Soil is fractally scaled, which means its structure is consistent, regardless of magnification. Bacteria, fungi, plants and soil animals, working unconsciously together, build an immeasurably intricate, endlessly ramifying architecture that, like Dust in a Philip Pullman novel, organises itself spontaneously into coherent worlds. This biological structure helps to explain soil’s resistance to droughts and floods: if it were just a heap of matter, it would be swept away.
It also reveals why soil can break down so quickly when it’s farmed. Under certain conditions, when farmers apply nitrogen fertiliser, the microbes respond by burning through the carbon: in other words, the cement that holds their catacombs together. The pores cave in. The passages collapse. The soil becomes sodden, airless and compacted.
Associated with this, Monbiot speaks with those farmers responding to the challenges of global warming and soil erosion by walking away from fertilisers and annuals and instead returning to nature and perenials. For example, Iain Tolhurst has developed what he calls ‘stockfree organic’, a trial and error method of mixing different plants to maintain the nutrients and soil fertility.
Tolly’s success forces us to consider what fertility means. It’s not just about the amount of nutrients the soil contains. It’s also a function of whether they’re available to plants at the right moments, and safely immobilised when plants don’t need them. In a healthy soil, crops can regulate their relationships with bacteria in the rhizosphere, ensuring that nutrients are unlocked only when they’re required. In other words, fertility is a property of a functioning ecosystem. Farm science has devoted plenty of attention to soil chemistry. But the more we understand, the more important the biology appears to be.
Monbiot also discusses this on the Today In Focus podcast, which includes further elaboration on precision fermentation, the production of protein and fat in breweries from soil bacteria, fed on water, hydrogen, CO2 and minerals.
This reminds me of discussions of permaculture and the act of letting nature do its thing. I guess it also offers the next step.