作物残茬与生物篱组合对减轻土壤风蚀的作用

    Effects of crop stubble combined with biological fences on reducing soil wind erosion

    • 摘要: 为了探究中国北方农牧交错带冬春风蚀季节生物篱与作物残茬组合对间作裸露秋翻地的防护作用,采用风蚀圈和野外移动式风洞试验的方法对研究区土壤风蚀情况进行监测,利用PC-3型自动气象站进行风速测定。结果表明,油葵秆生物篱减小了间作裸地近地面风速,提高了地表粗糙度;从防风蚀效果看草谷子茬优于油葵秆生物篱;在距油葵秆生物篱或草谷子茬下风向裸地不同位置处,土壤风蚀量基本呈先增加后减小的单峰曲线变化趋势,在4 m左右土壤风蚀量最大,在篱和茬的双重保护下,距茬5 m处发生了风积现象;土壤风蚀量降低率基本呈“V”字型分布;土壤风蚀模数随风速增大而增加,在生物篱的保护下5~15 m/s风速时土壤风蚀降低率为5.03%~20.53%。因此,油葵秆生物篱具有防风蚀作用,而且与草谷子残茬组合对间作裸地会起到更好的固土防蚀作用。

       

      Abstract: In order to explore protective effects of crop stubble combined with biological fence on bare intercropping autumn-ploughed farmland in spring and winter in ecotone between agriculture and animal husbandry, the methods of wind erosion ring and field movable wind tunnel instrument were adapted to monitor soil wind erosion with PC-3 automatic weather station used for measurement of wind speed in study region. The results showed that wind velocity near land surface was decreased and land surface roughness was increased by sunflower stalk as biological fence. It was found that the effect of reducing wind erosion of the millet stubble was better than that of biological fence, the reducing rate of wind erosion showed a shape of letter “V”, and the amount of wind erosion reached the maximum when the distance from biological fence or millet stubble was about 4 m. The wind deposit appeared at 5 m distance of the millet stubble in the bare field due to the protective effects of biological fence or millet stubble. The amount of wind erosion in the bare field was increased with the wind speed increased by movable wind tunnel, and the reducing rate of wind erosion was 5.03%-20.53% with the wind speed of 5 m/s to 15 m/s due to protection of biological fences. Therefore, sunflower stalk as biological fence can control the wind erosion and will play more efficient roles in holding soil if combining with crop stubble.

       

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