07.06.2021

Legume-based green manures (LGMs) are crops that are grown with the specific purpose of improving soil quality and consequently the long-term productivity of crops. Although the traditional focus has been on the supply of nitrogen (N) to the system, they have a wide range of potential benefits that include improving soil quality, reducing soil erosion and increasing the biodiversity of farmland. LGMs are a key component of organic farming systems where the use of synthetic N fertilizers is not permitted. However, increases in the cost of inputs, concerns about environmental impacts of intensive use of agrochemicals, and the recently announced measures for the ‘greening’ of the European Common Agricultural Policy have led to renewed interest in the use of LGMs more widely. In Europe, the legumes in LGMs may be annual or perennial plants, grown on their own or more often as part of crop mixtures with a range of other crop types such as grasses or brassicas.