Shifting Cultivation Effects on Soil Environment in Upland Watershed of Bangladesh

Abstract

This research reports the effects of shifting cultivation on soil environment collecting samples from 0-5 cm soil depth from five locations viz. at Burburichhara, Maichchari, Longadu, Sukurchhari and Muralipara in Rangamati district of Chittagong Hill Tracts (CHTs). Soil analyses showed that fungal and bacterial population, microbial respiration and active microbial biomass, maximum water holding capacity, conductivity and moisture contents were significantly (at least <TEX>$p{\leq}0.05$</TEX>) lower in shifting cultivated soil compared to adjacent mixed tree plantations at all the sites. On an average in soils of 5 different shifting cultivated lands fungal population was <TEX>$1.33{\times}10^5$</TEX> CFU/g dry soil and bacterial population <TEX>$1.80{\times}10^7$</TEX> CFU/g dry soil and in mixed plantations fungal population was <TEX>$1.70{\times}10^5$</TEX> and bacterial population <TEX>$2.5</TEX><TEX>1{\times}10^7$</TEX> CFU/g dry soil. Organic matter and exchangeable Ca and Mg contents were significantly (at least <TEX>$p{\leq}0.05$</TEX>) lower and bulk density significantly (at least <TEX>$p{\leq}0.05$</TEX>) higher in shifting cultivated land in most of the locations compared to adjacent mixed tree plantations. Ratios of microbial respiration and organic carbon as well as active microbial biomass and organic carbon were distinctly lower and pH higher at 3 locations in shifting cultivated soils compared to mixed plantations. Findings of various soil properties, therefore, suggest that shifting cultivation has deteriorating effects on soil environment.