Effects Of Conservation Tillage On Soil And Water Conservation Under Simulated Rainfall

The treatment of remaining stubble after crop on transverse slope and stubble mulch can significantly conserve soil and water on loess plateau. They can increase soil infiltration ratio, weaken the erosion caused by runoff, reduce runoff volume and sediment volume on slope. In my article, we studied the effects of stubble mulch height and stubble mulch on runoff and sediment volume by simulated rainfall. Revealing the regulation of soil and water conservation of conservation tillage. Results show that:1.Applications of remaining stubble can delay initial runoff time, and the higher the stubble is, the time delays longer. When under the situation of high remaining stubble, the regulation of time delaying is the same to loessial soil and sandy soil: time delays less as slope degree grows with the degree range 1 to 10. When degree grows to 15 degree, the time is shorter than that on 10 degree. The initial time of loessial soil is 1.5 times than that of sandy soil. The stubble mulch can delay initial by 14.3% to 54.5%, while 18.9% to 88.1% to sandy soil.2.The total runoff depth decrease along with the increase of stubble height. The total runoff depth of 5cm stubble height application reduce 16.77% compared with ck treatment, which is 19.29% to the 10cm, 29.19% to 15cm. When slope is 5 degree, high stubble can reduce runoff depth by 16.78%, which is 20.85% under 10 degree slope, 22.08% under 15 degree slope. When slope degree is between 1 to 10, runoff depth grows with degree, when the degree is 15, the runoff depth decreases compared to 10 degree treatment. Stubble mulch can reduce 55.26% to 72.63% under loessial soil, 54.69% to 77.78% to the sandy soil treatment. The stubble mulch can significantly reduce runoff depth.3. Under certain slope degree, 5cm remaining stubble application can reduce 16.77% sediment volume compared to CK application, 10cm can reduce 19.29%, while 15cm reduce 29.19%. And it is more significantly along with the growth of stubble height. Under 5 degree slope treatment, remaining stubble can reduce 20.85% of sediment volume, 20.85% to 10 degree, and 22.08% to 15 degree. The higher the slope degree is ,the effects shows more obvious. In the slope degree range of 1 to 10, the sediment grows with the slope degree, when the degree grows to 15, the sediment reduces. Stubble mulch can significantly reduce soil erosion both in the losessial soil and sandy soil treatments.4. Under the remaining stubble mulch, the accumulated runoff volume and accumulated sediment volume are power functioned ,when the stubble is higher than 5cm, runoff devotes more to sediment, when the stubble height, the coefficients decrease along with the slop degree, it shows that, runoff devotes less to sediment with the growth of slope degree. Accumulated runoff volume and accumulated sediment volume of high remaining stubble are power functioned . under the application of stubble mulch, the accumulated runoff volume and accumulated sediment volume are liner functioned, runoff devotes less to sediment volume with the growth of maze.