At any given time, Chris has 50% of land in cover crops and 50% in kale crops, rotating every two years.
A spring cover crop was sown in May after a winter harvested kale crop. Chris decided not to use any deep cultivations, instead allowing the strong plant roots to do the work. ‘It’s great because I can just leave it. There are a few weeds but the cover crop soon outcompetes them’.
After growing strongly through the summer and providing a flowering haven for bees, Chris decided to further enhance the benefits by leaving the mix to over-winter. He expects the frost susceptible annual clovers to be killed off and die down as a mulch on the surface. The winter hardy red, sweet & alsike clover & ryegrass will survive and grow away strongly in spring.
The next experiment will be to see if strip-till planting into the cover crop in spring 2022 with a kale crop can be successful.
Chris explains: ‘Because you’ve got good structure and a living soil, strip-tilling works so well. You don’t need to work the whole soil surface to get a decent crop. You just need to get the plant into a narrow worked band and nature does the rest.’
‘If we have bare land in autumn we use the Rye & Vetch mix. The forage rye is so vigorous it just takes off, getting to seven feet tall by spring, creating huge biomass, boosting organic matter, while vetch delivers nitrogen for the next crop. Most farmers would take this mix out in March, but this reduces the efficiency of legumes. You need land to warm up to fix nitrogen, so I leave it until early May and sow a kale crop from mid May onwards, this crop benefits from nitrogen fixed in the spring’ explains Chris.
Chris regularly sends his soil to be analysed for nitrogen availability and says the results are amazing. After a two year clover & grass mix, there can be 200-300 kg of available nitrogen.
The cover crops also help with soil permeability. After eighteen months you dig down and there are worms galore. It makes such a difference. One field with higher clay content struggles with surface capping but the permeability created by wormholes and the root biomass give a better quality crop, especially during autumn and winter production.