NO3-N by full soil column'; datalines; Plow 1 29.08906999 100 1 18.3748328 Alfalfa 1 24.34831893 Plow 2 32.90523678 100 2 31.94333937 Alfalfa 2 27.34601685 Plow 3 15.31896521 100 3 13.38871569 Alfalfa 3 12.08914835 Plow 4 20.82542311 100 4 13.11313383 Alfalfa 4 12.87466445 ; proc print; run; proc mixed data=nitrogen method=type3; class trt block; model N = trt/ outp=N2 residuals; random block; run; proc univariate data=nitrogen2 normal plot; var resid; run;
- 115 -
proc plot data=nitrogen2; plot studentresid*trt studentresid*block studentresid*pred/ VREF=0 VPOS=19 HPOS=50; plot N*block=trt; run; titl 'SAS co r ge de fo enerating alternative normal probability plot'; proc standard std=1.0; var resid; proc rank normal=blom ; var resid; ranks nscore; proc plot; plot resid*nscore /vref=0 href=0 vpos=29 hpos=50; run; /*the following interaction plot code joins the symbols with a line*/ SYMBOL1 v=circle I=JOIN V=circle color=black; SYMBOL3 v=diamond I=JOIN V=diamond color=green; SYMBOL5 v=star I=JOIN V=star color=red; SYMBOL7 v=plus I=JOIN V=plus color=black; proc gplot data=nitrogen2; plot N*block=trt; title 'Interaction Plot of Treatment and Block'; run;
Repeated Measures
Code for repeated measures was used to assess treatment effects for every depth
increment, depth effects, treatment x depth interactions, and block effects. Treatment was a fixed
effect, block a random effect, and depth a repeated effect. Data shown below is an unidentified
set, but an example run of SAS would be, for instance, summer 2007 incubated NH4-N
(potentially mineralizable nitrogen). Soil inorganic N data used in this analysis was expressed on
a concentration basis (mg kg-1) for each treatment and depth combination.
data nitrogen; Input block trt $ depth N @@; title 'Treatment, moisture, depth effects'; datalines; 1 Plow 0 11.41058417 1 Plow 1 2.352808602 1 Plow 2 3.243339501 1 Plow 3 7.111592935 1 Plow 4 5.473689382
- 116 -
1 Plow 5 2.773614469 1 Plow 6 0.928350203 1 Plow 7 1.260906825 1 Plow 8 1.28302877 1 100 0 27.60241836 1 100 1 5.449045053 1 100 2 7.355098157 1 100 3 7.119932445 1 100 4 5.61958288 1 100 5 2.730681829 1 100 6 1.346704017 1 100 7 0.89402955 1 100 8 1.201537901 1 Alfalfa 0 11.94437761 1 Alfalfa 1 4.485694181 1 Alfalfa 2 3.835552632 1 Alfalfa 3 4.459468503 1 Alfalfa 4 8.100096837 1 Alfalfa 5 1.674009146 1 Alfalfa 6 0.885193262 1 Alfalfa 7 0.837142695 1 Alfalfa 8 1.933798704 …etc for blocks 2, 3 and 4… ; proc print data=nitrogen; proc plot data=nitrogen; plot N*moisture=trt; title 'test of covariate'; run; proc mixed data= nitrogen; class block trt depth; model N = trt depth trt*depth; random block; repeated depth/ type = cs sub=depth(trt); run;
Tukey’s Pairwise comparisons
Additions to SAS code above to obtain probability of differences between treatments, and
then to estimate differences between specifically identified treatments were used. These include
a probability of differences statement with a Tukey’s pairwise comparison adjustment. In the
code immediately above, an “lsmeans” statement would followed the “repeated” statement:
lsmeans depth/pdiff cl adjust=tukey alpha=0.05;
- 117 -
Orthogonal contrasts using estimate statements
Estimate statements, known as orthogonal contrast statements also (McIntire, 1990) were
used to find out which treatments specifically were significantly different, and to calculate their
respective treatment means. An “estimate” statement as follows would follow the “lsmean”
statement:
estimate 'plow vs 100' treatment 1 0 -1;
The numbers following “treatment” references the order in which SAS reads the data as revealed
in the Class Level Information output, for example:
Class Level Information Class Levels Values block 4 1 2 3 4 trt 3 100 Alfalfa Plow depth 9 0 1 2 3 4 5 6 7 8
The coding “1 0 -1” following “treatment” directs SAS to compare “100” (undercutting sweep
with 100 percent coverage, or SW100), with “Plow” (the moldboard plow treatment, or MP). An
example output received from such code would be:
Differences of Least Squares Means Effect trt _trt Estimate Error DF t Value Pr > |t| Adjustment Adj P Alpha trt 100 Alfalfa 1.6987 0.6822 78 2.49 0.0149 Tukey-Kramer 0.0391 0.05 trt 100 Plow 1.3333 0.6822 78 1.95 0.0542 Tukey-Kramer 0.1305 0.05 trt Alfalfa Plow -0.3654 0.6822 78 -0.54 0.5938 Tukey-Kramer 0.8541 0.05
- 118 -