The Loess Plateau, which is located in the arid and semi-arid areas of China, experiences significant soil erosion due to intense human activities and soil erodibility. It is necessary to explore and identify the land...The Loess Plateau, which is located in the arid and semi-arid areas of China, experiences significant soil erosion due to intense human activities and soil erodibility. It is necessary to explore and identify the land-use types or land-use patterns that can control soil erosion and achieve certain agricultural production capabilities. This study established runoff plots with two slope gradients （5° and 15°） in north of Yan＇an, one area of the Loess Plateau, with 3 single land-use types （cultivated land, CL; switchgrass, SG; and abandoned land, AL） and 2 composite land-use types （CL-SG and CL-AL）. From 2006 to 2012, we continuously monitored the rainfall characteristics, runoff depth, soil loss, vegetation coverage, and soil physical properties. The results indicated a general trend in the number of runoff and soil loss events for the 5 land-use types： CL = CL-SG 〉 CL-AL 〉 SG〉 AL. The general trend for runoff depth, soil loss, their magnitudes of variation, and the slopes of rainfall-runoff regression equation was CL 〉 CL-SG 〉 CL-AL 〉 SG 〉 AL, whereas the rainfall threshold for runoff generation exhibited the opposite trend. Results of nonparametric test regarding runoff depth/EI3o and soil loss/EI3o, where EI3o is the product of rainfall kinetic energy and the maximum rainfall intensity over 30 min, and the runoff depth-soil loss relationship regression indicated that the effect of CL-AL was similar to that of SG; SG was similar to AL; and CL-AL, SG, and AL were superior to CL with regard to soil and water conservation. Runoff depth and soil loss significantly increased as the slope gradient increased. Runoff depth and soil loss were significantly correlated with the soil particle size composition and bulk density, respectively. The strongest significant correlations were found between runoff depth and vegetation coverage as well as between soil loss and vegetation coverage, which showed that vegetation coverage was the primary factor controlling soil erosion. Therefore, the composite land-use type CL-AL and the artificial grassland （SG） are appropriate options because both soil conservation and a certain degree of agricultural production are necessary in the study area.展开更多
基金This work was supported by the National Natu- ral Science Foundation of China （Nos. 41390462 and 41501201） and the foundation of the Ministry of Land and Resources, China （No. 2015-01-62）. The authors wish to acknowledge the Ansai Research Station of Soil and Water Conservation, Chinese Academy of Sciences for their support and contributions to this fieldwork. Special gratitude is expressed to two anonymous re- viewers for their valuable suggestions in improving the manuscript.
文摘The Loess Plateau, which is located in the arid and semi-arid areas of China, experiences significant soil erosion due to intense human activities and soil erodibility. It is necessary to explore and identify the land-use types or land-use patterns that can control soil erosion and achieve certain agricultural production capabilities. This study established runoff plots with two slope gradients （5° and 15°） in north of Yan＇an, one area of the Loess Plateau, with 3 single land-use types （cultivated land, CL; switchgrass, SG; and abandoned land, AL） and 2 composite land-use types （CL-SG and CL-AL）. From 2006 to 2012, we continuously monitored the rainfall characteristics, runoff depth, soil loss, vegetation coverage, and soil physical properties. The results indicated a general trend in the number of runoff and soil loss events for the 5 land-use types： CL = CL-SG 〉 CL-AL 〉 SG〉 AL. The general trend for runoff depth, soil loss, their magnitudes of variation, and the slopes of rainfall-runoff regression equation was CL 〉 CL-SG 〉 CL-AL 〉 SG 〉 AL, whereas the rainfall threshold for runoff generation exhibited the opposite trend. Results of nonparametric test regarding runoff depth/EI3o and soil loss/EI3o, where EI3o is the product of rainfall kinetic energy and the maximum rainfall intensity over 30 min, and the runoff depth-soil loss relationship regression indicated that the effect of CL-AL was similar to that of SG; SG was similar to AL; and CL-AL, SG, and AL were superior to CL with regard to soil and water conservation. Runoff depth and soil loss significantly increased as the slope gradient increased. Runoff depth and soil loss were significantly correlated with the soil particle size composition and bulk density, respectively. The strongest significant correlations were found between runoff depth and vegetation coverage as well as between soil loss and vegetation coverage, which showed that vegetation coverage was the primary factor controlling soil erosion. Therefore, the composite land-use type CL-AL and the artificial grassland （SG） are appropriate options because both soil conservation and a certain degree of agricultural production are necessary in the study area.
