Potential of Carbon Sequestration as Soil Carbonate in Arid and Semi-arid Region of North China: Impacts of Land Use Change

Abstract:

Soil carbonate (SIC) exceeds organic carbon (SOC) greatly in (semi-)arid lands, thus may be important for carbon sequestration. However, field data for studying SIC dynamics and quantifying SIC accumulation have been lacking. This paper consists of two parts. We first present our recent findings of SIC accumulation in the croplands of north China (Wang et al., 2014; 2015). We then report a meta-analysis of field based SIC data from 745 soil profiles in China.

Our recent findings were based on two sets of data: >100 soil samples recently collected from the Yanqi Basin of central Xinjiang and ~200 archived soil samples from four long-term experiment (LTE) sites in the north China. Our study showed that intensive cropping in the arid and semi-arid region leaded to a greater increase in SIC than in SOC; organic amendments enhanced SIC accumulation in the cropland of north China.

Our meta-analysis shows that despite a large variation of SIC stock (5-42 kg C m^-2), SIC storage in agricultural soils is generally higher relative to non-agricultural soils. We provide assessment how land use change may affect SIC storage in north China.