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

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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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