李琳　石颜通　杨林　聂紫瑾

摘    要：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。

关键词：冬春覆盖作物;近地表风速;农田土壤风蚀;颗粒物特征

中图分类号：S157          文献标识码：A         DOI 编码：10.3969/j.issn.1006-6500.2021.01.020

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

LI Lin，SHI Yantong，YANG Lin，NIE Zijin

（Beijing  Agricultural Technology Extension Station，Beijing 100096，China）

Abstract： 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 was  67.06% 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.

Key words： winter and spring cover crops; near-surface wind speed; farmland soil wind erosion; particle characteristics

近年来，多次发生严重的灾害性沙尘天气，给首都市民的生产、生活造成严重影响，引起社会各界的广泛关注[1-2]。有研究表明，北京大气沙尘颗粒物既有外来源，也有本地源，浮尘和尘暴颗粒物以外来源为主，而扬沙颗粒物主要产生于本地源。北京市近50 a的沙尘天气中，浮尘和沙尘暴分别占20%和9%，其余71%均为扬沙。可见，北京本地风蚀起沙问题也是比较严重，北京周边农田是北京沙尘暴的重要沙源[3-4]。冯晓静等[5]利用可移动野外风蚀风洞对北京周边典型农田进行了农田风蚀的研究，考察了耕作制度等因素对风蚀的影响规律。李晓娜等[6]应用风蚀圈方法测定了延庆县康庄不同土地利用方式下的风蚀量，王升堂等[7]利用集沙仪对玉米留茬地的地表风蚀量进行了野外观测，但以往研究大多局限于保护性耕作和土地利用方式，也有学者对北京冬季覆盖作物农田风蚀问题进行了研究[8-9]，但是针对北京农业结构调整后发展起来的冬季景观覆盖作物对北京市农田风蚀问题的研究还很不充分，尤其缺乏深入地实地观测。……