Effect Of Different Urea Types And Soils PH On Ammonia Emission From Farmland And Analysis Of Related Factors

In this paper,rice,rapeseed,corn and Chinese cabbage were used as research objects to study the effects of different nitrogen fertilizer types,soil pH and controlled release nitrogen fertilizer on ammonia volatilization in farmland in the main crop planting areas of Hunan Province.Monitoring the related factors of volatilization to find out the main controlling factors affecting the ammonia volatilization of farmland in this area,and provide experimental basis for ammonia volatilization and emission reduction of different crops in Hunan Province,improving crop nitrogen utilization and improving agricultural ecological environment.The main findings are as follows:1.The application of controlled release urea has obvious advantages over conventional urea in reducing ammonia emission during crop growth.The ammonia volatilization loss of corn,late rice and pakchoi under controlled release urea treatment is reduced by 28.22% compared with conventional urea treatment.14.01%and 30.95%;the ammonia volatilization loss rate decreased by 5.43,2.11 and 4.76 percentage points respectively.2.The ammonia volatilization loss is closely related to the nitrogen application rate.The ammonia volatilization loss increases with the increase of nitrogen application rate.Compared with the constant controlled release urea treatment,the controlled release urea-N10%,controlled release urea-N20%,controlled release urea-N30% treatment reduced the amount of ammonia volatilization by 11.26%,15.16% and 18.06%;the controlled release urea-N10%,controlled release urea-N20%,controlled release urea The amount of ammonia volatilization lost by N30% was reduced by 22.48%,33.97% and 51.26%,respectively.3.The soil ammonia volatilization loss under alkaline pH soil condition was significantly higher than that of acid soil.The ammonia volatilization loss of late rice,rapeseed and Chinese cabbage acid soil treatment decreased by 51.40%,14.52,30.80% compared with alkaline soil.The ammonia volatilization loss rate decreased by 8.22,2.55 and 7.35 percentage points,respectively.4.Correlation between soil ammonia volatilization and environmental factorsThe results show that soil ammonia volatilization is closely related to seasonal changes in climatic conditions.Summer high temperature and short-term precipitation can promote soil ammonia volatilization.When autumn rain and heat conditions are balanced,atmospheric pressure is constant.To a certain extent,it affects the ammonia volatilization of crop soil.The short-term precipitation and warming in winter can accelerate the ammonia volatilization rate of soil,while the long-term precipitation will inhibit the ammonia volatilization of soil.Compared with controlled-release urea,the ammonia volatilization rate is higher than that of conventional urea.Conditional reactions are more sensitive.