| The black soil region of Northeast China is one of the world’s three largest black soil region, it’s also an important grain production base in china. Soil and water loss in the area in recent years become an important limiting factor of regional sustainable development and food security. Agricultural production will increase the intensity of soil erosion, the accelerated erosion which makes the local shortage of water resources and development of the agricultural industry needs the contradictions have become increasingly prominent, grasp the main crops in the northeast slope farmland is one of main methods of local agricultural sustainable development and food security impacts on soil erosion characteristics. The study conducted in Bei’an City, Heilongjiang Province, the Red Star farm. Aiming at the realistic problems of serious soil and water loss on the sloping farmland in the gentle hilly region of the western Heilongjiang province, In 2013 and 2014 two years using standard runoff plots experiment which is 3 °,5m width,20 m long, use automatic recording system, sediment runoff collection system and digital image acquisition to data collection. The test for local crops widely cultivated soybean and corn. The soybean, corn and soybean monoculture Corn Intercropping plots in the natural rainfall runoff and sediment in the next process and rainfall, annual rainfall, runoff and runoff distribution and variation of soil water content, leaf area index and vegetation coverage changes were observed and studied, analyzed the influence on the characteristics of soil erosion different crops and tillage mode, and the establishment of different vegetation and cultivation mode of USLE model and the rainfall erosion quantity based on the model, in order to provide reference for the local crop breeding to achieve the sustainable development of agriculture, and realize the protection of black soil、 goal of scientific development, The preliminary conclusions are as follows:(1) The performances of runoff retaining, corn performed the best, while the intercropping of soybean-corn second and soybean the last. Compared to soybean, the surface runoff of individual rainfall decreased 15% and 10% under the cultivation modes of corn and intercropping of soybeancorn, low intensity rainfall also has the obvious difference. Compared with soybean plot, corn intercropping plot annual runoff decreased 12.84 mm and 5.91 mm respectively.(2) The performances of sediment yield control, corn performed the best, while the intercropping of soybean-corn second and soybean the last, consistent with the runoff retaining effect. Compared to the soybean plot the maize and intercropping polt soil erosion of growth period was decreased respectively 0.48t/hm2 and 0.25 t/hm2.(3)The temporal distribution characteristics of soil erosion, vegetation plot erosion mainly with monthly rainfall and change. The amount of soil erosion in July and August accounted for about 80% of the annual rainfall, similar to little annual rainfall variation. The corn on sediment yield control effect is best, followed by intercropping. Corn, soybean, intercropping and soil erosion were 5.04, 4.35 and 4.81t/hm2·a. Obviously we can see that the maize for soil and water conservation has a better ability of sediment yield control. In the same growth period of soybean, corn, and intercropping are large differences with that.(4)In the measure of different crops(corn, soybean) canopy effects on soil erosion, Leaf area index has better reflect the vegetation canopy of two representative control soil erosion compared with vegetation coverage rate. The leaf area index of various vegetation from big to small in maize, intercropping, soybean, and the vegetation interception and runoff and soil erosion control arrangement agreement. The vegetation coverage on the difference of vegetation is not obvious, or even part of growth period between runoff interception and soil erosion control ability on the contrary. The black soil area of cultivated soybean, broken corn leaf area index and the quantitative relationship between the vegetation coverage is rarely studied, and its effect on raindrop kinetic energy and soil erosion, these should be the future research can explore.(5)Compared with soybean plots, cron plots’ moisture evaporation of soil water fast, higher conversion rate, it’s conducive to the runoff interception. Intercropping soil water transformation rate between monoculture corn and soybean, soil water consumption faster than soybean plots, at the same time the deeper soil water is change also more obvious. Soybean maize intercropping patterns on soil water transformation, consumption and transport is more close to the maize monoculture mode. Some indicators or even superior maize monoculture.(6)The amount of sediment yield prediction model is established based on the difference vegetation of corn and soybean. Models are validated by the measured data. Also Through the Quantitative Theory I established the rainfall erosion model, to make up for the defects of the USLE cannot applicable individual rainfall erosion. Simulation results prove the validity of the model. |
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