Effects Of Organic And Inorganic Fertilizer On N₂O Emission、Soil Nutrients And Yield Of Wheat-maize Rotation System

This experiment was carried out in nongcui garden of anhui agricultural university from October 2017 to September 2019 to study the effects of organic and inorganic fertilizers on N2O emission,soil fertility,yield,quality of wheat-maize and nitrogen agronomic responses.The experiment was conducted in a random area group.Six treatments were designed:1)no N fertilizer(CK);2)Total chemical fertilizer(T1);3)Chemical N:organic N=2:1(T2);4)Chemical N:organic N=1:1(T3);5)Chemical N:organic N=1:2(T4);6)Total organic fertilizer(T5).By means of field sampling and indoor culture,the environmental effect of organic and inorganic fertilizers on farmland and the change of wheat and maize yield were analyzed.According to analysis of two years of datas,the results show that:(1)Fertilization,significantly promoted N2O emission flux.Compared with total organic fertilizer,the proper application of organic fertilizer on the basies of chemical fertilizer is beneficial to reduce accumulation of emissions of N2O.Combined with the cumulative emissions of N2O in two years,compared with total organic fertilizer,T2,T3 and T4 reduced by 15.71%,18.19%and 18.32%,respectively,moreover,there was no significant difference in N2O cumulative emissions with total chemical fertilizer.There was no significant difference in accumulation of emissions of N2O between treatments about the combination of organic and inorganic.(2)Fertilization increased soil organic matter,total N and available K;Compared with total chemical fertilizer,the application of organic fertilizer is beneficial to increase the total N and organic matter in the soil.Fertilization significantly increased the total amount of mineral nitrogen.In terms of net nitrification rate and net mineralization rate of soil,the results were as follows:Total organic fertilizer>the applications of organic and iroganic fertilizers>total chemical fertilizer>no fertilizers.(3)Compared with no fertilizer,fertilization significantly increased the yield of wheat and maize,and the yield of wheat and maize treated with organic fertilizer was higher;According to the total output of wheat-maize from 2017-2019 year,compared with total chemical fertilizer,T2,T3,T4andT5 increased total yields of wheat and maize.fertilization significantly increased grain protein of wheat and maize,and increased wheat or maize wet gluten,hardness,sedimentation value and fat to varying degrees.(4)Compared with total organic fertilizer,appropriate amount chemical fertilizer with organic fertilizer is benifical to reduce yield-scaled N2O emission and N2O emission factors.According to datas of the two years from 2017 to 2019 year,compared with total organic fertilizer,the yield-scaled N2O emission and N2O emission factors were reduced by the applications of organic and inorganic,and there was no significant difference with total chemical fertilizer.Compared with total chemical fertilizer,the application of organic fertilizer increased partial factor productivity of applied N and agronimic N use efficiency.The nitrogen supply capacity of organic fertilizer treatments was higher.To sum up,compared with total chemical fertilizer or total organic fertilizer,the combination of chemical fertilizer and organic fertilizer is more conducive to fertilizing the soil,reducing nitrogen loss and improving nitrogen utilization rate while guaranteeing crop yield.However,there is no significant difference between the treatments about the combination of organic and inorganic in accumulation of N2O、soil fertility and yield of wheat-maize,which may be related to the shorter planting years,so further study is needed in the later period.