The Research Of Influential Factors Of Nitrogen Loss In Meadow Black Soil

The tests of different kinds of fertilizer, the amount of fertilizer, rainfall intensity,vegetation coverage and vegetation pattern to nitrogen leaching are conducted undersimulated rainfall in order to find out the characteristics of meadow black soil nitrogen loss.The main conclusion after testing as follows:(1) With the increase of rainfall intensity, runoff and leakage of the fluid volume areincreased. Among them, in the middle and low rainfall intensity, the leakage is greater thanthe amount of runoff; But in the higher rainfall intensity, similar or lower than that ofrunoff and runoff amount of seepage.There was a significant difference between highrainfall intensity with low rainfall intensity in runoff and leakage.With the increase ofvegetation coverage, runoff decreases gradually, while seepage quantity increase. Therewas a significant difference between the different coverage processing in runoff when thereare significant differences between20%~80%coverage in leakage.(2) The concentration of loss of Total nitrogen, Dissolved nitrate nitrogen andDissolved ammonium nitrogen in leachate and runoff are positively related to the intensityof rainfall. There were significant differences between high rainfall intensity and lowrainfall intensity of Total nitrogen, Dissolved nitrate nitrogen loss concentration in runoffand leachate. Ammonium nitrogen in the runoff exists significant difference, but the loss ofammonium nitrogen in the leachate there was no significant difference.Ammoniumnitrogen in the runoff concentration exists significant difference, but the loss of ammoniumnitrogen concentration in the leachate there was no significant difference between In themiddle and low rainfall intensity, leakage loss is the main way of nitrogen loss; When highrainfall intensity, leakage loss compared with runoff erosion, tend to be close to or evenlower than that of runoff erosion.(3) With the increase of fertilizer rate, runoff and leakage of liquid nitrogen loss areincreased.There was a significant difference between Total nitrogen, Dissolved nitratenitrogen in runoff and leakage,the concentration of Dissolved ammonium nitrogen onlydouble fertilization exist.The seepage erosion is a major loss of various nitrogen forms. Theform of nitrogen loss are predominantly within Dissolved nitrate nitrogen, Dissolved nitrate nitrogen loss in runoff accounted for56.51%~64.19%of Total nitrogen; Dissolved nitratenitrogen loss in leachate accounts for66.81%~69.70%of Total nitrogen.(4) The concentration of Total nitrogen, Dissolved nitrate nitrogen loss in runoff andleakage exists significant difference between inorganic fertilizer, compound fertilizer andorganic fertilizer.Different kinds of fertilizing of different laws of nitrogen losses. Thenitrogen loss of inorganic fertilizer was highest in runoffand leskage. The rule of Totalnitrogen, Dissolved nitrate nitrogen loss in runoff is inorganic fertilizer＞compoundfertilizer＞organic fertilizer in the circumstances of equal nitrogen fertilization. The rule ofDissolved ammonium nitrogen loss is compound fertilizer＞organic fertilizer＞inorganicfertilizer. The rules of Total nitrogen, Dissolved nitrate nitrogen and Total dissolvednitrogen loss are agreement which is that inorganic fertilizer＞compound fertilizer＞organic fertilizer. Dissolved ammonium nitrogen loss concentration which is different fromTotal nitrogen is that compound fertilizer＞organic fertilizer＞inorganic fertilizer.(5) Rainfall interval is different, after fertilization of nitrogen loss is also different.After fertilization1~7d, the of concentrations of Total nitrogen loss reach more than50%of the concentration of total loss in runoff; The loss of Total nitrogen in leakage showed anegative correlation with rain fertilization interval, within Dissolved nitrate nitrogen andDissolved ammonium nitrogen loss in leachate which have reached the maximum at7d.(6) In all vegetation coverage,the loss of Total nitrogen、Dissolved nitrate nitrogen andDissolved ammonium nitrogen in leakage was all higher than in runoff. Coverage is40%,the total loss of Total nitrogen (accumulated runoff loss and leakage of cumulative loss) of1528.9mg/m2, lower than the coverage of0%,20%,80%respectively10.3%,2.8%,26.8%.(7) There was a significant difference between Total nitrogen, Dissolved nitratenitrogen and Dissolved ammonium nitrogen of under the slope pattern、in the slope and upthe slope pattern.Loss of Total nitrogen in leakage was all higher than in runoff no matterhow the vegetation pattern was. The effect of inhibit the loss of Total nitrogen is the bestwhen under the slope pattern. Under the slope pattern of15.4%and5.1%than in the slopepattern and on the slope pattern. Loss of Dissolved nitrate nitrogen and Dissolvedammonium nitrogen were agreement with Total nitrogen.