What is green manure?

Green manure.  It’s one of those terms that can lead to inaccurate mental images!  So what exactly is it? Green manure is s a term used to describe a crop which is grown without the intention of being harvested.

Instead, it is incorporated back into the soil to release the stored nutrients it holds.  These crops also help improve soil structure by preventing erosion while they grow and adding organic matter after they are incorporated into the soil.

Crops such as clover, alfalfa, oats or barley can be used for green manure.  All will trap nitrogen and hold it as long as the plant grows, then release it back into the soil once the crop is worked into the ground with tillage.

These “green manure” crops will help the crops planted in the following year, and help improve soil structure for a long time.