中国黑土资源分布格局与动态分析

PATTERN AND CHANGE OF BLACK SOIL RESOURCES IN CHINA

该文从冻层的角度分析了黑土性状特点与形成过程 ,揭示了黑土资源的纬向分布与冻层存在的密切关系 ,根据季节冻结层底面年平均温度和年平均气温关系式 ,计算出满足黑土形成所必需的与纬度有关的气温条件 ,从而证明季节冻层决定了黑土纬向的分布。论文从土壤地质学的角度分析了东北黑土资源的经向分布格局 ,根据黑土的基本性状反演了第四纪黑土成土环境 ,说明地质历史时期的一系列构造运动造成了东北地区明显的经向地貌差异 ,进而影响土壤形成的植被条件、母质条件、水文条件以及元素迁移和聚集 ,从而限定了黑土资源经向分布范围。探讨了黑土资源数量和质量上的变化及其影响因素 ,强调了人类不合理的土地利用及化肥。

Black soil is famous for its high fertility of soil, which is especially important for agricultural development. It is significant to understand pattern and change of black soil for sustainable use of black soil resources. This paper analyses the distribution pattern of black soil resources according to viewpoint of geo-pedology and the distribute of seasonal frozen soil layer in the Songnen plain. Firstly, the close relation between the special forming course and the properties of black soil and frozen layer is analyzed, furthermore, according to the relation formula of annual average temperature at seasonal frozen layer bottom and upper earth, the necessary temperature making black soil develop is obtained. The results indicate that black soil is sure to develop on long-term steady or steady seasonal frozen layer, which is a proof that seasonal frozen layer distribution dominates black soil distribution along latitude. Secondly, the landforms characteristics of black soil at geological historical period is researched, which are vital factors for black soil distribution along longitude. The paper also discusses the change of black soil resources' quantity and quality: It indicates that occupying cultivated land and soil erosion are the leading factors of quantity change for black soil resources; the quality change of black soil resources is an integrated result brought about by natural and human activities factors, the former includes seasonal frozen layer moving northward, rainfall eroding soil, and special topography, landforms, etc., and the latter involves irrational land use and abusing chemical fertilizer and pesticide. Research results show that physical and chemical properties of black soil have been getting deterioration, moreover, severe soil degradation have occurred.