Using legume-based mixtures to enhance the nitrogen use efficiency and economic viability of cropping systems (Legume LINK)
This is the final report for the Defra funded and ORC-led Legume LINK project, which studied the use of species-rich legume-based leys in relation to fixing the required quantity of nitrogen and performing reliably under varied local environmental conditions, maximising agricultural productivity.
The report explains that while the potential for nitrogen fixation by commonly used grass-clover mixture leys is high, ley establishment can be sub-optimal due to cool, moist conditions required by clover species. There can also be a lack of synchrony between the release of nutrients after incorporation of the green manure and the demands of the following crop. One way to improve the efficiency of a rotational system is to combine several legume species in a mixture, resulting in a more complex residue structure with a better nutrient release profile. The project involved trialling twelve legumes species with a range of growth habits and physical compositions, with four grass species on research sites and farms across the UK. The report explores how mixing different species was shown to help suppress early and late weeds, extend forage availability for key pollinator species, increase productivity over time, and increase the stability of production.
See also 'Fertility Building Leys'.