The Effect of Nitrogen Fertilizer Infiltration on Nitrogen Transport in Shallow Groundwater in the West Erhai

LAI Meidan; CAO Guangzhu; WANG Renmin; QIANG Yi; LU Yanfeng; QIN Ronggao

doi:10.19672/j.cnki.1003-6504.1442.23.338

Abstract：The nitrogen leaching of agricultural non-point source pollution is the key factor of eutrophication pollution in plateau lakes,and it is important to study the seasonal nitrogen leaching in growing region to alleviate the nitrogen contamina-tion of agricultural non-point source pollution to groundwater and surface water in plateau lake deposit areas.In this study,the nitrogen leaching characteristics of a new type of water-soluble nitrogen fertilizer(calcium nitrate ammonium)and tradi-tional urea under different fertilization and rainfall conditions were studied through indoor column experiments.The results indicate that during the fertilization period,the new nitrogen fertilizer(T1)releases more NO3--N,but its cumulative emis-sions of NH4+-N and TN are much smaller than urea(T2).Seasonal precipitation has a certain impact on T1 nitrogen leaching,The total nitrogen content lost during fertilization and rainfall simulation periods accounts for 76.60%and 81.97%of the total nitrogen application in rainy seasons and the dry season,respectively.However,it has a significant impact on T2 nitrogen leaching,with leaching rates of 93.18%and 87.95%,respectively.In the rainy season with strong and frequent rainfall in Er-hai Lake,the replacement of traditional urea by new nitrogen fertilizer will have a certain mitigation effect on agricultural non-point source pollution,and the denitrification in lake sediments has a retention effect on nitrogen in the shallow vadose zone.This study has certain guiding significance for the timing and methods of agricultural planting and fertilization in the lake deposit areas around plateau lakes.