Steve Townsend rounds up his series exploring the benefits and practicalities of a modern no-till approach
Leading soil husbandry specialist, Steve Townsend of Soil First Farming rounds up his series exploring the benefits and practicalities of a modern no-till approach.Putting it all together
We all recognise that soils are our most precious resource. And, deep down, I suspect even the most diehard of complete cultivators appreciates the need to better manage them for greater resilience in the face of growing arable intensification and an increasingly uncertain climate.
This autumn and the early winter have provided some welcome relief in the tillage department. But let’s not forget how we were feeling this time last year. Or, for that matter, in any of the run of difficult springs, summers and harvests we suffered prior to that.The wholesale move to reduce tillage of the past 15 years has clearly been driven by economic and workload considerations. While these remain important, I have no doubt soil health and resilience are fast becoming far more compelling reasons for change. Nor that the change we need is a change of approach rather than merely cultivation kit.Our over-riding objective has to be soils that are less susceptible to damage and better able to recover from difficult conditions. Soils that drain better on the one hand, hold water better on the other and have a greater machinery carrying capacity in whatever state. All of which demands a much healthier biological, physical and chemical soil structure than we’ve come to accept.This is why I’m such an advocate of reducing tillage to the bare minimum in an approach which combines the most appropriate direct drilling with the most positive whole rotation management of residues and cover as well as cash crops.Less steel
Confining cultivation to the immediate area of soil into which we’re drilling our seed has innumerable advantages. Not least in leaving the remainder of the ground untouched to build-up the healthiest possible structure, courtesy of nature’s ploughmen (worms) and subsoilers (root runs).
As well as keeping cold hard steel well away from these essential soil workers, restricting tillage to the minimum limits the tragic destruction of soil carbon that happens whenever air is injected into the system. In turn, this encourages the build-up of the soil organic matter and bacterial activity crucial to soils with greater water-holding capabilities, more consistent nutrient supply capacities and better drainage abilities.Of course, it’s very effective in controlling problem grass weeds too. By leaving the majority of their seeds soundly asleep in undisturbed soil, the only ones to emerge do so precisely where they face the most intense crop competition.Yes, cultivation is a good way of disrupting the bane of our crop establishment lives – slugs. But then so are firmer soils which reduce the blighters’ mobility and force them to the surface where they’re exposed to predation, not to mention altogether better drained ground and more biologically active crop growing environments.The scourges of persistent slugs and difficult grass weeds can, of course, be dramatically reduced by moving away from wall-to-wall winter cereal and OSR growing.Maintaining a diverse rotation – with no more than 60-75 per cent of our ground in winter cereals, a decent mixture of break crops and at least one spring planting – is another no-till essential.
With the right crop mix it can also work wonders for disease control and significantly improve soil structure and fertility by encouraging greater biological activity and diversity.Direct drilling and wider rotations need to be combined with the most effective management of cover, though. Contrary to the modern obsession many have with ‘neat and tidy’ residue incorporation, this means chopping all our residues, spreading them evenly and keeping them on the surface.
Leaving residues where nature intended is so much better than employing large amounts of time and diesel to mix them into the soil where they hoover-up available N and compromise crop germination and establishment.Surface mulch
Straw and chaff decay better in the open air anyway, allowing them to make the greatest contribution to the organic matter in the rooting zone. There they also act as a surface mulch to conserve moisture in dry weather, reduce the harmful effects of heavy downpours and actively restrict weed seed germination – thanks to the allelopathic chemicals produced by their decay.In achieving the best cover we need to think beyond crop residues. Effective cover cropping is equally important. Hand-in-hand with minimal soil disturbance, cover crops keep essential soil microbial populations thriving. They dry out ground far better than we can ever do mechanically. Their roots are excellent cultivators in their own right. At the same time, they protect the soil surface from both desiccation and deluge, and their residues positively build carbon.Soil health and resilience are fast becoming far more compelling reasons for reducing tillage, rather than simply for economic and workload reasons, says Soil First Farming’s Steve Townsend.Extra carbon
Carbon building is central to every aspect of the no-till approach. Though it doesn’t come in a bag, carbon is our number one soil nutrient. As organic matter or humus, the biological activity centred on soil carbon is crucial in regulating the supply of water, N, P, K, S and all the other key minerals to our crops.In cutting down cultivations we’re reducing the wasteful oxidation of organic matter to CO2 as well as the disruption of the soil microbes that are an essential part of its value. In balancing our rotations we’re creating healthier, more biologically diverse and active soil environments. And in better managing cover and crop residues we’re capturing as much carbon from them as we can to add to our soil store.Organic matter building in this way builds both fertility and resilience into our cropping. To such an extent that, as well as reducing agronomic risk, my no-till clients and I find we can cut nitrogen applications by a good 20 per cent or more after a few years. Healthier soils and crops also mean we have far fewer problems with weeds, pests and diseases.On top of all these benefits, the icing on the no-till cake for us is the very much lower establishment costs we’re incurring – less than six litres of diesel and half an hour of time per hectare compared with 50 litres or more and well over two hours with conventional tillage.Add this to the fertiliser savings we’re making and the lower agrochemical inputs we need as we progressively improve our soil biology, crop productivity and soil and crop resilience and I fail to see what’s stopping everyone taking this approach.Alright, it’s not a simple fix. Changing isn’t without its challenges. And it does require time, persistence and a willingness to replace the equipment-using and machinery-buying strategies of the past with more than a small amount of fresh thinking. But the rewards are out of all proportion with the risks involved. Or, for that matter, with the risks associated with continuing to ignore the need for serious soil improving change.Through this series, I hope I’ve at least persuaded you to see your most important resource a little differently, if not to actively consider what you can do to improve its productivity – and your farm’s – through the combination of less steel, more balance, better cover, extra carbon and lower costs that is the no-till way.Although signing off from his column this month, Steve Townsend is more than happy to discuss any tillage or soil management issues, interests or concerns with Farmers Guide readers at any time by email on [email protected] or by phone on 01452 862696.