Growing green manure crops

Growing green manure crops is the key to maintaining soil fertility at Sandhill Farm. A green manure crop is planting a crop to feed the organisms and web of life in the soil: usually, the crop is turned under and incorporated when it is in the flowering stage – at that time, the plants reach their greatest biomass. It is just before seed begins to form, at which time plants use a lot of their own resources and the soil to grow the seed.

We grow at least one green manure crop for every crop that we harvest; sometimes two or three. The photo is of a buckwheat/soybean green manure crop: the soybeans have the large dark green leaves; the buckwheat is flowering. I wish you could hear the sounds – buzzzzzzz – our honey bees love these flowers and the entire field hum. This crop is only 4 weeks old – that’s a lot of biomass we will be incorporating into the soil in a week or two. It will make a lot of soil organisms very happy.

After this crop, we will plant our winter green manure crop – wheat, hairy vetch, oats, & buckwheat. The buckwheat will die with the first frost, the oats will be killed after repeated hard frost – usually Dec-Jan, and the wheat and vetch go dormant in the winter and grow again next spring. The oats and buckwheat put out a lot of biomass in the fall. When they die, the wheat and vetch take over.

Buckwheat – we grow buckwheat as a green manure crop a lot. It is a bio-accumulator – it brings up phosphorus in particular and makes it available to subsequent crops. However, the main reason I grow it is that I find it spiritually uplifting: hearing the bees in it makes my heart sing and seeing acres of bouncing white flowers in the wind is aesthetically pleasing. I feel like it makes the whole farm more happy and joyous.