农牧交错带不同农田耕作模式土壤风蚀的风洞实验研究

在农牧交错带——内蒙古自治区太仆寺旗采集的土壤样品的风洞实验研究结果表明:耕作模式的不同导致土壤风蚀状况的差异。在深松、翻耕、翻耕碾碎、小麦茬10 cm、荞麦茬10 cm、胡麻茬10 cm与无残茬等7种耕作模式的风洞实验中,翻耕碾碎风蚀速率均值最大,达到124.8 g m-2 min-1,胡麻茬最小,为15.14 g m-2 min-1,前者是后者风蚀速率的8.24倍。7种耕作模式风蚀速率均值的大小顺序为:翻耕碾碎>无残茬>深松>荞麦茬>翻耕>小麦茬>胡麻茬。结合对不同耕作模式土壤风蚀速率与风速关系的进一步分析可定量揭示出:翻耕碾碎、无残茬模式防风蚀效果最差,胡麻茬、小麦茬、翻耕模式防风蚀效果最好,深松、荞麦茬防风蚀效果居中。本文结论对农牧交错带旱作农业增强农田防风抗蚀能力有借鉴意义。

WIND TUNNEL EXPERIMENT ON EFFECTS OF DIFFERENT CULTIVATION PATTERNS ON SOIL WIND EROSION IN AGRO-GRAZING ECOTONE, INNER MONGOLIA

Soil was collected from Taipusi County, Inner Mongolia, for wind tunnel experiment. Results indicate that different cultivation patterns result in objective difference in wind erosion. In the wind tunnel experiment, seven cultivation patterns were simulated with the soil, such as subsoiling, deep plowing, plowing and scrunching, 10 cm high wheat stubbles, 10 cm high buckwheat stubbles, 10 cm high benne stubbles, and no-stubble. Among them, the pattern of plowing and scrunching was the highest in wind erosion rate, being 124.8 g m-2 min-1, whereas the pattern of benne stubbles the lowest, being 15.14 g m-2 min-1 . The seven farming patterns were in the order of plowing and scrunching > no-stubble > subsoiling > 10 cm high stubble of buckwheat > deep plowing > 10 cm high stubble of wheat > 10 cm high stubble of benne in average wind erosion rate. The relationship between wind erosion rate and wind speed was analysed, showing that in terms of effect of wind erosion control, the patterns of plowing and scrunching and no-stubble were the poorest and the patterns of benne stubbles, wheat stubbles and plowing were the best, and the patterns of subsoiling and buckwheat stubbles were medium. The conclusion drawn in this paper is of some significance for reference in controlling wind erosion in dryland agriculture in the agro-grazing ecotone.