REGENERATIVE AGRICULTURE

  • Written by Andrew Davis
  • Posted on Apr 30, 2021
  • Articles

Regenerative agriculture has become the latest trend, the husbandry that many farmers, agronomists and policy makers advocate as the way forward.  There is no clear definition, which is an advantage as it is not shackled by strict rules and standards in the way that organic farming is.

The principle is to reverse the trend of soil degradation of the past fifty years and improve soil structure and fertility.  To do that, it is essential to increase the organic matter content and encourage microbial activity.  This will increase carbon sequestration, thus contributing to climate change targets, improve water percolation and retention, thus reducing soil erosion and diffuse pollution, and improve productivity by reducing inputs.

It seems extraordinary that we have been growing crops since hunter gatherers gave way to farmers thousands of year ago and yet we still have such little understanding of soils.  This lack of knowledge has become critical since the Green Revolution fifty years ago when productivity was vastly improved by plant breeding, fertilisers and crop protection chemicals.  This huge increase in yields brought on by artificial means caused changes in the soil chemistry and biology that we are only now beginning to understand.

Ploughing and cultivation is expensive and damages the microbiome by killing earthworms, fungal mycelia and other microorganisms.  Many farmers have experimented with minimum or zero tillage but results have been disappointing for some, even disastrous.  That is because organic matter content is low and soils are compacted.  It is essential to correct this before changing husbandry techniques, far easier to achieve with grazing livestock.  However, it is unrealistic to expect a large-scale reversion to mixed farming, not least to perceptions of greenhouse gas emissions and exhortations to reduce red meat consumption.

The NFU held a recent webinar on regenerative agriculture which I attended.  One of the speakers was Michael, a farmer from Shropshire who adopted the husbandry over six years ago.  His soils were dry with low organic matter so he introduced a sheep flock, broadened his rotation of crops and started to reduce inputs.  He started to see the benefit after three years, productivity and profitability have improved markedly since.

He uses no insecticides or seed dressings and very little fungicide.  Silicon is sprayed on his crops to strengthen cell walls rather than growth regulator.  Cropping now includes leys for the sheep, beans, quinoa and cover crops containing ten different species, on which his lambs are fattened in early spring without any concentrates.  This eating off of the covers enables him to drill spring crops without any cultivation.  Achieving a seedbed after cover crops is a problem especially on heavy soils and, whilst it is possible without livestock, it would be the more difficult if glyphosate were to be banned or withdrawn.  The only way then is to use a crimp roller, preferably combined with a hard frost.

When asked what he meant by applying biology to his crops, Michael answered that there are a number of products available to boost microbial activity in the soil.  85% to 90% of crop nutrition is facilitated by microbes so a lack of organic matter is one reason why average crops yields have risen so little over recent decades.  An estimate by another speaker was that only 50% to 60% of applied nitrate fertiliser is taken up by the crop, leading to leaching and wasted cost.

It is not just the overall volume of the soil microbiome that is critical but the composition, Michael says.  A balance of 50% bacteria to 50% fungi is ideal for the combinable crops he grows.  And yet, most soils have more bacteria, especially when cultivations destroy fungi.  Restoring the balance not only improves crop growth but also weakens problem weeds such as blackgrass and sterile brome making them easier to control.

The beauty of regenerative farming is that it is based on a set of principles, leaving farmers to find their own individual applications.  Maximising the capture of free energy in sunshine and of carbon in the soil is one, as is having ground cover for as much of the year as possible.  A rotation containing regenerative crops such as clover and herb rich leys or pulses helps to improve fertility, whilst raising organic matter and microbial activity in the coil is critical.  One study found that each increase of 1% in organic matter enables the soils to hold 20,000 gallons more water per acre, reducing run-off and the risk of drought.

Companion cropping and growing mixtures of varieties can reduce the impact of pests and diseases, reducing the need for pesticides.  Always trying a natural approach rather than automatically reaching for an artificial response is a key mindset.  Using as little input as possible but as much as is necessary is one way to describe it.

The benefits of this approach are huge but it is not a quick fix.  The more degraded the soil, the longer it takes to get it back into good heart and the investment may be significant.  Adequate grants through the forthcoming Environmental Land Management Scheme will be critical but there is also potential funding from the private sector, carbon and biodiversity offsetting for example.  It is essential to maintain or increase food production in this country or we simply export the problems, but we also need to enhance the environment and encourage wildlife.  Regenerative farming offers an exciting way forward.