【摘要】 为探讨连续种植绿肥对土壤团聚体中氮分布的影响以及其中氮的固持特征,以箭筈豌豆(Vicia sativa L.)、肥田萝卜(Raphanus sativus L.)、蓝花苕子(Vicia cracca L.)、毛叶苕子(Vicia villosa Roth)、光叶苕子(Vicia villosa var.)为对象开展研究。结果表明:光叶苕子能够显著提高土壤全氮含量。肥田萝卜、蓝花苕子提升耕层土壤团聚体各粒径中氮含量的效果较为明显,光叶苕子提升> 2 mm粒径土壤团聚体中氮含量的效果较为明显。随着粒径减小土壤团聚体氮含量也呈现下降的趋势,各粒径中氮的富集系数在1.24与0.89之间。在> 1 mm粒径中,几乎所有处理富集系数均大于1,处于积累状态,≥0.25 mm粒径的团聚体氮贡献率占了85%以上,其中> 5 mm粒径的氮贡献率最大,0.5～0.25 mm粒径的氮贡献率最小。连续种植绿肥,土壤全氮的积累随着各粒径土壤团聚体中氮含量的增加而增加,全氮与> 0.5 mm粒径的团聚体中氮含量显著正相关,且5～2 mm粒级土壤团聚体中氮的增加对土壤全氮的影响较为突出,连续种植绿肥促进了氮在大团聚体中的固持。更多还原

【Abstract】 The objective of this study was to investigate the effects of long-term cultivation of green manure crops(Clean tillage, Vicia sativa L., Raphanus sativus L., Vicia cracca L., Vicia villosa Roth, and Vicia villosa var.) on the distribution of nitrogen(N) in soil aggregates and its sequestration. The results showed that the content of soil total N was significantly increased under the cultivation of Vicia villosa var. The cultivation of Raphanus sativus L. and Vicia cracca L. increased obviously the content of aggregate N. And the N content in the ≥2 mm aggregate was increased under the cultivation of Vicia villosa var. The composition of aggregate N showed an increased tend with the aggregate sizes. The enrichment coefficient(EC) of aggregate N was between 1.24 and 0.89. The EC of > 1 mm aggregate N was nearly more than 1, which means N accumulation. The contribution of N in ≥0.25 mm aggregate to total N was more than 85%. It was the highest in the > 5 mm aggregates and differed among various green manure crops, while it was the lowest in the 0.5 ～ 0.25 mm aggregates. The long-term cultivation of green manure crops increased the content of aggregate N and then promoted the accumulation of soil total N. There was a positive correlation between the contents of soil total N and > 0.5 mm aggregate N. The increase of N in 5 ～ 2 mm aggregate had a great influence on the N accumulation in soil. Long-term cultivation of green manure crops promotes the N sequestration in macro-aggregates.更多还原