关键词: 生物埂 , 蓄水保土 , 效应 , 坡耕地 , 紫色丘陵区

Abstract: 【Objective】 The article aimed to study the soil and water conservation benefits of four bunds at edges of sloping land in purple hilly area. 【Method】 A systematic analysis of the soil and water conservation benefits and its influencing factors of various bunds was made through such comprehensive research approaches as soil physical and mechanical properties analysis and so on. 【Result】 Soil total porosity of different bunds planted with vegetation were shown as mulberry＞prickly ash＞alfalfa＞natural grass; a similar varying trends of initial infiltration rate, final infiltration rate and mean infiltration rate for each kind of bund existed, which showing a trend of mulberry＞prickly ash＞alfalfa＞natural grass. Soil available water storage of all bunds was obviously different (P＜0.05) from natural grass, which presented as the bund planted with tree＞grass＞natural grass. During the process of water storage for all bunds, the higher the soil non-capillary porosity and soil total porosity was, the better the soil infiltration capacity could be. The larger the soil bulk density was, the worse soil infiltration capability and soil perviousness would be, which leading to larger unavailable soil reservoir, and also making it is difficult for crops on sloping lands to absorb soil water. Soil shear strength of all bunds was in the order as alfalfa (0.38 kg•cm-2)＞prickly ash (0.25 kg•cm-2)＞mulberry (0.22 kg•cm-2)＞natural grass (0.18 kg•cm-2), and internal friction angle of the bunds of prickly ash was the biggest（20.76°）among these bunds. The internal friction angle of all bunds had a significant negative correlation with fractal dimension of particle size distribution, initial water content of soil, while it had a significant positive correlation with fractal dimension of aggregate size distribution. However, soil cohesion and shear strength had a significant negative correlation with fractal dimension of particle size distribution and a significant positive correlation with soil dispersion, but soil cohesion and shear strength did not correlate significantly with fractal dimension of aggregate size distribution. 【Conclusion】 All bunds in purple hilly area improved the available soil reservoir by the way of improving soil physical properties such as soil pore structure and so on, which preventing sloping land from the damage of local seasonal drought. Moreover, the bunds also enhanced the soil shear strength and the ability of resistance to rainfall and runoff erosion, which obviously ensuring the stable productivity of sloping land in purple hilly area

Key words: bunds planted with vegetation , soil and water conservation , benefit , sloping land , purple hilly area