河北坝上农田垄向对土壤风蚀的影响

Effects of ridge direction in a field on soil erosion in Hebei Bashang region

在河北省坝上选择试验区 ,利用移动式风洞研究了农田起垄方向对土壤风蚀的影响。结果表明 ,农田起垄方向对土壤风蚀具有影响作用 :垄向与风向成 0°时风蚀量最大 ,90°时风蚀量最小 ;在 15m·s-1风速和 3cm表土含水率为 4 5 %的条件下 ,垄向与风向成 0°时的风蚀量为 90°时的 4 8倍。为减轻土壤风蚀危害 ,在河北坝上地区农田起垄的方向宜采用与自然风向NW (西北风向 ,315°)成 90°,即东北方向 4 5°。

A field experiment was conducted on farmland in Heibei Bashang region by means of field wind tunnel. The results showed that the direction of ridge in a field effects on soil wind erosion. The wind blown mass of farmland is maximum when the direction of ridge is 0°,and minimum when the direction of ridge is 90°. Furthermore, the wind blown mass in the direction of ridge 0° is same as 4 8 times in that of 90° at 15?m/s wind speed and 4 5 % moisture content in surface soil. Therefore, the direction of field ridge in Heibei Bashang region is suitable with 90° to NW(natural wind direction 315°), that is the direction in NE(45°).