我国中亚热带缓丘区红粘土红壤肥力的演化Ⅰ.物理学肥力的演化

我国东南丘陵区有丰富的气候和生物资源，红壤肥力是限制其潜力发挥的重要因子。本文着重探讨中亚热带红粘土红壤物理学肥力在不同利用过程中的演化特征，然后通过数理统计分析筛选出评价指标，确定各自的权重系数，最后对土壤的物理学肥力进行了评价。结果表明．与林草地土壤相比，耕垦后表层红粘土红壤的物理学肥力在江西发生退化，表现在土壤结构遭破坏，大团聚体和微团聚体数量减少，土壤通气和气管孔隙减少，毛管孔隙分布不均匀

FERTILITY EVOLUTION OF RED SOIL DERIVED FROM QUATERNARY RED CLAY IN LOW-HILLY REGION IN MIDDLE SUBTROPICS I. EVOLUTION OF SOIL PHYSICAL FERTILITY

The characteristics of physical fertility evolution under various land use patterns of red soil derived from Quaternary red clay in low-hilly region in the middle subtropics were researched, then the evaluation indexes were selected with cluster analysis and their weight coefficients determined with factor analysis.Results showed that the soil physical fertility in forest and grass land systems was not obviously lower than in cultivated land systems as soil chemical fertility showed.In the systems in Jiangxi Province, the soil physical fertility degraded with the reclamation, which was mainly expressed by the destroy of soil structure, the decrease of soil larger aggregate and microaggregate, the drop of soil aeration and capillary porosity and the uneven-distributed capillaries.However in those systems in Zhejiang Province, it rose with the reclamation.In cultivated land systems, the upland soil physical fertility increased with the cultivation, but the upland crops-rice rotation has a disadvantageous effect.The soil physical fertility in tea garden system was higher than that in citrus orchard.