Mitigation of NH3 emissions due to cattle slurry fertilisation.

Agriculture is known as the major source of atmospheric ammonia (NH3). The strategies to reduce the emissions of this gas have become an important focus in many countries to prevent environmental issues and to reduce the loss of nutrients and energy from cropping systems. Appropriate slurry application techniques are fundamental strategies to reduce nitrogen losses. This study presents an evaluation of the best agronomical practices for reducing NH3 emissions from cattle slurry spreading on arable lands. Two different application techniques with two incorporation procedures were assessed in four different field trials in the Po Valley. The NH3 concentration measurements were performed using passive samplers, while a dispersion model has been used for estimating NH3 fluxes at field scale. The best abatement strategy from slurry application has proved to be the direct injection into the soil, with a reduction of about 95% with respect to the surface spreading, while a contextual incorporation was able to reduce the emission of more than 85%.