多花木蓝与狗牙根不同种植模式对三峡黄棕壤抗蚀性影响

Impact of Different Planting Patterns of Magnolia multiflora and Cynodon dactylon on the Antierodibility of Yellow Brown Earth in Three Gorges Area

通过静水崩解试验及对土壤各抗蚀性指标的探索研究,分析了三峡库区黄棕壤在多花木蓝和狗牙根不同种植模式下的抗蚀性。结果表明:(1)静水崩解过程中,土壤崩解速率表现为空白地>多花木蓝>狗牙根>混播;较空白地土壤,有根试样土壤其崩解速率有很大的减缓,其中混播效果最好,且根系各密度指标与抗蚀性增强值均表现为显著线性相关。(2)与空白地相比,不同种植模式下,土壤水稳性团聚体含量、平均重量直径、有机质含量、团聚状况、团聚度、土壤黏粒含量均有明显的提高,而结构破坏率、分散率则明显下降。(3)通过主成分分析表明:以>0.25mm湿筛团聚体含量、结构破坏率、团聚状况、分散率、有机质为指标能较好地衡量黄棕壤在植被恢复下土壤抗蚀性能。

In order to analyze the soil antierodibility characteristics of the yellow brown earth in the planting pattern of Magnolia multi flora plus Cynodon dactylon （Linn.） Pers. in Three Gorges Area, hydrostatic disintegration test has been conducted to investigate different soil antierodibility indexes. The results are as follows. First of all, in the process of hydrostatic disintegration, soil disintegration rate decreases in the order： bare land〉Magnolia multi flora 〉Cynodon dactylon （Linn.） Pers〉mixture sowing. Compared with the bare land, the disintegration rate of the soil, which included roots, has greatly slowed down, while mixture sowing of that was the slowest. The density of the root system were significantly linearly correlated with the antierodibility enhancement. Secondly, compared with the control sample, soil water stable aggregate contents, mean weight diameters, organic matter contents, agglomeration status, reunion and soil clay contents were significantly improved under different planting modes. What＇s more, structural damage rate and dispersion ratio decreased significantly. Thirdly, principal component analysis showed that the indexes of wet sieve aggregate （〉0.25 mm） content, structural damage rate, agglomeration status, dispersion rate and organic matter could better measure erodibility resistance of yellow brown earth under vegetation restoration.