Evaluating Different Catch Crop Strategies for Closing the Nitrogen Cycle in Cropping Systems—Field Experiments and Modelling

For arable stockless farming systems, the integration of catch crops (CC) during fallow period might be a key for closing nitrogen (N) cycle, reducing N leaching and increasing transfer to subsequent crop. However, despite considerable research efforts, fate in such integrated systems remains unclear. To address this, two-year field experiment was carried out northern Germany with different CC, including frost-tolerant frost-killed CC. The started following ryegrass/red clover ley, which subsequently sown cereal (CE) or grain legume (field pea, PE). This provided two contrasting high residual autumn. results showed uptake ranging from 84 136 kg ha?1 PE as pre-crop, 33 110 CE. All CC reduced compared control, bare over autumn/winter. Of various higher other CCs, indicating mineralisation residue later autumn/winter period. process based APSIM (Agricultural Production SIMulator) model used simulate cycling rotation, frost resistant While simulated biomass by crops, well reduction use well, it under-estimated study that all were affective at leaching, but winter hard should preferred, there is risk increased residues