Green manure crops: are they worth it?

摘要

Field trials by a farming group in north-west Victoria have shown that while growing green-manure crops can significantly increase the yields of following cereal crops, there is some doubt about the economic worth of the practice. The Birchip Cropping Group has conducted extensive trials at Marnoo, Charlton, Glenloth and Birchip to identify the benefits of green manuring (see tables). They have found the return of legume crop residues to the soil can fix large amounts of nitrogen, while canola and mustard residues can have a beneficial biofumigation effect.