Dynamic variation characterization of soil organic and inorganic carbon of saline-alkali paddy fields and the influence factors

Abstract

The paper aims at revealing the dynamic variation characterization of soil carbon content and the influence factors. The experiments were conducted in the Qianguo irrigation area located in western Jilin Province, and the soil samples were collected from saline-alkali bare land and saline-alkali paddy fields of different reclamation years. The dynamic variations of soil organic carbon (SOC) and soil inorganic carbon (SIC) during various growing stages were analysed. The effects of soil enzymes and chemical properties on SOC and SIC were illustrated. The results showed that SOC content initially decreased at the seedling and tillering stages, then increased at the heading stage, and finally decreased at the grain filling stage. However, SIC content initially increased at the seedling and tillering stages, then decreased at the heading stage, and finally increased at the grain filling stage. Rice growth had the effect of carbon sink. Both the reclamation of paddy field and the growing stages had significant effects on SOC and SIC contents. SOC was significantly positively correlated with the available nitrogen, invertase and catalase, and was negatively correlated with SIC, pH and conductivity, while SIC presented to be totally opposite. The conductivity and catalase had significant effects on SOC contents, while the available nitrogen and conductivity had significant effects on SIC.