稻草和紫云英联合还田下施氮水平对水稻产量及土壤氮素形态的影响  

Effects of different nitrogen inputs on rice yield and soil nitrogen forms under incorporation of rice straw and Chinese milk vetch

作　　者：朱强[1] 张静[1] 郭再华[1] 耿明建[1] ZHU Qiang;ZHANG Jing;GUO Zai-hua;GENG Ming-jian(Microelement Research Center of Huazhong Agricultural University,Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of Yangtze River),Ministry of Agriculture and Rural Affairs,Wuhan,Hubei 430070,China)

机构地区：[1]华中农业大学微量元素研究中心/农业农村部长江中下游耕地保育重点实验室,湖北武汉430070

出　　处：《植物营养与肥料学报》2020年第12期2177-2183,共7页Journal of Plant Nutrition and Fertilizers

基　　金：国家绿肥产业技术体系(CARS-22);公益性行业(农业)科研专项经费项目(201503122)。

摘　　要：【目的】紫云英和稻草联合还田时其有机成分的分解和释放具有互补性。研究紫云英和稻草联合还田条件下水稻的适宜施氮水平,为稻田绿肥和稻草联合还田后优化养分管理提供依据。【方法】两年定位试验位于江汉平原稻区,在稻草全量还田基础上,设置冬季种植并翻压紫云英和冬闲两种模式。水稻季氮肥处理设不施氮(N0)和常规施氮量(N 165 kg/hm^2)的50%(N50)、100%(N100)和150%(N150)共4个水平,以不施氮、冬闲和稻草不还田作为空白对照,共9个处理。测定水稻籽粒产量、氮含量及累积量,分析耕层土壤无机氮及有机氮组分。【结果】在稻草和紫云英联合还田条件下,减少常规氮肥量的50%(SMN50)获得的稻谷产量较稻草单独还田的SN50处理高21%~23%,与联合还田或稻草单独还田下的SMN100、SMN150、SN100、SN150处理之间没有显著差异。稻草和紫云英联合还田的SMN0、SMN50、SMN100处理的稻谷氮累积量均显著高于对应的稻草单独还田处理(SN0、SN50、SN100),增幅分别为65%、27%和22%。水稻收获后各处理间土壤全氮、非酸解性氮含量差异不显著,酸解性氮含量有差异,在N150处理下,稻草单独还田处理(SN150)的土壤酸解性氮含量显著高于稻草和紫云英联合还田处理(SMN150);在酸解性氮组分中,SN150处理的未知酸解态氮成分的含量显著高于稻草单独还田的其他处理及所有稻草和紫云英联合还田处理。【结论】减少常规施氮量的50%情况下,与稻草单独还田处理相比,稻草和紫云英联合还田可显著增加稻谷氮素累积量、提高水稻产量,而保持常规施氮量和提高施氮量不能增加水稻的氮素吸收和产量;紫云英与稻草联合还田可以改善土壤氮素的有效性,显著降低高施氮量下稻草单独还田带来的酸解性氮组分中未知态氮的残留量。【Objectives】The decompostion and nutrient release of Chinese milk vetch(CMV)and rice straw are complementary when jointly incorporated into soil.Thus,the effect of nitrogen application rates on rice yield,nitrogen-use efficiency,and soil organic nitrogen under incorporation of CMV and rice straw was studied.【Methods】A two-factor complete split field trial was conducted for two years in Jianghan plain.The two factors were:1)combined incorporation of CMV and rice straw(SM)or incorporation of rice straw alone(S);2)N application rate[50%(N50),100%(N100),and 150%(N150)of the conventional N input(165 kg/hm^2),and no N input(N0)].The grain yield and biomass were weighed,grain N concentration,plant N concentration,and inorganic and organic N concentrations in surface soil were analyzed【Results】The rice yield of SMN50 treatment was 21%-23% higher than that of SN50 treatment,but similar to those of SMN100 and SMN150.The grain N uptake in SMN0,SMN50,and SMN100 treatments were significantly higher than those recorded in SN0,SN50,and SN100 treatments,with increase rate of 65%,27%,and 22%,respectively.The soil total N and non-acid-hydrolysable N concentrations after rice harvest were similar for all treatments,but the acidhydrolysable N contents varied significantly.Among the four forms of the acid-hydrolysable N,the unidentified N increased significantly in SN150 treatment than that in other treatments.【Conclusions】Compared with rice straw returning alone,the co-incorporation of rice straw and CMV increased rice yield and grain N uptake under 50% reduction of conventional N application rate,while conventional rate or 50%increase in N input did not.The co-incorporation of CMV and rice straw could improve the availability of soil N and significantly decrease the residual acid-hydrolysable unidentified N content under high N input.

关 键 词：绿肥 稻草还田 氮肥用量 氮素回收率 土壤有机氮组分 

分 类 号：S511[农业科学—作物学] S153.6