Dynamics of phosphorus fractions and potential bioavailability along soil profiles from seasonal-flooding wetlands in a Chinese estuary

• Published in: Environmental science and pollution research international Vol. 28; no. 6; pp. 6549 - 6560
• Main Authors: Zhang, Ling, Zhuang, Tao, Bai, Junhong, Ye, Xiaofei, Wang, Dawei, Wang, Wei, Guan, Yanan
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.02.2021; Springer Nature B.V
• Subjects: Acid phosphatase; Alkaline phosphatase; Aquatic ecosystems; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bioavailability; Biological Availability; China; Earth and Environmental Science; Ecosystem; Ecotoxicology; Electrical conductivity; Electrical resistivity; Environment; Environmental Chemistry; Environmental Health; Environmental science; Estuaries; Estuarine ecosystems; Eutrophication; Flooding; Iron; Moisture content; Organic matter; Organic phosphorus; Organic soils; pH effects; Phosphatase; Phosphorus; Phosphorus - analysis; Research Article; Sampling; Seasonal variations; Seasons; Soil; Soil depth; Soil dynamics; Soil organic matter; Soil profiles; Soil properties; Spring; Spring (season); Summer; Waste Water Technology; Water content; Water Management; Water Pollution Control; Wetlands; China; Organic phosphorus; Soil profiles; Phosphorus availability; Phosphorus fractions; Seasonal-flooding wetlands; Inorganic phosphorus
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-020-10732-0

Soil phosphorus fractions in wetland ecosystems have received increasing attention due to its high eutrophication risks. Soil samples were collected to 40 cm depth in three sampling seasons to investigate the seasonal dynamics of organic and inorganic phosphorus fractions, bioavailability, and relationship between those and soil properties in a seasonal-flooding wetland in the Yellow River Estuary. The results showed that inorganic phosphorus (IP) and organic phosphorus (OP) contents exhibited much higher levels in the top 10 cm soils, and declined along soil profiles in spring. IP kept constant along soil profiles in fall, while OP decreased in summer and fall. They were greatly affected by water content (WC), pH, Cl − /SO 4 2− , soil organic matter (SOM), and electrical conductivity (EC). Middle labile organic phosphorus (MLOP) and non-labile organic phosphorus (NLOP) accounted for higher percentages of total OP in summer and fall respectively than labile organic phosphorus (LOP) in spring. MLOP and NLOP levels showed a decrease along soil profiles in spring and in spring/fall, respectively, while NLOP significantly increased with depth in summer. Ca-P was the dominant IP fraction in all soils in three sampling seasons, declined with depth in spring/fall and increased in summer. Comparatively, soluble/loosely-P(S/L-P) generally decreased with depth along soil profiles in three sampling seasons. And residual P (Res-P) kept little change with depth in spring. Fe/Al-P levels decreased firstly and then increased with depth in spring and summer. Available phosphorus and potential bioavailable phosphorus contents decreased with depth in spring and summer not in fall, and had a strong significant positive correlation with WC and SOM. Alkaline phosphatase not acid phosphatase was the key factor influencing soil MLOP levels. Generally, the fractions and bioavailability of phosphorus as well as phosphatase in this region were affected by soil depth, sampling seasons, and soil properties (e.g., WC, pH, Cl − /SO 4 2− , SOM, and EC).