Soil health at Crediton Monitor Farm


James Lee and his family took on the tenancy of the 305-acre Huxham Farm at Stoke Canon, near Crediton, only 18 months ago but already he’s been getting the best out of the land.

“Looking to the long term, my intention is to look after this land but, at the same time, to farm how I want to farm. There’s a tendency in modern farming of ‘take take take’ and farming for the moment, rather than for the future,” James explains.

“My objective is simple: to farm profitably, effectively and responsibly. We should feel we leave the land in good heart and improve it as best we can.”

James’s philosophy focuses on better grassland management for his beef and duck operations, and improved soil structure across the whole farm. “The light soil on the arable land is very susceptible to damage. By making the most of the muck from our livestock enterprises, we can not only build a well-planned nutrition cycle but also boost soil structure and quality. Coupled with the adoption of a direct drilling system, which we’ve been using in other operations since 2007, we’re hoping to see a huge benefit here.”

He’s also hoping that by sharing his experiences through AHDB’s Monitor Farm programme, he can help other farmers to think differently about their own operations. At the most recent meeting, held in December, he was joined by Philip Wright, an independent soil consultant who’s been working with James to advise on soil structure, and the importance of managing and minimising soil compaction during field operations.

“Soil’s about being far more than a growing substrate,” Philip explained to attendees. “Crops need soils with an adequate supply of air and oxygen for the plant roots, and a good amount of water. To deliver that, we need to maintain the soil’s porosity – in effect, a measure of the soil’s level of compaction. On a well-structured soil, the aim should be for about 50% porosity – an equal number of ‘gaps’ in the soil as there are soil particles.

“But if we start to squeeze those pores shut, for example when soil’s been heavily cultivated or deep loosened when too damp, then we lose a lot of that natural structure. It’s very easy, even on lighter soil, to close up those pores through high pressures and high axle loads.”

Out in the field, in a crop of winter wheat following grass, Philip pointed out that it was difficult to see – on the surface – where the power harrow combination tractor had passed through. Digging a couple of inspection holes – one in the line of the track and one dead-centre – allowed a visual inspection of soil compaction. An even clearer measure came from conducting infiltration tests.

“Although not truly scientific, by recording the amount of time taken for a given amount of water to drain away we can have a measure of the soil’s compaction,” explains Philip. “We recorded a 20-fold reduction in infiltration rate where there’s been traffic.

“With a crop like this, which has established very well, you’re looking at an underlying effect that’s not easy to spot. But if it gets wet, with a reduction in infiltration rate like that you could expect waterlogged soils and the crop start to yellow as its roots stay wet.”

Trafficking vulnerable soils can put pressure on the soil throughout the profile, Philip warned, but there are ways to reduce it. “Tyre pressures are the simplest and most ‘accessible’ option,” he said, citing one example where just a 0.4bar reduction in tractor tyre pressure resulted in a 10-fold increase in infiltration rate.

“It’s really worth making the effort on pressure. It’s such an easy way to make a big difference to crop performance, and it’s easy to get advisory visits from some of the tyre manufacturers to help you find the options best suited to you.

“It’s also important to emphasise that, when it comes to conserving soil structure, prevention is far better than cure. Don’t compact the soil in the first place, rather than trying to alleviate the effects afterwards.”

Even if the benefits to crop and soil structure fail to impress, the potential savings in fuel should sway any doubters. Trials showed that lower tyre pressures during field operations could deliver a £4/ha saving in diesel. That’s because a high-pressure tyre in soft ground creates a deep rut; in moving forward, the tyre is constantly trying to climb out of that rut. It’s effectively going uphill all the time, resulting in the increased fuel consumption.

“We’ve given him confidence to try some of the more radical approaches. Already I’ve seen a change in the soil. There’s more life, more fibre, more spring in it; it’s a heartening result.

“James is a good choice as a Monitor Farmer, because as a contractor as well as a farmer he needs practices that clearly work. I hope the enthusiasm with which he’s adopted them will rub off on the farmers who’ve been following his progress.”

The next Crediton Monitor Farm meeting is on 11 February 2016 at 11am. To attend the meeting, email AHDB Cereals & Oilseeds Regional Manager Philip Dolbear,

Crediton monitor farm


About Author

Leave A Reply