Quantitative Estimation of Carbon Stock and Sequestration in Cashew Nut (Anacardium Occidentale) and Mango (Mangifera Indica) Orchards in Gujarat's Valsad District

Abstract

To determine the carbon stock and sequestration of mango and cashew nut orchards in Kaprada and Dharmapur tehsils of Valsad District, Gujarat. The field survey was conducted on the family’s farm of 60 mango and cashew nut orchards of ages between 11 to 20 years. The age categories are further separated into two subgroups: those aged 11 to 15 and 16 to 20 years. The carbon sequestration potential of trees in the orchard was estimated using the non-destructive harvesting method in the sample size of 15 x 15 m quadrate sampling method in each plot.

The volumetric equation was used to determine the potential carbon stored in the woody biomass of mango trees and the 11 to 15 age group estimated that, the carbon stock  16.1 MT or 58.9 MT CO_2e from woody biomass produced in 6 ha. Similarly, in the Cashew orchard of 11 to 15 age group, it is estimated the carbon stock was 11.4 MT or 41.9 MT CO_2e.

In the age group of 16 to 20 years of Mango orchard, the potential carbon store was 34.2 MT, or 125.5 MT CO_2e, and in cashew nut orchards the carbon stock in woody biomass was 30.2 MT, or 110.6 MT CO₂e from 6 ha area.

The study revealed that mango and cashew nut orchards store significant soil carbon. In the 11–15 year age group, mango orchards stored 20.8 MTha⁻¹ (76.1 MTha⁻¹ CO₂e) and cashew nut orchards 19.1 MTha⁻¹ (69.9 MTha⁻¹ CO₂e). In the 16–20 year age group, mango orchards stored 42.8 MTha⁻¹ (156.9 MTha⁻¹ CO₂e) and cashew nut orchards 23.5 MTha⁻¹ (86.1 MTha⁻¹ CO₂e). The results highlight the increasing carbon sequestration potential with orchard age.