机构地区:[1]四川农业大学资源学院,成都611130 [2]福建农林大学资源与环境学院,福州350002 [3]雅安市农业农村局,四川雅安625000
出 处:《农业资源与环境学报》2022年第1期88-98,共11页Journal of Agricultural Resources and Environment
基 金:四川省科技计划项目(2020YJ0354);国家重点研发计划项目(2016YFD0300301-02);国家玉米产业技术体系项目(CARS-02-04)。
摘 要:为探究不同施氮量下春玉米季土壤矿质态氮淋失特征及产量变化,以春玉米为研究对象,设置不同施氮量(0、90、180、270、360 kg·hm^(-2),分别用N_(0)、N_(90)、N_(180)、N_(270)、N_(360)表示),采用地下淋溶原位监测的方法,测定了玉米生育期间的土壤氮素淋失动态、玉米产量及氮肥利用率。结果表明:硝态氮(NO_(3)^(-)-N)是春玉米季旱地土壤矿质态氮淋失的主要形态,占总淋失量的90%~91%;施用基肥和苗期追肥后1~3周出现氮素淋失高峰,是防控氮素淋失的关键时期;随施氮量增加,矿质态氮淋失量呈指数上升趋势,表现为N_(360)(70.46 kg·hm^(-2))>N_(270)(39.65 kg·hm^(-2))>N_(180)(26.33 kg·hm^(-2))>N_(90)(18.55 kg·hm^(-2))>N_(0)(6.54 kg·hm^(-2)),各处理间差异达显著水平(P<0.05)。氮肥表观淋失率随施氮量增加呈先降后升趋势,在N_(180)处理下,淋失率最低,为10.99%,较N_(270)、N_(360)处理分别降低1.27、6.76个百分点;玉米籽粒产量先随施氮量增加而显著提高(P<0.05),施氮超过180 kg·hm^(-2)后进入平台期,N_(180)处理下氮肥表观利用率达到最高,较其他处理增加14.50~27.75个百分点。总体来看,该研究区域春玉米的最佳施氮量为180 kg·hm^(-2),既能稳产也能保肥,同时土壤的氮素淋失率最低。The aim of this study was to explore the effects of different nitrogen(N)applications on the characteristics of soil mineral nitrogen leaching during spring maize season and changes in maize yield.A field experiment was carried out with five different N applications(0,90,180,270,and 360 kg·hm^(-2),represented by N_(0),N_(90),N_(180),N_(270),and N_(360),separately),using spring maize as the test material.Soil N leaching dynamics during maize season were measured by underground leaching in-situ monitoring,and spring maize yield and N fertilizer utilization efficiency were analyzed.The results showed that nitrate(NO_(3)^(-)-N)was the main form of mineral N leaching in upland soil during spring maize season,and accounted for 90%~91%of the total mineral N loss.Nitrogen leaching peak occurred 1~3 weeks after base fertilization and top fertilization at the seedling stage,which was the key period to take measures to prevent N leaching.Significantly different effects on mineral N leaching were found between different N application rates.The leaching of mineral N increased exponentially with increased N application,following this order:N_(360)(70.46 kg·hm^(-2))>N_(270)(39.65 kg·hm^(-2))>N_(180)(26.33 kg·hm^(-2))>N_(90)(18.55 kg·hm^(-2))>N_(0)(6.54 kg·hm^(-2)).The apparent N leaching rate first decreased and then increased with increased N application.The minimum N apparent leaching rate was 10.99%under N_(180) treatment,which was reduced by 1.27 and 6.76 percentage points compared with those of N_(270) and N_(360) treatments,respectively.The grain yield of maize significantly increased with increasing N application(P<0.05)and then reached a plateau stage when the N rate exceeded 180 kg·hm^(-2).The apparent use efficiency of N fertilizer reached the maximum under N_(180) treatment,which increased by 14.50~27.75 percentage points compared with other treatments.In conclusion,the application of 180 kg·hm^(-2) could be considered the optimum N rate to obtain stable maize grain yield,maintain fertility,and achieve the lo
分 类 号:X52[环境科学与工程—环境工程] S513[农业科学—作物学]
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