Field experiments for evaluating the effects of water management and phosphate application on inorganic arsenic accumulation in water spinach (Ipomoea aquatica Forssk.).

Autor: Ke YH; Department of Agricultural Chemistry, National Taiwan University, Taipei City, Taiwan., Syu CH; Agricultural Chemistry Division, Taiwan Agricultural Research Institute, Council of Agriculture, Executive Yuan, Taiwan., Liao YJ; Department of Agricultural Chemistry, National Taiwan University, Taipei City, Taiwan., Lee DY; Department of Agricultural Chemistry, National Taiwan University, Taipei City, Taiwan. Electronic address: dylee@ntu.edu.tw.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Oct 20; Vol. 844, pp. 157232. Date of Electronic Publication: 2022 Jul 08.
DOI: 10.1016/j.scitotenv.2022.157232
Abstrakt: Water spinach (Ipomoea aquatica Forssk.) is a commonly planted vegetable in the Southeast Asia; it is a semi-aquatic leafy vegetable with high inorganic arsenic (As) accumulation capability and can be planted under both upland and flooding cultivation conditions. To date, a limited number of field studies have investigated the effect of soil management on As phytotoxicity and accumulation of water spinach. Therefore, in this study, a field experiment was conducted to investigate the effects of water management and phosphate (P) application on the As phytotoxicity and accumulation of water spinach grown in As-contaminated fields (121 mg As kg -1 ). Water spinach was planted in the study field with two water management (flooding and upland cultivation) and two P application rates (90 and 180 kg P 2 O 5 ha -1 ), and continuously harvested three times. Results reveal that the concentration and estimated daily intake (EDI) of inorganic As in the edible parts of water spinach under flooding cultivation were approximately twofold higher than those under upland cultivation. It was also found that the accumulation of As in the shoot of water spinach was strongly related to the As concentrations, rather than P/As molar ratio in pore water due to that P application rates were lower than the maximum capacity for P retention of the tested soil. Moreover, the As phytotoxicity and accumulation of water spinach were reduced at the third harvest relative to the first two harvests because of the increase in iron plaque formation on the root surface and the decrease in the growing temperature during the experimental period. Our results suggest that upland cultivation is the better practice than flooding cultivation for reducing inorganic As accumulation in the edible parts of water spinach grown in As-contaminated soils. Further, ratooning may be a feasible cultivation approach to reducing inorganic As accumulation in water spinach.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2022 Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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