N2O Emissions As Response of Process-Related Soil Microbial Activity to Different Irrigation and Nitrogen Fertilization Regimes in Potato Cropping

Agricultural soils are one of the main sources of N2O emissions. The objective of the proposed project is to reveal the complex microbial-mediated processes behind N2O emissions – i.e. composition, distribution and especially activity of the soil-inhabiting microbial community – depending on different irrigation-fertilization regimes. Irrigation technologies and N fertilization regimes influence the spatial and temporal distribution of water and N in the soil and are hence expected to affect N2O producing microbial populations. The project combines agronomic and microbial investigations and N2O emissions measurements in a field experiment with a potato cropping system under sprinkling, drip irrigation, fertigation and non-irrigation. Cumulative area- and product-related N2O emissions and the major physical, chemical and biological factors are determined to derive appropriate management strategies.