Abstract

Teak is a major component of the man-made forests in Kerala. As a result of monoculture of teak, changes may occur in soil properties and whether such changes are beneficial or detrimental to the succeeding teak crops should be of concern. The project, properties of soils under teak, was started with the objective of evaluating changes in soil properties due to continuous teak cropping. Literature suggests tht without proper soil management, clearfelling of natural or plantation forests and monoculture of teak may result in soil deterioration depending on the initial soil conditions, topography, climate and management practices. However, in a long-rotation crop like teak, soil properties may recuperate and there may be stabilization of properties provided no drastic disturbances to the sites occur. Soil profiles were chosen from teak preservation plots at Perinthomuzhi, Elencheri and Begur for comparative study of first and second rotation profiles. One hundred and two surface samples (0-20 cm) were also taken at random from several plantations for an overall evaluation of soil properties in first and to some extent in second rotation teak plantations. Particle-size separates, pH, organic carbon and cation exchange capacity analyses were done. The data indicate similarity of the first and second rotation profiles of Perinthomuzhi and Begur in relation to distribution of particle-size separates, pH, organic carbon and cation exchange capacity. Although the second rotation Elencheri profile has a different distribution of these properties, increased levels of organic carbon and cation exchange capacity in ti demonstrate no deterioration of these integrative properties. In fact, the profile data reveal recuperation of these soil parameters during the long rotation of 60-70 years. Thus, the relatively higher levels of organic carbon and cation exchange capacity in the surface horizons of profiles and in the surface samples suggest that soil parameters should not limit growth of teak in first and to some extent in second rotation plantations