Just a phenomenal article on soil and farming in the Gaurdian
Some people have responded to these threats by calling for the relocalisation and de-intensification of farming. I understand their concerns. But their vision is mathematically impossible.
Almost single-handedly, through trial and error, Tolly has developed a new and revolutionary model of horticulture. At first it looks like magic. In reality, it’s the result of many years of meticulous experiments.
Two of his innovations appear to be crucial. The first, as he puts it, is to “make the system watertight”: preventing rain from washing through the soil, taking the nutrients with it. What this means is ensuring the land is almost never left bare. Beneath his vegetables grows an understorey of “green manure”, plants that cover the soil. Under the leaves of his pumpkins, I could see thousands of tiny seedlings: the “weeds” he had deliberately sown. When the crops are harvested, the green manure fills the gap and soon becomes a thicket of colour: blue chicory flowers, crimson clover, yellow melilot and trefoil, mauve Phacelia, pink sainfoin.
“There’s green manure under the green manure,” Tolly told me. “As soon as we cut the bigger plants, it comes into flower, and the bees go crazy.”
Some of the plants in his mix put down deep roots that draw nutrients from the subsoil. Every so often, Tolly runs a mower over them, chopping them into a coarse straw. Earthworms pull this down and incorporate it into the ground. “The idea is to let the plants put back at least as much carbon and minerals as we take out.”
Tolly tells me that “the green manure ties up nutrients, fixes nitrogen, adds carbon and enhances the diversity of the soil. The more plant species you sow, the more bacteria and fungi you encourage. Every plant has its own associations. Roots are the glue that holds and builds the soil biology.”
The other crucial innovation is to scatter over the green manure an average of one millimetre a year of chipped and composted wood, produced from his own trees or delivered by a local tree surgeon. This tiny amendment appears to make a massive difference. In the five years after he started adding woodchip, his yields roughly doubled. As Tolly explains: “It isn’t fertiliser; it’s an inoculant that stimulates microbes. The carbon in the wood encourages the bacteria and fungi that bring the soil back to life.” Tolly believes he’s adding enough carbon to help the microbes build the soil, but not so much that they lock up nitrogen, which is what happens if you give them more than they need.
Microbes are ‘unknown unknowns’ despite being vital to all life, says study
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What Tolly appears to be doing is strengthening and diversifying the relationships in the rhizosphere – the plant’s external gut. By keeping roots in the soil, raising the number of plant species and adding just the right amount of carbon, he seems to have encouraged bacteria to build their catacombs in his stony ground, improving the soil’s structure and helping his plants to grow.
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.
https://www.theguardian.com/environment/2022/may/07/secret-world-beneath-our-feet-mind-blowing-key-to-planets-future(I have been into permaculture a long time, but lots of stuff in here i didn't know)
edit: add the land institute website
https://landinstitute.org/our-work/perennial-crops/
