Effects Of Long-term Conservation Tillage On Soil Properties And Crop Yield In Sloping Fields

Northern Shaanxi is one of the areas of agricultural land to natural disasters often occur, as well as global soil water and wind erosion, one of the worst areas. Type of agricultural land in the region mainly to the main slope farmland, its situation is more serious soil erosion. In the long-term adoption of conservation tillage practices, the study of changes in soil physical and chemical properties of sloping farmland, the choice of suitable farming methods in the region plays an important role. This study is located in Yulin City, Shaanxi Province, Shenmu six Gou Xiang River. Take conventional tillage and no-tillage farming process, straw mulching, plastic film mulching, ridging and mulching process, alfalfa intercropping five kinds of tillage representative, through long-term positioning of experiments, process control treated as an ordinary plowing expand farmland weather measurement techniques, analysis of soil bulk density Dry land in northern Shaanxi, the physical properties of soil saturated hydraulic conductivity of saturated soil moisture and soil roughness topsoil, topsoil farmland nutrients and other chemical properties and crop yields dynamic fluctuations. To explore the Loess Plateau dryland farming area provide valuable theoretical basis of the most efficient and rational agricultural practices, thus creating favorable conditions for the sustainable development of the region to optimize agricultural environment.(1) Taking conservation tillage cell surface soil total nitrogen, organic matter and other basic elements of content and available phosphorus, potassium and nitrogen, etc. radiate slow and steady increasing trend. 2015 interplanting and organic matter content of straw mulch increase 71.1%, 60.3% more than in 2008 respectively. Ridge coating, laminating and intercropping total nitrogen content of 2008 3.3 times, 3.1 times, 2.6 times. Total nitrogen content of the soil in order to harvest the cell straw mulch up to 0.426 g / kg, minimum tillage cell as 0.209 g / kg.(2) Straw mulching, film mulching treatment can effectively improve the surface soil moisture, respectively 6.31% and 5.93% higher than the control. After rainfall, higher processing performance straw mulch, 7.91% higher than the control treatment, after about 48 h can also provide its soil to absorb moisture. Soil tillage bulk gravity gradually stabilized value, and soil bulk density is relatively small, suitable for strong plant root growth. Straw mulching and no-tillage soil saturated hydraulic conductivity at a high level, 9.97% higher than the control treatment and 11.21%, after leveling off around 72 h.(3) Analysis of the soil when the ground temperature under different weather conditions of performance, the straw mulching and film mulching treatment can effectively adjust the temperature in the soil level. Wherein at a low temperature below 15 ℃, the treatment may be effective mulching to keep the soil in ground temperature above 18.6 ℃. In the temperature exceeded 38 ℃, the straw mulch cover can play a role in reducing the heating effect of the sun on the soil surface can be maintained less 33.5 ℃.(4) Straw mulching and film mulching can shorten the growth of soybeans, compared with an average reduction of 4 days control treatment; and to increase soybean germination rate, germination rate average increase of 11.2% compared with the control. Intercropping soybean growth of alfalfa processing longest was 174 days. Soybeans yields straw mulching, film mulching on yield and ridge mulching treatment are high. Soybean yield is the lowest alfalfa intercropping treatment. 2015 straw mulch, mulching, crop yield compared with the control ridge mulching increased by 15.71%, 14.41%, 51.74%. Intercropping treatment year after year yield fell to its lowest soybean yield substantially RPM> PM> SM> NT> CK> In trend.