cultivations opportunities, timing and threats 2014-15/cultivations...1. a plough anywhere in the...
Post on 10-Mar-2020
4 Views
Preview:
TRANSCRIPT
Cultivations – opportunities,
timing and threats
Dick Godwin
Soil Physical Conditions
Required For Crop Production
• Crop factors
• Soil and water conservation
• Mechanisation requirements
Overview
Tillage alternatives - benefits & limitations
Tillage forces/energy/costs
Crop Yield
Controlled Traffic and Lower Ground Pressure
Weed control
Opportunities, timing and threats
What Tillage?
• Conventional
• Deep
• Shallow
• Minimum tillage
• Direct drill
• No-Till
Considered “Reduced tillage”
Just attempting to plant
directly into the soil
Overall disturbance
to a shallow depth
Perceived benefits of reduced tillage
The main reasons to use min-till are:
To reduce energy consumption
To reduce labour costs
To conserve moisture
To retain plant cover to minimize erosion
Minimise loss of organic matter*
• Each point is very appealing to the farmer who wants to make the best profit margins in terms of field efficiency, fuel economy and work rate. The min-till is also appealing to the farmer who wants to look after the land.
• However, min-till growers are most affected by poor weather conditions, as dry ground conditions are essential for sowing in order to avoid compaction and smearing in the final seed bed.
• For anybody new to min-till, one of the best tools in your tool box for min-till is patience.
• The best advice is to wait until conditions are excellent for sowing. There is little point in sowing a crop (especially winter barley) into a compacted or smeared seed bed.
Independent 07/08/07 * Not in the Independent
Disadvantages
• Crop establishment problems
during very wet or very dry spells
• Weed control problems
• Cost of herbicides, herbicide
resistance
• Risk of increased N2O emissions
and increased dissolved P
leaching
• Reduced reliability of crop yields
• Unsuited to poorly structured
sandy soils
• Unsuited to poorly drained soils
• Risk of topsoil compaction
• Increased slug damage
Advantages and disadvantages of
“No-till” systems.
Advantages
• Lack of compaction below plough
furrow
• High work rates and area capability
• Increased bearing capacity
• Reduced erosion, runoff and loss of
particulate P
• Opportunities to increase area of
autumn sown crops
• Stones not brought to the surface
• Reduced overall costs
After: Soane et al., 2012.
No-till: World wide climatic effects
Analysis of 5,000 observations, indicated on average “No-till”
reduces yields at the global scale, yet opportunities exist for more
closely matching or even exceeding conventional tillage yields.
•For example, yield reductions were minimized when the principles of
crop rotation and residue retention were also practiced.
•In dry climates “No-till” farming performed significantly better than
conventional tillage, due to the higher retention of soil moisture.
•In regions with moist climates “No-till” resulted in yields that were on
average 6 to 9 percent lower than with conventional tillage.
After: Pittelkow, et al., 2014 (Nature - 22nd October) http://news.ucdavis.edu/search/news_detail.lasso?id=11062
Proportion of winter wheat area
using alternative establishment
methods in England
Knight et al 2012
• Soil type - Clays and sands
can both be problems
• Moisture content – plasticity
• Residue levels and condition
• Weed density
Direct drilling constraints in the UK
Provisional
classification for soil
suitability for direct
drilling of combine
harvested crops.
After: Cannell et al., 1978.
50 sites; 214 site x years
Climatic effects:UK
A draft manuscript concluded that after reviewing the work of Soane
(2012) and Cannell (1985) the UK cereal growing areas lie at the
boundary between two European agro-climatic regions: -
• The southern and eastern areas, which are drier and warmer and
direct drilling has shown equal or better yields than conventional
tillage where the barriers to adoption are non-technical, and
• The northern and western areas, where technical problems of
compaction, straw management, reduced soil temperatures and
wetter conditions prevent successful direct drilling.
Cannell, Pidgeon, Davies and Finney - Unpublished manuscript
Likely short and long term trends in
converting from tillage to no-tillage
Increase
Decrease Current position with tillage
Time - years
After: Carter, 1994
Tillage tools
Tine geometry and soil disturbance
After: Godwin, 1974
2 key factors:
1.Rake angle
2.Depth/width ratio
Effect of rake angle on soil forces
UPWARD
DOWNWARD
After: Godwin 1974
Rake angle Direction of travel
Soil surface
Implement face
Effect of implement depth on soil
forces
After: Godwin 1974
Effect of speed on soil forces
0
1
2
3
4
5
0 2.5 5 7.5 10 12.5 15 17.5 20
Speed, km/h
Forc
e,
kN
After: Wheeler and Godwin, 1996
HORIZONTAL
VERTICAL
16% increase for 2x speed
RTF Zero
RTF Deep RTF Shallow
Effect of Tillage on Surface Residues
Effect of tillage/residues on winter wheat yields. Clay soils
TillageTreatment / Site Childerley
t/ha
Childerley
%
Gt. Staughton
t/ha
Gt. Staughton
%
Burnt - 80mm disc 7.92 100 8.25 100
Burnt -150mm plough - - 8.03 97
Burnt - 150mm plough
+roll
7.86 99 8.12 98
80mm Disc 7.13 90 8.18 99
150mm Disc + tines 7.17 90 8.16 99
150mm plough - - 7.99 97
150mm plough + roll 7.71 97 8.19 99
225mm plough - - 7.99 97
225mm plough + roll 7.93 100 8.20 99
Cranfield University/ADAS/Ransomes, Simms and Jefferies, 1987
Implement Depth % Covered
• Mouldboard Plough 150 - 200 mm 90 - 100
• Disc 50 - 75 mm 30
• Disc 50 - 175 mm 70
• Tandem disc 50 - 75 mm 50
• Tines 150 mm 25
• Sweeps 150 mm 10
• Direct drills 25 - 50 mm ~5
Source: ASAE/USDA
Tillage and residue burial
Tillage effects on residues I
From: Illinois Agronomy Handbook
Implement adjustment – clod size distribution and residue levels
no discs,
tines @ 150mm,
plus wings,
no pack.
discs @ 60mm,
tines @ 100mm,
plus wings,
hard pack.
discs @ 60mm,
tines @ 150m,
no wings,
no pack.
discs @ 60mm,
tines @ 100mm,
plus wings,
no pack.
Direct Drill: Disc types
Direct Drill: Tine types
Fertilizer
Seed
Problems with earlier (1970’s)
“disc” drills
Smearedslot
Trappedstraw
Photographs courtesy of Gordon Spoor
Improved disc type drills
StrawSeeds StrawSeeds
DiscCoulter
StrawSeedexitpoint
Disc
Inverted‘T’share
Presswheel
Straw
Seeds
a.b.
c.d.e.
a. ‘Cross slot’ seed placement mechanism. b. Location of seed
relative to the straw.
c. ‘Uni-drill’ seed placement mechanism.
d. Un-modified seed position. e. Modified seed position.
After: Earl and Spoor, 1994.
Winged opener – “Baker Boot”
Baker, Saxton and Ritchie, 1996
Wheat Yields in STAR project 2007 The Arable Group (TAG)
WC - Winter Cropping
SC - Spring Cropping
CWW - Cont. Wheat
AF - Alternate Fallow
AP - Annual Plough
MA - Managed Approach
ST - Shallow Tillage
DT - Deep Tillage
Following Winter
Oilseed rape
Following Winter
Spring beans
Continuous
wheat
Following mustard
cover crop
CV - (Yield) 7.4% LSD - (Yield) 0.97t/ha
0
2
4
6
8
10
12
WC -
AP
WC -
MP(S
T)
WC -
ST
WC -
DT
SC - AP
SC - MA(D
T)
SC - ST
SC - DT
CWW
- AP
CWW
- MA(p
loug
h)
CWW
- ST
CWW
- DT
AF - A
P
AF - M
A(DT)
AF - S
T
AF - D
T
Yie
ld (t/ha
)
Stobart –TAG, 2008
No traffic Trafficked
Shallow plough 13 (£5) Shallow plough 32.5 (£13)
Harrow 7.0 Spring tine 16.0
Drill 7.5 Power Harrow 30.0
Roll 7.5 Harrow 8.0
Drill 8.6
Roll 8.4
TOTAL 22 (£9) 71(£30)
After: Chamen, 1992
A 70% reduction
A 60% reduction
Traffic control effects on energy
requirements and costs (kWh/ha) (£/ha*)
*After: Nix 43rd Edition (2013) c £0.25/kWh
at 65% Tractive efficiency (Innes and Kilgour, 1980)
RTF Deep Tillage RTF Shallow Tillage RTF Zero Tillage
LGP Deep Tillage LGP Shallow Tillage LGP Zero Tillage
CTF Deep Tillage CTF Shallow Tillage CTF Zero Tillage
Winter wheat – 29th May 2013
Zero tillage has a problem in wheel marks in all traffic systems
Smith, E.K., Misiewicz, P.A., Chaney,
K., White, D.R., Godwin, R.J. 2013
Tillage system After: Smith et al., 2014
10% lsd = 0.6t/ha
19% (1.39t/ha) increase in yield.
Tillage v Traffic Study
Winter Wheat Yield Combine harvester results
(Estimated)
No-till
Tillage and Traffic Study
Winter Wheat Yield Hand Sample Results
8.97 8.10
10.72
7.69 7.04
4.34
0
2
4
6
8
10
12
Deep Shallow Zero
Yie
ld t
/ha
Untrafficked Wheelways
Untrafficked yields significantly higher than wheelways (p<0.05)
No-till
Draught force and
fuel consumption
After: Arslan et al 2014
Factors effecting
establishment costs
• Farm size.
– Annual cropped area.
• Average tractor size.
– Power availability.
• Labour availability.
– Can tillage be started before harvest is finished
• Local climate. Number of working days
– Weather conditions in autumn.
Cost comparison of alternative tillage
systems (100 kW/130hp tractor)
After: Vozka, 2007
Cost comparison of alternative tillage
systems (225 kW/300hp tractor)
After: Vozka, 2007
Effect of Tractor & Implement Size
The costs/ha of different sizes (102, 162, 224 kW tractors) of alternative
tillage systems are very similar at optimum working areas.
Mouldboard plough £ 80.33/ha £ +2.48/-1.93/ha
Shallow mouldboard plough is £ 68.85/ha £ +2.02/-1.64/ha
Stubble cultivator is £ 42.05/ha £ +2.02/-1.27/ha
Direct drill is £ 20.76/ha £ +0.89/-0.75/ha
Direct drill with herbicide application £ 43.15/ha £ +0.41/-0.53/ha
After: Vozka, 2007
Black Grass Control by Cultivation
102 108 5 27 72 199
Black Grass Ears/m2
All Drilled12th October 25th September
lsd 8.38%, cv =17.8%
1. A plough anywhere in the system reduces black grass numbers.
2. Use good ploughing techniques. Poor ploughing is of little help as it will not bury the weed seeds.
3. Ploughing for a second year brings resistant black grass seeds back to the surface too soon for effective control.
4. Good ploughing followed by 2 years of direct drilling has reduced black grass and increased yields.
5. Continual direct drilling or shallow min till allows black grass numbers to increase. These systems work well if a good stale seedbed is achieved first and the herbicide chemistry works well.
6. With resistance issues, cultivations are having a greater effect on black grass control than current pre and post–emergence chemical options.
Black Grass Control by Cultivation
Mouldboard plough adjustment
http://www.agrii.co.uk/blog/2013/10/24/the-good-ploughing-guide-from-agrii-and-lemken/
• Work deep enough to bury all weed seeds
• Set skimmers to the correct depth
• Fully invert furrow slice
• Use a slatted mouldboard if soil is sticky
• Use a press to close the furrow
• Ensure the line of draft enables the tractor
to pull effectively with the tractor on the
land when ploughing with larger ploughs.
Opportunities, timing and threats
• Opportunities
– Move to min-till (less risk) or no-till (more risk)? Save time and money
– Integrate with CTF/LGP practices
– Improve yield?
– Save energy
– Improve mechanical weed control
• Timing
– Weather and soil condition
– System capacity (labour availability and machine size)
– Alternative cultivation practice (No-till < min-till < conventional tillage)
• Threats
– Weather
– Weeds
– Capitalisation and cash flow
Conclusions
• To lower cost of tillage and save energy:-
–work shallower, wider and faster
–minimise wheelings and avoid soil structural damage at depth
–modified traditional systems can be cost effective for smaller farms (< c. 250 ha)
• Undertake a thorough financial analysis before finally deciding upon
investment in a reduced tillage system
• Consider controlled and low ground pressure traffic
• Do not throw away the plough - you may still need it for weed control!
N.B. Attempt to achieve the desired soil condition with the
minimum amount of energy, time and investment
top related