Reversibility of glyphosate sorption in pampean loess-derived soil profiles of central Argentina.

Autor: Graziano M; Departamento de Química Inorgánica, Analítica y Química Fisica, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE-UBA/CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina. Electronic address: marting@ege.fcen.uba.ar., Porfiri C; Estación Experimental Agropecuaria Anguil 'Ing. Agr. Guillermo Covas', Instituto Nacional de Tecnología Agropecuaria (EEA Anguil, INTA), Anguil, La Pampa, Argentina., Tufo AE; Departamento de Química Inorgánica, Analítica y Química Fisica, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE-UBA/CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina., Montoya JC; Estación Experimental Agropecuaria Anguil 'Ing. Agr. Guillermo Covas', Instituto Nacional de Tecnología Agropecuaria (EEA Anguil, INTA), Anguil, La Pampa, Argentina., Afonso MDS; Departamento de Química Inorgánica, Analítica y Química Fisica, Instituto de Química Física de los Materiales, Medio Ambiente y Energía (INQUIMAE-UBA/CONICET), Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Buenos Aires, Argentina.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2023 Jan; Vol. 312 (Pt 1), pp. 137143. Date of Electronic Publication: 2022 Nov 08.
DOI: 10.1016/j.chemosphere.2022.137143
Abstrakt: There is a growing concern about glyphosate's behavior in the environment. Herbicide behavior in soils greatly depends on adsorption-desorption phenomena, which have shown great variability in soils, although the reversibility of this process has been less examined. The adsorption-desorption behavior of glyphosate was measured on representative soil profiles of the northeast region of Argentinean Pampas, a semi-arid crop cultivating region. Two soil profiles samples (P1 and P2, both Entic Haplustoll) were collected and segmented into depth increments of 0-10, 10-20, 20-40, 40-60, 60-80, and 80-100 cm. Batch adsorption/48 h-desorption isotherms were performed in a controlled setup. Soil samples had a high sand content (77-92%), and a low content of clay (<3%), but markedly differing in the available P content, especially in the upper layers of soil profiles (0-40 cm, P1 range 133-170 ppm; P2 range 7-43 ppm). Adsorption-desorption isotherms showed a similar range of variation, between 150 and 1400 L kg -1 for K Fads and 450-1400 L kg -1 for K Fdes , without appreciable evidence of hysteresis (0.95 ± 0.05). Sorption capacity parameters showed a distinct behavior with depth, P1 exhibiting a U-shape with minimum values at intermediate depths (20-60 cm), while P2 decreases sharply between 0 and 40 cm. General linear models considering the specific surface area (SSA) of each sample and the spatial correlation structure for soil profiles showed a main positive association of K Fads and K Fdes with the soil organic matter, together with a positive association with iron content (K Fads ), and a negative association of K Fdes with available P content. These results indicate high adsorption extents and sorption reversibility of glyphosate to sandy loam soils of the region, which implies the potential for the herbicide to be available for leaching or degradation under a scenario of intensive use.
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 Ltd. All rights reserved.)
Databáze: MEDLINE
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