不同草篱种植模式对土壤侵蚀的控制效应

    Effects of Different Patterns of Contour Grass Hedgerow on Soil Erosion Control

    • 摘要: 选取我国南方红壤丘陵区5种等高草篱种植模式,结合径流小区法和稀土元素示踪技术,开展不同草篱控制坡地水土流失、减少地表径流的效应研究,分析等高草篱对坡面侵蚀空间分布的影响。结果发现,径流小区土壤流失量显著受降雨量影响,不同草篱种植模式下,各径流小区的平均土壤流失量和地表径流量较对照组(裸坡)均显著降低(P<0.05),其中麦冬双行草篱处理平均土壤流失量和地表径流量最小,分别为4 047 g 和 1 554 L,对照组(裸坡)最大,分别为19 793 g 和2 403 L;麦冬双行草篱在控制坡面土壤流失和径流方面效果最佳;通过平均土壤流失量和平均径流量的二次线性拟合模型发现,随着地表径流量的变化,不同处理下土壤流失量的边际值存在差异;坡面中、下部是侵蚀泥沙的主要溯源地,产生了接近总流失量85%的泥沙;草篱改变了降雨过程中坡面内部土壤因沉积作用导致的再分布,但对整个坡面土壤侵蚀的空间分布规律无明显影响。

       

      Abstract: A run-off plot method combined with the rare earth elements tracing technique was used to study effects of contour grass hedgerows on control of soil erosion and surface run-off and spatial distribution of soil erosion on slope land in red soil hill regions of South China. Five different patterns of contour grass were planted for the experiment. It was found that soil losses from the run-off plots were obviously affected by rainfall. In run-off plots with contour grass hedgerows established, regardless of pattern, mean soil loss and surface run-off was significantly lower than in CK (bare land)(P<0.05). Among the five patterns of grass hedgerows, the one of double-row Ophiopogon japonicas was the most effective in controlling soil erosion and surface run-off. So the plot was the lowest in mean soil erosion and surface run-off, being 4 047 g and 1 554 L, respectively, while CK was the highest, being 19 793 g and 2 403 L, respectively. It was also found that through quadratic linear fitting using a model that differences existed between treatments in marginal value of soil loss as a result of variation of surface runoff. The middle and down slopes were the major source of sediments, contributing nearly 85% to the total soil loss. Although the grass hedgerows changed the soil re-distribution through sedimentation within the slope, they did not have any obvious effect on spatial distribution patterns of soil erosion on the slope.

       

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