Dynamics of Litter Carbon and Nitrogen in Forest Fallows following Shifting Cultivation in Mizoram, Northeast India

Abstract

In this study, a field trial was carried out on organic matter, carbon (C) and nitrogen (N) dynamics of different litter components (i.e. leaf, branch, roots less than 2 mm and 2-5 mm) in forest fallows (3 years: FL-3, 5 years: FL-5 and 10 years: FL-10) at Muallungthu, Mizoram using litter bag techniques. The rate of organic matter loss and release of C and N was faster in leaf and fine root (less than 2 mm) compared to branch and coarse roots (2-5 mm). Further, litter mass loss rate was higher in longer fallow (FL-10) compared to shorter fallow (FL-3 and FL-5). Results showed that mass loss and release of C and N was largely depending on the initial litter quality, abiotic variables and litter microorganisms. Release of C followed the patter similar to that of mass loss, whereas, N release showed an initial release followed by a slow release or marginal increase that indicate the tendency of N immobilization. Results indicate that the addition of litter from the adjoining forest adds organic matter, C and N in shifting cultivation that may help in sustaining soil fertility and crop productivity of shifting agriculture sites in northeastern hill regions of Mizoram.