I. Effect of Three Organic Waste Soil Fertilizers – Cow Manure, Institutional Com-

post, and Tomato Processing Refuse – on the Yield of Corn and on Soil Properties of

Two Different Soil Types on a Northeastern Indiana Small Farm

II. Catherine Latimer, November 19, 2008, 236 W Reade Ave., Upland, IN 46989

III. Abstract

Like the growing quantities of organic wastes themselves, interest in the study

and utilization of alternative sources of fertilizer is growing itself. Many of these organic

waste sources can provide abundant useful nutrients to the soils for increase in crop pro-

duction in agriculture, but thus far many of these sources have remained untapped on a

large scale. The study of some of these locally-available organic waste composts would

be particularly useful in the region of northeastern Indiana, where farming is prolific.

Three sources in particular: cow manure, tomato refuse from a local ketchup-processing

facility, and previously unused food scraps from Taylor University’s Dining Commons,

will be stabilized for 5 months into viable compost before being applied to two fields of

different soils (Glynwood and Bono) on a small agricultural farm in Upland, Indiana.

The stabilized composts will then be separately applied to plots one month before the

planting of sweet corn. Total yield, as weighed by dry biomass, total soil organic C, total

soil N, and soil C/N ratio will be determined using methods available to the experimenter.

Additional soil samples will be sent away to a laboratory for further analysis of soil

health. All three composts are expected to influence the soils positively, though the

poorly drained Bono soil may benefit less than the Glynwood and the corn growing on

the Glynwood soil.

IV. Problem Statement

A. There are a vast number of studies available on the subject of organic fertilizer

alternatives and the ranges of their effects on crops, soil, agricultural, and environmental

health. Similar variables can be studied by a variety of methods and under an almost

endless set of varying conditions. Cai & Qin (2006) address dynamics of crop yields and

soil organic carbon in a long-term fertilization experiment in China, while Gabrielle et al.

(2005) studied field-scale modeling of carbon and nitrogen dynamics in soils amended

with urban waste composts. Differences in soil types were addressed by articles like

Cassman et al. (1993), who studied the input/output analysis of cumulative soybean re-

sponse to P on an Ultisol, or Castillo & Wright (2008), who studied soil P pools for His-

tosols under sugarcane and pasture in the Everglades.

Microbial activity in the soil is a factor that has great influence on crop yields and

health, and can be highly influenced by the type of organic fertilizer used. This topic is

addressed by Abd-El-Malek et al. (1968), Lee et al. (2004), Gallardo-Lara & Nogales

(1987), Ros et al. (2006), and Tsai et. al. (2007), among others. These articles address

issues such as how initial and changing C/N levels in various compost types can effect

microbial activity, such as whether the soil microbes are competing with the plants for

Nitrogen or not; or issues such as how different compost types effect measures on micro-

bial biomass, and results on the bacterial community. Many of the variables used in these

studies to measure these responses were testing pH, temperature, organic matter content,

sodium concentrate, soil biomass, and soil enzyme activities in the rhizosphere, etc.

Most of this research found there to be a positive effect for soil microbial populations un-

der the use of organic fertilizers, though large doses of compost could produce an in-

hibitory effect.

Compost types in these studies varied widely, as well, such as Baran et al.’s

(2001) study on composted grape marc as a growing medium for hypostases, Bustamante

et al.’s (2008) look at composts from distillery wastes as peat substitutes for transplant

production, or Cheung & Wong’s (1983) look at the utilization of sewage sludge versus

animal manures for growing vegetables, the effects of anaerobically prepared wheat straw

composts and city garbage composts on yields and N and P uptake by wheat.

Other related topics such as the economic benefits of utilizing alternative organic

fertilizers are addressed in studies such as van Assche & Uyttebroeck’s (1982) “Demand,

supply and application possibilities of domestic waste compost in agriculture and horti-

culture,” Zobac & Vana’s (1974) study on the agronomical effectiveness of industrially

produced compost in dependence of the technology of production, and Ryan et al’s

(1985) short-term greenhouse evaluation of non-conventional organic wastes.

B. The study will be carried out on Victory Acres Farm, 5275 S. 800 E., Upland,

Indiana, located in Grant County, latitude 40.476 and longitude -85.494, elevation 935

feet above sea level. Annual precipitation counts and temperature are measured from the

nearest weather station in Hartford City, 11.5 miles South-East, and temperatures range

from a 15.2 degrees F low to an 84.1 degrees F July high. Annual precipitation measure-

ments also taken from the Hartford City weather station record Uplands annual precipita-

tion (combined rainfall/snowfall) to be 37.25 inches, with most rain occurring in July.

The Indiana state soil is Miami, of which there are 794,994 acres of within the state, and

which contains a surface layer and a subsurface layer of brown silt loam, a subsoil of

dark yellowish brown clay loam, and a substratum of brown loam. These soils are used

mostly for corn, soybean, or winter wheat production, with steeper areas used for pasture,

hayland, or woodland. The Miami soils are calcerous, loamy till, are fertile and have a

moderate available water capacity. The two soils in particular that will be utilized in this

study are Glynwood and Bono types. Glynwood is a clay silt loam that consists of deep,

moderately well drained, slowly permeable soils on till plains and moraines. These soils

are formed in silty material over glacial till. Slopes range from 2 to 6 % and are strongly

acid to slightly acid in the upper part and neutral or mildly alkaline in the lower part.

Bono soils consist of deep, very poorly drained, slowly permeable soils in depressions on

lake plains. These soils form in lacustrine sediments. Slopes range from 0 to 2 %.

Fertilizers and composts for the study will also be obtained from various sources

and locations. Cow manure is already being obtained by Victory Acres Farm from their

neighboring farm as a fertilizer. Victory Acres has recently just set in place windrows on

the northwest edge of the South Vegetable Field for the purpose of composting their own

household food scraps and leaf litter. This will be the location for the dumping and sta-

bilizing of the Taylor Dining Commons compost. Initially, the source for this compost

will be obtained on Taylor University’s campus in Upland, IN – specifically from the

Dining Commons. The final source of compost will be from the Red Gold Processing

Facility located at 120 East Oak Street, Orestes, IN 46063.

C. 1) – 3) What is the effect on sweet corn yield of:

a) institutional compost derived from college dining hall organic waste

b) agricultural compost from cow manure

c) commercial compost from a tomato processing facility

4) What is the effect on health of calcerous, silty clay loam soils from each of

these three compost types?

5) Is the utilization of these organic waste composts reasonable for farms in the

northeastern Indiana region, and if so, how do these locally-derived compost types com-

pare to one another as determined by regional soil types?

V. Statement of Questions, Objectives, and Hypotheses

A. There is an increasing focus on the use and application of a large variety of or-

ganic soil amendments and products from organic wastes, such as bio-fertilizers, com-

posts, green manures, fly-ash and sewage sludge in scientific literature. This is in large

part due to the problems created by the increasing waste and consumption of growing

populations around the world, bringing with it an increased drive towards seeking out en-

vironmentally acceptable solutions towards alleviating these problems (Ros 2006, citing

Lalande et al., 2000).

Composts and bio-fertilizers created as products of organic wastes can be useful

in helping to supplement soils with certain essential nutrients, such as C, N, and P,

needed for healthy plant growth, as well as helping to increase soil organic matter content

and other biological and chemical properties within the soil (Ros, 2006). Soils can, in

fact, adsorb and utilize large amounts of organic waste into usable nutrients (Ryan, 1985).

However, the agronomic effectiveness of organic wastes can be highly variable depend-

ing on their source. Solid wastes alone can be classified into at least six different cate-

gories: agricultural, commercial, institutional, industrial, residential, and municipal.

(Ryan, 1985, citing McCalla et al., 1977). Focus on the utilization of any one of these

specific types would depend upon the importance and abundance of any of these sources

for a particular region, regional soil types and physical and chemical properties, compara-

tive prices of alternative materials available on a regional basis, and even social attitudes

towards to the utilization of various organic wastes (Ryan, 1985).

Timing of organic wastes to the soil is a crucial factor in agricultural utilization.

Compost should be allowed to stabilize, or humify, for 5-6 months miniumum before it is

added to the agricultural soil (Zucconi et al., 1981). This allows for the naturally-occur-

ring process of biological oxidative transformation to take place, creating a stable product

(de Bertoldi, 1982), and allowing for the metabolization and mineralization of simple car-

bon compounds (de Bertoldi, 1982). If sufficient time is not allowed for this process to

take place away from the crop soil, micro-organisms in the agricultural soil will degrade

the amended organic matter and thus will actually compete with crops for soil nitrogen,

and which will produce intermediate metabolites and high concentrations of ammonia in

the soil that is not compatible with plant growth (Golueke, 1977). Nitrogen content is an-

other critical factor that is allowed to stabilize with mature compost. In terms of absolute

value, the process of ammonia volatilization during stabilization allows for a decrease in

nitrogen content (de Bertoldi, 1982). However, in terms of dry weight, nitrogen increases

with stabilization due to mineralization of the organic matter and thus the loss of H2O and

CO2. These levels can be monitored by C/N ratios, which should decrease as the compost

matures (de Bertoldi, 1982). As indicated above, high C/N ratios are not favorable, as

they are an indicator that micro-organisms must continue to oxidize off excess carbon,

but low C/N ratios will slow decomposition and increase nitrogen loss (de Bertoldi,

1982). Extensive experimentation as cited throughout the literature determined that the

general optimum C/N ratio in the starting compost is about 25 (de Bertoldi, 1982). As

Table 5 indicates (as cited by de Bertoldi), cow manure and the organic fraction of many

solid urban wastes fall near or within this range, which is useful in terms of this study (de

Bertoldi, 1982).

For our experimental purposes for an area located a) in an agriculturally-domi-

nated region of the northeastern section of Indiana, b) close to a collegiate campus, and c)

close to a number of commercial vegetable processing plants, three of these solid organic

waste types will be utilized and tested: agricultural, institutional, and commercial. Agri-

cultural waste will be studied in the form of cow manure acquired from a dairy farm lo-

cated in Upland, IN close to the site of study. Institutional solid organic waste will be

collected from the dining facility on Taylor University’s campus, in the form of leftover

food scraps collected from the dining hall and kitchen. Commercial solid organic waste

will be collected from the Red Gold Processing Facility in Orestes, IN. This compost is

composed of the peels and seeds leftover from processing ketchup in the factory. The

peels and seeds are dumped into a bog area where it is turned on a regular basis, allowing

the waste to aerate and stabilize into viable compost.

Recommendations regarding the effectiveness of alternative organic waste

amendments available in this region of Indiana must be based on field testing that com-

pares each treatment type on the same crop, with equivalent application rates, and on soil

types that are representative of local agricultural utilization. In this study each treatment

type was applied at equivalent rates and under identical application techniques to all soils

one month before planting of sweet corn (Zea mays var. rugosa) took place. Sweet corn

is a variety of maize with high sugar content that is harvested when it is still immature,

and is representative of a common commercial crop in the Midwest (citation).

Effectiveness of treatment types will be determined by total yields of corn, C/N

ratios in the soil – determined by carbon loss on ignition and the Kjeldahl method – and

by further laboratory soil analysis to determine soil pH, cation exchange capacity, percent

organic matter, soluble salts, and the levels of agriculturally significant soil nutrients.

Table 1 below, as cited from Ros, 2006, shows a reasonable example of the differ-

ent chemical properties of different composts similar to some of those used in this study.

Of particular interest to this study are the total organic C, total N, and C/N. Study of this

data can aid in forming predictions for our own data;

B. The null hypotheses for this study would be that there would be no difference

between the control plot and all treatment types, on either soil type. The central hypothe-

sis is that there will a large difference between the control and the various treatment types

on both soil types, and that treatments will vary according to average initial C/N ratios as

cited in the literature, as well as according to the turnover rates, or stabilization periods,

of each treatment. A sub-hypothesis would be that soil types will cause a variation be-

tween response to treatments, with Bono soils being less productive than Glynwood soils.

C. This entire experiment should last about nine months, and all resources needed

are being provided by the experimenter herself, Victory Acres Farm, Professor Robert

Reber and the Taylor University Environmental Science Department, and the Red Gold

Processing Facility in Orestes, Indiana.

VI. Methods

A. The independent variables in this study are the differences in organic waste

composts used – commercial, agricultural, and institutional. These variables were chosen

because they are locally found alternatives to traditional fertilizer types. The two differ-

ent soil types being utilized for the planting of the corn crops – Glynwood clay silt loam,

and Bono – are also independent of changes in the others, though soil health will be de-

pendent on changes in variable compost types. These soil types were chosen as indepen-

dent variables because they are highly representative of the different types of soils found

in local agricultural settings. Sweet corn yield, soil health, as determined by soil C/N ra-

tio (determined by carbon loss on ignition and % nitrogen as by the Kjeldahl test) and by

various nutrient measurements, pH testing, % organic matter, and cation exchange capac-

ity in both Glynwood and Bono soil types are variables dependent on adjustments in

treatments. Sweet corn was chosen because it is a popular local crop that responds read-

ily to changes in soil health levels. Soil C/N ratios are an easy and inexpensive way to

test general soil health and response to compost treatments, and overall soil health test-

ings were already part of an ongoing investigation by farm ownership.

B. Other sources of variation that could effect the results of this study include du-

ration of compost stabilization from the cow farm, as the historical utility of this compost

type by VAF has had a much faster turnover rate than the 5-6 month stabilizing period

recommended. Dan Perkins has agreed to attempt to let this manure begin to sit and sta-

bilize when other compost stabilizations are beginning, though he may have to use some

of the cow manure on other fields before the 5 months is completed. Other factors that

might effect this study are historical use of the two fields being tested, and how initial nu-

trient levels in these soils might differ due to differences in past applications and utiliza-

tions. As the Bono soil fields have not been as highly utilized for agriculture yet by

VAF, Dan Perkins has directed the use of a lesser-utilized Glynwood soil field in hopes

that this will help to control these variables a little bit better.

C. & D. Before sweet corn planting can begin, all composts must be sufficiently

stabilized. As this takes a minimum of five months to occur, collection of Taylor Univer-

sity Dining Commons food scraps will commence on Dec. 1, 2008. Two 44-gallon Brute

plastic waste containers will be placed in the DC – one in the kitchen for the disposal of

kitchen scraps, and one in the dish room. Instead of emptying all food scraps into the

garbage, as is current practice, some trays will be emptied into one of these Brute con-

tainers until it is full, and both containers will be collected by the experimenter at the end

of each day. This process will continue for 13 more days until the DC closes, and will

recommence on Jan. 5th, 2009. At the end of each day during these two periods, both bins

will be transported to Victory Acres Farm, where they will be spread into preexisting

windrows already set in place on the northwestern edge of the South Vegetable Field, but

not yet highly utilized, for composting food scraps and leaf litter. Dan Perkins, VAF’s

CSA Manager, will turn this compost once a month with his bucket loader. Field experi-

ments have determined that 1-3 weeks minimum are needed for the organic waste com-

post to digest into the soil (de Bertoldi & Zucconi 1980; Zucconi & de Bertoldi 1982).

All composts used for this experiment will be stabilized and ready to apply to the soil by

April 30th, giving the soil once month to incorporate it before corn planting.

Another compost alternative will be obtained on April 30th, 2009, 30 days before

planting, from the Red Gold Processing Facility in Orestes, IN. As this compost will al -

ready be stabilized on the Red Gold premises, it will simply be picked up and transported

to VAF.

VAF CSA Manager, Mr. Perkins, obtains and stores cow manure from the neigh-

boring cow farm, Carter Farms, and presently uses this as fertilizer. This will also be uti -

lized on the experimental fields, as described below.

On April 30th each of these three treatments can be incorporated into their treat-

ment plots by ploughing at a 0-25 cm depth, and applied in equivalent doses of 15 t ha−1.

Since the experimenter is aware of specific differences among the groups of ob-

jects within this experimental group, the experiment out-line was set up as a completely

randomized block design to control variation by accounting for spatial effects. Three ran-

domized blocks of dimensions 20 meters x 28 meters will be tested on two different soil

types, chosen based on differences in soil qualities, giving a total of six randomized test

blocks. Each of the six blocks is divided into four different treatment plots of dimensions

20 meters x 8 meters each. Planting should take place on May 30st, 2009. Three rows of

corn should be planted per treatment plot, planting the seeds 30 in. apart, with rows 2 me-

ters apart, resulting in 24 corn plants per row, for a total of 72 plants per plot, 288 plants

per block, 864 plants per soil type, and 1,728 individual corn plants total. For the pur-

pose of comparison, one of these four sections is a control treatment (C), which will re-

ceive no fertilizer or compost. Each row should be irrigated with 1 to 1½ in. of water

once a week. Be sure to water from the bottom, never from above – watering from above

can wash the pollen away.

By the end of the growing period, which will take 50 days, all corn can be har-

vested, being careful to transfer all 72 ears to labeled, separate bags for each treatment

plot. These bags will be transported to Taylor University’s Randall Science Center and

stored in the greenhouse to dry for one week. Dry biomass can then be taken by weigh-

ing all corn plants from each treatment plot.

Also upon completion of harvesting, four 6 in. x 6 in. soil cores should be taken

from each plot. The location of each of these cores should be obtained using a random

number table. These cores should be labeled and refrigerated until further analysis can be

performed up on them. Three samples from each plot should be used for loss on ignition

(LOI) analysis, and three samples should be used for the Kjeldahl method. LOI will be

run at Taylor University using a muffle furnace. Only samples for one treatment/block

should be analyzed at one time. The procedure follows the method described by Schlute

and Hopkins (1996).

Equivalent volumes (approximately 8 g) of <2-mm air-dry soil should be placed

into 15-mL crucibles and then oven-dried at 105 degrees C overnight. Samples then

should be cooled in a desiccator and weighed. The samples should then be combusted at

360 degrees C for 2 hours in the muffle furnace. After this two hour combustion period,

samples should be transferred to an oven at 105 degrees C for several hours. Samples

will then be cooled in a desiccator and weighed. LOI will be calculated using the follow-

ing equation:

Repeat this process for all three core samples per 24 treatment/control blocks. The

weight-loss-on-ignition is a common method of approximating the organic and carbonate

content of sediment samples (Heiri et al. 2001). % Nitrogen in the soil samples can be

determined using the Kjeldahl method.

Another four 6 in. x 6 in. soil cores should be selected from each plot using a ran-

dom number table. These soil samples should then be properly labeled and sent immedi-

ately to A & L Great Lakes Laboratories, Inc. in Ft. Wayne. This company will analyze

soil pH, % organic matter, cation exchange capacity (CEC), soluble salts, P, K, Mg, Ca,

H, Na, Cu, S, Zn, Fe, Mn, and B.

Testing should be done using a general linear model. Residuals should be

checked for normality and saved from this model. Fixed factors are soil type, block, and

treatment. An F test should be used to test for interactions between the blocks and the

soil types, and between the blocks and the treatments. If there is interaction, then the data

fits our assumptions. If the F Test reveals no interactions, then two further statistical tests

can be run to indicate whether a) soil types differ, or b) treatments differ. A probability

plot can then be constructed using MiniTab from the saved residuals, and using this data

it can be determined whether the data is normal (p>0.01). ANOVA can then be used to

determine whether P values are significant for block (expected to not be significant), soil

(expected to be significant), and treatment (expected to be significant). For those that are

significant a multiple comparison analysis can be run and the effect of qualitative factors

will be separated by the a Tukey’s MRT or Duncan’s MRT at the 5% level of signifi-

cance.

An Example of Experimental Data

VII. Budget and Schedule

A. & B. See attached chart for three-column budget. Most equipment and soil

testing provided by Victory Acres Farm free of charge.

-(2) 44-gallon Brute waste containers purchased from eBay = $32.00 total, to be deliv-

ered to Taylor University location by Dec. 1st, 2008.

-Golden Bantam sweet corn seed should be purchased from Main Street Seed and Supply

Company @ $1.50/342 seeds on April 1st, 2009. 1,728 seeds can be purchased for $7.50

online.

-During the period of collecting dining commons compost and transporting it to Victory

Acres Farm, one 7.1 trip a day will be made for 14 days straight between Dec. 1 st, 2008

and Dec. 14th, 2008. Trips will resume again when the Dining Commons reopen from

Jan. 5th, 2009 to Jan. 28th, 2009. Beginning Feb. 7th, 2009 trips will only be made from

Taylor University’s Dining commons to VAF once a week, for 12 weeks. With estimated

gas prices at $3.00/gallon and a vehicle that performs at aout 27 miles/gallon, the total

cost of all of these trips will be $40.90.

-Gas between Upland, IN and the Red Gold Processing Facility at 120 East Oak Street,

Orestes, IN 46063, estimated cost at approximately $3.00/gal. One round-trip will be

conducted on April 30th, 2009, and will be 37.6 miles. Experimenter’s vehicle performs

at approximately 27 miles/gallon, thus one trip should cost $4.18.

-As this would be a joint project undertaken with Victory Acres Farm and building on

their previous work, the farm will cover the costs of all equipment needed to rotate and

haul all compost once it has been transported to the farm . The farm is already in the

habit of rotating their compost windrows once a month, and this compost rotation will be

done with a bucket loader and tractor, and will continue to be performed once a month by

Dan Perkins beginning Dec. 1st, 2008 until all composts are applied to the soil on April

30th, 2009.

-All transport of cow manure was already being undertaken by the farm, as well, and this

they will also continue at their own expense and on their schedule.

-On April 30th, 2009, all compost types will be ploughed into their designated plots. Dan

Perkins will perform this task.

-On May 30th, 2009 the sweet corn seeds will be sown into each plot on VAF. Dan

Perkins and Catherine Latimer will do this task together.

-On July 20th, 2009 all corn will be harvested, as a joint task by Dan Perkins and Cather-

ine Latimer.

-Corn will be transported to Randall Science Center on Taylor University’s campus by

Ms. Latimer and stored to dry for one week. Upon completion of this week, biomass per

plot will be weighed and recorded.

-VAF has already been sending their soil samples to A & L Great Lakes Laboratories,

Inc. for soil analysis, and continues to do so for the next several years, so this cost is also

a moot point for the purposes of my budget. These samples will be obtained upon har-

vest on July 20th, 2009 and mailed directly.

-LOI (loss on ignition) testing equipment and Kjeldahl testing equipment, to be used a

week after harvesting, on July 27th, will be provided by the Taylor University Environ-

mental Science Department, as authorized by Professor Robert Reber.

-Analysis of data will begin following this testing, with continual reporting to and meet-

ings held with Professor Reber and Dr. Ken Constantine, both of Taylor University.

Three-Column Budget Proposal

2008-2009

Purposes Begin End TotalSalaries $0 Corn Seed Apr. 1, 2009 Apr. 1, 2009 $7.50 Tractor w/Bucket Loader Dec. 1, 2008 Jul. 31, 2009 $0 2 44-gal. Plastic Waste Containers Dec. 1, 2008 Jul. 31, 2009 $32 Gas for Transport: Taylor Univ. to VAF Dec. 1, 2008 Dec. 14, 2008 $11.83

Jan. 5, 2009 Jan. 28, 2009 $18.93 Gas for Transport once a week Feb. 7, 2009 Apr. 25, 2009 $10.14 Gas for Transport: Upland-Orestes Apr. 30, 2009 Apr. 30, 2009 $4.18 A & L Great Lakes Laboratories Analyses $0 LOI (loss on ignition) test Jul. 27, 2009 Jul. 27, 2009 $0 Kjeldahl Test Jul. 27, 2009 Jul. 27, 2009 $0

$84.58

VIII. Results and Discussion

While it is expected that treatment type will effect differences in corn yield and

soil health respond, soil type is not expected to make a significant difference here. Ex-

pectations for the effectiveness of each treatment is based upon general ranges in initial

C/N ratios as cited throughout the literature. The organic fraction of stabilized municipal

and institutional wastes tended on average towards a more stable C/N ratio than com-

pared to wastes derived from solely plant material or solely manure origins, as cited by de

Bertoldi et al., Gallardo, etc.. Thus, for the purposes of this experiment, expectations

would be for a higher yield of corn and higher soil health in the plots treated with stabi -

lized dining commons waste, and slightly lower yield and health for those treated with

the tomato refuse, slightly lower yield and health for plots treated with stabilized cow

manure, and the lowest yield and soil health for the untreated control plot. Stabilized

tomato refuse-originated compost will possibly be higher than that of cow manure origin

possibly because the Red Gold facility has had such a large stabilizing lagoon already in

place for a few years, while the compost based on cow manure used by VAF has a much

higher turnover rate, and thus less time to reach an equilibrium in C/N ratios. As the soils

in this area were actually not very different from one another, it is expected that results

should be similar on both soil types, though there will likely be a decrease in yield on the

Bono soils due to poorer drainage. If yields are similar across soil types, however, this

could certainly be viewed as a positive thing for Indiana farmers, as this would mean less

discrimination would be needed in the planting of their fields. Thus, the null hypothesis

should be rejected and the central hypothesis confirmed.

Evaluation of the fertilizing value of a compost by determining crop yield, or

biomass produced, is a method that has generally produced positive results in the litera-

ture (Gallardo, 1987). Zobac and Vana (1974) showed that the application of organic fer-

tilizer treatments increased yield in corn, and numerous studies have shown similar ef-

fects for other crops as well, including sorghum, potatoes, tobacco, tomatoes, and rye-

grass (Gallardo, 1987). Many of these studies combined application of manure with vari-

ous compost and found better yields than with manure or compost alone (Shisler &

Grable, 1976), and several found similar results for the combined application of compost

together with a mineral fertilizer (Gallardo, 1987).

Many of these studies were undertaken on a longer-term basis than were possible

under the parameters of this experiment. Some of these experiments compared long-term

use of composts against use of NPK commercial fertilizers and found that, though com-

posts might be less efficient for obtaining immediate crops than the commercial fertilizers

(Terman et al., 1973; Mays et al., 1973; Diez & Weigelt, 1980; Ryan et al., 1985, as cited

in Gellardo, 1987), continual high-dosage use of composts over a longer-term period

could prove to be more efficient than normal mineral fertilizers (Hortenstine & Rothwell,

1973).

As far as measuring composting effectiveness by C/N ratio, this data varies

widely for compost materials, even sufficiently stabilized materials (Gallardo, 1987).

However, in general it has been found that immature composts tend to contain C/N ratios

above 30, and that these ratios are less effective, creating a need for increased competi-

tion for soil nitrogen between micro-organisms degrading the compost and the crops

themselves (Koma Alimu et al., 1977), while those under 20 can cause a smaller increase

in micro-organisms, thus indicating that soil nitrogen is not being biologically immobi-

lized (Abd-El-Malek et. al., 1968). However, over time, biological activity and the C/N

ratio in soils treated with compost amendments tend towards an equilibrium (Gallardo,

1987), making them a viable option for long-term use.

Further study on an experiment like the one conducted here would be useful over

a longer time period – preferably over several seasons, to see if any significant changes

will be observed. Not only would reporting be more accurate over a longer time scale,

but if soils continued to stabilize under the various compost treatments over time, then

this would lend even further weight to the use of alternative fertilizer treatments over

time – helping farmers to save money, as most of these organic wastes are disposed of

free of charge from the sources where they were obtained. Long-term effectiveness of al-

ternative organic waste fertilizer treatments would not only benefit the local farming

community economically, but it would also help reduce local additions to regional mu-

nicipal waste landfills, creating an environmental benefit as well.

Considering that the corn plants gave different responses according to the investi-

gated doses and analyzed parameters, it would also be useful to investigate increasing in-

cremental doses higher than 15 t ha−1 to confirm up to which dose for which there is no

more change in response of corn yield and/or soil health for each treatment type.

The creation of economic indices for each of these treatment types might be an-

other useful application of the use of this data, as much of the benefit of this study,

though environmentally rewarding, will most likely be viewed by the farming community

as most beneficial in economic terms.

IX. Literature Cited and Annotated

Abd-EI-Malek, Y., A. I. Naguib, and M. A. Guirguis. 1968. The effect of organic matter additions on soil respiration, soil nitrogen and activity. Annales De L'Institut Pasteaur, 115: 657-68.

This study was useful for its experiments on C/N ratios, soil respiration, and mi-crobial activity in soil treated with various organic fertilizers. The study found that C/N ratios under 20 can cause a smaller increase in micro-organisms in the soil, thus indicat-ing that soil nitrogen is not being biologically immobilized.

Akinnifesi F. K., J. Mhango, G. Sileshi, and T. Chilanga. 2008. Early growth and survival of three miombo woodland indigenous fruit tree species under fertilizer, manure and dry-season irrigation in southern Malawi. Forest Ecology and Management, 255:546-557.

This article looks at three different members of the miombo fruit tree species and their response to fertilization, manure application, and dry-season irrigation, particularly on early growth and survival. The study showed poor response to manure application, some response to fertilizer, and greatest response to irrigation. This article will be useful in looking at the response of one species of plant to three different variables that might influence growth, health, etc. and in shedding light into methods of such a type of study.AbstractAlthough a large number of miombo tree species bear edible fruits which are important sources of vital nutrients and incomes to rural households, their conservation and cultiva-tion remain challenging because of lack of information on their ecology and manage-ment. Therefore, the objective of this study was to evaluate the effects of fertilization, manure application and dry-season irrigation on the early growth and survival of the miombo fruit tree species, Uapaca kirkiana, Sclerocarya birrea and Vanguaria infausta with Mangifera indica as relative control. At 33 months after planting, growth and sur-vival of U. kirkiana and S. birrea were lower in plots that received fertilizer, compost and

irrigation compared with those that did not. The best growth and survival in U. kirkiana was obtained when irrigation was applied with neither fertilizer nor manure. The best growth in S. birrea was recorded where plants received irrigation without fertilizer and manure, while survival was highest when none of the treatments was applied. Growth and survival of V. infausta was not affected by manure application, but fertilizer and irriga-tion increased root collar diameter, leaf, shoot and branch numbers. At 33 months after planting, U. kirkiana and S. birrea had not reached reproductive maturity, while V. in-fausta and M. indica had started fruiting in the second year. It is concluded that fertiliza-tion, manure and irrigation do not increase early growth or survival of U. kirkiana and S. birrea contrary to the commonly held assumption about factors that affect growth and survival in this species. The poor response to fertilizer and dry-season irrigation could be attributed to either their adaptation to infertile soils and unimodal rainfall regimes in their natural stands or delayed response that could not have been observed in the short period of the study.

Alumi, F. X., I. E. Soe Angnie, B. H. Janssen. 1977. Evaluation of municipal refuse from Dahomey (Benin) as an organic manure. In: Proceedings of a Symposium on Soil Or-ganic Matter Studies. Vol. II, International Atomic Energy Agency, Vienna, 291-300.

This study found that immature composts tend to contain C/N ratios above 30, and that these ratios are less effective than at other C/N ratios, creating a need for in-creased competition for soil nitrogen between micro-organisms degrading the compost and the crops themselves.

Amlinger F., B. Götz, P. Dreher, J. Geszti, and C. Weissteiner. 2003. Nitrogen in biowaste and yard waste compost: dynamics of mobilisation and availability—a review. European Journal of Soil Biology, 39:107-116.

This study looks at the application of biowaste composts as opposed to other forms of ferilizer in farming and the resultant dynamics of nitrogen in the soil through the compilation of several studies. Predictions are made that, with regular application of biowaste compost, balances between N-supply and N-uptake and losses should be reached within 40-100 years. This is useful to my study in the specific focus on nitrogen effects in soils from the specific application of biowaste compost over time.

Baran A., G. Çaycı, C. Kütük, and R. Hartmann. 2001. Composted grape marc as grow-ing medium for hypostases (Hypostases phyllostagya). Bioresource Technology, 78:103-106.

A specialized type of biological compost material – composted grape marc – was tested in seven different ratios mixed with different concentrations of CGM, peat and per-lite. Some replicates were grown in greenhouse conditions. Physical and chemical prop-erties were tested, as well as some horticultural parameters, with findings that up to 50% composted grape marc is effective with mixtures of peat for good nutrient fertilizing and low cost. This is useful to my study in showing a good design for testing different mix-tures of one kind of biological compost and its effects at different levels on increased nu-trient levels in plants.

Bustamante M. A., C. Paredes, R. Moral, E. Agulló, M. D. Pérez-Murcia, and M. Abad. 2008. Composts from distillery wastes as peat substitutes for transplant production. Re-sources, Conservation and Recycling, 52:792-799.

The purpose of this study was to see if composts from distillery wastes would be a viable substitute for peat in order to avoid further environmental damage from peat har-vesting. The composts were mixed with variations of grape marc, cattle manure, and poultry manure, and tested on four different vegetable species on nine variations of sub-strates. Germination, morphological and nutritional responses were studied. This study shows a good example of testing another type of biological compost on variable crop species in variable environments.AbstractThe use of composts from distillery wastes as alternative growing media ingredients for transplant production instead of peat, whose harvesting constitutes a severe environmen-tal damage, was studied. Two composts were prepared with exhausted grape marc and cattle manure (C1), and with exhausted grape marc and poultry manure (C2). Four veg-etable species, lettuce (Lactuca sativa), chard (Beta vulgaris), broccoli (Brassica oleracea) and coriander (Coriandrum sativum) were grown. Nine substrates were compared: limed white peat (control); compost C1; compost C2; and six mixtures containing 25%, 50% and 75% by volume of each compost with the corresponding peat as diluent. The germi-nation and the effects on the transplant morphological and nutritional aspects of the dif-ferent mixtures peat/compost considered were studied. All media elaborated showed ade-quate physical, physico-chemical and chemical properties compared to peat for their use as growing media in horticulture, being these two composts suitable ingredients for the partial substitution of peat, in quantities of 25–50% by volume, without causing any loss in the yield and in the results obtained for the nutritional status when compared to those obtained using the control.

Cai Z. C., S. W. Qin. 2006. Dynamics of crop yields and soil organic carbon in a long-term fertilization experiment in the Huang-Huai-Hai Plain of China. Geoderma, 136:708-715.

This was a long-term fertilization experiment over 14 years, applying different treatments of N, P, and K in inorganic and organic forms of fertilizer on wheat and maize plants. Soil organic carbon and crop yields were the responses measured. This is another example of a thorough, varied study of the effects of different types of fertilization on plant growth and soil health.AbstractWe analyzed the dynamics of crop yields and soil organic carbon content (SOC) in a long-term fertilization experiment carried out in the Huang-Huai-Hai Plain of China. The experiment with crop rotation of winter wheat and summer maize started in 1990 and had seven treatments receiving N, P, and K at the same rates if it was applied. The treatments were inorganic fertilization (NPK, NP, PK, NK), organic fertilization (ON), half amount of N from inorganic fertilizer and another half from compost (1/2ON), and no fertiliza-tion as control (CK). On average, over 14 years (1990–2003), both wheat and maize yields were the highest and most stable in the NPK treatment. Average wheat and maize yields were 23.7% and 18.0% lower in ON, respectively, and slightly but significantly lower (1.9% and 1.5%, respectively) in 1/2ON than those in NPK. Unbalanced inorganic

fertilization without K (NP) was not sustainable for achieving high yields. There was a significant logarithmic relationship between roots and compost input and SOC content in 0–20 cm in 2003. Over the time of the study SOC storage in 0–20 cm increased by 12.2 Mg C ha− 1 in ON, 7.8 Mg C ha− 1 in 1/2ON, and 3.7 Mg C ha− 1 in NPK, and de-creased by 1.6 Mg C ha− 1 in NK and 1.4 Mg C ha− 1 in CK. Measured dynamics of SOC and model simulation predictions showed that the SOC in NPK, ON and 1/2ON al-most reached equilibrium in 2003. These results indicate that although the balanced ap-plication of chemical fertilizers of N, P, and K maintains the crop production in the re-gion, it is not an ideal practice from the point view of carbon sequestration in soil. Appli-cation of compost alone has a reverse effect on crop yields and carbon sequestration in soil. Therefore, mixed application of organic and inorganic fertilizers is a compromise between food security and soil carbon sequestration in the region.

Cassman K. G., P. W. Singleton, and B. A. Linguist. 1993. Input/output analysis of the cumulative soybean response to phosphorus on an ultisol. Field Crops Research, 34:23-36.

Cumulative effects of P input regimes on soybean yield, N and P budgets, and soil P availability in four consecutive crops in a 2-year period on a Humoxic tropohumult soil were compared in this study. Contributions of biological N2 fixation were regarded in re-sponse to the soil P supply. It was found that a positive net P balance resulted in in-creased extractable P in topsoil, a reduction in the proportion of P fixed from subsequent additions, and there was greater apparent P uptake efficiency from applied fertilizer in subsequent crop cycles. This article helped me particularly with some my methods for measuring P and N2 fixation in soybeans and associated roots and soils.AbstractAlthough biological N2 fixation (BNF) by legumes can provide significant N inputs to crop systems on highly weathered tropical soils, potential inputs from BNF largely de-pend on soil P supply. We compared the cumulative effects of P input regimes on yield, N and P budgets, and soil P availability in four consecutive soybean crops in a 2-year pe-riod on a Humoxic tropohumult. In each crop cycle, nodulating (nod) and nonnodulating (nonnod) isolines were subplots in P-regime mainplots (kg P ha−1 by crop cycle): P0 = control without P inputs; LP = 50, 35, 35, 35; MP = 100, 70, 70, 70; and HP = 300, 210, 210, 210. Seed yields of the nod isoline in the HP regime were 3700 kg ha−1 in the two summer seasons and 2400 to 2500 kg ha−1 in the fall seasons, with a mean increase of 85% compared to yields of the nod P0 control. Nonnod seed yields and N accumulation were unaffected by the P regime, averaging 870 and 48 kg ha−1, respectively. The contri-bution of BNF to nod soybean N assimilation was linearly related to P uptake, and mean P uptake by nod plants was 60% greater than by nonnod soybaen, despite 35% greater root length of nonnod plants at 0–50 cm depth. For the four crop cycles, total BNF input to the system ranged from 330 kg N ha−1 (P0, or 65% of total aboveground N, to 710 kg N ha−1 (HP), which was 78% of total aboveground N. After accounting for P removal at harvest, a net P input of just 99 kg P ha−1 after four crops increased cumulative seed yield by 3600 kg ha−1 and BNF by 227 kg N ha−1 in the LP treatment. A positive net P balance also resulted in (1) an increase in extractable P in the 0 to 25 cm topsoil, (2) a re-duction in the proportion of P that would be fixed from subsequent additions as indicated by a shifted P sorption isotherm, and (3) greater apparent P uptake efficiency from ap-

plied fertilizer in subsequent crop cycles. As a result, the yield response of nod soybean per unit P input increased from 13 kg seed kg−1 P applied in the first crop to 44 kg seed kg−1 P applied in the fourth crop of the LP treatment. Cumulative effects of this magni-tude emphasize the need to consider the longer-term nutrient balance of the crop system in developing cost-effective P management strategies on highly weathered soils. The po-tential for greater P input use efficiency with time when inputs exceed outputs means that farmers' average and marginal return from investment in P fertilizer will also increase with time.

Castillo M. S., A. L. Wright. 2008. Soil phosphorus pools for Histosols under sugarcane and pasture in the Everglades, USA. Geoderma, 145:130-135.

The effects of phosphorous fertilizer in soil heath, nutrient cycling, and sugarcane and pasture health were studied for the purposes of long-term land management and fu-ture land use. The effects of a nutrient fertilizer on soils and associated plant species is relevant to my focus of study. Histosols are a common soil type in Indiana, so the com-parison was useful.AbstractLand use changes in the Everglades Agricultural Area (EAA) in southern Florida may in-fluence the distribution and availability of P. Cultivated soils in the EAA are being con-verted back to their historic use as seasonally-flooded prairies as part of Everglades restoration projects. The objectives of this study were to determine the distribution of P in soil chemical fractions in relation to long-term land management to predict P cycling and transformations for future land uses. Soil under pasture (100 yr) and planted to sugarcane (Saccharum sp.) for 50 yr were amended with P (0, 10, 50, 150 kg P ha− 1), and its distri-bution in labile, Fe–Al bound P, Ca-bound P, humic–fulvic acid P, and residual P pools determined for surface soil (0–15 cm). Most P fertilizer entered Fe–Al and Ca-bound fractions. Cultivation contributed to higher pH and increased the Ca content in soil com-pared to pasture due to incorporation of bedrock limestone into soil by tillage. The land uses were differentiated by P storage in different pools. Subsequently, long-term fertiliza-tion increased soil total P for cultivated soil relative to pasture, but plant-available P con-stituted less than 1% of the total P. Labile P increased with increasing P application rate, ranging from 1.3 to 7.2 mg kg− 1 for cultivated soil and 1.4 to 10.7 mg kg− 1 for pasture. Most of the applied P was recovered in the Fe–Al fraction for pasture and the Ca-bound P fraction for cultivated soil. The Ca-bound P fraction represented the greatest proportion of total P for sugarcane (41%), but only 12% for pasture. The majority of P in the pasture was present in the humic–fulvic acid fraction (45%), compared to only 23% for sugar-cane. The higher pH of the cultivated soil (6.8) favored retention in Ca fractions while the lower pH of pasture (5.3) favored P retention in the humic–fulvic acid fraction. The pro-portion of total P as organic P was greater for pasture (78%) than cultivated soil (52%). Higher P levels in more recalcitrant fractions for cultivated soils indicated that more of the applied fertilizer P was sequestered in stable fractions, which decreased P availability to crops and may subsequently increase P fertilizer requirements necessary to maintain optimal plant-available nutrient levels. Subsequently, continuation of current farming practices and tillage regimes promotes the redistribution of Ca from subsurface to surface soil, which leads to greater P sequestration in the Ca-bound fraction. However, P in inor-ganic fractions may be released upon onset of changes in land use. Thus, conversion to

seasonally-flooded prairies may have a more dramatic effect on P release from cultivated than pasture soils since cultivated soils have more P in inorganic pools.

Cheung, Y. H., Wong, M. H. 1983. Utilisation of animal manures and sewage sludges for growing vegetables. Agricultural Wastes, 5:63-81.

Activated sludge, digested sludge, chicken manure and pig manure were used as soil additives for the growth of a local vegetable, flowering Chinese Cabbage, Brassica parachinensis. Edaphic properties of the waste-amended soils were measured. It was found that animal manures supported better growth than sewage sludges. Vegetables treated with animal manures had higher productivity, earlier maturity, absence of anatom-ical abnormalities and lower heavy metal contents. Application of chicken manure to agricultural land is a common practice of the local farmers. However, pig manure pro-duced higher yields of the vegetable than chicken manure. This indicated that pig manure also has a high potential as a fertiliser. Recycling of pig manure is highly essential as some of the streams in the New Territories of Hong Kong are grossly polluted by pig ma-nure.

The inferior growth of the vegetables harvested from sewage sludge amended soils was correlated with the edaphic properties of the sewage sludge amended soils. Such soils were lower in pH, conductivity and extractable phosphate, but higher in heavy metal content. Because of the high uptake of heavy metals in the sludge-grown vegeta-bles, it is suggested that sewage sludge should be used as a soil additive only for non-edi-ble crops. Furthermore, caution should be taken if crops like carrots were planted, due to the higher uptake of heavy metals in the root portion.

Courtney R. G., G. J. Mullen. 2008. Soil quality and barley growth as influenced by the land application of two compost types. Bioresource Technology, 99:2913-2918.

Different concentrations of two specific types of compost – spent mushroom and forced aeration – were tested to illuminate influence on soil properties and quality and yield of barley. This should be relevant to my study’s focus on different fertilizing types and their influence on plant growth and quality and soil quality.

de Bertoldi, M., G. Vallini, and A. Pera. 1983. Biology of composting; a review. Waste management & research: Journal of International Solid Wastes and Public Cleansing As-sociation, 8:157-76.

Gabrielle B., J. Da-Silveira, S. Houot, and J. Michelin. 2005. Field-scale modeling of car-bon and nitrogen dynamics in soils amended with urban waste composts. Agriculture, Ecosystems & Environment, 110:289-299.

In this study a deterministic soil-crop model is used to simulate C-N dynamics in a field undergoing application of different types of disposable urban waste composts, in hopes to aid with good management techniques of the proper management and increased utilization and renewing of these otherwise urban wastes. This model should be useful in looking at the use of simulation models in the testing of human compost materials on soil qualities.Abstract

Municipal solid waste compost (MSWC) can enhance soil organic matter and crop nutri-ent supply. High C:N ratio composts can temporarily deplete plant-available soil N re-serves, requiring supplemental N fertilization to ensure optimum crop growth. The objec-tive of our research was to measure seasonal soil NO3–N dynamics to serve as an indica-tion of N mineralization, immobilization, and leaching as affected by MSWC and N fer-tilizer rates. The MSWC (C:N 40:1) was applied in one year only to a Galestown sand (sandy, siliceous, mesic Psammentic Hapludults) at rates of 0, 63, 126, and 189 Mg ha-1. Maize (Zea mays L.) was planted and N fertilizer rates of 0, 168, 336, 504, and 672 kg ha-1 were applied as split-plot treatments. First-year maize total dry matter production plateaued at the 250 kg ha-1 N rate, averaged across MSWC rates. Soil NO3–N de-creased inversely proportional to MSWC rates, due to MSWC immobilization of soil and fertilizer N. Cereal rye (Secale cereale L.) winter cover crop total dry matter yield and to-tal crop N increased linearly with increasing MSWC rates. Second-year maize total dry matter, total plant N, maize grain yield, and grain N increased linearly with increased MSWC rates applied the first year. During the second growing season, there was an in-creasing supply of plant-available N, due to mineralization of organic N in the MSWC with increasing MSWC rate; however, the supply of mineralized N was inadequate to meet crop growth requirements for maximum maize yield.

Gallardo-Lara F., R. Nogales. 1987. Effect of the application of town refuse compost on the soil-plant system: A review. Biological Wastes, 19:35-62.

The focus of this study is the possible use of town refuse compost as a fertilizer for crops, as opposed to organic and mineral fertilizers. Compost application was, in general, found to have a positive effect on soils, though an inhibitory effect on seed ger-mination was found in large application quantities. This is part of the aim of my study – in the possible implementation and use of compost from Taylor University’s Dining Commons – so this article was certainly relevant.AbstractThis paper reviews the currently available information concerning the use of town refuse compost as a potential fertilizer. Many studies have generally shown that the application of this material has promoted a positive influence on a wide variety of craps. Neverthe-less, contradictory results of crop yields have been obtained when the fertilizing capacity of compost has been contrasted with those of organic and mineral fertilizers. It has been demonstrated that the application of compost to soil improves some physical properties such as porosity, water-holding capacity and bulk density. It also promotes buffering ca-pacity of soil and increases the percentage of organic matter and cation exchange capac-ity. Occasionally, negative aspects can emerge from compost incorporation, such as an increase in organic pollutants and electrical conductivity of soils. In general, compost ap-plication to soil has a positive effect on the microbial population and rhizosphere micro-organisms and also contributes to the reduction of nemotode populations in plants. How-ever, when big doses of compost are used, an inhibitory effect on seed germination may appear. The nitrogen availability of the municipal compost is closely related to the matu-rity of this material. A wide range of results has been obtained from different studies per-formed to evaluate the efficiency of compost as a source of phosphorus, sulphur, calcium and magnesium for plants. The incorporation of municipal compost constitutes a valuable

resource for supplying potassium and some micronutrients (i.e. boron and zinc), but also presents potential pollution hazards associated with some heavy metals.

Garcia-Gomez A., M. P. Bernal, and A. Roig. 2002. Growth of ornamental plants in two composts prepared from agroindustrial wastes. Bioresource Technology, 83:81-87.

Two different composts – one created from brewing waste (yeast and malt) plus lemon tree prunings, and the other from the solid fraction of olive mill wastewater plus olive leaves – were each combined with varying concentrations of Sphagnum peat or commercial substrate and influence on soils and growth and health of calendula and cal-ceolaria plants were measured. These agroindustrial composts were found to be viable alternatives to peat and commercial substrates.

Golueke, C. G. 1977. Biological Reclamation of Solid Wastes. This article was found online and in formative on the issue of timing of compost

on agriculture. The article proves that if sufficient time is not allowed for this process to take place away from the crop soil, micro-organisms in the agricultural soil will degrade the amended organic matter and thus will actually compete with crops for soil nitrogen, and which will produce intermediate metabolites and high concentrations of ammonia in the soil that is not compatible with plant growth.

Heiri, O., A. F. Lotter, and G. Lemcke. 2001. Loss on ignition as a method for estimating organic and carbonate content in sediments: Reproducibility and comparability of results. Journal of Paleolimnology 25 :101-110.

Good article on the methods to be followed the meanings of carbon loss on igni-tion testing in a muffle furnace.

Hortenstine, C. C., D. F. Rothwell. 1973. Pelletized municipal refuse compost as a soil amendment and nutrients source for sorghum. J. Environ. Qual., 2(3), 343-5.

This study revealed that continual high-dosage use of composts over a longer-term period could prove to be more efficient than normal mineral fertilizers.

Lee J., R. Park, Y. Kim, J. Shim, D. Chae, Y. Rim, B. Sohn, T. Kim, and K. Kim. 2004. Effect of food waste compost on microbial population, soil enzyme activity and lettuce growth. Bioresource Technology, 93:21-28.

Variations of fertilizers and food waste composts were tested on lettuce growth, soil enzyme activities and fungal and bacterial populations in a greenhouse setting. The different composts and fertilizers were food waste combined with “Miraculous Soil Microorganisms,” commercial compost, and a mineral fertilizer. PH, total nitrogen con-tent, organic matter, sodium concentrate, soil biomass, and soil enzyme activities in the rhizosphere were the tested responses.

Lima J. S., J. E. G. de Queiroz, and H. B. Freitas. 2004. Effect of selected and non-se-lected urban waste compost on the initial growth of corn. Resources, Conservation and Recycling, 42:309-315.

Composting in Brazil was looked at as an improvement for the destination of the 76% of domestically-produced residues that were being dumped out of doors. Two types

of compost made from urban waste were tested on corn, and the responses were used to consider the use of this organic waste compost for purposes such as soil recovery, com-mercial production, pastures, lawns, reforestry, and agriculture. Chemical analyses of the corn were taken, as were height and stem diameter measurements, and biomasses, and corn cultivated with organic waste compost was found to have superior gain to corn grown with non-selected compost taken from a 15-year-old landfill.

Mbarki S., N. Labidi, H. Mahmoudi, N. Jedidi, and C. Abdelly. 2008. Contrasting effects of municipal compost on alfalfa growth in clay and in sandy soils: N, P, K, content and heavy metal toxicity. Bioresource Technology, 99:6745-6750.

Mature municipal solid waste compost (MSWC) was applied to clay and sandy soils from cultivated fields, and opposite trends in the two soil types were observed, showing the MSWC as useful in soil conditioning for clay soils but not for sandy soils.

Mehta S. A., and S. Y. Daftardar. 1984. Effects of anaerobically prepared wheat straw composts and city garbage composts on yield and N and P uptake by wheat. Agricultural Wastes, 10:37-46.

Wheat straw composts and granulated city garbage composts were found to be poor suppliers of N and P and did not increase wheat yield in this study, while sieved garbage compost increased wheat yield to a slight extent. These composts were then combined with an NPK fertilizer, showing an increase in yield for the wheat straw com-post-NPK association, but not for the city garbage compost-NPK association.AbstractBonemeal (0, 25, 50 and 75 kg/500 kg wheat straw), wheat straw, cattle dung and urea were used in the preparation of anaerobic ‘compost’ by the ‘Bangalore’ method. The N content of the ‘composts’ increased and C/N ratio decreased with increase in the bone-meal used for composting. Besides these ‘composts’. a sieved sample of city garbage compost and a granulated sample of city garbage compost were tried in two field experi-ments using wheat (cv. Kalyan Sona) as a test crop. In experiment l, quantities of the composts to supply 100 kg N/ha were added to soil to compare them for their effect on a wheat crop on an equal nitrogen basis. Wheat straw ‘composts’ and granulated city garbage compost were poor supplilers of N and P and did not increase the wheat yield, while sieved garbage compost increased the wheat yield to some extent. In experiment 2, the effects of association of each of the composts (at 5 t/ha) with fertilizer (N, P, K: 100, 21·81, 41·51 kg/ha respectively) on a wheat crop was studied. Application of NPK along with wheat straw ‘composts’ increased the wheat yield, but application of NPK with city garbage composts did not increase the wheat yield over the NPK control.

Murillo J. M., F. Cabrera, R. López, and P. Martín-Olmedo. 1995. Testing low-quality urban composts for agriculture: germination and seedling performance of plants. Agricul-ture, Ecosystems & Environment, 54:127-135.

Two different types of urban composts were tested on the effects of seeding per-formance and seedling composition for soil cress, ryegrass and sunflower seeds – one was a very coarse, low in organic matter but mature urban compost. The other was a par-ticulated, high in organic matter but not well stabilized urban compost. Mature composts

were found to be “excellent” in quality, while the less mature compost showed strong in-stant toxicity.

Pascual J. A., C. García, and T. Hernandez. 1999. Comparison of fresh and composted organic waste in their efficacy for the improvement of arid soil quality. Bioresource Technology, 68:255-264.

Fresh and composted urban wastes were used on the organic matter of an arid soil and the effects were tested. The fresh, organic compost improved the arid soil more than did the composted urban waste. High mineralization rates occurred in soils under influ-ence of the fresh compost treatment.

Ros M., J. A. Pascual, C. Garcia, M. T. Hernandez, and H. Insam. 2006. Hydrolase activ-ities, microbial biomass and bacterial community in a soil after long-term amendment with different composts. Soil Biology and Biochemistry, 38:3443-3452.

This paper was useful in the comparison of effects of different kinds of composts to investigate to what extent and to which soil depth four major types of composts would effect the soil and it microbiota. Different compost types had differing effects on total or-ganic C, total N, basal respiration, specific enzyme activities related to C, N and P cycles, and less influence on the composition of microbial communities, which were more ef-fected by soil depth.

Rousseau G. X., S. Rioux, and D. Dostaler. 2006. Multivariate effects of plant canopy, soil physico-chemistry and microbiology on Sclerotinia stem rot of soybean in relation to crop rotation and urban compost amendment. Soil Biology and Biochemistry, 38:3325-3342.

Two soils (clay loam and sandy loam) were used for the assessment of the effects of canopy and soil physico-chemical and microbiological variables on Sclerotinia stem rot (SSR) on soybeans. Multiple regression and canonical redundancy analysis (RDA) were used, which revealed the minimal sets of variables that best explained the variance of SSR’s survival. The use of urban compost had a conducive effect that was explained by better soil surface drainage.

Ryan J., S. N. Harik, and R. Shwayri. 1985. A short-term greenhouse evaluation of non-conventional organic wastes. Agricultural Wastes, 12:241-249.

Several organic fertilizing-soil addiditves were evaluated on tomatoes in a green-house trial on clayey calcareous soil. Imported and local commercially processed wastes were included, as well as plant extract sprays, farm manures and a compound inorganic fertilizer. Dry matter yield and nitrogen uptake were measured responses. Most materi-als increased growth rate relative to the control, most effectively with chicken manure.AbstractIn this greenhouse trial several organic fertilizing-soil additive materials were evaluated on a clayey calcareous soil, using tomatoes as a test crop. These included imported and local commercially processed wastes, i.e. Dubaline, Humobacter, Bovisol, Biotersan, Fer-tilaid, Cofuna, and plant extract sprays, Raimul and Tecrop. Municipal waste, farm ma-nures and a compound inorganic fertilizer were used for comparison in terms of dry mat-ter yield and nitrogen uptake. Most materials increased growth relative to the control; the

most effective were chicken manure, Biotersan, the inorganic fertilizer and, to a lesser ex-tent, Dubaline. Responses to most other materials were not significantly higher than the control. Yields from Bovisol were less than the control, while Fertilaid inhibited germina-tion and plant establishment. Most of these novel materials are less competitive economi-cally than the traditional organic or inorganic fertilizer sources. Opportunity costs associ-ated with disposal of material, which is otherwise waste, should be considered in estab-lishing market prices.

Sæbø A., F. Ferrini. 2006. The use of compost in urban green areas – A review for practi-cal application. Urban Forestry & Urban Greening, 4:159-169.

The benefits of the use of compost for soil amendment and mulching are studied for use in urban green areas, particularly noted was an increase in quality during the es-tablishment and management phases. Several site-specific designed composts were looked at, and it was noted that specific quality demands of each compost must be related to nutrient content and particle size.

Salvagiotti F., K. G. Cassman, J. E. Specht, D. T. Walters, A. Weiss, and A. Dobermann. 2008. Nitrogen uptake, fixation and response to fertilizer N in soybeans: A review. Field Crops Research, 108:1-13.

Six hundred and thirty-seven data sets were analyzed from field studies published in peer-reviewed journals from 1966 to 2006 that studied the relationships among soy-bean seed yield, N uptake, biological nitrogen fixation, and the response to N fertiliza-tion. The information from these studies is useful in developing guidelines for managing BNF and fertilizer N in high-yield environments, and in improving soybean simulation models.

Schulte, E.E., and B.G. Hopkins. 1996. Estimation of organic matter by weight loss-on-ignition. In F.R. Magdoff et al. (ed.) Soil organic matter: Analysis and interpretation. SSSA Spec. Publ. 46: 21-31.

Another good article on the methods to be followed when conducting a carbon loss on ignition test, as well as the interpretation of these results for soil organic matter.

Shisler, L. C., M. Grable. 1976. Utilization of composted municipal refuse for mushroom production. 352.

This article compared the effectiveness of utilizing municipal waste compost on its own vs. utilizing it as a fertilizer to be mixed with other composting organics, such as manure. Treatments were found to be more effective utilizing a mixture.

Tsai S., C. Liu, and S. Yang. 2007. Microbial conversion of food wastes for biofertilizer production with thermophilic lipolytic microbes. Renewable Energy, 32:904-915.

Since food waste is approximately one quarter of the total garbage in Taiwan, conversion of microbial food waste to multiple functional biofertilizer was investigated. The conversion of the food waste to biofertilizer was found to be a feasible and potential technology for Taiwan in the future to aid in maintaining natural resources and reducing the nation’s impacts on environmental quality.

Vallini G., A. Pera. 1989. Green compost production from vegetable waste separately collected in metropolitan garden-produce markets. Biological Wastes, 29:33-41.

An urban garden produce market was used for the recovery and recycling of veg-etable wastes, and experiments were carried out to evaluate the viability of these prac-tices. The aerated static pile composting system was successful in obtaining humified or-ganic matter, which was then used as agricultural soil conditioner. AbstractExperiments were carried out to evaluate the possibility of recovering and recycling veg-etable waste originally collected in an urban garden-produce market. These organic pu-trescible residues were biologically stabilized through composting in an aerated static pile in order to obtain humified organic matter (green compost) to be used as agricultural soil conditioner.Performances of the composting system adopted together with physico-chemical charac-teristics of the starting material and the final product are reported here. Some microbio-logical and phytotoxicological details concerning this green compost production are also given.

van Assche C., P. Uyttebroeck. 1982. Demand, supply and application possibilities of do-mestic waste compost in agriculture and horticulture. Agricultural Wastes, 4:203-212.

This study showed that increasing the quantities of domestic waste compost re-sulted in a decrease in the production of Lactuca sativa (lettuce) , whereas it resulted in a yield increase in Apium graveolens (celery). Increasing quantities of domestic waste compost in enriched sand-loam soil showed a rapid increase in Cu, Pb and Zn concentra-tions, as well as a positive influence on the health of ornamental plants, in comparison with the control substrate. AbstractIncreasing quantities of fermented domestic waste compost resulted, in the present exper-iments, in a decrease in the production of Lactuca sativa (lettuce) in contrast to a yield in-crease for Apium graveolens (celery).The application of a calculated quantity of ion exchangers can modify the phytotoxic ef-fect of the presence of heavy metals as well as the salt concentration of the domestic waste compost. The use of anion exchangers in the lettuce culture resulted in a consider-able yield increase in comparison with the control.With regard to Chrysanthenum morifolium cv. ‘Angora’, Pelargonium zonale cv. ‘Flirt’ and Dieffenbachia perfecta, it was demonstrated that the use of a mixture of domestic waste compost and coniferous soil in a ratio of 1:3 is very useful for these ornamental plants, on the basis of comparison of results of vegetative development with the control substrate.Analysis of the vegetables cultivated with increasing quantities of domestic waste com-post enriched sand-loam soil showed that the concentrations of Cu, Pb and Zn fairly quickly exceeded the normal average values.As far as pathogenesis is concerned, increasing quantities of domestic waste compost positively influenced the health index of Phaseolus vulgaris and Pisum sativum with re-gard to Rhizoctonia solani and Pythium ultimum.

Zobac, J., J. Vana. 1974. The agronomical effectiveness of industrially produced

compost in dependence of the technology of production, 20(9): 931-9. This article gives useful insight on different types of industrial produced composts and how these can be used in an agronomical sense most effectively. One finding that was particularly useful was their experimental design that revealed an increase in corn pro-duction under organic fertilizer treatments.

Zucconi, F., Forte, M., Monaco, A., and de Bertoldi, M. 1981. Biological evaluation of compost maturity. Biocycle, 22(4): 27-29.

This article is very informative about the importance of timing for organic waste composts. Timing of organic wastes to the soil is a crucial factor in agricultural utiliza-tion. As this study shows, compost should be allowed to stabilize, or humify, for 5-6 months miniumum before it is added to the agricultural soil. This is a key aspect of this study.