Biological Factors involved in the Formation of Soils in Established Grasslands ----A Suggestion of Ecological Method of Grassland Establishment----

Abstract

The authors summarized the biological factors involved in the formation of several kinds of soils in established grasslands and suggested the future course of the method of grassland establishment which was payed regard to the conservation of natural environment. The authors described mainly the effect of root system on the clay mineralogical characteristics as well as physical and chemical ones of some kinds of soils, and also described briefly the importance of the roots of grasses and legume, soil fauna and soil microbe as the biological factors involved in the formation of grassland soil. After discussing the classification and the problems of the methods of grassland establishment adopted in Japan recently, it was considered to be introduce Landscape EcologyM which studied the method of grassland establishment with attention to the conservation of natural environment and the beautiful landscape. And the authors suggested the ploughless method with a stumpcutter-bushcutter system as an ecological method of grassland establishment which would satisfy those needs.