Land-use systems for biomass, carbon storage, and carbon credit: implications for climate change mitigation in subtropical pockets of Vindhyan region, India

Biomass estimation forms the foundation for tackling global climate issues across diverse land use systems (LUSs). A research initiative was undertaken to identify the maximum biomass allocation using an allometric approach, and to assess the carbon stock, CO₂ sequestration, and carbon credit across diverse land use systems (LUSs) in the Vindhyan region of Mirzapur, Uttar Pradesh, India. This study aims to address climate change by identifying land-use strategies that stabilize income and are easily adoptable by farmers. Tropical dry deciduous forest, agriculture, plantation, horticulture and agri-horticulture LUSs were investigated using three combinations of custard apple (Annona squamosa), guava (Psidium guajava), bael (Aegle marmelos), mustard (Giriraj) (Brassica nigra), mustard (Pitambri) (Brassica juncea), and lentil (Lens culinaris) in an agri-horticulture system. Seven treatments with varying carbon stocks were identified: tropical dry deciduous forest (T₁) LUS (TDDFLUS); wheat based agriculture (T₂) LUS (WBALUS); plantation based on teak (Tectona grandis) (T₃) LUS (TBPLUS); horticulture based on karonda (Carissa carandas) (T₄) LUS (KBHLUS); bael + lentil (Hul-57) (T₅) LUS (BLBLUS); guava + mustard (Giriraj) (T₆) LUS (GMBLUS); and custard apple + mustard (Pitambri) (T₇) LUS (CAMBLUS). The results indicate that the lowest and the highest bulk densities (ρ_b) were recorded in TDDFLUS and WBALUS at the depths of 0–20 cm and 20-40 cm, respectively. The mean value of the soil organic carbon (SOC) stock ranged from 11.24–18.09 t ha⁻¹. The average value of biomass, biomass carbon stock and biomass CO₂ sequestration of seven treatments varied from 9.76–88.49 t ha⁻¹, 4.88–44.25 t ha⁻¹, and 17.91–162.39 t ha⁻¹, respectively. The total carbon stock, CO₂ sequestration, and carbon credit for the seven treatments varied from 16.57–64.64 t ha⁻¹, 60.82–237.28 t ha⁻¹ and 3040.821–11 863.89US$ ha⁻¹, respectively. The results demonstrated that different LUSs have specific advantages and their application at farm level can encourage sustainability and increase biomass accumulation, leading to carbon sequestration. Agri-horticulture-based LUSs can lead to better livelihoods and can also offer numerous advantages such as increased yields of staple food crops and fruits, improved soil health, reduced soil erosion, and significant contributions to the mitigation of anthropogenic warming through CO₂ sequestration.