Sulfate supply decreases barium availability, uptake, and toxicity in lettuce plants grown in a tropical Ba-contaminated soil

• Published in: Environmental science and pollution research international Vol. 30; no. 18; pp. 53938 - 53947
• Main Authors: de Souza Cardoso, Arnon Afonso, Nunes, Ana Paula Pereira, Batista, Éder Rodrigues, Nataren, Lorena del Carmen Hernandez, Nunes, Márcio Felipe Pinheiro Neri, Gomes, Fabrício Teixeira de Lima, Leite, Aline do Amaral, Guilherme, Luiz Roberto Guimarães, Faquin, Valdemar, Silva, Maria Ligia de Souza
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2023; Springer Nature B.V
• Subjects: Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Barite; Barium; Barium chloride; Barium Sulfate; Bioavailability; Biological Availability; Contamination; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Lactuca - physiology; Lettuce; Organic matter; Phytotoxicity; Plant growth; Plants; Potassium sulfate; Research Article; Soil; Soil conditions; Soil contamination; Soil Pollutants - analysis; Soil pollution; Sulfates; Sulfur; Sulfur Oxides; Toxicity; Waste Water Technology; Water Management; Water Pollution Control; Soil chemistry; Barium fractionation; Sulfur; Plant stress; Lactuca sativa
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-023-25960-3

Barium (Ba) is a non-essential element that can cause toxicity in living organisms and environmental contamination. Plants absorb barium predominantly in its divalent cationic form Ba
2+
. Sulfur (S) can decrease the availability of Ba
2+
in the soil by causing its precipitation as barium sulfate, a compound known for its very low solubility. The objective of this study was to evaluate the effect of soil sulfate supply in soil Ba fractions, as well as on plant growth, and Ba and S uptake by lettuce plants grown in artificially Ba-contaminated soil under greenhouse conditions. The treatments consisted of five Ba doses (0, 150, 300, 450, and 600 mg kg
−1
Ba, as barium chloride) combined with three S doses (0, 40, and 80 mg kg
−1
S, as potassium sulfate). The treatments were applied to soil samples (2.5 kg) and placed in plastic pots for plant cultivation. The Ba fractions analyzed were extractable-Ba, organic matter-Ba, oxides associated-Ba, and residual-Ba. The results indicate that the extractable-Ba fraction was the main one responsible for Ba bioavailability and phytotoxicity, probably corresponding to the exchangeable Ba in the soil. The dose of 80 mg kg
−1
of S reduced extractable-Ba by 30% at higher Ba doses while it increased the other fractions. Furthermore, S supply attenuated the growth inhibition in plants under Ba exposure. Thus, S supply protected the lettuce plants from Ba toxicity by reduction of Ba availability in soil and plant growth enhancement. The results suggest that sulfate supply is a suitable strategy for managing Ba-contaminated areas.
Graphical Abstract