Despite the deluge in autumn 2019, damage to soil is not as serious or widespread as feared, growers reported at a Bayer / Farmers Weekly soil roundtable in late May. Instead, bigger concerns were around rotational planning and cash flow. Here are our 6 key takeaways from the discussion.
After such a wet autumn, the assumption is that there will be lots of soil structure problem at depth, but this doesn’t seem to be the case, according to Hutchinson’s Dick Neale.
“Nationally we have been doing healthy soils assessments for our customers and what we are seeing is not what you may expect. Most of the problems are near the surface in the top 6–7 inches and not at depth.”
Heavy rain started in late September and carried on until the New Year so that it was simply not possible to take a tractor on the field. Although crops didn’t get drilled, no damage was done to the soil which will be beneficial this autumn.
“The rapid onset of heavy rainfall meant that water couldn’t infiltrate as quickly as it fell. Slumping prone soils were particularly badly affected but most soils struggle to take in that quantity of water which simply flowed off the surface. As a result, the top layers were unworkable, drilling stopped, and land wasn’t travelled, and damage not done at depth.”
There is likely to be some damage at depth on headlands or after root crops but the more frequently occurring problems are near the surface which are more straightforward to solve with machinery.
Wet conditions demonstrated the value of drainage to Essex famer David Lord. Fields where drainage is poor or failed were highlighted by the wet autumn. These areas are seeing crop losses in oilseed rape and beans while, winter wheat is struggling in dry conditions due to shallow rooting. Mr Lord stopped fieldwork in October so has avoided doing any major damage to his soils.
“We checked across the farm with the penetrometer and couldn’t find compaction issues except a little on the headland. Differences in crop performance are all linked to drainage quality. The whole season has shown where drainage is good and poor.”
Mr Lord improves drainage annually by mole ploughing heavy land areas every five years and renewing defunct drainage systems. But this year he may not do as much as he would like. “Cash flow is the big concern this autumn, we may have to reduce or skip a year of drainage upgrades. But most land is still in decent good condition, picking the best crop is the difficult part.”
Soil conditions have surprised many people so avoid unnecessary and expensive work at depth if not necessary by properly assessing soils before making any plans. Dry weather may make digging sample pits a bit tricky, but two feet is sufficient to find the main problems. Look for rooting, if there are roots to depth then there is no serious compaction.
“The most badly affected soils tended to have high silt and sand, and low clay. But the biggest factor is how much they were worked in wet conditions. The farmers who persisted despite the rain won’t necessarily have more problems at depth, but the surface is more messed up and will definitely need work in autumn, land which was left until spring may have very few issues,” says Mr Neale.
After a wet autumn, there is likely to be a reaction by some growers for an earlier start to drilling winter cereals. But with many soils likely to need cultivation this could create black-grass problems.
“Deep non-inversion cultivation is likely to be common this autumn because of the soil conditions,” says Bayer’s Darren Adkins. This means seed will be mixed to different depths within the seedbank including some old seed brought back to the surface.
“Usually this means a protracted germination. Drilling early in this context is likely to be a recipe for trouble as it will be difficult and costly to put it right with herbicides and if populations are too high, the potential to lose the whole crop.”
5. Spring crops are great, except the return.
Norfolk farm manager Simon Brock avoided damaging the soil at depth but has seen the financial implications of drilling a much larger area of spring crops.
“We have no problems at depth because we didn’t maul it. By spring the surface had dried, and we could drill spring crops which looked great until the drought. I don’t expect we’ll need to do much more than normal to our soils this autumn.
“I like growing spring crops because it spreads risk, but the margin isn’t there. We have spring wheat, barley, peas and canary seed but when I stopped drilling in autumn, I worked out that we would lose £60k in margin across the 1000ha farm.”
Oilseed rape remains an option this autumn for both farmers but only if conditions are right. Large areas of poorly established oilseed rape are a magnet for pests, so they are intending to drill smaller areas if conditions allow.
“Oilseed rape performance is variable, we avoid the worst of flea beetle, but we find a huge difference between drilling dates,” says Mr Brock. “I plan to reduce my area and make sure it gets drilled when there is moisture so that it properly establishes. Once the crop is up and away, I don’t find it suffers from stem damage so much – that is a problem that really becomes apparent in crops that don’t establish well in my experience.”
Mr Lord agrees and will wait and see if there are good drilling conditions before committing to the crop.
Improving and maintaining soil health is one of the most effective ways to increase returns from cropping. Finding ways to achieve this on your farm can give you a critical advantage in crop establishment, weed control, nutrient and water availability, and more.
Assessing or measuring is a vital cog in the soil management wheel. Here, leading experts answer some key questions on how best to assess soils for improved crop performance.