Plough, minimal till or direct drill? Establishment method and production efficiency

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1 Plough, minimal till or direct drill? Establishment method and production efficiency S M KNIGHT The Arable Group, Manor Farm, Daglingworth, Cirencester, GL7 7AH Summary Volatile grain prices and expanding farm sizes mean that improving production efficiency is a priority for wheat growers. Choice of establishment method is one opportunity in the production process to make savings. Reduced cultivations for consecutive wheat crops present the greatest challenge, especially in the presence of chopped straw. A four-year HGCA-funded project was undertaken between 1998 and 2002 to examine the effects of lower-cost establishment combined with minimum pass husbandry on production efficiency of consecutive wheat crops. Three establishment methods (plough/press, disc/press and direct sown) were compared over a 3-4 year period on different soil types. On the light chalkland, minimal tillage produced the highest yields. On the medium loam, differences were small except in On the heavy clay loam, yield effects varied with season. Production costs per tonne of wheat increased as the project progressed, especially following the wet autumn of In the first year, direct sowing was the cheapest option at all locations, but this was not sustainable on the heavy soil due to low plant populations and grass weeds. On the light soil, minimal tillage had the lowest costs per tonne when averaged over three years. Margins per hectare varied with season and according to the grain price. On the heavy soil in particular, the need for a flexible approach to method of establishment was clear. A minimum pass approach to husbandry of the crop did not necessarily compromise the effectiveness of non-inversion techniques, although there were interactions between establishment method and pass strategy. Energy costs per hectare were minimised, and work rates maximised, by opting for direct sowing. However with inputs accounting for most of the total energy used, minimal tillage resulted in the lowest costs per tonne. Introduction With grain prices falling to as low as 50/tonne during harvest 2002, the incentive for achieving major improvements in production efficiency for wheat is clear. Reductions in variable inputs alone are unlikely to achieve savings of sufficient magnitude, and therefore other costs must also be addressed. As average arable farm sizes continue to increase, and with winter wheat ever more dominant in the rotation, the need to save time can be as important as the need to save money. 12.1

2 For winter wheat, opportunities to reduce the unit cost (whether measured in money, time or energy) per tonne of output exist at various stages: Planning stage where to grow wheat on the farm Establishment stage choice of method used Emergence to harvest husbandry system adopted. Changes in the Common Agricultural Policy under Mid Term Review, and in particular the proposal to decouple support payments from production, should provide an opportunity for growers to focus on producing wheat on their farms only in those fields, or even parts of fields, where yield potential is good and the efficiency of field operations is high (Orson et al., 2003). Savings made during the crop establishment phase are a vital part of cost reduction, and on many units this is one of the main factors restricting further expansion of the production area. However, establishment shortcomings can be particularly damaging, as they will affect the crop for the rest of the season, and may limit its potential from day one. First wheats following a break undoubtedly offer the easiest opportunities to make savings. Trash management is usually less of a problem, although a current HGCA-funded project (no. 2799) is investigating how best to deal with this in both first and second wheat non-inversion situations. In most (but not all) cases there is less need to bury grass weed seeds. However, second and subsequent wheats present a greater challenge on most farms. HGCA-funded work conducted by Arable Research Centres in the mid 1990s showed that the number of passes needed to apply fertiliser and crop protection inputs to winter wheat can be decreased, without reducing profitability (Poole, 1998). Having opted for a lower-cost establishment technique, this then raises the question of what impact this might have on the success of a minimum pass approach to the application of inputs. A 4-year HGCA-funded project (Knight, 2003) was undertaken by Arable Research Centres between 1998 and 2002, which set out to examine the effects of combining lower-cost establishment methods with minimum pass husbandry, in a consecutive wheat crop situation and in the presence of chopped straw. A key objective was to study the longer-term effects of establishment, so the trials were conducted in the same place for the duration of the project. In addition to examining yield and production costs, a further objective was to evaluate the energy requirements of the various systems, and to study their impact on weed populations, disease incidence and soil nitrogen status as the project progressed, as these could all affect the sustainability of the approaches. This paper is based on the findings of that project. 12.2

3 Methods Replicated large-block winter wheat field trials were established at three locations: Andover (light chalkland), Cirencester (medium loam) and Biggleswade (heavy clay loam), starting in autumn 1998 and continuing in the same place for three seasons. Cropping began with second wheats, progressing to third and fourth. The wet autumn of 2000 severely affected yields at all sites in the third season. In each case Consort was sown at 350 seeds/m 2 in early October, apart from Biggleswade when the wet autumn of 2000 forced a change to spring wheat. The variables examined were: Establishment method: plough / press, heavy disc / press, or direct sown, all sown with a disc cultivation drill. Straw from the previous wheat crop was chopped. Slug pellets were added to the seed, and a pre-sowing glyphosate herbicide was applied. The use of a take-all seed treatment (silthiofam). Number of input passes: two minimum pass strategies were compared with a standard system, for application of all crop protection and nitrogen fertiliser inputs. The exact numbers of passes in each trial varied according to season, but the core inputs were as shown. All pass systems received the same total amount of nitrogen fertiliser. Additional inputs could be included at each of the spray timings without constituting an extra pass. It was therefore only the number of passes that was limited. Core Inputs Applied min pass 3 min pass 4 control 7 Autumn herbicide + insecticide yes yes yes First nitrogen dose in early March no yes yes Main nitrogen dose in early April yes yes yes Early plant growth regulator at GS30-31 no no yes T1 fungicide at GS32 no no yes T2 fungicide at GS39 yes yes yes T3 fungicide at GS65 no no yes The combination of establishment method, seed treatment and number of passes gave eighteen treatments in total. However, for this discussion the effects of seed treatment have been excluded, and only the effects of establishment method and its interaction with husbandry system (minimum 3 pass compared to standard 7 pass) are considered. At the two sites where trials were extended into a fourth season, only the impact of establishment method on yield is reported here. Grain yields were recorded using a plot combine fitted with a weighing system. Standard costs for cultivations (plough/press 40/ha, disc/press 25/ha), drilling (direct 30/ha, cultivated 25/ha, roll 10/ha) and application passes ( 7.50/ha), and average input prices, have been used to calculate the production costs and margins for each treatment. Harvesting, storage, finance and land rental costs, and area payments have not been included. Tractor forward speed and horsepower, and implement width, were recorded to allow work rates and energy requirements to be calculated. 12.3

4 Yield (t/ha) Effect of establishment method on winter wheat grain yield The effect of establishment method on yield varied between locations. Minimal tillage gave the highest yield in all years on the chalk soil. On the medium loam differences were small, with the exception of 2000/01 when yield was higher after ploughing than after direct sowing. On the clay soil, direct sowing was lower yielding than minimal tillage or ploughing in all but the first season, when there were no differences. Despite poor yields in 2001, in the fourth season at Andover and Cirencester all establishment methods produced yields that were similar to or better than 1999/ Direct Min till Plough 1998/ / / /02 Andover, light chalkland soil. LSD 5%: 0.56 (99), 0.65 (00), 0.74 (01), 0.27 (02) Yield 7.0 (t/ha) Direct Min till Plough 1998/ / / /02 Cirencester, medium loam soil. LSD 5%: 0.73 (99), 0.78 (00), 0.79 (01), 0.35 (02) Yield 6.0 (t/ha) Direct Min till Plough 1998/ / /01 Biggleswade, heavy chalky clay loam. LSD 5%: 0.83 (99), 1.21 (00), 1.03 (01) 12.4

5 Effect of establishment method on winter wheat production costs In all cases, production costs per tonne of wheat increased as the project progressed. This was due to a combination of falling yields and rising input costs with successive wheat crops. The large cost increases observed in the third season at Biggleswade and at Andover were mainly due to the very low yields obtained following autumn Andover Wheat Production Costs ( /t) Establishment 2 nd Wheat 3 rd Wheat 4 th Wheat 2 nd -3 rd 2 nd -4 th Method 1998/ / /01 Wheat Wheat Direct sown Minimal tillage Plough and press Cirencester Wheat Production Costs ( /t) Establishment 2 nd Wheat 3 rd Wheat 4 th Wheat 2 nd -3 rd 2 nd -4 th Method 1998/ / /01 Wheat Wheat Direct sown Minimal tillage Plough and press Biggleswade Wheat Production Costs ( /t) Establishment 2 nd Wheat 3 rd Wheat 4 th Wheat 2 nd -3 rd 2 nd -4 th Method 1998/ / /01 Wheat Wheat Direct sown Minimal tillage Plough and press Minimal tillage resulted in the lowest production costs per tonne at Andover, when averaged over the three years. Direct sowing was marginally lower in the first season, but considerably higher in 2000/01, giving a similar three-year average to ploughing. At Cirencester, direct sowing resulted in the lowest production costs per tonne in the first two seasons, but had the highest costs in the third. Over three years, differences between establishment methods were small, but direct was marginally the lowest. As at the other locations, direct sowing resulted in the lowest production costs per tonne in the first year at Biggleswade, although differences between methods were small. However, the costs for direct sowing more or less doubled in subsequent seasons. In the second season, minimal tillage resulted in the lowest costs, and in the third season ploughing. When averaged over three years, differences between ploughing and minimal tillage were small, with direct sowing considerably higher, but if the third year is excluded minimal tillage had a clear advantage. 12.5

6 Effect of establishment method on winter wheat margin Whilst achieving the lowest cost per tonne is a key indicator of production efficiency, it does not necessarily represent the most profitable scenario. Margins per hectare for each establishment method are shown in the following tables, using wheat prices of 60, 80 and 100/t, for the first year only (second wheat), first and second, or the mean of all three years (second through to fourth wheat sequence). Andover Wheat Margin ( /ha) Establishment 2 nd Wheat 2 nd -3 rd Wheat 2 nd -4 th Wheat Method Direct sown Minimal tillage Plough and press Cirencester Wheat Margin ( /ha) Establishment 2 nd Wheat 2 nd -3 rd Wheat 2 nd -4 th Wheat Method Direct sown Minimal tillage Plough and press Biggleswade Wheat Margin ( /ha) Establishment 2 nd Wheat 2 nd -3 rd Wheat 2 nd -4 th Wheat Method Direct sown Minimal tillage Plough and press Highest margins were obtained in the first year at all three locations. In the third season (fourth wheat), margins were in many cases negative with grain priced at 60/t, although only a couple were negative with grain at 100/t. On the chalk soil, minimal tillage produced the highest margins in all three seasons, regardless of the grain price. This was despite a fractionally lower production cost per tonne with direct sowing in the first year. At Cirencester, direct sowing produced the highest margins in all but the final season, but still gave the top three-year average. On the clay loam, margin rankings were influenced by grain price. For example, when averaged over two years, ploughing and direct sowing produced similar margins with a wheat price of 60/t, but ploughing was 30/ha higher with wheat at 100/t. The only situations where ploughing produced the highest margins (regardless of grain price) were at Cirencester and Biggleswade in the 2000/01 seasons. 12.6

7 Effect of husbandry strategy on second wheat production costs and margin Whilst reducing establishment costs is clearly an important objective, it may not be considered to have improved production efficiency if a higher level of husbandry input is then required to achieve similar yields. The following graphs show the impact of the husbandry system adopted, here comparing just 3 passes through the crop (minimum) with 7 passes (standard), for each of the establishment methods, in the first year of the project (second wheat situation) Cost ( /t) Margin ( /ha) Andover, light chalkland soil Cost ( /t) Margin ( /ha) Cirencester, medium loam soil Cost ( /t) Margin ( /ha) Biggleswade, heavy clay loam 12.7

8 In all cases, minimum pass husbandry resulted in lower production costs per tonne of wheat, although the differences were sometimes relatively small (following minimal tillage at Cirencester or direct sowing at Biggleswade). However, minimum pass did not always give a higher margin. At Andover differences were small regardless of the establishment method. At Cirencester, minimal tillage and ploughing resulted in a penalty from minimum pass, whereas direct sowing did not. At Biggleswade, the very opposite was true. Effect of establishment method on energy usage Financial costs are not the only measure of production efficiency. The amount of energy consumed, directly or indirectly, during establishment and then during the spring husbandry period, could also be considered. Energy Costs per hectare (MJ/ha) Energy Costs per tonne (MJ/t) Total Energy Total Energy Establishment Min-pass Std-pass Establishment Min-pass Std-pass Andover Direct Min till Plough Cirencester Direct Min till Plough Biggleswade Direct Min till Plough Analysis conducted by Long Ashton Research Station Ploughing had the highest establishment energy cost, and direct sowing the lowest, at all locations. The difference was greatest on the heavy soil at Biggleswade, due to greater power requirement and slower forward speed when ploughing, and pressing as a separate operation. When total energy costs are included, relative differences between establishment methods were much smaller, although ploughing still had the highest cost per hectare. Yield differences had a substantial impact on total energy costs per tonne of grain. Averaged over the three years, in all but one case (when followed by the standard pass system at Cirencester) minimal tillage resulted in the lowest costs per tonne. At Biggleswade, the total energy costs were higher for direct sowing than for ploughing, due to the low yields obtained in the second and third years. 12.8

9 Effect of establishment method on work rate The work rate achieved for each establishment method will clearly depend on the size of the equipment used, the ground conditions and the area of the field. In this project ploughing and pressing was the slowest operation (as it would be on farm), but the advantage to drilling only was exaggerated by the short cultivation lengths (80m). Establishment Rates of Work (hectares per hour) Operation Typical farm* Andover Cirencester Biggleswade Plough/press ** Disc/press Drilling * Source: Nix (2003) Premium rates of work ** Ploughing and pressing carried out as separate operations at Biggleswade Conclusions Ideally, improvements to the production efficiency of winter wheat on a farm would be achieved through a combination of increased yield, and reduced financial, time and energy costs. However, as long as yield is not reduced, costs savings would be justified. In this project, for a consecutive wheat crop situation over three or four years, the only situation where ploughing resulted in a higher yield than non-inversion establishment was after the wet autumn of 2000, which not only reduced overall yields but also heavily penalised direct sowing. Crucially, at the two locations where the trials continued into the following season, there was once again no yield advantage to ploughing, indicating that the problem in 2000/01 was not the beginning of a general decline in non-inversion performance. It does, however, reinforce the need to retain flexibility in method of establishment, especially on heavier soil types with a high grass weed burden. In order to produce wheat at least cost per tonne, the most appropriate establishment method in the first season (second wheat) was direct sowing at all locations. The actual difference in cost ranged from 4 to 7 per tonne. At Cirencester a similar advantage to direct sowing was obtained in the second year. However this was not sustainable in subsequent years on the heavy land at Biggleswade, and minimal tillage also proved to be more consistent on the chalkland soil. Margins per hectare showed a similar pattern to cost per tonne, but due to the large variations in performance at Biggleswade, the ranking order of margins is very dependent on the season and grain price. This again emphasises the need for flexibility. As neither autumn weather conditions nor grain price can be predicted with any certainty when the decision to plough or disc has to be made, and with the need to consider opportunities for out-of-crop grass weed control on most heavy soils, minimal tillage is likely to represent the best compromise. Minimum pass husbandry is clearly a means of achieving lower production costs per tonne, although this does not necessarily mean an increase in margin per hectare. In the second wheat situations reported here, choice of establishment method did affect which husbandry strategy was the most profitable. However it was not simply a case of savings at establishment leading to more input passes being required. There was 12.9

10 evidence throughout the project that levels of take-all, eyespot and Septoria tritici were either the same or lower following non-inversion than after ploughing. The same was true of broad-leaved weed populations. Grass weeds were an exception, and rising levels of brome combined with a lower plant population are the main reasons why the minimum pass strategy was less effective after direct sowing at Biggleswade. The amount of energy used for cultivation and drilling is a relatively small proportion of the total amount consumed from sowing until harvest. The potential to reduce energy costs per hectare by direct sowing is clear. However where yields were reduced by non-inversion, costs per tonne were increased, as the biggest proportion of energy used (for inputs and their application) was then less productive. It is also worth remembering that, even at typical work rates on farm, direct sowing should take only half the time of minimal tillage, or one third the time of a plough-based system. Non-inversion establishment can often result in more efficient production of wheat, even in a consecutive cereal situation. However under adverse conditions yields may be compromised, so flexibility is crucial. Achieving production costs of 30/t or less (before land rent and harvesting) would be a pyrrhic victory if yields were halved. Acknowledgements The author would like to thank the following for their contributions to the 54 month project upon which this paper is based: Vic Jordan, Jo Hutcheon and Alex Nichols, formerly of IACR Long Ashton Research Station, Vaderstad Ltd, Monsanto UK Ltd, the three host farmers at the Andover, Biggleswade and Cirencester locations, and finally colleagues past and present. The project was funded by a grant from HGCA. References HGCA Project No Trash distribution and cultivation depth in minimal tillage and direct establishment systems. August January In progress. Knight SM (2003). Effects of establishment technique and number of management passes on winter wheat production costs. HGCA Project Report No Home- Grown Cereals Authority, London. Orson JH; Lemaitre G; Hanus D (2003). Increasing the cost competitiveness of wheat production in Northern Europe. Proceedings of the BCPC International Congress: Crop Science and Technology, 1, Poole NF (1998). Comparison of winter wheat Profitability using 3-pass, 5-pass and 7-pass production systems. HGCA Project Report No Home-Grown Cereals Authority, London