Land use changes: Strategies to improve soil carbon and nitrogen storage pattern in the mid-Himalaya ecosystem, India

A thorough knowledge of the effects of land use systems (LUS) on the soil carbon pool and soil total nitrogen (STN) are critical to planning effective strategies for adaptation and mitigation in future scenarios of global climate and land use systems. This study conducted with the objectives of investigating soil carbon, nitrogen storage and carbon management index (CMI) in different LUS under middle Indian Himalayan ecosystem, four LUS: barren land (BL), cultivated land (CL), grass land (GL) and forest land (FL) were selected in Indian mid Himalaya. A total of 111 composite soil samples [4 treatment (land use systems) 3- soil depths (0-15, 15-30 and 30-45 cm) and 8, 11, 8 and 10 replication for BL, CL, GL and FL systems, respectively] were collected for laboratory analyses. Forest land use system has the highest Walkley-Black Carbon (WBC), total carbon (TC), total nitrogen (TN), carbon and nitrogen (C and N)-storage and CMI values while barren land use system having least amount of WBC, TC, TN, CN-storage and CMI. Land use system had minimum effect on non-labile carbon (NLC), lability of carbon (LC), lability index (LI) and carbon pool index (CPI) of the ecosystem. Moreover, TC and TN were increase in the grass and forest land as compared to barren and cultivated land. The TC concentration was highly correlated with TN (R-2 = 0.88, p < 0.01) and soil N-sequestration (R-2 = 0.93, p < 0.01) concentrations. However, carbon storage and NSP relationship (p < 0.01) was NSP = 0.0916 x + 0.7088 (R-2 = 0.93). Overall results indicated that LUS and C-storage were associated with N-storage and CMI. These results suggest restoration of degraded barren and cultivated land to grass and forest land and decrease in intensity of land use could increase carbon and nitrogen storage in the study area as well as other similar mountainous regions of Indian mid-Himalayas.