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采用野外定位观测,研究三峡库区坡耕地7种林草治理措施下土壤活性有机碳组分(颗粒性有机碳、可溶性有机碳、易氧化有机碳和微生物生物量碳)含量和团聚体数量特征,并分析了团聚体的分形特征和可蚀性.结果表明,不同林草治理措施下,土壤有机碳及活性有机碳组分含量随土壤深度的增加而降低,其中0～10 cm土壤有机碳及各活性有机碳组分含量显著高于20～30 cm.林草措施治理对土壤团聚体稳定性也具有显著影响,>0.25 mm水稳性大团聚体总量总体上表现为:栾树+黄花槐>植物篱>封山育林>自然恢复>经济林>传统农作>裸地对照,且与土壤有机碳含量呈正相关.不同林草治理措施下土壤具有一定的土壤分形特性.其中栾树+黄花槐措施下土壤的分形维数、可蚀性K值最小,土壤结构稳定性和抗侵蚀能力相对较强.不同土壤深度下活性有机碳组分与土壤可蚀性K值均呈极显著负相关关系,以上研究表明通过不同林草治理措施的治理可改变土壤性状,从而影响土壤抗蚀能力.
Field observations were conducted to study the characteristics of soil active organic carbon (particulate organic carbon, soluble organic carbon, readily oxidizable organic carbon and microbial biomass carbon) and the number of aggregates under seven forest and grassland management measures in sloping farmland in the Three Gorges Reservoir Area , And the fractal characteristics and erodibility of the aggregates were analyzed.The results showed that the content of soil organic carbon and the content of active organic carbon decreased with the increase of soil depth under different forest management measures, of which 0 ~ 10 cm soil organic carbon And the content of each active organic carbon was significantly higher than 20 ~ 30 cm. The management of forest grass and grasses also had a significant effect on the stability of soil aggregates. The total amount of> 0.25 mm water-stable large aggregates showed as follows: Huai> hedgerows> closed hillsides afforestation> natural recovery> economic forest> traditional farming> bare land control, and positively correlated with soil organic carbon content.The soil had certain soil fractal characteristics under different forest and grass management measures, among which, Soil fractal dimension, erodible K value is the smallest, soil structure stability and erosion resistance is relatively strong.Under different soil depths, the values of active organic carbon and soil erodibility K are extremely significant Correlation between the above studies have shown that by forest and grass control measures of governance can change the soil properties, thus affecting soil resistance to corrosion.