Comparative assessment of mustard (Brassica juncea) genotypes under Populus dectoloides and Eucalyptus teretectornis based agroforestry systems for soil carbon maintenance: an implication for climate change alleviation

The current situation of climate variability can be buffered by the inclusion of agroforestry as a critical land management system.The enormous potential of trees to capture and store carbon from the atmosphere and their role in soil nutrient cycling are globally acknowledged.Alongside this, we need to develop crop varieties that could perform well in competition with trees to share resources like sunlight, water, and soil nutrients.Therefore, the present study was undertaken in the tarai belt of the Himalayan foothills to screen suitable mustard varieties and under Poplar and Eucalyptus-based agroforestry systems.Besides this, biomass and carbon sequestration potential were also quantified for different components.In.Ten different Indian mustard varieties were screened under Populus deltoides and Eucalyptus tereticornis.Variety CS56 produced higher biomass in all three land management systems, i.e., poplar, eucalyptus agroforestry system, and open field E. tereticornis was found to have larger climate resilience potential with higher biomass production (91.99 18.21 to 270.19 16.55 Mg ha -1 ) and CO 2 mitigation (151.92 30.08 to 446.21 27.33 Mg CO 2 ha -1 ).However, biomass production of the mustard crop was better in a poplar-based agroforestry system..The total Biomass accumulation, carbon content, and carbon dioxide mitigation showed the following trend: eucalyptus + mustard > poplar + mustard> mustard (open field).Biomass deposition in mustard crops varies from sole crop (open field) > Poplar + mustard > Eucalyptus + mustard.The changes in soil carbon stock after two rabi season was recorded to be higher in eucalyptus-based agroforestry (1.29 Mg ha -1 ) system and lowest in open field (0.43 Mg ha -1 ).SOC showed improvement under an agroforestry system compared to an open field or pure crop system.