中国西部冬油菜种植的生态效应评价

为探讨在中国西部推广种植冬油菜的生态效益，以河西走廊4月份的冬油菜、冬小麦、麦茬和春播4种农田地表进行风洞模拟研究.结果表明：冬油菜具有显著的抗风蚀效果，其地表粗糙度可达4.08 cm，起动风速高达14 m·s^-1，而且在相同试验条件下，其风蚀模数和输沙率分别是春播农田的4.1%和485%，其土壤有机质、碱解氮、速效磷、速效钾及土壤过氧化氢酶、脲酶、碱性磷酸酶、转化酶活性和微生物数量等的流失量也仅分别是春播农田的1.4%、5.1%、1.6%、2.7%、9.7%、3.6%、6.3%、6.7%和1.5%.因此，在地表风蚀的我国西部地区研发、推广种植冬油菜，可有效防治农田土壤风蚀，蓄水保肥，并可增加复种指数和经济效益，具有防治土地沙漠化、改善区域生态环境的作用.

Ecological benefits of planting winter rapeseed in western China.

To evaluate the ecological benefits of popularizing winter rapeseed planting in western China, a wind tunnel simulation test was conducted with four kinds of farmland surface, i.e., winter rapeseed, winter wheat, wheat stubble, and bare field just after spring sowing, collected from west Gansu in April. The results showed that winter rapeseed surface had a roughness of 408 cm and a threshold wind velocity as high as 14 m·s-1, being more effective in blown sand control than the other three surfaces. Under the same experimental conditions, the wind erosion modulus and sand transportation rate of winter rapeseed surface were only 41% and 485% of those of the bare field just after spring sowing, and the losses of soil organic matter, alkali-hydrolyzed N, available P and K, catalase, urease, alkaline phosphatase, invertase, and microbes of winter rapeseed surface due to wind erosion were only 14%, 51%, 16%, 27%, 97%, 36%, 63%, 67% and 15% of those of the bare field, respectively. It was suggested that popularizing winter rapeseed planting in west China could control wind erosion, retain soil water and nutrients, increase multi-cropping index, and improve economic benefits of farmland. In addition, it could benefit the regional desertification control and ecological environment improvement.