Mapping atrazine persistence in soils at the landscape scale

GIANNINI-KURINA, FRANCA; BORELLO, JULIETA; CAÑAS, IRENE; HANG, SUSANA; BALZARINI MÓNICA

SOIL & TILLAGE RESEARCH

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2021

0167-1987

The length of time an herbicide molecule remains in soils is an indicator of diffusecontamination risks. Atrazine, a residual herbicide with a wide range of reportedenvironmental impacts, has been extensively applied in agricultural soils cultivated withgramineous crops. While atrazine persistence in soils has been extensively studied byquantifying half-life (t½) from experimental dissipation curves, the spatial variability oft½ at the landscape scale has been poorly explored. The objectives of this work wereto estimate atrazine persistence in diverse soils and to map its spatial variability bymodelling t½ as a function of environmental variables. Based on lab determination andenvironmental data, atrazine persistence in soils was digitally mapped across Córdobaterritory, in central Argentina. First, we determined the dissipation parameters ofatrazine under a variety of environmental conditions in 60 sites. Second, we fitted aBayesian hierarchical model for the estimated atrazine t½, considering multiple sitespecificsoil properties and land use (gramineous crop, non-gramineous crop, pasture,and forest) as covariates by using R-INLA. Results suggest that atrazine t½ can bespatially predicted by soil organic carbon content and land use, with atrazinedissipation being faster in sites with previous gramineous crop and high soil organicmatter. The derived digital map allowed us to visualize the spatial variability of atrazinepersistence at the landscape scale. The modelling strategy might be applied to otherherbicide molecules by selecting proper environmental covariates.