Study On Soil Character And Soil And Water Conservation Measures Of Sloping Farmland In Typical Black Soil Area

The study of soil physical and chemical properties under different measures showed that: The clay content in the same slope of the three measures showed the hedgerow>the terrace covered with vegetation>the longitudinal terrace the clay content of the three measures in spring all presented the medium-slope>lower slope>upper-slope,among which the down-slope of the the hedgerow was 1.1% higher than the up-slope.The lower slope of the ridge was 14.6% higher than the upper one.The lower slope of hedgerow was 3.5% higher than the upper slope,and there was a significant difference in both the upper slope and the lower slope between hedgerow and ridge.(p<0.05).In autumn,the clay content of the three measures was the highest at the lower slope,among which the lower slope of the hedgerow was 32.9% higher than the upper slope.The lower slope of the terrace covered with vegetation was 9.3% higher than the upper one.The lower slope of the longitudinal terrace was 2.7% higher than the upper one.The soil porosity of the three measures under the same slope was different in spring and autumn.In spring,the three measures had the lowest porosity in the longitudinal terrace at the same slope,and the highest porosity in the terrace covered with vegetation in autumn.In spring,the porosity of the longitudinal terrace and the hedgerow decreases with the decrease of the slope position.The porosity of the longitudinal terrace was the highest in the middle slope In the autumn,the distribution of the hedgerow porosity was upper slope>lower slope>middle slope.The distribution of porosity of the terrace covered with vegetation was the upper slope>middle slope>lower slope.The porosity of the longitudinal terrace was the same with the spring results.In spring,the contents of organic matter,total nitrogen and available potassium in three different measures at the same slope were the highest in the longitudinal terrace,from the terms of soil nutrients,The available phosphorus content in the upper and lower slopes of the longitudinal terrace>the terrace covered with vegetation>the hedgerow,and in the middle slope was the terrace covered with vegetation>the longitudinal terrace>the hedgerow.The three measures of organic matter and available phosphorus in the same slope were all presented as the terrace covered with vegetation>the longitudinal terrace>the hedgerow,in autumn.The total nitrogen content in the upper slope and the middle slope showed the hedgerow>the terrace covered with vegetation>the longitudinal terrace.The lower slope was the hedgerow>the longitudinal terrace>the terrace covered with vegetation,the CEC at the same slope was the smallest,in spring and autumn.In the spring,the organic matter content in the hedgerow and the longitudinal terrace at different slope positions presented lower slope>upper slope>middle slope,the terrace covered with vegetation was gradually increasing from the upper slope to the lower slope.The hedgerow content of organic matter increased with the decrease of the slope in autumn.The terrace covered with vegetation showed a trend of decreasing after a small amplitude increasing.The content of organic matter in the longitudinal terrace presented upper slope>lower slope>mddle slope.Under the three measures,the total nitrogen and total phosphorus contents all presented lower slope>middle slope>upper slope.The contents of available phosphorus and total phosphorus of the three measures under the same slope were significantly different.The distribution of available phosphorus and total phosphorus in The terrace covered with vegetation and the hedgerow was opposite.The stability of soil aggregates under different measures was studied,After wet screening,>0.25 mm particle size content was higher in autumn than in spring.The average weight diameter(MWD)of the three measures on the upper slope was showed the longitudinal terrace>the hedgerow>the terrace covered with vegetation,the longitudinal terrace was 0.8% and 28.7% higher than the hedgerow and the terrace covered with vegetationt,The middle slope and the lower slope were in the form of the hedgerow>the terrace covered with vegetationt>the longitudinal terrace.The terrace covered with vegetation and the longitudinal terrace in the middle slope were lower 3.6% and 25.7% than the hedgerow,the lower slope were lower 5.0% and 33.2%.In autumn,the results of the three measures were consistent on different slopes,and the longitudinal terrace in the upper slope was 18.3% and 43.9% higher than the hedgerow and the terrace covered with vegetation.The hedgerow in the middle slope was higher 3.6% and 25.7% than the longitudinal terrace and terrace covered with vegetation.The distribution trend of MWD in different slopes under the three measures is the same in spring and autumn,and the MWD shows the descending lower slope>middle slope>upper slope,and there was a significant difference in different slopes under the same measure(p<0.05).Through RUSLE2.0 simulation and prediction of the measures,hedgerow combination with a spacing of 18 m at low slope is the best,and the measures with a ridge belt as the main effect is the most obvious after the slope is increased,especially in 8°,the soil conservation capacity was higher than other measures.The main innovation of this study was that Combined with the RUSLE2.0 model to simulate the allocation of three measures to predict the amount of soil loss under different measures,through the model more intuitive and visual combination of existing measures,combined with the physical and chemical properties of soil,comprehensive analysis of different measures under the control of soil erosion effect,optimization of measures allocation,It could A new method for soil erosion assessment was developed,and it was of great significance to further study the stability of soil aggregates in sloping farmland,which provides a theoretical basis for the prevention and control of soil erosion in sloping farmland in the black soil area of northeast China.