FARMERS in Devon and Cornwall are taking part in a project to help our rivers by cutting plough use when growing maize. 

They are testing to see if a selective approach to tilage can help them grow maize productively, while also reducing costs and environmental impacts, in two field labs with Innovative Farmers. 

According to the Soil Association, maize is typically a plough-dependent crop in the UK, as it needs a fine seed bed to establish and is easily outcompeted in its early growth stage. But heavy ploughing can lead to degraded and compacted soils that risk polluting rivers via run-off. 

Working with the Farm Net Zero project in Cornwall, farmers are trying a field lab testing strip-till approach. This is where the top layer of soil is disturbed in strips, rather than ploughing the entire field. 

And the Soil Association says this approach has not yet negatively impacted yeilds, and it has reduced fuel and machinery costs, and boosted soil health. 

Cornish farmer, Malcolm Barrett, trialled two different types of strip-till drill, which he compared to a control of disc cultivation – a min till technique he had already found to be a better approach for his soils.

He said: “The difference we can see in the soil in the last two years since we started a min till approach is phenomenal. The cattle aren’t poaching the fields, we can drive our machinery across the soil without it sinking, and the number of worms we’ve now got is unbelievable. The first thing you notice when you walk the field is the worm holes, and how the water is being absorbed into the soil instead of sitting on top.

“Where we have seen slight reductions in yield it’s been offset by reducing our establishment costs, and some of the losses are due to where we didn’t get our machinery to line up properly. A lot of this is just about experimenting and learning the best approach to get the best result.

“It’s been a real change in mindset to get off the treadmill. We used to take our soils for granted whereas now I call myself a livestock farmer because there’s livestock that live in the ground and we need to look after them as much as the ones above the ground.”

Andy Gray, a farmer from Devon, is working on a separate field lab also testing strip-till, but while growing a permanent living understory of clover.

He said this practice is commonplace in Switzerland as a method of preventing run-off into rivers resulting from growing maize.

Gray hopes the clover will maintain cover for the soil and roots to anchor it, while feeding the soil biology from October until the maize is established.

Clover was established last year using an interrow drill into growing maize – providing winter soil cover post-harvest – and Gray will then strip-till ahead of precision drilling maize this Spring.

He said: “Maize produces enormous amounts of carbon for soils if you grow it well, but if you’re destroying your soil structure every year then you’re letting all that benefit out again.

“With a living mulch we should be able to get combined soil health benefits through continuous cover and maize’s extraordinary ability to photosynthesis during the summer months.

“I’m determined this approach will work, but it’s a long-term way of thinking to deliver a financially sustainable system. I'm willing to put up with a yield penalty initially if I can see that in the long term I'm building the asset value of my farm – my soil.

“To me it’s a no brainer, we just have to find a way to make it work profitably.”