Quantitative estimation of carbon stock and carbon sequestration in smallholder agroforestry farms of mango and Indian gooseberry in Rajasthan, India

Abstract

Tree-based farming systems have the potential to sequester large quantities of carbon. An agroforestry system, promoted among small farmers in rural development projects in India, combines fruit and forestry trees with annual crops. As the carbon sequestration potential of this system has not been quantitatively estimated, a study was conducted on 25 orchards each of amla (Emblica officinalis) and mango (Mangifera indica) in two districts of Rajasthan, India. The orchards, aged between 7-14 years, were selected randomly and biomass accumulation of the trees was estimated using non-destructive allometric methods with quadrate sampling. The mean accumulated carbon in above-ground woody biomass of an amla tree was 0.05 t and that of mango was 0.04 t at an average age of 10 years. Similarly, the estimated carbon sequestered by multipurpose forestry trees growing along the border of the orchard was 0.012 t m2. Besides the above-ground biomass, the orchards also accumulated 8.1 t carbon ha-1 in the upper 15 cm of the soil. The study estimated that the total above and below-ground biomass in a 10 year old agroforestry farm having amla or mango with forestry trees contained 23 t ha-1 of carbon which was equivalent to 84.67 t CO2 ha-1.