Fertility and Green Manure
We manage three main pillars of fertility in the garden. 1. for the health of the system biological diversity is essential - for this the use of a well-planned crop rotation is very useful. 2. the management of organic materials, wastes and residues. These include animal manures and crop residues - we mainly put these into composting piles and use the mature compost around the garden as and when we need it. 3. The use of cover crops and green manures. These have the well-documented benefit of keeping the soil covered, building organic matter in the soil and feeding the soil microbes and earthworms which feed the following crop.
People often talk about green manures, but the truth is in market gardening they are not used nearly enough. There is a reason for this, as the use of green manures make planning more complicated, and mean a break in cropping, but the benefits are so great that we are dedicated to building green manures and crop covers more into our production. We have a couple of good examples on the go. Before planting our celeriac we grew a mix of clover and oats, which we turned into the soil before planting out the transplants. We have just tried a new technique - which you could call a "living mulch". We planted out our Hokkaido squash a week ago, and this week we cultivated between the rows we sowed lines of Alexandrine clover. As the squash grows the ground between the plants will be covered with nitrogen-fixing clover (instead of weeds we hope!). This keeps the soil fully covered, fertilised and should mean we don't need to do any hoeing - just go and pick the beautiful Hokkaido in October, when the crop is ready.
For more information on green manures check out: https://www.reinsaat.at/shop/EN/green_manure/