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Excessive fertilization combined with unreasonable irrigation in farmland of the Hetao Irrigation Area (HIR),China,has resulted in a large amount of nitrogen (N) losses and agricultural non-point source pollution.Application of soil amendments has become one of the important strategies for reducing N losses of farmland.However,there is still no systematic study on the effects of various soil amendments on N losses in the HIR.In this study,three types of soil amendments (biochar,bentonite and polyacrylamide) were applied in a maize-wheat rotation system in the HIR during 2015-2017.Yields of maize and wheat,soil NH3 volatilization,N2O emission and NO3-leaching were determined and soil N balance was estimated.The results showed that applications of biochar,bentonite and polyacrylamide significandy increased yields of maize by 9.2％,14.3％ and 13.3％,respectively,and wheat by 9.2％,16.6％ and 12.3％,respectively,compared with the control (fertilization alone).Applications of biochar,bentonite and polyacrylamide significantly reduced soil N leaching by 23.1％,35.5％ and 27.1％,soil NH3-N volatilization by 34.8％,52.7％ and 37.8％,and soil N surplus by 23.9％,37.4％ and 30.6％,respectively.Applications of bentonite and polyacrylamide significantly reduced N2O-N emissions from soil by 37.3％ and 35.8％,respectively,compared with the control.Compared with appfication of biochar,applications of bentonite and polyacrylamide increased yields of maize and wheat by 5.1％ and 3.5％,respectively.Our results suggest that soil amendments (bentonite and polyacrylamide) can play important roles in reducing N losses and increasing yield for the maize-wheat rotation system in the HIR,China.