Effect of soybean inoculation with Bradyrhizobium and wheat inoculation with Azotobacter on their productivity and N turnover in a Vertisol
Effect of soybean inoculation with Bradyrhizobium and wheat inoculation with Azotobacter on their productivity and N turnover in a Vertisol
复制标题
大豆接种慢生根瘤菌和小麦接种固氮菌对其生产力和变性土中氮周转的影响
DOI：
10.1080/03650340.2012.740555
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发表时间：
2013
影响因子：
2.4
通讯作者：
R. Sahu
中科院分区：
文献类型：
--
作者：
A. Rawat;D. Rao;R. Sahu
在印度中部的变性土上进行了为期8年的长期田间试验，以定量评估大豆-小麦轮作中大豆接种慢生根瘤菌和小麦接种固氮菌的直接和残留N效应。每年种植大豆后，在同一地块种植小麦之前，使用四种氮水平（120，90，60和30 kg ha−1）和固氮菌接种去除其气生残留物。接种大豆使谷物产量增加了10.1%（180 kg ha−1），但接种小麦产量的增加幅度很小（5.6%; 278 kg ha−1）。大豆收获后，土壤氮素始终保持正平衡;对照区（由原生根瘤菌接种）的土壤氮素平均为+28 kg/ha−1/yr−1，而接种根瘤菌的土壤氮素平均为+41 kg/ha−1/yr−1。根瘤菌和固氮菌接种剂的残留和直接效应导致小麦的肥料氮信用为30 kg ha−1。施用化肥或接种微生物有利于作物根际根瘤菌的增殖，有利于作物生长。通过接种，大豆和小麦作物分别额外吸收了14.9 kg N ha−1和20.9 kg N ha−1，小麦收获后0-15 cm土层每年增加了+38.0 kg N ha−1。因此，在一次大豆-小麦轮作后，接种剂对作物和土壤的总氮贡献为73.8 kg N ha−1 yr−1。由于在大豆-小麦轮作中定期长期使用微生物接种剂，土壤的总氮效益为13.8 kg N ha−1 yr−1。
A long-term field experiment was conducted for 8 years on a Vertisol in central India to assess quantitatively the direct and residual N effects of soybean inoculation with Bradyrhizobium and wheat inoculation with Azotobacter in a soybean–wheat rotation. After cultivation of soybean each year, its aerial residues were removed before growing wheat in the same plots using four N levels (120, 90, 60 and 30 kg ha−1) and Azotobacter inoculation. Inoculation of soybean increased grain yield by 10.1% (180 kg ha−1), but the increase in wheat yields with inoculation was only marginal (5.6%; 278 kg ha−1). There was always a positive balance of soil N after soybean harvest; an average of +28 kg N ha−1 yr−1 in control (nodulated by native rhizobia) plots compared with +41 kg N ha−1 yr−1 in Rhizobium-inoculated plots. Residual and direct effects of Rhizobium and Azotobacter inoculants caused a fertilizer N credit of 30 kg ha−1 in wheat. Application of fertilizers or microbial inoculation favoured the proliferation of rhizobia in crop rhizosphere due to better plant growth. Additional N uptake by inoculation was 14.9 kg N ha−1 by soybean and 20.9 kg N ha−1 by wheat crop, and a gain of +38.0 kg N ha−1 yr−1 to the 0–15 cm soil layer was measured after harvest of wheat. So, total N contribution to crops and soil due to the inoculants was 73.8 kg N ha−1 yr−1 after one soybean–wheat rotation. There was a total N benefit of 13.8 kg N ha−1 yr−1 to the soil due to regular long-term use of microbial inoculants in soybean–wheat rotation.