摘要
建立田间原位试验,采用静态箱-气相色谱法,研究了常规尿素及其与硫包膜和聚氨酯包膜控释尿素配施(比例分别为30%∶70%、 50%∶50%和70%∶30%)对黄河故道沙性潮土玉米生长季氧化亚氮(N2O)排放的影响.研究发现:常规尿素处理N2O排放量(以N计,下同)为1.78 kg·hm-2,排放系数为0.38%;与之相比,配施30%、 50%和70%硫包膜尿素处理的N2O排放量分别降低了1.12%、 22.5%和11.2%,排放系数下降2.63%~26.3%.相反,配施聚氨酯包膜尿素处理增加N2O排放量0.02~0.41 kg·hm-2,其中70%聚氨酯包膜尿素处理增幅最大,达到23.0%.回归分析表明,各处理N2O排放通量与10 cm处土温、土壤NH+4-N和NO-3-N含量呈极显著正相关(P<0.01),而与土壤孔隙含水量和溶解性有机碳含量无显著关系.与常规尿素相比, 50%常规尿素+50%硫包膜控释尿素处理玉米产量略有增加,而30%常规尿素+70%硫包膜尿素处理稍微降低了玉米产量,但不显著(P>0.05).因此,控释肥减缓土壤N2O排放以及对作物产量的影响主要受控于包衣材料.
A field experiment was conducted in maize-cultivated sandy loam soil in the old flooded area of the Yellow River to evaluate the responses of N2O emissions to application of different type of controlled-release urea.An inorganic N fertilizer was applied at 270 kg·hm-2 during the maize season.Urea was applied alone and in combination with sulfur-coated urea(SCU)or polyurethane-coated urea(PCU)at N ratios of 30%:70%,50%:50%,and 70%:30%,respectively.Cumulative N2O emission under urea treatment alone(CN)was 1.78 kg·hm-2 with a N2O emission factor of 0.38%.In comparison to CN,70%urea+30%SCU,50%urea+50%SCU,and 30%urea+70%SCU treatments reduced N2O emission by 1.12%,22.5%,and 11.2%,respectively.In contrast,application of urea in combination with PCU(with the proportion varied from 30%-70%)increased N2O emission by 0.02-0.41 kg·hm-2 compared with the CN,while 30%urea+70%PCU treatment showed a 23.0%increase.Regression analysis showed that N2O flux was significantly(P<0.01)correlated with soil temperature at 10 cm depth and concentrations of soil NH4+-N and NO3--N in all the treatments,but not with soil moisture or dissolved organic carbon concentration.Compared with the CN,the 50%urea+50%SCU and 50%urea+50%PCU treatments slightly,but not significantly,increased the maize yield,whereas the 30%urea+70%SCU treatment showed a reduction effect.Overall,the mitigation effect of controlled-release urea on N2O emission may primarily depend on its coating material and application rate.
作者
姜右锦
袁俊吉
丁维新
刘阳
张松林
JIANG You-jin;YUAN Jun-ji;DING Wei-xin;LIU Yang;ZHANG Song-lin(College of Geography and Environmental Science,Northwest Normal University,Lanzhou 730070,China;State Key Laboratory of Soil and Sustainable Agriculture,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2020年第7期3402-3409,共8页
Environmental Science
基金
国家重点研发计划项目(2016YFD0200304)
国家自然科学基金项目(41701297)
江苏省农业科技自主创新资金重点项目(CX(17)1001)
江苏省自然科学基金项目(BK20171105)。
关键词
控释肥
N2O排放
玉米
产量
潮土
controlled-release urea
N2O emissions
maize
yield
sandy loam soil
