Innovative techniques to reduce ammonia and methane emissions from digestate application to field

This study deals with the innovative micro-injection technique, which allows the slurry to be injected at 5 cm deep into the soil with a reduced traction force, a crucial point for the farms. To this purpose, two slurry spreading techniques were compared in laboratory under controlled temperature and humidity conditions: (i) the band spreading application (BS) and (ii) the microinjection application (MI) of a liquid fraction of cow digestate. The slurry spreading was simulated using 6 glass vessels filled by 3770 g of sieved soil at 5 mm, characterized by a waterfilled pore space (WFPS) of 60%. During a monitoring period of 5 days after the slurry application, ammonia and methane emissions were measured. The cumulative ammonia emissions measured for the band spreading and microinjection were 985,2 mgN m-2 and 24,6 mgN m-2, respectively.