Comparative Study of Soil Properties under Gamhar (Gmelina arborea) Based Agrisilvicultural System

A two year experiment was conducted during kharif and rabi season of 2016-2017 and 2017-2018 at experimental site near Faculty of Forestry in main campus of Birsa Agricultural University, Ranchi, Jharkhand, India. Sole cropping and gamhar based agrisilviculture systems with four different intercrops (arhar, cowpea, greengram and mustard) were under investigation. To study the overall scenario of soil properties under agrisilviculture system, soil samples were analysed at different profile depths (0-15 and 15-30 cm) to measure the changes in soil properties under the influence of gamhar (Gmelina arborea) tree and intercrops grown in between. Soil pH, electrical conductivity (dsm-1), organic carbon (%), available nitrogen, phosphorus and potassium (kg ha-1) were found higher at the soil depth 0-15 cm as compared to 15-30 cm due to addition of organic residue on the surface soil. Soil OC, available N, P and K in 0-15 cm as well as in 15-30 cm profile was found to be statistically significant. It showed an increase from initial value in all the treatments in 2016-17 and 2017-18. The increase was more in gamhar based agrisilviculture system than in sole tree and sole crops in both the years

Carbon sequestration and credit potential of gamhar (Gmelina arborea Roxb.) based agroforestry system for zero carbon emission of India

Abstract The agroforestry system is the best option to achieve the net zero carbon emissions target for India. Keeping this view, carbon sequestration and credit potential of gamhar based agroforestry system has been assessed. The experiment was carried out in randomized block design in seven different treatments with five replications. Gamhar tree biomass accumulation was higher in gamhar based agroforestry system compared to sole gamhar. Among different tree components, stem contributed a maximum to total gamhar tree biomass followed by roots, leaves and branches. The average contributions of stems, roots, leaves and branches in total tree biomass in two annual cycles (2016–17 and 2017–18) varied between 50 and 60, 19.8 and 20, 19.2 and 20, and 10.7 and 12.7 percent, respectively. In case of crops, above ground, below ground and total biomass was significantly higher in sole intercrops than gamhar based agroforestry system. Total (Tree + interrops + Soil) carbon stock, carbon sequestration, carbon credit and carbon price were significantly affected by treatments, and was maximum in Sole Greengram-Mustard. Net carbon emission was also recorded lowest in Sole Greengram-Mustard for which the values were 811.55% and 725.24% and 760.69% lower than Sole Gamhar in 2016–17, 2017–18 and in pooled data, respectively