Study Of The Effect Of Phosphorus On The Biochemical Process Of Urea Nitrogen Transformation

Urea is the most widely used nitrogen fertilizer in the field of agriculture,played an important role in agricultural production of our country.However,the irrational use of nitrogen fertilizer has also bring some negative impact,not only led to significant loss of nitrogen, resulting in the waste,but also to have a negative impact on the ecological environment,so that the nitrogen has become one of the most important source of pollution.Interaction of nitrogen and phosphorus has always been a hot and focus research in the field of plant nutrition science and fertilizer science.The results show that at home and abroad, phosphorus has a certain effect to reduce evaporation of ammonia and increase nitrogen utilization.At present,there are many reports about the validity effect of nitrogen and phosphorus,nitrogen,phosphorus and potassium combined application on crop growth,nutrient absorption and soil nutrients,However,there are only a few reports about a mixture application of urea and phosphate fertilizer impact on nitrogen into the biochemical process.So far,lack of the research that phosphorus affect of urea nitrogen transformation under the different soil moisture content,so this article gave a research of the biochemical process of phosphorus affect of urea nitrogen under the different soil moisture content.It has a great significance to improve nitrogen use efficiency and reduce nitrogen loss,protect the human living environment.In a simulated field test,we debugged the tested soil to have different moisture content of 10%,20%and 30%respectively.We applied nitrogen and phosphate as a base fertilizer to the tested soil at the same time,studied the biochemical process of phosphorus effects of nitrogen.The research result show,the dynamic changes of NH₄⁺-N varied under the different water content after applying phosphorus.Under low water conditions(10 percent and 20 percent),the content of NH₄⁺-N were increasing firstly and then decrease with the increase of the time,the peak value appeared at the twelve days,decreased gradually from twelve to thirty day.Under high water conditions(30 percent),the content of NH₄⁺-N appeared peak value twice,at third day and twelve day respectively.There was a positive correlation between NH₄⁺-N concentration and dosage of applying phosphorus,no matter which moisture content.The dynamic change of NO₃^--N concentration was in the same trend under the different water conditions.Show the trend of increase from the first day to the thirty day,NO₃^--N concentration increase slowly before the twelve day,but then increase rapidly.The level of moisture had little to do with the nitrification. During the same period,the dynamic changes of NH₄⁺-N varied with the increase of applying phosphorus.Under low water conditions(10 percent and 20 percent),the content of NH₄⁺-N were raise with the increase of applying phosphorus;under high water conditions(30 percent),the content of NH₄⁺-N appeared raise and descend with the increase of applying phosphorus.Soil accelerated the urea hydrolysis rate under high water conditions.During the same period,the change of NO₃^--N concentration was not evidence with the increase of applying phosphorus under the different water conditions.This shows that the water content of the soil restrain the influence that increase phosphorus to NO₃^--N concentration.Under the different water conditions,urease activity did not change significantly over time with the different disposal of the applying phosphorus.Under high water conditions(30 percent), the number of nitrosation bacteria increased significantly.The results show that the high moisture content of soil was good for the growth of nitrosation bacteria. NH₄⁺-N concentration were quite high under high water conditions,it was bad for the loss of nitrogen.The number of nitrosation bacteria increased significantly under high water conditions, so enhanced the transformation from NH₄⁺-N to NO₃^--N and brought a negative impact of Nitrogen leakage loss.