Nitrate and Ammonium Leaching in Variable-and Permanent-Charge Paddy Soils  

作　　者：XIONG Zheng-Qin HUANG Tai-Qing MA Yu-Chun XING Guang-Xi ZHU Zhao-Liang 

机构地区：[1]College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing 210095 （China） [2]State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences,Nanjing 210008 （China）

出　　处：《Pedosphere》2010年第2期209-216,共8页土壤圈（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (No. 30390080);the Nanjing Science and Technology Bureau,China (No. 200901063)

摘　　要：A variable-charge （VC） and a permanent-charge paddy soil （PC） were selected to study nitrate-N （NO3^--N） and ammonium-N （NH4^＋-N） leaching with N isotopes for one consecutive year. An irrigation and intermittent drainage pattern was adopted to mimic natural occurrence of rainfall during the upland crop season and drainage management during the flooded rice season. Treatments to each soil type were no-N controls （CK）, ^15N-labeled （NH4）2SO4 （NS）, and milk vetch （NV） applied at a rate equivalent to 238 kg N ha^-1 to unplanted lysimeters, totaling six treatments in triplicates. Results indicated that the soil type dominated N leaching characteristics. In the case of PC, NO3^--N accounted for 78% of the total leached inorganic N; NS was prone to leach three times more than the NV, being 8.2% and 2.4% of added ^15N respectively; and 〉 85% of leached NO3-N came from of the total inorganic N in leachate. Moreover, NH4^＋-N native N in the soil. In the case of VC, NH4^＋-N made up to 92% leaching was detected throughout the whole incubation, and was particularly high during the flooded season. NO3^--N leaching in VC occurred later at a lower rate compared to that in PC. The findings of this study indicate that NO3^--N leaching during the drained season in permanent-charge paddy soils and NH4^＋-N leaching in variable-charge soils deserve more attention for regional environmental control.A variable-charge (VC) and a permanent-charge paddy soil (PC) were selected to study nitrate-N (NO 3-N) and ammonium-N (NH + 4-N) leaching with N isotopes for one consecutive year.An irrigation and intermittent drainage pattern was adopted to mimic natural occurrence of rainfall during the upland crop season and drainage management during the flooded rice season.Treatments to each soil type were no-N controls (CK),15 N-labeled (NH 4) 2 SO 4 (NS),and milk vetch (NV) applied at a rate equivalent to 238 kg N ha 1 to unplanted lysimeters,totaling six treatments in triplicates.Results indicated that the soil type dominated N leaching characteristics.In the case of PC,NO 3-N accounted for 78% of the total leached inorganic N;NS was prone to leach three times more than the NV,being 8.2% and 2.4% of added 15 N respectively;and > 85% of leached NO 3-N came from native N in the soil.In the case of VC,NH + 4-N made up to 92% of the total inorganic N in leachate.Moreover,NH + 4-N leaching was detected throughout the whole incubation,and was particularly high during the flooded season.NO 3-N leaching in VC occurred later at a lower rate compared to that in PC.The findings of this study indicate that NO 3-N leaching during the drained season in permanent-charge paddy soils and NH + 4-N leaching in variable-charge soils deserve more attention for regional environmental control.

关 键 词：drained/flooded rotations fertilizer-derived nitrate ion movement LYSIMETER ^15N tracing technique 

分 类 号：S511[农业科学—作物学] X832.02[环境科学与工程—环境工程]