Interrelationship of Carbon Sequestration, Soil Fertility, and Microbial Indices as Influenced by Long-Term Land Uses in Lower Himalayan Region, India.

The study was conducted to determine the long-term impact of different land uses on carbon sequestration, soil fertility, and microbial indices and to establish their interrelationship in a light-textured hyperthermic Udic Ustochrept. Soil samples were collected from existing land-use systems of (1)Eucalyptus tereticornis,(2)Terminalia chebula,(3)Acacia nilotica,(4)Leucaena leucocephala,(5)Embilica officinalis,(6)Zizyphusspp., and (7) maize–wheat rotation from depths of 0–15, 15–30, and 30–45 cm and examined for pH; organic carbon (OC); electrical conductivity (EC); available nitrogen (N), phosphorus (P), and potassium (K); micronutrients; microbial biomass carbon (MBC); microbial biomass nitrogen (MBN); and microbial biomass phosphorus (MBP). High-density plantations ofEucalyptus teriticornishad a greater potential in sequestering aboveground carbon (472.37 Mg ha−1), compared to widely spaced trees ofAcacia nilotica(376.05 Mg ha−1).Eucalyptus teriticornisexhibited the greatest impact in increasing soil OC in all depths, followed by AcaccianiloticaandTerminalia chebula,and the lowest was in agriculture (0.778, 0.749, 0.590, and 0.471%, respectively, in surface soil). Available zinc and iron contents were greatest underEucalyptus tereticornis, followed byAcacia nilotica,Zizyphus mauritiana,Embilica officinalis,Terminalia chebula, andLeucaena leucocephala. The MBC and MBN were greatest inEucalyptus tereticornis, followed byAcacia nilotica, and lowest in agriculture. Correlation matrix revealed significant and positive relationships between carbon sequestered with OC, MBC, MBN, and MBP. [ABSTRACT FROM AUTHOR]