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通过对子午岭林区顶级植被辽东栎群落0—100cm土层有机无机胶结物质的含量与类型、土壤大团聚体稳定性进行野外调查采样与室内测定,对胶结物质含量与分布及其对大团聚体稳定性的影响进行了研究,探讨了不同胶结物质对大团聚体稳定性的影响。结果表明:(1)土壤有机碳和碳酸钙含量在剖面上呈现出完全相反的分布规律。有机碳含量随土层的加深而降低,其中0—20cm土层中有机碳含量显著高于20—100cm土层;而碳酸钙含量随土层的加深而增加,其中20—100cm土层中碳酸钙含量显著高于0—20cm土层。土壤黏粒含量随土层的加深逐渐增加,但总体上变化不明显。(2)土壤大团聚体稳定性随土层的加深而降低,其中在20—70cm土层中大团聚体稳定性随土壤深度的增加变化最为剧烈(与0—20cm土层相比,破坏率增加了581.00%)。40—100cm土层中大团聚体破坏率是0—20cm土层中的7.25倍,表明表层大团聚体稳定性远远高于底层。(3)黄土大团聚体稳定性的提高主要取决于土壤有机碳含量。而在有机碳组分中,矿物结合态有机碳对大团聚体稳定性的提高起最直接作用。研究结果揭示了黄土主要胶结物质在土壤剖面中的分布特征,明确了矿物结合态有机碳是直接影响黄土大团聚体稳定性最强烈的胶结物质,这为培育良好的土壤结构体提供了一定的科学依据。
Through the field investigation and indoor determination of the content and type of organic-inorganic cements and the types of soil organic aggregates and the stability of soil macroaggregates in Quercus liaotungensis, a top-grade vegetation in Ziwuling Mountains, The effects of different cements on the stability of large aggregates were investigated. The results showed that: (1) The content of soil organic carbon and calcium carbonate showed the completely opposite distribution in the profile. The content of organic carbon decreased with the deepening of soil layer, in which, the content of organic carbon in 0-20cm soil layer was significantly higher than that in 20-100cm soil layer; while the content of calcium carbonate increased with the soil depth increasing, Calcium content was significantly higher than 0-20cm soil layer. Soil clay content increased with the deepening of soil layer, but the overall change is not obvious. (2) The stability of soil macroaggregates decreased with the deepening of soil depth. The stability of large aggregates in 20-70cm soil layer changed most rapidly with the increase of soil depth (compared with 0-20cm soil layer, the damage rate An increase of 581.00%). The failure rate of large aggregates in 40-100cm soil layer is 7.25 times of that in 0-20cm soil layer, indicating that the stability of large surface aggregates is much higher than the bottom layer. (3) The improvement of the stability of loess macromer mainly depends on the soil organic carbon content. Among the organic carbon components, mineral-bound organic carbon plays the most direct role in improving the stability of large aggregates. The results revealed the distribution characteristics of the main cements in the loess soil profiles. It is clear that the mineral-bound organic carbon is the most stable cementitious material that directly affects the large-scale aggregates. This provides a certain Scientific basis.