减量施氮对玉米-大豆套作系统下作物氮素吸收和利用效率的影响  

Effects of reduced nitrogen application on nitrogen uptake and utilization efficiency in maize-soybean relay strip intercropping system

作　　者：雍太文[1,2] 刘小明 刘文钰[1,2] 周丽 宋春[2,3] 杨峰 蒋利[1,2] 王小春 杨文钰 

机构地区：[1]四川农业大学农学院,成都611130 [2]农业部西南作物生理生态与耕作重点实验室,成都611130 [3]四川农业大学资源环境学院生态环境研究所,成都611130

出　　处：《生态学报》2015年第13期4473-4482,共10页Acta Ecologica Sinica

基　　金：国家自然科学基金(31271669);国家大豆现代产业技术体系建设专项(CARS-04-PS19);国家公益性行业(农业)科研专项(201203096)

摘　　要：为探索玉米-大豆套作系统中作物对N素吸收的差异特性,揭示减量施N对玉米-大豆套作系统的N高效利用机理。利用15N同位素示踪技术,结合小区套微区多年定位试验,研究了玉米单作(MM)、大豆单作(SS)、玉米-大豆套作(IMS)及不施N(NN)、减量施N(RN:180 kg N/hm2)、常量施N(CN:240 kg N/hm2)下玉米、大豆的生物量、吸N量、N肥利用率及土壤N素含量变化。结果表明,与MM(SS)相比,IMS下玉米茎叶及籽粒的生物量、吸N量降低,15N%丰度及15N吸收量增加,大豆籽粒及植株的生物量、吸N量及15N吸收量显著提高;IMS下玉米、大豆植株的N肥利用率、土壤N贡献率、土壤15N%丰度降低,15N回收率显著增加。施N与不施N相比,显著提高了单、套作下玉米、大豆植株的生物量、吸N量、15N丰度及15N吸收量;RN与CN相比,IMS下,RN的玉米、大豆植株总吸N量提高13.4%和12.4%,N肥利用率提高213.0%和117.5%,土壤总N含量提高12.2%和11.6%,土壤N贡献率降低12.0%和11.2%,玉米植株15N吸收量与15N回收率提高14.4%和52.5%,大豆的则降低57.1%和42.8%,单作与套作的变化规律一致。玉米-大豆套作系统中作物对N素吸收存在数量及形态差异,减量施N有利于玉米-大豆套作系统对N肥的高效吸收与利用,实现作物持续增产与土壤培肥。To investigate the N uptake difference features between crops in the relay strip maize-soybean intercropping system, and reveal the efficient N utilization mechanism under reduced N application condition, the 15^N isotope tracer and plot location experiment combined with micro plot test assays were employed in the present study. Two field experiments were performed to analyze the biomass, N uptake, N use efficiency and soil N content of maize and soybean with 3 planting patterns, including maize monoculture （MM）, soybean monoculture （SS） and maize-soybean relay strip intercropping （IMS）, under 3 N application rates, including no N application （NN）, reduced N application （RN： 180 kg N/hm2） and conventional N application （CN： 240 kg N/hm2）. The results showed that the biomass and N uptake of maize stem and grain with IMS decreased, and 15^N% abundance and 15^N uptake increased, compared to monoculture system; the biomass, N uptake and 15^N uptake of soybean grain and plant with IMS increased significantly; and the N fertilizer utilization efficiency, soil N contribution rate, and soil 15^N% abundance of maize and soybean with IMS reduced. However, the 15^N recovery rate of maize and soybean increased. Comparing N application to no N application, the total N uptake, N fertilizer utilization efficiency and soil total N content of maize and soybean with N application increased, and the soil N contribution rate reduced, both in monoculture and relay strip intercropping systems; Furthermore, the 15^N% abundance, 15^N uptake and the recovery rate of maize aboveground plant increased significantly, but those indices of soybean decreased remarkably. Comparing reduced N application to conventional N application, the total N uptake of aboveground plant of maize and soybean with IMS raised 13.4% and 12.4%, and N fertilizer utilization efficiency raised 213.0% and 117.5%, and the soil total N content increased 12.2% and 11.6%, but the soil N contribution rate decreased 12.0% and 11.2%.In addition, t

关 键 词：玉米-大豆套作 减量施N N素吸收利用 15^N 

分 类 号：S513[农业科学—作物学] S565.1