Yuan et al. (2011) found a significant negative correlation between MBC and soil solution conductivity, indicating the inhibition of microbial growth by soil salinity. In our experiment, each of the organic matter fractions – SOC, MBC and DOC had a significant positive correlation with net salt content of soil (4S) before sowing and at maturation (Table 2), from which we could see the benefits of reducing soil salinity in this arid region. Jing et al. (2013) also found that soil carbon decreased considerably with salt accumulation. Thus, reductions in salt content played an important role in increasing the MBC, SOC and DOC. Conversely, high salt content would impair microbiological activity and MBC, which would also reduce root growth and hence, decrease the SOC and DOC accumulation. Therefore, there is a need for management practices to control soil salinity and build the stock of carbon in arid soils.