Changes in soil properties after land degradation associated with various human activities in Thailand

Abstract

Abstract This work is a part of the “Waste Land Project” implemented with a view to developing a management plan to improve four different types of degraded lands throughout Thailand. Among them^two sites could be improved by proper fertility management^i.e.|sandy soil degraded after lowland shifting cultivation in Northeast Thailand (Somdet^Karasin province).|gravelly silicious deposit after tin mining in southern Thailand (Takuapa^Panga-nga province). Moreover^soil physical properties should be improved together to secure the development of a vegetational cover.|sound growth of crops. As for the two other sites^soil fertility was not always a limiting factor on plant growth while soil physical properties posed a more significant constraint^as indicated in the previous paper (Sakurai et al. 1995: Tropics, 4, 151-172).