低丘红壤林地开垦利用过程中土壤肥力退化的数值分析

通过对林地开垦后不同利用年限红壤旱地的肥力分析，发现红壤旱地有以有机质和粘粒下降为中心的肥力退化行特征，因此增加有机特的投入，减缓有机质下降速率和水土流失是防治红壤旱地退化的关键，有机质状况也可作为评价红壤旱地退化的一英重要指标。

Numerical analysis of soil fertility degradation in the reclamation process of forest land on low hilly red soil

Numerical analysis method was used to study the soil fertility degradation in the reclamation process of forest land on low hilly red soil with cultivated time.It was found that fertility degradation of the soil after reclamation of forest land was mainly characterized by the decrease of organic matter and clay contents.It was suggested that increasing input of organic materials,weakening decrease rate of organic matter and controlling water and soil erosion was the key of preventing degradation of upland on low hilly red soil.The level of soil organic matter could be a criterion to evaluate fertility degradation of upland on low hilly red soil.