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

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.