ZHOU Xiaoming1, FANG Fang1, WANG Chao1, GUO Jinsong1, ZHANG Rui1, YUAN Ziyue1, WANG Chong1
(1. College of Urban Construction & Environmental Engineering,Chongqing University, Chongqing 400045, China)
Abstract: The soil samples were collected from the water-level-fluctuating zone (WLFZ) of the Pengxi river watershed in the Three Gorges Reservoir area. The content of organic phosphorus in soil samples was determined by the NaOH-EDTA extraction method and the bioavailability of organic phosphorus in soil samples was evaluated by the enzymatic hydrolysis method. Results from the present study indicated that, ① the content of total phosphorus(TP) was 74.55~140.54 mg·kg-1 and the content of inorganic phosphorus(IP) was 49.91~104.23 mg·kg-1 in WLFZ soil. The content of organic phosphorus (OP) in WLFZ soil of was 14.61~36.31 mg·kg-1, which is lower than that in unflooded bankside soil. ② The average content of EHP in WLFZ soil was 6.23 mg·kg-1, accounted for 26.7% of extractable OP. The content of EHP was positively correlated with the content of OP(n=6，p<0.01). ③ The content of EHP and labile monoester phosphorus were positively correlated with content of organic matter(n=6，p<0.01), indicated the content of organic matter is an important factor affecting the bioavailability of organic phosphorus. ④ EHP in both WLFZ soil and unflooded bankside soil showed the same component characteristics. However, the EHP content of WLFZ soil was significantly lower than that of unflooded bankside soil. The drying-rewetting causes the release of OP in WLFZ soil. The potential impacts of OP in WLFZ soil on overlying water should not be neglected.
Keywords: Three Gorges Reservoir; soils of water-level-fluctuating zone; organic phosphorus; enzymatic hydrolysis; bioavailability
EARTH AND ENVIRONMENT Vol.47, No.4, Tot No.330, 2019, Page 495-501
