“小麦/玉米/大豆”套作体系中不同作物间的相互作用及氮素的转移、吸收

在根系分隔盆栽条件下，采用15N土壤稀释标记方法，研究了“小麦/玉米/大豆”三熟套作体系不同作物间的相互作用及氮素的转移、吸收利用特性。结果表明，“小麦/玉米/大豆”套作体系促进小麦对肥料氮和土壤氮的吸收，不分隔处理的生物产量、15N总吸收量和总回收率得到显著提高，土壤残留15N丰度及总氮含量明显降低；玉米表现出套作优势（Awc<0，NCRwc<0），不分隔处理的籽粒产量、籽粒15N吸收量、15N总回收率、土壤残留15N丰度及总氮含量较分隔处理提高17.17%、24.52%、17.63%、13.9%和10.1%；大豆表现出套作劣势，不分隔处理的15N总吸收量、籽粒15N吸收量、15N总回收率和土壤残留15N丰度降低，土壤总氮含量提高6.06%。“小麦/玉米/大豆”套作体系存在氮素的双向转移，以玉米向小麦、大豆向玉米转移为主。

The Reciprocity and Nitrogen Transfer in Inter-Cropping and Inter-Planting System of "Wheat/Maize/Soybean"

A root barrier pot experiment was carried out to investigate the nitrogen transfer,uptake and utilization in the relay-planting system of "wheat/maize/soybean" using the method of 15 N-isotope dilution.The results showed that it was useful to accelerate the nitrogen uptake of wheat from fertilizer and soil in the relay-planting system of "wheat/maize/soybean".With no barrier,the biomass and 15 N total uptakes and recovery rate were significantly higher than that of solid barrier,and 15 N % abundance and tot...