Before the recent rain, it was just dry enough to tidy and spread compost on our weed-infested artichoke, cardoon, and rhubarb fields. We have a range of machines that work between the rows, weakening the invasive, perennial (growing back year after year) weeds like couch, creeping buttercup, thistle, and docks. With such strong roots, the weeds can never be completely controlled; our aim is just to weaken them enough to allow the crop to emerge with a competitive advantage in spring, and close canopy and exclude light from the weeds before they can recover. The weeds’ roots also bind the soil and protect it from loss during winter rains.
Watching the machines work up and down the rows in the gentle Devon drizzle, I was concerned about damaging the soil’s structure. The wetter it is, the less stable the soil aggregates: clumps of particles, whose varied shapes create pore-like gaps and allow air and water to move through the soil. Instability increases the risk that violently disturbing the soil will cause this delicate structure to collapse. Without oxygen, soils become anaerobic, sour smelling, and toxic – to our crop roots, and to the mycorrhizal fungi that help them access nutrients and fight disease.
But despite seven years of continuously growing veg, and the machine cultivation associated with that, our soil is remarkably stable and resilient. That is largely thanks to about 20 tonnes per acre per year of mature, well-made compost. (That amounts to about 5kg per m2, or a depth of 15mm, for the gardeners amongst you.)
Unlike fresh manure, compost breaks down slowly in the soil, releasing nutrients over many years. The idea is to feed the soil, rather than feeding the crop directly. I don’t claim to understand exactly how, but after yearly application of compost and careful cultivation, our crops and soils seem to be in perfect harmony. The crops never look over-fed, but always have enough; they fight off disease, develop full flavour, and the soil’s structure is certainly stronger.
This heathen has seen the light. In a late Damascene moment, under the tutelage of Milan, our compost-making head grower, I have renounced manure and converted to compost. And as so often when I renounce the narrow, reductionist approaches that I was taught at college, our farm, soil, crops, and those who eat them are all the better for it.
Our News from the Farm posts come from Riverford. They are the digital versions of the printed letters which go out to customers, every week via Riverford’s veg boxes. Guy Singh-Watson’s weekly newsletters connect people to the farm with refreshingly honest accounts of the trials and tribulations of producing organic food, and the occasional rant about farming, ethical and business issues he feels strongly about.
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