北京冬春覆盖作物对农田土壤风蚀扬尘的影响

Effect of Winter and Spring Cover Crops on Soil Wind Erosion and Dust Emission in Farmlands of Beijing

为了确定北京主要越冬作物对农田土壤风蚀及扬尘排放的影响,通过野外观测的方法,对比研究了春季玉米根留茬地、金银花地、越冬油菜地的近地表风速、风蚀量及颗粒物排放量的差异。结果表明:(1)冬春季地表绿色覆盖能够显著降低农田近地表风速(P<0.05),金银花地的平均风速比玉米根留茬地低15.86%;(2)油菜地的月平均输沙量比玉米根留茬地低67.06%;(3)金银花地与玉米根留茬地相比,TSP和PM10浓度降低35.18%和35.42%,差异显著(P<0.05),冬油菜地的PM2.5浓度比玉米根留茬地低11.63%,差异显著(P<0.05)。因此,可以通过推广冬春覆盖作物来减少北京或华北地区的农田土壤风蚀扬尘,提高土地生产力。

In order to determine the influence of winter and spring cover crops on soil wind erosion and dust emission in farmland of Beijing,the difference of near-surface wind speed,wind erosion and particulate matter emission in corn stubble fields,honeysuckle fields and winter rapeseed fields in several wind erosion events were comparatively studied by field observation.The results indicated that:(1)The green cover could significantly reduce the wind speed near surface(P<0.05).and the average wind speed in honeysuckle fields was 15.86%lower than that in corn stubble fields.(2)Monthly mean values of soil wind erosion in winter rapeseed fields was67.06%lower than that in corn stubble fields.(3)Compared to corn stubble fields,the concentrations of total particulate matter(TSP)and PM10 in honeysuckle fields decreased by 35.18%and 35.12%with significant difference(P<0.05)and PM2.5 concentrations of winter rapeseed fields decreased by 11.63%with significant difference(P<0.05).Therefore,winter and spring cover crops could be promoted to control soli wind erosion and dust emission in farmlands to improve land productivity in Beijing or Northern China.