Soil Organic Carbon Pools and Microbial Population in Extremely Saline Soils: A Case Study in Salt Desert of Rann of Kachchh, India

Abstract

Saline soils are not suitable for plant growth due to higher osmotic potential and impair crop productivity to a great extent. Globally vast tract of land in arid and semiarid regions are affected by salinity and hardly supports any economic activities. Soil acts as the largest sink of terrestrial carbon and can help in climate change mitigation through sequestration of organic carbon. Therefore, an attempt has been made to assess the carbon concentration as well as microbial activity of soils of Rann of Kachchh (salt desert), Gujarat, India. The soil and water samples were found dark black in colour and the water was extremely saline (electrical conductivity>700 dS m-1) in nature. Results showed that the total carbon and oxidizable organic carbon concentration was 7.1 and 5.3 g kg-1 at 0-15 cm soil depth. About 25.4% of the total carbon was present in recalcitrant form. We calculated that the salt desert of Rann of Kachch stored about ~3640 ton carbon at 0-15 cm soil depth. Fungi were absent and bacteria and actinomycetes were found in those soils. These highly saline soils of Rann of Kachchh can serve as a great sink for carbon sequestration with higher stability and help to achieve the goal of “4 per 1000” initiative.