COMPARISON OF SOME CHEMICAL PROPERTIES OF SOIL UNDER TEAK AND NATURAL FORESTS AT MTIBWA, MOROGORO, TANZANIA

Abstract

This study was initiated to compare some soil chemical properties of natural forests and first rotation teak plantations at Mtibwa Forest Project, Morogoro, Tanzania. A total of 240 soil samples were taken from 24 paired plots, i.e. 24 plots from each teak plantation and from the adjoining natural forests. These samples were analysed for pH, electrical conductivity (EC), total N, available P and exchangeable cations. The soil pH and exchangeable cations from the teak plantations were not significantly different (p <0.05) from the natural forests. The soil EC within 0-70 cm depth in young teak plantations decreased by
24% while in semi-mature teak plantations it increased by 36% as compared to the adjoining natural forests. In general there was a decrease in the young plantations but an increase in the semi-mature plantations in total N. In both young and semimature stands there was a decrease in available P. The results of this study suggest that there is a need for continued monitoring of soil chemical properties in teak plantations since there are indications of changes in soil properties.