北京市保护性耕作防治土壤风蚀的效果研究

对北京市昌平区耕地少耕、残茬覆盖防治风蚀效果的试验研究结果表明:与传统的秋翻耕地相比,少耕、残茬覆盖能够减小农田土壤风蚀量,尤其对减小18m/s以上大风侵蚀效果显著。秋翻地风蚀量是留茬地风蚀量的几倍甚至几十倍,残茬量对风蚀量的影响有一临界值,当地表覆盖的残茬量达到这个数值时风蚀量即明显减小。土壤中大粒径团聚体含量的增加能够减小风蚀量。我国北方雨水量较少的地区,降雨后形成地表结皮,如果结皮后长时间不再降雨导致地表干燥和土块少,反而会使风蚀量增大。土壤含水率和地表残茬覆盖共同影响着土壤的风蚀量。

Study on Effects of Wind Erosion Prevention and Control through Protective Cultivation in Beijing Municipality

According to the study on few tillage and residual coverage for wind erosion prevention and control conducted on the cultivated land in Changping District of Beijing Municipality, it shows that the method of few tillage and residual coverage can reduce the wind erosion of farmland comparing with the traditional tillage of ploughing up in autumn, especially it has remarkable effects for reducing the wind erosion of stronger than 18 m/s. The amount of wind erosion of ploughing up fields in autumn is several times even tens times higher than that of the fields with residuals. The influence of residuals on wind erosion has a critical value and when the residuals of ground coverage reach to the value, the quantity of wind erosion will be reduced. The increase of large particle size concentration of the soil can reduce the quantity of wind erosion. After raining, the ground surface of the region where has less precipitation in northern China would be hardened. If there is no more rainfall after hardening for a long time, it will result in dry ground surface, less lumpy soil and increase the quantity of wind erosion. The percentage of soil moisture content and surface residual coverage jointly influence the quantity of wind erosion.