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Effects of Different Nitrogen Treatments on Nitrogen and Organic Matter Loss of the Loessial Soil

Author: ZhangXiaoMei
Tutor: HeBingHui；HaoMingDe
School: Southwestern University
Course: Soil and Water Conservation and Desertification Combating
Keywords: Artificial rainfall Loess soil Organic matter Nitrogen Loss Characteristics
CLC: S157
Type: Master's thesis
Year: 2010
Downloads: 79
Quote: 2
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Abstract

A large area of ??distribution of the Loess Plateau loess soil is a serious soil erosion areas worldwide. Fertilization of research in the areas of agricultural land of the loess soil organic matter and nitrogen loss were investigated, help to improve the effective use of nitrogen fertilizer in agricultural production, achieve higher economic yield agriculture under less input, the nutrients needed for crop growth establish a balanced relationship between the amount of reducing environmental pollution. In this paper, the indoor artificial simulation of rainfall to study the loess soil nitrogen treatments runoff process organic matter and nitrogen loss characteristics, draw the following conclusions: 1) different fertilization treatments runoff and sediment loss characteristics of that fertilization can extend the initial time of runoff control treatment compared to high-fat, fat, low fat extend the initial time of runoff were 5.5 times, 5.2 times, 2.6 times, high fertilizer treatment to extend the initial runoff longest ; different handle runoff is basically the same trend to stabilize after the first increases rapidly to the maximum late runoff and a sharp decline in; sediment concentration and runoff, rainfall early sediment concentration sharp decline, followed by the entire runoff process to achieve stability. Power function derived from regression analysis of runoff and sediment accumulated loss under different fertilization treatments, the loss of runoff and rainfall time significant correlation between soil loss and rainfall time there is a significant linear relationship. Compared with the control treatment, nitrogen fertilization can minimize runoff and soil loss. 2) loss of organic matter under different fertilization treatments characteristics of various fertilization treatments sediment organic matter content of the change in the total trend similar to the first sharp decline, with some fluctuations, but volatility is not in the runoff 12min stable content, organic matter content of the control treatment. change is the most unstable; different fertilization treatments amount of organic matter accumulated loss curve level of order: control gt; low fat gt; in fat gt; least cumulative loss amount of high fat processing, high fertilizer treatment; processing organic matter loss and rainfall time exists y = a BLN (x) of the logarithmic regression equation relationship. Fertilization of different organic matter Loss, the regression analysis fertilizer and organic matter loss between T = 97.2161e-0.004805q exponential function. Enrichment of organic matter present in the sediment, the enrichment rate of the order of various fertilization treatments: control gt; low fat gt; high fat gt; fertilizer, the enrichment of the lowest rates in the fertilizer treatment, fertilization can reduce sediment enrichment of organic matter, but its relationship to reduce the enrichment of organic matter is more complicated, is not a simple positive correlation. 3) total nitrogen loss characteristics of different fertilizer treatments showed that the changes in the total nitrogen content of different fertilizer treatments the entire rainfall total nitrogen content: high fat gt; in fat gt; low fat gt; controls; different fertilization processing total nitrogen accumulated loss change its content, reducing the total amount of nitrogen losses after fertilization, compared with the control, high-fat, fat, low fat, total nitrogen reduction were 67.7%, 45.6%, 44.1%, T = 97.2161e-0.004805q exponential function relationship exists fertilization and nitrogen losses. Total nitrogen accumulated loss of the amount of rainfall time also there is a correlation, regression analysis, y = a bLn (x) with logarithmic relationship. Total nitrogen in sediment enrichment, contrary to different fertilizer treatments on total nitrogen enrichment with organic matter, high fertilizer treatment enriched rate significantly higher than other treatments, and fat and low-fat processing enrichment rate is basically the same, enrichment of the lowest rates of the control treatment. Nitrogen fertilization can reduce the total amount of nitrogen losses, but exacerbated the total nitrogen enrichment. 4) under different fertilizer treatments ammonium nitrogen, nitrate nitrogen loss characteristics show that ammonium and nitrate concentrations in the different fertilization treatments runoff extended rainfall trends basically similar: high-fat, fat, low fat processing first sharp down to a stable concentration to the end of rainfall; N loss in runoff mainly minimal loss of ammonium nitrogen; However, both loss and rainfall time there is a significant linear relationship. Trend of ammonium nitrogen content in the sediment is to first reduce and then gradually increase to a maximum rainfall late to the content in the early runoff and reduce the nitrate content trend is to slowly increase to maximum rainfall extend and declined slightly; ammonium and nitrate total loss compared with runoff sediment are relatively small, but different nitrate and ammonium nitrogen fertilization treatments and rainfall time there are significant logarithmic function. Ammonium nitrogen and total N loss in the process of erosion processes, mainly in nitrate and nitrate is mainly due to the loss of runoff.

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