Pedosphere 31(5): 683--693, 2021
ISSN 1002-0160/CN 32-1315/P
©2021 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Phosphorus accumulation and leaching risk of greenhouse vegetable soils in Southeast China |
Yusef KIANPOOR KALKHAJEH1,2,3,4, Biao HUANG3,4 , Helle S?RENSEN5, Peter E. HOLM2,4, Hans Christian B. HANSEN2,4 |
1Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention, School of Resources and Environment, Anhui Agricultural University, Hefei 230036 (China)
2Department of Plant and Environmental Sciences, University of Copenhagen, Thorvaldsensvej 40, Frederiksberg DK-1871 C (Denmark)
3Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China)
4Sino-Danish Center for Education and Research (SDC), Beijing 101408 (China)
5Data Science Lab, Department of Mathematical Sciences, University of Copenhagen, Universitetsparken 5, DK-2100 Copenhagen East (Denmark) |
| ABSTRACT |
| Over-fertilization has caused significant phosphorus (P) accumulation in Chinese greenhouse vegetable production (GVP) soils. This study, for the first time, quantified profile P accumulation directly from soil P measurements, as well as subsoil P immobilization, in three alkaline coarse-textured GVP soil profiles with 5 (S5), 15 (S15), and 30 (S30) years of cultivation in Tongshan, Southeast China. For each profile, soil samples were collected at depths of 0–10 (topsoil), 10–20, 20–40, 40–60, 60–80, and 80–100 cm. Phosphorus accumulation was estimated from the difference in P contents between topsoil and parent material (60–100 cm subsoil). Phosphorus mobility was assessed from measurements of water-soluble P concentration (PSol). Finally, P sorption isotherms were produced using a batch sorption experiment and fitted using a modified Langmuir model. High total P contents of 1 980 (S5), 3 190 (S15), and 2 330 (S30) mg kg-1 were measured in the topsoils versus lower total P content of approximately 600 mg kg-1 in the 80–100 cm subsoils. Likewise, topsoil PSol values were very high, varying from 6.4 to 17.0 mg L-1. The estimated annual P accumulations in the topsoils were 397 (S5), 212 (S15), and 78 (S30) kg ha-1 year-1. Sorption isotherms demonstrated the dominance of P desorption in highly P-saturated topsoils, whereas the amount of adsorbed P increased in the 80–100 cm subsoils with slightly larger P adsorption capacity. The total P adsorption capacity of the 80–100 cm subsoils at a solution P concentration of 0.5 mg L-1 was 15.7 (S5), 8.7 (S15), and 6.5 (S30) kg ha-1, demonstrating that subsoils were unable to secure P concentrations in leaching water below 0.5 mg L-1 because of their insufficient P-binding capacity. |
| Key Words: greenhouse vegetable production,Langmuir model,P adsorption capacity,P desorption,P immobilization,P mobility,subsoil,topsoil |
| Citation: Kianpoor Kalkhajeh Y, Huang B, S?rensen H, Holm P E, Hansen H C B. 2021. Phosphorus accumulation and leaching risk of greenhouse vegetable soils in Southeast China. Pedosphere. 31(5): 683–693. |
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