Ammonia Volatilization Loss and Its Affecting Factors under Different Amounts and Ways of N Application in Field

This paper aims to study the ammonia volatilization loss,its affecting factors and NH_3 volatilization from topsoil in winter wheat field at Fengqiu State Experimental Station for Agroecosystem in Henan Province in the Huang-Huai-Hai Plain under different amounts(F_1: 150 kg/hm2;F_2: 225 kg/hm2;F_3: 300 kg/hm2) and ways of applying base and dressing nitrogen fertilizer.The factors affecting ammonia volatilization,such as the dynamic change of NH+_4-N concentration,temperature and pH value in topsoil(0-5 cm),are analyzed.The result shows that ammonia volatilization from topsoil occurs mainly within hebdomad after fertilization.Ammonia volatilization rate,total ammonia(N) loss and its proportion in total amount of applied N fertilizer are all increased with the increase of applied fertilizer amount under different application ways.Ammonia volatilization is considerably influenced by the depth of applied fertilizer in soil,and the accumulated amount of ammonia volatilization under furrow fertilization of base fertilizer is obviously higher than that under the traditional fertilization except the situation under N fertilizer application amount of 150 kg/hm2;while the situation is opposite for topdressing.Deep application of N fertilizer is currently one of the most effective ways for reducing ammonia volatilization loss.The proportions of ammonia volatilization loss from winter wheat field vary in ranges of 4.78%-6.72% and 4.31%11.24% of the total applied amount of N fertilizer under the traditional fertilization and furrow fertilization respectively.Moreover,the ammonia volatilization loss is less than 10% under both the traditional fertilization and furrow fertilization of 150 kg N/hm2,and the ammonia volatilization loss is in an order of F_3B(D) F_2B(D) F_3A(C) CK F_1A(C) F_1B(D).Correlation analysis reveals that there is a positive correlation between the ammonia volatilization rate and the NH+_4-N concentration in topsoil,but a negative correlation between the ammonia volatilization rate and pH value.Climatic conditions,such as temperature and rainfall,affect ammonia volatilization to a certain degree,and lower temperature and rainfall restrict ammonia volatilization.