Utilization of nitrogen in legume-based mobile green manures stored as compost or silage

Summary

The utilization of nitrogen (N) in green manure leys can be improved by harvesting, storage and spreading of the plant material as manure in other crops. By green manure storage as silage, storage losses of N are lower than by composting. Also, a relatively high fertilizer value of silage N is achievable depending on the C/N ratio of the material. Nitrogen availability in green manure leys is higher after storage as silage compared to composting. Use of mobile green manures is mainly relevant in arable cropping systems without livestock where utilization of the roughage for animal feed or biogas production is impossible, as costs for ley/roughage harvest and transport can be relatively high. Our study showed that surface application of green manure silage to growing crops can damage plants and is therefore not recommended, whereas incorporation of silage before sowing has significant positive effects on crop yields.