‘Soils First’ Farm Visits 2016
– Southern Event, 27 June 2016
An all-arable no-till system
David Miller is managing Director of the Wheatsheaf Farming Company near Basingstoke. Faced with plateauing yields and rising costs across the company’s 1600 hectares, in 2010 David, a Nuffield Scholar, began experimenting with cover cropping, introducing different mixtures to improve soils, capture nutrients, and suppress weeds. The results were positive, with organic matter levels rising to 6-8% and the cover crops adding around 100-150kg of nitrogen/hectare into the soil each year. However, David became convinced that the key to improving productivity lay in the biological health of the soil. Concerned by the detrimental effect of cultivation on soil biology, in 2014 the partners in the Wheatsheaf Farming Company switched to a no-till system.
The no-till system has 3 principal goals: (1) minimising soil disturbance; (2) maintaining constant cover with living roots; and (3) increasing crop diversity.
Minimising disturbance. To minimize soil disturbance, the business invested in a Cross Slot drill, which places the seed into horizontal slots that are then re-covered with residues. After harvest the straw is left on the ground and cover crop is drilled immediately into the trash. A Claydon straw rake is occasionally used to disturb trash and help control slugs, which are a real problem across all of the company’s 1600 hectares. The cover crops are sprayed off a few days before drilling.
Maintaining ground cover with living roots. A key focus of the system is to encourage mycorrhizal fungi that form symbiotic relationships with plants, providing them with vital nutrients and water from areas beyond the reach of the plant’s own roots. As mycorrhizae need carbohydrates from plant roots to survive, populations decline rapidly in bare soils. It is therefore important to keep living roots (whether cash crops, cover crops, or catch crops) in the ground at all times. The business has also largely removed oilseed rape (which does not form an association with mycorrhizae) from the rotation, unless it is sown with a companion crop (e.g. berseem clover).
“Select cover crops according to the specific needs of individual fields”
Increased crop diversity. The main crops on the farm are winter wheat and barley (mainly spring-sown). Around 15% of the cropped area goes into spring-sown break crops (beans, peas). Diversity is achieved through cover crops (oil radish, till radish, phacelia) and catch crops (mustard, lupins, sunflowers), which provide a varied diet for soil microbes and help to build structure with their variety of rooting depths. Cover crops are selected according to the specific needs of individual fields and specific objectives: are you trying to build organic matter? Increase root matter? Will you graze the crop? Does it need to be easy to drill into? Do you want the frost to kill it off? These questions help to identify not only the most suitable species, but also the most appropriate variety and management of the cover crop.
Better soil health. The farm has experienced significant improvements in the workability and penetrability of the soils since introducing cover cropping and switching to no-till. The soils fracture very easily and are full of worm and root holes. This has significantly improved infiltration; even after heavy rain there is virtually no capping or erosion, and the soils drain so quickly that they can be travelled almost immediately.
Changes to crop management. The switch to no-till has required changes to several aspects of crop management. First, in the absence of the N mineralisation associated with cultivation, N applications for winter crops are now programmed earlier. Autumn crops will be drilled earlier (from 1st September) next year into warmer soils where there is higher N availability for crop establishment. The farm has moved to more spring cropping this year because a wet end to the harvest last autumn left no time for drilling. Cropping flexibility is key to success. Finally, David is hoping that the benefits from his cover crops in terms of soil nutrients and disease control (particularly take-all) will enable him to get a third wheat in some areas this year.
A steep learning curve. The move to no-till has not been without challenges. In particular, David has found that growing conditions in the early years of transition have varied considerably. Slugs have also been a huge problem, particularly where wet conditions have meant that the Cross Slot has left the seed slot open. In fact, slug damage in some winter OSR required re-drilling with spring cereals in some fields this year.
David emphasized that no-till involves a tough learning curve, with a number of peaks and troughs along the way. Switching to no-till requires a long-term, wholesale commitment; “you need to be convinced that it is the right way to go”, he says.
However, just two years in, the business has already begun to reap the benefits. Aside from the improvements to soil health, diesel consumption on the farm has cropped from 85 litres/hectare to 65 l/ha. He also anticipates that his fertiliser requirements will start to fall after about five years, once the soil biology is fully restored and nutrient cycling becomes more efficient.
Switching to no-till requires a long-term, wholesale commitment; “you need to be convinced that it is the right way to go”.
No-till with livestock
Inspired by the writings of Newman Turner and Allan Savory, in 2013 Tim May, a Nuffield Scholar, began to re-think his all-arable farming system at the Kingsclere estate in Hampshire. Faced with plateauing yields, rising costs, and declining soil quality, he believed a greater focus on soil health and land use diversity was required to secure long term sustainability and profitability. The farm began by switching to a no-till system and extending the rotation to include four year grass clover and herb rich leys. Arable inputs were then reduced, lowering operational costs in order to free up the capital required to re-introduce livestock enterprises. The farm is now home to a flock of 1400 North Country mules mob grazed behind a herd of beef cattle housed on a B&B basis.
“The key is getting the right fungi and bacteria in the soil to help plants access nutrients in the soil”.
At this early stage in restructuring the farm, Tim’s main priority is rebuilding soil health. The key, he says, is getting the right fungi and bacteria in the soil to help plants access nutrients (including magnesium, manganese, and potash) in soil. That said, he does not believe measuring the level of individual elements is a meaningful way of measuring overall soil health. He would rather look at the soil’s ability to sequester carbon, hold water, support biological activity, and capture sunlight. Once your soil is performing all of these functions, you have a healthy system.
The mixed no-till system is built on two core principles: flexibility and diversity.
Flexibility. The system is very adaptable, with stock numbers and crop sales varied according to market prices, availability of grazing, and crop quality. This creates a huge amount of flexibility – a crop with a poor yield or that is unlikely to meet market requirements can simply be used as forage for the sheep or cattle.
Many of the winter sown cereal crops are grazed over the winter by sheep, which are moved onto the field using mobile electric fences and watered from home-made mobile water troughs (see right). This helps tillering, and reduces weed and disease pressure.
In the spring crops are assessed for growth and quality, and are either grazed further, cut for silage, or left to develop for harvesting. Only those left for harvest are sprayed to against pests or disease, helping to reduce cost.
Diversity. The rotation has been extended, with four years of cash crops (spring oats/beans, winter barley/oats, a winter or spring crop, and a spring crop) now followed by four years of grass, clover and herbs. Similar diversity can be found within individual crops. A single field of barley, for example, may include up to varieties in order to try and improve disease resistance. The grass leys include more than 16 species (e.g. plantain, yarrow, chicory), the variety of rooting depths and chemical exudates intended to bring about greater structural improvements and stimulate a wider range of different soil microbes. The farm is also been experimenting with companion cropping. For example, spring beans undersown with red clover saw lower levels of pea/bean weevil damage, was clean of chocolate spot, and suffered almost no aphid damage without any fungicide/pesticides.
More than anything, Tim believes in experimenting to find the system that fits your particular situation. Going forward he is keen to look at ways of working with local partners to stack additional enterprises (e.g. pigs, poultry) into his grazing system.
Partnerships. These are a strong component of Tim’s DNA. In addition to creating new partnerships with beef graziers and shepherds, he is also working with a third party to develop a new outdoor, mobile dairy enterprise.
Whether developing business partnerships or working in partnership with nature, Tim firmly believes that a partnership approach is the best way to reduce risk and create an economically and environmentally resilient business.