Management Strategies Can Reduce Nitrous Oxide from Legume Crops and Manure Applications

Penn State University researchers report that management strategies can be used to reduce the nitrous oxide emissions generated when manure is applied to legume cover crops. Legume cover crops and manure applications are both ways to increase the fertility of cropland and are often used in conjunction by organic growers in particular. However, large quantities of carbon and nitrogen in both of these soil amendments can lead to formation of nitrous oxide, an extremely powerful greenhouse gas. This is particularly the case when high levels of fast oxygen consumption in the soil result from the burial of cover crop residues and manure. The scientists suggest removing a portion of legume cover crops’ biomass before applying manure, to control the amount of nitrogen on site.