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Study of the Effect of Phosphorus on the Biochemical Process of Urea Nitrogen Transformation

Author: LiJinYan
Tutor: WangJiHong
School: Jilin Agricultural University
Course: Environmental Engineering
Keywords: Nitrogen and phosphorus Nitrogen transformation Water content Biological processes Chemical processes
CLC: X131.3
Type: Master's thesis
Year: 2008
Downloads: 63
Quote: 1
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Abstract

Urea is the most widely used nitrogen fertilizer, nitrogen fertilizer in world agriculture has played an important role in China's agricultural production, but unreasonable application of nitrogen fertilizer also had some negative impact, unreasonable, nitrogen fertilizer utilization is low, not only led to nitrogen large losses, resulting in a waste, but also have a negative impact on the ecological environment, the Farmland nitrogen to become one of the important sources of pollution. Nitrogen and phosphorus interaction has always been the focus of scientific research and hotspots of plant nutrition science and fertilizer. Different domestic and foreign research results show that the phosphorus on ammonia volatilization and improve nitrogen utilization. Currently, nitrogen and phosphorus, NPK fertilizer on crop growth, nutrient uptake and soil nutrient availability report there are many mixed application of phosphate fertilizer and urea nitrogen transformation biochemical processes, but research still less. So far, however, the lack of phosphorus in the water content of the soil in the different urea nitrogen into the study, so the different water content of the paper focuses on the conditions under phosphorus urea nitrogen into the biochemical processes. And so is of great significance to improve nitrogen use efficiency, reduce the loss of nitrogen fertilizer to protect the environment for the survival of the human. In simulated field trials, tested soil with different moisture contents debugging, and to reach the tested soil humidity 10%, 20% and 30%, three water content conditions. Nitrogen and phosphorus fertilizer as basal fertilizer into the soil tested to study phosphorus affect the biochemical processes of nitrogen transformation. The results show that the dynamic changes of the different water content of ammonium nitrogen and phosphorus application under conditions of low moisture content (10% and 20%), ammonium nitrogen content changes over time upward trend, in 12 Telsda to peak, 12 days gradually declined to a 30-day period. Under the conditions of high water content (30%), ammonium nitrogen content in 3 days and 12 days twice reached the peak. Three moisture conditions, the concentration of ammonium nitrogen and phosphorus content is positively correlated. Under different moisture conditions, the dynamic trend of nitrate concentration the same upward trend from one day to 30 days, but 12 days before the nitrate concentration trend is slowly rising, rose sharply from 12 days to 30 days. Water content level of nitrification relationship. Ammonium nitrogen content with the facilities during the same period, the trend of increase in the phosphorus content. Under the conditions of low moisture content (10% and 20%), ammonium nitrogen content with applied phosphorus increase in the amount of the rise; under the conditions of high moisture content (30%), ammonium nitrogen content with applied phosphorus content increases upward and down by two trends. Under the conditions of high moisture content of the soil to promote the rate of hydrolysis of the urea. The same period, the nitrate concentration with different water content under the conditions applied phosphorus increase in the amount of no significant change. This shows that the water content suppress the increase in the amount of phosphorus application on nitrate concentration. Different P treatments under different moisture conditions, urease activity did not change significantly over time. The nitrosated significantly increased the number of bacteria under the conditions of high moisture content (30%). The results show that, under conditions of high moisture content of soil suitable for the growth of nitrification bacteria. The moisture content is too high, the high concentration of ammonium nitrogen, an adverse impact on nitrogen fertilizer use. The nitrification bacteria also too high water content under the conditions of the increasing number, thereby enhancing the conversion of ammonium nitrogen to nitrate, an increase of farmland nitrogen leaching losses.

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CLC: > Environmental science, safety science > The basic theory for the Environment and Science > Environmental Chemistry > Environmental pollution, chemical > Soil pollution chemistry
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