The Law And Mechanism Of Ammonia Volatilization Under Various Nitrogen And Phosphorus Proportions In Farmland Ecosystem

Ammonia volatilization is one of important ways of nitrogen loss in farmland ecosystem. Ammonia volatilization reduces nitrogen use efficiency, moreover interferes with our ecosystem and environment. Applying field experiment pot experiment and soil incubation experiment, the law of ammonia volatilization and the effect of phosphorus on ammonia volatilization were studied under two fertilization methods, one of which is nitrogen fertilizer and phosphorus fertilizer as basal manure, and the other of which is phosphorus fertilizer as basal manure and nitrogen fertilizer as top dressing. The research will benefit to apply fertilizer reasonably and protect eco-environment.Ammonia volatilization appears regular change in the condition of the same amount of urea applied to the soil with different treatments of phosphorus fertilizer application. The changes of ammonia volatilization rate rose first, and then fess. The peak of ammonia volatilization rate increased with the increase of phosphorus fertilizer application. The total amount of ammonia volatilization increased with the increase of phosphorus fertilizer application. While ammonia volatilization was not observed in the condition of nitrogen fertilizer and phosphorus fertilizer as basal manure.The relationship between ammonium nitrogen content and ammonia volatilization with different phosphorus fertilizer application was studied. At the time of 7 days and 12days after phosphorus fertilizer as basal manure and nitrogen fertilizer as top dressing, ammonia volatilization rate related to the concentration of ammonium nitrogen. At the time of 3 days 7 days and 12days after phosphorus fertilizer as basal manure and nitrogen fertilizer as top dressing, the concentration of ammonium nitrogen displayed an increasing trend with the increase of phosphorus fertilizer application. Ammonia volatilization rate followed the change of the concentration of ammonium nitrogen. While ammonium nitrogen content is lower, ammonia volatilization was not observed in the condition of nitrogen fertilizer and phosphorus fertilizer as basal manure.The research on the relationship between nitrification rate and ammonia volatilization with different phosphorus fertilizer application indicated, at the time of 3 days 7 days and 12days after phosphorus fertilizer as basal manure and nitrogen fertilizer as top dressing, nitrification rates were not significant changes with the increase of phosphorus fertilizer application. Nitrification has no influence on alterative trend of ammonium nitrogen content. Ammonia volatilization rate was decided by ammonium nitrogen content of urea hydrolysis.The effect of phosphorus fertilizer application on soil pH and the relationship between soil pH and ammonia volatilization were studied. At the time of 7 days and 12days after phosphorus fertilizer as basal manure and nitrogen fertilizer as top dressing, soil pH changed from 7.3 to 8.5, and ammonium nitrogen easily transformed ammonia, then ammonia volatilization was observed in the condition of phosphorus fertilizer as basal manure and nitrogen fertilizer as top dressing. While soil pH was less than 7, ammonia volatilization was not observed in the condition of nitrogen fertilizer and phosphorus fertilizer as basal manure.