Effects of Organic Maize Cropping Systems on Nitrogen Balances and Nitrous Oxide Emissions

Silage maize cultivation is gaining importance in organic farming, and thus its environmental climate impacts. The effects of digestate fertilization combination with different catch crops tillage intensities are investigated a long-term field experiment southern Germany. tested variants (a) after winter rye, plowed, unfertilized (b) fertilized biogas digestate, (c) legume-rich cover crop mixture, mulch seeding, (d) white clover living system, digestate. Over three years (2019 to 2021), yields N balance were analyzed, N2O emissions measured high temporal resolution using the closed chamber method, soil moisture, ammonium, nitrate contents continuously determined. Maize dry matter ranged from 4.2 Mg ha−1 (variant a, 2021) 24.4 t c, 2020) depending on cropping intensity annual weather conditions. Despite relatively nitrogen balances negative or nearly balanced; only 2021 did surplus exceed 100 kg b c) due low yields. In cultivation, N2O-N (1.0 3.2 ha−1) variant (a), very (5.6 19.0 ha−1). sometimes extremely also climatic conditions (high denitrification potential). experimental results show that crops, mulch, reduced silage can reduce emissions, improve increase