Leaf Litter Decomposition and Nutrient Release Dynamics of Flemingia semialata Roxb. - A Potential Woody Perennial Species for Mountain Agroforestry

Leaf litter decomposition and nutrient release dynamics of Flemingia semialata Roxb. were studied from May 2016 to April 2017 using the litter bag technique. The study on litter dynamics is needed to assess the nutrient release pattern before introduction in degraded or marginal lands or agroforestry systems for soil nutrient management practices in hilly northeast states of India. The initial N concentration, lignin content, and lignin/N ratio of leaf litter had significant positive correlations with decay coefficients. The annual decay rate constant (k) for dry matter was 0.01 day(-1) (3.65 year(-1)) with t(50) and t(99) values of 96.43 and 695.73 days, respectively, indicating faster leaf litter decomposition. Initial C (51%), N (2.38%), and low lignin concentrations with low C/N (21.53) and lignin/N (4.05) ratios could be important factors in faster mass loss from the litter samples. The P mineralization k(P) (2.19) rate was higher than k(N) (0.73), indicating the slower release rate of N. The weight loss during decomposition was positively correlated with rainfall (r = 0.42) and temperature (r = 0.39). The study suggests that F. semialata leaf litter could be useful for regulating soil nutrient pool through faster litter turnover and can therefore be exploited as plantation and/or agroforestry species for soil and water conservation in degraded slopy terrain of the region.