Why Farmers Should ADOPT Cover Crop Trials and Practices

The UK’s funding mechanisms for supporting innovation in agriculture have repeatedly exposed gaps between agricultural research and real-world application. Farmers looking for financially beneficial and environmentally responsible production systems often hit the buffers when it comes to interpreting complex trials data and results.

So, the latest ADOPT fund (Accelerating Development of Practices and Technologies) was launched last year. In particular an Oakbank/Toby Simpson/Velcourt Cover Crop trial caught my attention. Farmers are often encouraged to use cover crops, yet their full potential is not always fully utilised.

With rising global costs of inorganic fertilisers, increasing focus on water quality through the 25 Year Environment Plan, and the prospect of a future carbon tax, a more detailed investigation into the role and benefits of cover crops is well justified.

Can cover crops cut fertiliser bills?

Cover crops can reduce nitrate leaching losses by up to 90% compared to weedy stubble, found a recent NiCCs study by ADAS.

At the recent ADOPT roadshow meeting, Ana Reynolds from Oakbank gave an outline of the upcoming trials and confirmed some rules of thumb from historic cover crop work:

In UK conditions, cover crops sown in late summer take up around 30-120 kg N/ha by the following spring. Well grown and terminated, they can contribute 30-60kg N/ha to the following crop, with higher amounts possible where management and conditions align.​​​

With nitrogen prices reaching around £1.50/kg, a potential £45-90+ per hectare gross saving is not one that growers should be ignoring. But it's only real if you can actually reduce your applied nitrogen rate.

The ADOPT project is now investigating the potential to reduce fertiliser N inputs following cover crops, and how the reduction should be calculated. It involves multi site field trials across the UK to measure nutrient release under different conditions and validate decision support tools that help farmers predict fertiliser needs. The aim is to improve confidence in using cover crops by generating practical UK specific data, enabling farmers to optimise inputs, improve margins and enhance sustainability.

If nutrient release can be more reliably predicted, we will have greater confidence in optimising inputs, - said Ana at the ADOPT meeting earlier this month, -

Data sets and tools already exist in other countries – and we can benefit from all that work. For example, MERCI is a French decision-support model for predicting nutrient release from cover crops. It was built from more than 25,000 measurements across 74 species! We will now be validating it in UK conditions.

Oakbank, Toby Simpson and Velcourt, in partnership with Defra’s Farming

Innovation Programme and Innovate UK, are using ADOPT funding to take the next practical step in a real UK evidence gap: measuring how much nitrogen cover crops release and how confidently farmers can adjust fertiliser inputs on working farms.

There is an opportunity for growers to join in this ADOPT trial with a more streamlined version on their own demonstration field. A couple of crops sown across the field and two nitrogen rates applied is all it could take to give the project an expanded database of results.

So why should growers adopt these practices? Even after accounting for the cost of cover crop seed, the value extends well beyond simple financial savings. These practices offer a broader range of benefits, including protecting soils from increasingly extreme weather, maintaining living root systems to improve soil structure, reducing erosion, and capturing nutrients that might otherwise be lost and contribute to environmental issues beyond the farm gate.

If you’re interested in registering an interest you can do so here , we’ll keep you up to date with the project and, more importantly, the results!