Reduced Potential for Nitrogen Loss in Cover Crop-Soybean Relay Systems in a Cold Climate.
Reduced Potential for Nitrogen Loss in Cover Crop-Soybean Relay Systems in a Cold Climate.
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寒冷气候下覆盖作物-大豆中继系统氮损失的可能性降低。
DOI：
10.2134/jeq2018.09.0350
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发表时间：
2019
影响因子：
2.4
通讯作者：
D. Wyse
中科院分区：
文献类型：
--
作者：
S. Weyers;Matthew D. Thom;F. Forcella;Carrie Eberle;Heather L. Matthees;R. Gesch;Matthew A. Ott;G. Feyereisen;J. Strock;D. Wyse
冬季覆盖作物可能会减少中西部地区因淋溶造成的养分损失。新的含油籽经济覆盖作物，如冬亚麻荠 (L.) 和矮芥菜 (L.)，可能会提供所需的激励。然而，这些作物吸收不稳定土壤养分的能力尚不清楚。为了解决这一未知问题，在春小麦 (L.) 茬中建立的覆盖作物和休耕处理中，测量了地上部生物量中的氮、土壤中植物有效氮和磷、以及从放置在 30、60 和 100 厘米处的蒸渗仪收集的土壤水中的 NO-N 和可溶性活性磷，并进行了覆盖作物-大豆 [(L.) Merr.] 轮作。将五种免耕覆盖处理（饲草萝卜 [ L.]、冬黑麦 [ L.]、田芥菜和冬亚麻荠）与两种休耕处理（凿耕和免耕）进行比较。黄豆和冬亚麻荠在大豆套播后成熟时收获。冬季黑麦和萝卜在秋芽生物量中固存了更多的氮，范围为 26 至 38 千克氮/公顷，但越冬油籽的氮吸收量与春季的氮吸收量相当或超过，在大豆种植前为 28 至 49 千克氮/公顷。与休耕处理（平均值 = 31 mg·L）相比，所有覆盖处理（平均值 = 4 mg·L）覆盖作物和间作阶段土壤水 NO-N 的减少反映了氮的吸收。金钱草和冬亚麻荠等经济作物为种植者提供了环境和潜在的经济资源。它们是创收作物，能够吸收不稳定的土壤养分，从而保护和促进从秋季到初夏的土壤健康。
Winter cover crops might reduce nutrient loss to leaching in the Upper Midwest. New oilseed-bearing cash cover crops, such as winter camelina ( L.) and pennycress ( L.), may provide needed incentives. However, the abilities of these crops to sequester labile soil nutrients are unknown. To address this unknown, N in shoot biomass, plant-available N and P in soil, and NO-N and soluble reactive P in soil water collected from lysimeters placed at 30, 60, and 100 cm were measured in cover crop and fallow treatments established in spring wheat ( L.) stubble and followed through a cover crop-soybean [ (L.) Merr.] rotation. Five no-till cover treatments (forage radish [ L.], winter rye [ L.], field pennycress, and winter camelina) were compared with two fallow treatments (chisel till and no-till). Pennycress and winter camelina were harvested at maturity after relay sowing of soybean. Winter rye and radish sequestered more N in autumn shoot biomass, ranging from 26 to 38 kg N ha, but overwintering oilseeds matched or exceeded N uptake in spring, ranging 28 to 49 kg N ha before soybean planting. Nitrogen uptake was reflected by reductions in soil water NO-N during cover crop and intercropping phases for all cover treatments (mean = 4 mg L), compared with fallow treatments (mean = 31 mg L). Cash cover crops like pennycress and winter camelina provide both environmental and potential economic resources to growers. They are cash-generating crops able to sequester labile soil nutrients, which protects and promotes soil health from autumn through early summer.