A field experiment with separately tile‐drained plots was used to study the ability of oilseed radish (Rhaphanus sativus L.), as a cover crop sown after harvest of a main crop of cereals or peas, to reduce nitrogen (N) and phosphorus (P) leaching losses from a clay loam in southern Sweden over 6 years. In addition to oilseed radish in pure stand, two cover crop mixtures (hairy vetch (Vicia villosa) and rye (Secale cereale) for 3 years and oilseed radish in mixture with buckwheat (Fagopyrum esculentum) for 2 years) were tested. The cover crop plots (three replicates per treatment) were compared with unplanted plots as a control. Plots cropped with oilseed radish during autumn (August–November) had significantly smaller yearly mean N concentration in drainage water over 5 of 6 years compared with unplanted controls. Mineral N content in the soil profile in autumn was significantly less in oilseed radish plots than for control plots in all years. The cover crop mixtures of hairy vetch and rye or buckwheat and oilseed radish also showed the potential to reduce soil mineral N in autumn and N concentration in drainage water, compared with unplanted controls. The cover crops had no impact on P leaching. In conclusion, oilseed radish has the ability to reduce leaching losses of N, without increasing the risk of P leaching.

中文翻译：

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秋季播种覆盖作物对氮、磷浸出的影响

使用单独的瓷砖排水地块进行田间试验，研究油菜萝卜 (Rhaphanus sativus L.) 作为主要谷物或豌豆作物收获后播种的覆盖作物，以减少氮 (N) 和磷的能力。 P) 6 年来瑞典南部黏壤土的浸出损失。除了纯林中的油籽萝卜外，还测试了两种覆盖作物混合物（毛状紫云英 (Vicia villosa) 和黑麦 (Secale creame) 3 年，油籽萝卜与荞麦 (Fagopyrum esculentum) 混合 2 年）。将覆盖作物地块（每个处理三个重复）与作为对照的未种植地块进行比较。与未种植的对照相比，在秋季（8 月至 11 月）种植油籽萝卜的地块在 6 年中有 5 年的排水中年平均 N 浓度显着降低。在所有年份，油菜萝卜地块秋季土壤剖面中的矿物质氮含量显着低于对照地块。与未种植的对照相比，紫云英和黑麦或荞麦和油籽萝卜的覆盖作物混合物也显示出降低秋季土壤矿物质 N 和排水水中 N 浓度的潜力。覆盖作物对磷浸出没有影响。总之，油菜萝卜能够减少氮的浸出损失，而不会增加磷浸出的风险。覆盖作物对磷浸出没有影响。总之，油菜萝卜能够减少氮的浸出损失，而不会增加磷浸出的风险。覆盖作物对磷浸出没有影响。总之，油菜萝卜能够减少氮的浸出损失，而不会增加磷浸出的风险。