Response of Timber Yield, Biomass, CAI and Carbon Sequestration to Varied Pruning Intensities of Dalbergia sissoo Roxb. in Agrisilviculture System in Central India

Abstract

In Central India, an experiment was carried out on a 22 year old Dalbergia sissoo based agrisilviculture model in 2020-21 to investigate the response of different pruning intensities on Rabi seasonal diameter growth, timber production, CAI of total biomass, and carbon sequestration potential. Each year, paddy followed by wheat is grown under trees spaced at 5m × 5m continuously being treated with four different pruning intensities, i.e., 0% (P0: No pruning), 25% (P25: Light pruning), 50% (P50: Moderate pruning) and 75% (P75: Heavy pruning) of the total tree height. It was reported that different rates of pruning had a significant effect. Maximum Rabi seasonal D.B.H. increment was recorded in P0 (0.68 cm) and minimum in P75 (0.49 cm). Maximum seasonal yield of large-sized timber, small-sized timber, and fuelwood (5.80 m3 ha-1, 0.62 m3 ha-1 and 7.48 q ha-1, respectively) were recorded under light pruning treatment (P25). However, the minimum seasonal yield of large-sized timber and fuelwood (5.80 m3 ha-1 and 5.14 q ha-1, respectively) were under heavy pruning (P75) and the minimum seasonal yield of small-sized timber (0.32 m3 ha-1) under moderate pruning (P50).  Maximum annual above-ground biomass, annual below-ground biomass and current annual increment of total biomass (171.63 q ha-1 yr-1, 34.33 q ha-1 yr-1, and 205.95 t ha-1 respectively) were recorded under light pruning treatment (P25), while minimum (84.50 q ha-1 yr-1, 16.90 q ha-1 yr-1 and 101.40 t ha-1 respectively) under heavy pruning (P75). Carbon sequestration potential was reported to be higher with light pruning (92.68 q ha-1 yr-1), followed by moderate pruning (63.69 q ha-1 yr-1), while minimum under heavy pruning (45.63 q ha-1 yr-1) and no pruning (46.91 q ha-1 yr-1) at all. It was concluded that light pruning of 25% was best among the four treatments in terms of timber and biomass yield.