Effects Of Different Influencing Factors On Nutrient Loss On Brown Soil Slope

As one of the soil types with the highest distribution rate in Western Liaoning,the importance of cinnamon soil is self-evident.However,the current situation of cinnamon soil in Western Liaoning is not optimistic.The problem of soil erosion is becoming more and more serious,especially the indispensable sloping farmland in agricultural industry,which has become a serious disaster area of soil erosion in Western Liaoning cinnamon soil area.Affected by rainfall and unscientific irrigation and fertilization,nutrient loss directly leads to the decline of land productivity,which leads to the gradual reduction of grain production and environmental deterioration,and has become a vicious circle occurring on the cinnamon slopes.Therefore,it is an urgent task to investigate the crux of nutrient loss of cinnamon soil in depth and put forward joint efforts to protect the cinnamon soil resources in Western Liaoning from the source,and to improve the utilization efficiency of land(especially slope farmland).In this paper,N,P and K nutrients in cinnamon slopes were studied.Artificial rainfall experiments were carried out through indoor simulation.Nutrient migration and loss patterns of cinnamon slopes under different initial water content,soil bulk density and fertilization modes were investigated in an all-round way.A nutrient loss simulation model for cinnamon slopes in Western Liaoning Province was built.On the basis of revealing the root cause of agricultural non-point source pollution,this study explores the treatment path rationally,which provides sufficient theoretical foundation and technical support for the solution of the problem.The conclusions are as follows:(1)Effect of initial Water Content on Nutrient Loss on Cinnamon SlopeUnder the conditions of indoor artificial rainfall,the process of soil nutrient loss on cinnamon soil slopes with different initial contents was studied.The result shows that if the initial content was limited to less than 15%,the nitrate nitrogen leaching depth would be Under circumstances of 20% water content,the nitrate nitrogen leaching content in soil nutrient was a slight amount.Once the initial water content was higher than 25%,The nitrate nitrogen leaching will be extremely little.The P and K content in soil decreased slightly,and their concentration is negatively correlated with rainfall duration,their loss and the initial water content parabolic.When the initial water content remains in the range of 10% to 15%,there will be a peak value in.In conclusion,the optimal initial water content in cinnamon soil should be between 11.28%-16.86%.(2)Effect of rainfall intensity on nutrient loss on cinnamon slopeThe greater the rainfall intensity,the higher the total amount of runoff and sediment yield,and the loss of nutrient concentration and leaching are also further deepened.The total amount of surface runoff was positively correlated with rainfall intensity;when the rain intensity is less than 1.1 mm/min,the sediment yield does not change much,when the rain intensity begins to exceed 1.1 mm/min,the sediment yield and runoff yield increase sharply,until the rain intensity reaches 1.6 mm / min,and the total sediment yield reaches its peak,when the concentration of three elements was higher than the rain intensity's nutrient concentration which was lower than that of 1.1 mm/-min;quadratic equation with one unknown can reflect best the mathematical model of phosphorus concentration change,nitrogen and potassium ion content and concentration change process is very similar,which together with the logarithmic function fitting coefficient is higher.Under the premise of three kinds of rain intensity,the depth of the loss of soluble phosphorus is basically the same,the greater the rain intensity is,the deeper the loss of nitrogen element is;and under the premise of 1.6 mm/min rain intensity,the content and concentration of the three nutrients in the cinnamon soil are all in the lowest value.(3)Effect of Fertilizer Application on Nutrient Loss on Cinnamon SlopeIn the early stage of runoff production,the higher concentration of solute fertilizer was the surface spraying treatment.The initial runoff concentration of N,P and K in the runoff produced by spraying on the slope under different bulk density was 2.6-3.2,2.1-2.6 and 1.7-2.1 times of the mixed treatment.If the bulk density is the same,the total loss of nitrate nitrogen under surface fertilization is about 10 times of that under mixed fertilization,the loss of water-soluble phosphorus is 7-10 times in contrast,and the loss of potassium ion is 3-6 times in contrast.