In defence of the plough

An interesting article on soil health and tech just popped up on BBC News. A great introduction to issues around soil health, it covers quite a bit around the emergence of new technology and how it can help keep soils healthy.

A tractor ploughing a field
Establishing surface-sown winter beans with a plough and furrow press

The article maligns the plough, but it’s still an important part of the toolkit for many farms, particularly organic farms.

In 2020 at Deepdale Farm we enthusiastically adopted the regenerative practice of minimising tillage, and very nearly sold the plough, opting instead to cultivate with disc harrows to establish crops – disc harrows chop the soil up but don’t turn it over (non-inversion tillage). This despite converting to organic status from August 2020 and getting rid of glyphosate.

An experienced organic farmer who came to do some contracting work establishing vetch and clover leys in late 2020 said, “you’re going to have to plough”. Yeah yeah, we thought. It’s OK. We’re regenerative.

Harvest in 2021 was a mess, with wheat in the barley crop, rye and other cover crop volunteers in the wheat crop, and marestail infesting the spring beans. Harriet described 2021 as our ‘wonky pancake’ year. First one out of the pan, looked a mess, didn’t taste bad but you wouldn’t give it to anyone else.

We had unquestioningly adopted the regenerative mantra of minimising soil disturbance without thinking through what the ramifications would be in an organic system. That and, truthfully, we didn’t know what we were doing.

A field of barley with a lot of weeds in it
Barley established without ploughing
A field of barley
Barley drilled after ploughing

We learned our lesson, and established spring crops in 2022 by ploughing – turning the soil over was the only option to terminate clover leys and cover crops, and bury weed seeds, leaving a clean soil surface (and burying organic matter to feed the crop and soil biology). Harvesting in 2022 was easier, with clean crops that provided excellent samples. Not just because we ploughed, but our barley yield per hectare in 2022 was up 73%.

Ploughing remains a part of the toolkit at Deepdale for the time being, but it’s done no deeper than necessary, down to 5-6 inches, and done only when necessary to establish a cash crop – our last multi-species leys and winter cover crops were direct drilled into the stubble of the previous crop.

A multi-species ley direct drilled into crop stubble
A multi-species ley direct drilled into crop stubble

Healthy, biologically active soil can better tolerate and ‘buffer’ the effects of occasional ploughing than soil that has been cultivated more often than necessary and has been dosed with chemicals rather than mulched with cover crops and manures. A 2007 study suggests that the additional organic matter and manures added as part of an organic farming system more than offset soil organic matter losses from ploughing.

Ploughing isn’t the only option to establish crops in an organic system, and farmers are finding new ways to grow crops without the use of the plough. Farmers in low-input and organic systems are developing no-till with living mulches and pasture cropping, where crops are grown through clover and herbal leys or in rows between them. This involves more than just adopting new tech, it is an approach that requires planning and a change of methodology as well as new tools. Regenerative organic is gaining traction.

At Deepdale Farm tools like pasture cropping could easily be adopted in the future, but I always felt coming through organic conversion and changing the way we farmed, with limited experience, that we couldn’t run before we could walk.

Sweeping generalisations about soil health are hard to make. There is no ‘silver bullet solution’ for soil health and there is no short cut for building soil carbon.

Soil Association – To plough or not to plough

The plough is not the only reason for the deterioration in soil health on farms, but it makes a good fall guy. The arable soils on Deepdale Farm were in very poor shape when I started working on the farm but this wasn’t just excessive tillage (though that was a factor, with fields being cultivated for weed control even when left fallow). It was also a lack of organic matter being added, no manures, no cover cropping and a heavy reliance on artificial inputs. The plough is a big scary lump of metal invading the soil and ripping everything up, so is a good symbol for what is more likely to be the systematic neglect of soil.

An agricultural robot on a field of barley stubble in front of a bale of straw
An agricultural robot being tested at Deepdale Farm

The BBC article flags new technologies that could all play a part in improving and conserving soils in the future. I’m here for it all. I’ve always been an early adopter of tech and find it exciting to try new stuff. Indeed for the past year at Deepdale Farm, we’ve been working with robotics company Antobot and Loughborough University to test emerging agritech.

But it’s not out with the old and in with the new, it’s just that there is a bigger toolkit available all the time to improve and maintain soil health; the final point that the BBC article fortunately also makes. Nurturing soil health comes from a whole-system approach. Knowledge transfer, mindset, finances, time and context all also have a part to play – without also considering those things, all the tech in the world won’t help that much.

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