Sustainability | Free Full-Text | Evaluating Different Catch Crop Strategies for Closing the Nitrogen Cycle in Cropping Systems—Field Experiments and Modelling


For arable stockless farming techniques, the combination of catch crops (CC) throughout the fallow interval is likely to be a key for closing the nitrogen (N) cycle, lowering N leaching and growing the switch of N to the next crop. Nonetheless, regardless of appreciable analysis efforts, the destiny of N in such built-in techniques stays unclear. To deal with this, a two-year area experiment was carried out in northern Germany with totally different CC, together with frost-tolerant and frost-killed CC. The experiment began following a two-year ryegrass/purple clover ley, which was subsequently sown with a cereal (CE) or a grain legume (area pea, PE). This supplied two contrasting techniques with excessive residual N in autumn. The outcomes confirmed excessive N uptake of the CC, starting from 84 to 136 kg N ha−1 with PE because the pre-crop, and from 33 to 110 kg N ha−1 with CE. All CC lowered N leaching in contrast with the management, a naked fallow over autumn/winter. Of the assorted CC, the frost-killed CC confirmed greater leaching in contrast with the opposite CCs, indicating mineralisation of the CC residue within the later autumn/winter interval. The method based mostly APSIM (Agricultural Manufacturing SIMulator) mannequin was used to simulate N biking for a cereal grain legume rotation, together with a frost-killed and a frost resistant CC. Whereas the mannequin simulated the biomass and the N uptake by the crops, in addition to the discount of N leaching with using CC properly, it under-estimated N leaching from the frost-killed CC. The research confirmed that each one CC have been affective at lowering N leaching, however winter arduous catch crops ought to be most well-liked, as there’s a threat of elevated leaching following the mineralisation of residues from frost-killed CC.

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