Nitrogen contributions from faba bean (Vicia faba L.) reliant on soil rhizobia or inoculation
Nitrogen contributions from faba bean (Vicia faba L.) reliant on soil rhizobia or inoculation
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DOI：
10.1007/s11104-012-1393-2
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发表时间：
2013-04-01
期刊：
影响因子：
4.9
通讯作者：
Peoples, Mark B.
中科院分区：
文献类型：
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作者：
Denton, Matthew D.;Pearce, David J.;Peoples, Mark B.
了解土壤根瘤菌种群和接种根瘤菌在提供足够结瘤方面的影响，对于优化豆科作物的N-2固定至关重要。研究了不同根瘤菌接种率和对照土壤根瘤菌接种对蚕豆结瘤固氮的影响。用7种根瘤菌接种率中的一种接种蚕豆，从不接种到正常接种率的100倍，在有或没有土壤根瘤菌存在的两个田间地点播种，测定它们的结瘤和固氮能力。在没有土壤根瘤菌的情况下，接种根瘤菌增加了根瘤的数量，使固氮率从21 kg地上部增加到129 kg N ha(-1)。在背景土壤根瘤菌较高的地点，N-2固氮量从132 kg地上部增加到218 kg N ha(-1)。在没有根瘤菌的土壤上，接种使地上部N浓度从14 mg g(-1)增加到24 mg g(-1)，籽粒N浓度从32 mg g(-1)增加到45 mg g(-1)，粮食产量增加1.0 mg(吨)ha(-1)。根瘤的差异影响了固定氮对系统的贡献，从没有根瘤菌的情况下从系统中净去除20 kg N ha(-1)，到考虑谷物收获中N的去除后，从豆科植物地上部和根残体中净输入199 kg N ha(-1)。接种和土壤根瘤菌的影响强烈地影响了粮食产量、籽粒N浓度和豆科作物种植对土壤氮素肥力的潜在贡献。在有根瘤菌存在的土壤中，只有在接种最高接种率的情况下，才能提高固氮效果。
Understanding the impact of soil rhizobial populations and inoculant rhizobia in supplying sufficient nodulation is crucial to optimising N-2 fixation by legume crops. This study explored the impact of different rates of inoculant rhizobia and contrasting soil rhizobia on nodulation and N-2 fixation in faba bean (Vicia faba L.).Faba beans were inoculated with one of seven rates of rhizobial inoculation, from no inoculant to 100 times the normal rate of inoculation, sown at two field sites, with or without soil rhizobia present, and their nodulation and N-2 fixation assessed.At the site without soil rhizobia, inoculation increased nodule number and increased N-2 fixation from 21 to 129 kg shoot N ha(-1), while N-2 fixation increased from 132 to 218 kg shoot N ha(-1) at the site with high background soil rhizobia. At the site without soil rhizobia, inoculation increased concentrations of shoot N from 14 to 24 mg g(-1), grain N from 32 to 45 mg g(-1), and grain yields by 1.0 Mg (metric tonne) ha(-1). Differences in nodulation influenced the contributions of fixed N to the system, which varied from the net removal of 20 kg N ha(-1) from the system in the absence of rhizobia, to a net maximum input of 199 kg N ha(-1) from legume shoot and root residues, after accounting for removal of N in grain harvest.The impact of inoculation and soil rhizobia strongly influenced grain yield, grain N concentration and the potential contributions of legume cropping to soil N fertility. In soil with resident rhizobia, N-2 fixation was improved only with the highest inoculation rate.