Including hairy vetch (Vicia villosa Roth.) in a crop sequence before maize (Zea mays L.) can enhance the cash crop grain yield and reduce nitrogen (N) fertilizer needs, though the effects are inconsistent. This study aimed to identify the variables influencing maize grain yield response to hairy vetch as a preceding cover crop and N fertilization in maize following hairy vetch. We conducted 70 experiments evaluating four treatments resulting from the inclusion (or not) of hairy vetch previous to maize with and without subsequent N fertilization. Our findings revealed significant (p<0.05) positive response of maize to hairy vetch in 21 % of the experiments (average increase of 2.79 t ha−1) and yield reductions in 13 % (average decrease of −2.02 t ha−1). The magnitude of this response was explained by the N-limited yield index (ratio between N-fertilized and non-N fertilized maize yield), N contribution from vetch, water balance of the whole sequence, and management practices of both crops (e.g., sowing dates and hairy vetch cycle length). Maize grain yield following hairy vetch showed positive response to N application in 27 % of the experiments (average of 2.68 t ha−1). Positive responses to N fertilization were evident in environments with a high N-limited yield index, low N contribution from hairy vetch, favorable water availability, and low soil organic matter concentration. These findings provide valuable insights for producers seeking to optimize the use of hairy vetch to reduce reliance on synthetic fertilizers on succeeding maize crop, ultimately contributing to more sustainable and diversified cropping systems.

中文翻译：

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了解大紫云英对玉米产量的影响及其对氮肥施用的反应的新见解


在玉米 （Zea mays L.） 之前的作物序列中加入毛茸茸 （Vicia villosa Roth.） 可以提高经济作物的产量并减少氮 （N） 肥料的需求，尽管效果并不一致。本研究旨在确定影响玉米籽粒产量对毛茸茸作为前一季覆盖作物和大紫云英后玉米氮肥反应的变量。我们进行了 70 个实验，评估了在玉米之前加入（或不加入）毛豌豆的 4 个处理，有和没有随后的氮肥。我们的研究结果显示，在 21% 的试验中，玉米对大紫云英的显著 （p<0.05） 积极反应（平均增加 2.79 t ha-1）和 13% 的产量减少（平均减少 -2.02 t ha-1）。这种反应的大小可以通过 N 限制产量指数（N-施肥和非 N 施肥玉米产量之间的比率）、紫云英的氮贡献、整个序列的水分平衡以及两种作物的管理做法（例如，播种日期和毛茸茸的紫云英周期长度）来解释。在 27% 的实验中，毛豌云英后的玉米籽粒产量对施氮表现出积极反应（平均 2.68 t ha-1）。在氮限制产量指数高、茱萸花氮贡献低、水可用性好和土壤有机质浓度低的环境中，对氮肥施用的积极反应是明显的。这些发现为寻求优化大紫云英使用以减少后续玉米作物对合成肥料的依赖的生产者提供了宝贵的见解，最终有助于实现更可持续和多样化的种植系统。