[Effects of selenium valence states and application concentrations on plant growth, ascorbate-glutathione cycle in Citrus junos cv. Ziyang Xiangcheng].

Potted Citrus. junos cv. Ziyang Xiangcheng seedlings were used to study the effects of selenium (Se) valence states (Se and Se) on plant growth and antioxidants and antixodases in ascorbate(AsA)-glutathione (GSH) cycle.

[Distribution characteristics of soil humus fractions stable carbon isotope natural abundance (delta 13C) in paddy field under long-term ridge culture].

A 16-year field experiment was conducted in a ridge culture paddy field in the hilly region of Sichuan Basin, aimed to investigate the distribution characteristics of stable carbon isotope natural abundance (delta 13C) in soil humus fractions. The soil organic carbon (SOC) content in the paddy field under different cultivation modes ranked in the order of wide ridge culture > ridge culture > paddy and upland rotation. In soil humus substances (HS), humin (HU) was the main composition, occupying 21% - 30% of the total SOC.