so much for the drought
Wednesday 25th April 2012
Here in Devon the reservoirs are full, the river is topping its banks, our fields are sodden and planting has ground to halt. The crops that are already in the ground are lapping it up, especially the leafy brassicas, but this should be our busiest time for planting. With a current backlog of 250,000 plants, we’ll have a gap when it comes to picking in May and June.
The gardeners among you will appreciate that, at these times, there’s a world of difference between a light sandy soil (‘boy’s land’), an intermediate loam, and a heavy clay (‘man’s land’). Sands are made up of relatively big, widely-spaced particles which allow rain to drain quickly through, and you need far less horsepower to make a fine seed bed. The down side is that they dry out quickly in summer and do not hold on to soluble nutrients. Conventional veg growers with access to irrigation and synthetic fertiliser love them for their predictability and ease of cultivation however. Clay soils have smaller particles which absorb a lot of water and nutrients and give them up slowly to plant roots, making them less prone to drought and potentially very productive if managed well. The problem is that they require lots of power and skill to cultivate effectively; they are unstable when wet (that’s why they smear and stick to your boots) and bake out like bricks when dry. As such, they need to be worked at just the right stage of drying. Loams are somewhere in between, being a mixture of sand, clay and organic matter. They are often the best soils, especially for organic farming where we like some clay to aid fertility.
Over centuries the soil beneath our feet has shaped the agriculture, landscape and wildlife above, so its influence is greater than you might first think. Where you see livestock, lots of grass, small fields and oaks growing, you can be pretty sure there’s clay. Knowing and managing each field according to its type is critical to farming success; right now it would be handy to have a few acres of sand to get out on, but we have an intermediate soil and must wait. On the whole our land is pretty good though, if a little thin and steep. Besides, I have a largely unproven prejudice that balanced intermediate soils grow the tastiest veg, so I’m not complaining.