Soil phosphorus composition, loss risk and contribution to the aquatic environment in a typical agricultural area

• Published in: Water Quality Research Journal Vol. 56; no. 2; pp. 111 - 125
• Main Authors: Ma, Tianhai, Bai, Ying, Ruan, Xiaohong
• Format: Journal Article
• Language: English
• Published: London IWA Publishing 01.05.2021
• Subjects: Agriculture; Apatite; Aquatic environment; Environmental factors; Eolian soils; Eutrophication; Fluvial sediments; Geostatistics; Heterogeneity; Organic carbon; Phosphorus; Plastics; Risk; River basins; Rivers; Sandy soils; soil p loss risk; Soil types; Soils; source of aquatic p; spatial variability; Surface water; Total organic carbon; Water quality; China; Huaihe River
• ISSN: 2709-8044; 2709-8052
• DOI: 10.2166/wqrj.2021.004

River eutrophication risk increased significantly in agricultural areas. In this paper, spatial variability of soil phosphorus (P) and loss risk in the Jialu River Basin, China, were analyzed using a geostatistical approach. The correlation between soil and river sediment P was analyzed to identify the main aquatic P source. The results showed that inorganic phosphorus (IP) was the main form of soil TP (82.13%), but the ratio of apatite phosphorus (AP) and non-apatite phosphorus (NAIP) varied between different soil types. AP was the primary form of IP in fluvo-aquic cinnamon soil, while NAIP dominated in meadow aeolian sandy soil. Calculated soil total dissolvable P (TDP, 94–622 mg/kg) exceeded the environmental threshold. High TDP (>400 mg/kg) in mixed soil and sandy soil indicated a high P loss risk. The spatial variability of soil P was moderate to weak, indicating a low heterogeneity. In sediment, IP and AP showed a significant correlation with total organic carbon (p