Abstract

Four soil profiles were taken from a natural forest (South Indian Moist Deciduous) and two teak plantations (established in 1973 and 1940) of Thiruvananthapuram Forest Division and samples were collected from 0-15, 15-50 and 50-100 cm layers. It was found that texture of soils under natural forest varied from loam in the surface to sandy clay loam in deeper layers. In the case of 1973 and 1940 plantations, texture was sandy loam in the 0-15 and 15-50 cm layers. This changed to sandy clay loam, in 1973 while in 1940 plantation, it was sandy loam in the 50-100 cm layer. Acidity, cation exchange capacity and organic carbon decreased with depth as well as in the sequence natural forest, 1973 and 1940 teak plantations. Total as well as different form of N also followed the same trend. It has been observed that all properties exhibited significant difference due to vegetational types