氮肥管理对秸秆还田下土壤氮素供应和冬小麦生长的影响  

Effects of nitrogen fertilizer managements on soil nitrogen supply and winter wheat growth under straw return

作　　者：赵士诚[1] 魏美艳[1] 仇少君[1] 何萍[1] 

机构地区：[1]农业部植物营养与肥料重点实验室,中国农业科学院农业资源与农业区划研究所,北京100081

出　　处：《中国土壤与肥料》2017年第2期20-25,共6页Soil and Fertilizer Sciences in China

基　　金：中央级公益性科研院所基本科研业务经费专项资金项目(2015-1);国家重点基础研究发展计划课题(2013CB127404)

摘　　要：通过田间试验研究了秸秆和氮肥管理对小麦生育期土壤无机氮、微生物量碳、氮和小麦生长的影响,设置秸秆还田不施氮(CK)、农民习惯施氮FN5∶5(5∶5为氮肥基追比,下同)、推荐施氮SN3∶7、SN5∶5、SN7∶3和秸秆移走推荐施氮N5∶5处理。施氮显著提高苗期土壤无机氮含量,其与基肥氮量成正比且在拔节期显著降低,拔节后追肥提高了后期无机氮且其与追肥量成正比。小麦生育前期土壤微生物没有增加对无机氮的固持,而在拔节和抽穗期显著增加,此后逐步降低。秸秆还田较秸秆移走增加了无机氮固持,且生育中期固持量远高于前期。氮肥基追比过高导致小麦前期氮奢侈吸收和旺长且影响后期生长,氮肥3∶7基追施能满足小麦养分供求同步并实现高产和提高氮肥利用效率。Field experiment was conducted to study the effects of straw and nitrogen （N） fertilizer managements on soil inor- ganic N, microbial biomass carbon and N during winter wheat growing season and wheat growth, experimental treatments included no-N control （CK） , farmer practice N FNS： 5 （5：5 is the ratio of basal N to topdressing N, the same as below）, recommended N rate SN3： 7, SNS： 5, SN7：3 under straw return and NS： 5 under no-straw return. Results showed that N ferti- lization significantly increased soil inorganic N in the seeding stage for all N fertilization treatments, their inorganic N concen- trations were positive correlation with the rates of basal N and significantly decreased in the shooting stage, the topdressing N after shooting stage increased inorganic N concentrations in wheat later growth stage and their concentrations were positive corre- lation with the topdressing N rates. Soil microbial inorganic N retention did not increase in the early growth stage of wheat com- pared with before sowing, but the inorganic N retention significantly increased in the shooting and heading stages, and then gradually decreased with wheat growing. Relative to the removement of crop straw, straw return increased soil microbial inor- ganic N retention, and the inorganic N retention was great higher in wheat middle growing stage than the early stage. High ratio of basal N to topdressing N resulted in wheat luxury N uptake and excessive growth in early stage and inhibited wheat growth in later stage, the application of basal and topdressing N at 3：7 ratio could meet the demand of wheat whole growing stage, and realize higher grain yield and increase N use efficiency.

关 键 词：秸秆还田 氮肥运筹 土壤无机氮 土壤微生物量碳氮 冬小麦 

分 类 号：S158[农业科学—土壤学] S512.11[农业科学—农业基础科学]