辽西低山丘陵区不同密度荆条实地放水冲刷试验研究

【目的】揭示辽西低山丘陵区植被密度对土壤抗冲性的影响。【方法】采用野外实地放水冲刷的方法,以荒草地为对照,对不同密度荆条(Vitex negundo var. heterophylla)的土壤抗冲性进行了研究。【结果】1)荆条对土壤的改良作用随密度的增加而增加;2)各样地地表径流量随着冲刷时间的延长呈波浪式增长的趋势,其中低密度荆条样地土壤抗冲系数在23.46～26.07(L·min)/g之间,中等密度荆条样地土壤抗冲系数在26.87～29.84(L·min)/g之间,而高密度荆条样地和荒草地在设计流量为4 L/min时,土壤抗冲系数大于8(L·min)/g和12(L·min)/g;3)各样地土壤抗冲系数随着冲刷量的增大逐渐减小,在上方来水量较小时荒草地的土壤抗冲系数最大,荆条的土壤抗冲系数在26.07～46.55(L·min)/g之间,在上方来水量逐渐增大时荆条的土壤抗冲性强于荒草地,在23.46～36.75(L·min)/g之间,且随荆条株密度的增大呈增大趋势。【结论】植被密度是影响土壤抗冲性的主要关键因子,该研究可以为辽西北地区水土保持林建设提供参考依据。

On-site Experimental Study on Water Washout for Vitex Negundo of Different Density in the Hilly Areas of Western Liaoning Province

【Objective】Reveal the effect of vegetation density on soil erosion resistance in low mountain and hilly areas of Western Liaoning Province.【Method】In this experiment, the soil scouring resistance of Vitex negundo var. heterophylla with different densities was studied by field drainage and scouring method, with barren grassland as control.【Result】(1) The improvement of soil by Vitex negundo increased with the increase of soil density, which was closely related to the change of soil physical and chemical properties by root system;(2) the surface runoff of different plots increased in a wave-like manner with the extension of scouring time. The coefficient of soil erosion resistance of low-density Vitex negundo plot ranged from 23.46 to 26.07 L/(min · g), and that of medium-density Vitex plot ranged from 26.87 to 29.8. The soil erosion resistance coefficients of high density Jingdao plot and barren grassland were greater than 8 L/min and 12 L/min when the designed flow rate was 4 L/min.(3) The soil erosion resistance coefficients of different plots gradually decreased with the increase of erosion amount, and the soil erosion resistance coefficient of barren grassland was the largest when the water inflow above was small, and the soil erosion resistance of Jingdao was stronger when the water inflow above was gradually increasing, and with Jingdao, the soil erosion resistance of barren grassland was stronger than that of barren grassland.【Conclusion】The density of strips increased. Vegetation density is the main key factor affecting soil erosion resistance.