Cultivations opportunities, timing and threats. Dick Godwin

Transcription

1 Cultivations opportunities, timing and threats Dick Godwin

2 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

3 What Tillage? Conventional Deep Shallow Minimum tillage Direct drill No-Till Overall disturbance to a shallow depth Considered Reduced tillage Just attempting to plant directly into the soil

4 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

5 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., Disadvantages Crop establishment problems during very wet or very dry spells Weed control problems Cost of herbicides, herbicide resistance Risk of increased N 2 O 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

6 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)

7 Knight et al 2012 Proportion of winter wheat area using alternative establishment methods in England

8 Direct drilling constraints in the UK Soil type - Clays and sands can both be problems Moisture content plasticity Residue levels and condition Weed density

9 Provisional classification for soil suitability for direct drilling of combine harvested crops. 50 sites; 214 site x years After: Cannell et al., 1978.

10 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

11 Likely short and long term trends in converting from tillage to no-tillage Increase Decrease Current position with tillage Time - years After: Carter, 1994

12 Tillage tools

13 Tine geometry and soil disturbance 2 key factors: 1.Rake angle 2.Depth/width ratio After: Godwin, 1974

14 Effect of rake angle on soil forces Implement face Rake angle Direction of travel Soil surface UPWARD DOWNWARD After: Godwin 1974

15 After: Godwin 1974 Effect of implement depth on soil forces

16 Force, kn Effect of speed on soil forces % increase for 2x speed HORIZONTAL 1 VERTICAL After: Wheeler and Godwin, 1996 Speed, km/h

17 Effect of Tillage on Surface Residues RTF Deep RTF Shallow RTF Zero

18 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 Burnt -150mm plough Burnt - 150mm plough +roll mm Disc mm Disc + tines mm plough mm plough + roll mm plough mm plough + roll Cranfield University/ADAS/Ransomes, Simms and Jefferies, 1987

19 Tillage and residue burial Implement Depth % Covered Mouldboard Plough mm Disc mm 30 Disc mm 70 Tandem disc mm 50 Tines 150 mm 25 Sweeps 150 mm 10 Direct drills mm ~5 Source: ASAE/USDA

20 Tillage effects on residues I From: Illinois Agronomy Handbook

21 Implement adjustment clod size distribution and residue levels no discs, 60mm, 150mm, 100mm, plus wings, plus wings, no pack. hard pack. 60mm, 150m, no wings, no pack. 60mm, 100mm, plus wings, no pack.

22 Direct Drill: Disc types

23 Direct Drill: Tine types Fertilizer Seed

24 Problems with earlier (1970 s) disc drills Smeared slot Trapped straw Photographs courtesy of Gordon Spoor

25 Improved disc type drills a. Cross slot seed placement mechanism. b. Location of seed relative to the straw. Disc Press wheel Straw Inverted T share Seeds a. b. Coulter Disc Seed exit point Seeds Straw Straw Seeds Straw c. d. e. c. Uni-drill seed placement mechanism. d. Un-modified seed position. e. Modified seed position. After: Earl and Spoor, 1994.

26 Winged opener Baker Boot Baker, Saxton and Ritchie, 1996

27 Yield (t/ha) Wheat Yields in STAR project 2007 The Arable Group (TAG) Following Winter Oilseed rape WC - AP WC - MP(ST) WC - ST WC - DT Following Winter Spring beans SC - AP SC - MA(DT) SC - ST SC - DT Continuous wheat CWW - AP CWW - MA(plough) CWW - ST CWW - DT Following mustard cover crop AF - AP AF - MA(DT) AF - ST AF - DT WC - Winter Cropping SC - Spring Cropping CWW - Cont. Wheat AF - Alternate Fallow CV - (Yield) 7.4% Stobart TAG, 2008 LSD - (Yield) 0.97t/ha AP - Annual Plough MA - Managed Approach ST - Shallow Tillage DT - Deep Tillage

28 Traffic control effects on energy requirements and costs (kwh/ha) ( /ha*) *After: Nix 43 rd Edition (2013) c 0.25/kWh at 65% Tractive efficiency (Innes and Kilgour, 1980) No traffic Trafficked Shallow plough 13 ( 5) Shallow plough 32.5 ( 13) A 60% reduction 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

29 RTF Deep Tillage RTF Shallow Tillage RTF Zero Tillage LGP Deep Tillage LGP Shallow Tillage LGP Zero Tillage Zero tillage has a problem in wheel marks in all traffic systems CTF Deep Tillage CTF Shallow Tillage CTF Zero Tillage Winter wheat 29 th May 2013 Smith, E.K., Misiewicz, P.A., Chaney, K., White, D.R., Godwin, R.J. 2013

30 Tillage v Traffic Study Winter Wheat Yield Combine harvester results (Estimated) 19% (1.39t/ha) increase in yield. 10% lsd = 0.6t/ha No-till Tillage system After: Smith et al., 2014

31 Yield t/ha Tillage and Traffic Study Winter Wheat Yield Hand Sample Results Deep Shallow No-till Zero Untrafficked Wheelways Untrafficked yields significantly higher than wheelways (p<0.05)

32 Draught force and fuel consumption After: Arslan et al 2014

33 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.

34 After: Vozka, 2007 Cost comparison of alternative tillage systems (100 kw/130hp tractor)

35 After: Vozka, 2007 Cost comparison of alternative tillage systems (225 kw/300hp tractor)

36 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

37 Black Grass Control by Cultivation lsd 8.38%, cv =17.8% Black Grass Ears/m 2 All Drilled12th October 25 th September

38 Black Grass Control by Cultivation 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.

39 Mouldboard plough adjustment 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.

40 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

41 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