Soil carbon stocks in various types of land use in West Lombok

Abstract

Organic carbon greatly affects soil physical, chemical and biological fertility, so that this soil property is an indicator in determining soil health and quality. The amount of carbon stored in the soil can change due to land use, and its transformation from the ground to the air in the form of CO2, which can lead to global warming. This study aims to determine soil carbon stocks in various types of land use in West Lombok, West Nusa Tenggara Province, Indonesia. A number of soil samples (disturbed and undisturbed samples) were collected from various types of land use (forest, garden, paddy field, dry land and shrubs) using a soil drill (ring diameter 5.8 cm) from 3 depths; 0-10, 10-20, and 20-30 cm. Disturbed samples were dried, ground, sieved with a 2.00 mm sieve diameter, and analysed for their C-organic content using the Walkley and Black methods. Meanwhile, the undisturbed samples were processed in the laboratory to determine the bulk density (BV) of the soil. The results showed that the largest soil carbon stock was found in forests, followed by gardens, rice fields, moorlands, and shrubs. It was also found that the largest carbon stock was at a depth of 0-10 cm in all land use types and decreased with soil depth. These findings can be used as a reference in soil carbon management, considering that the carbon stock in rice fields, moor and shrubs is low to very low, which in turn can reduce soil fertility and productivity.