Transport of Atrazine Via Leaching in Agricultural Soil with Mineral Oil Addition

Abstract

Adjuvants, such as mineral oils, are widely used in the application of herbicides by reducing the drift and evaporation of the droplets and by increasing herbicide uptake by the plant. However, little is known about how mineral oil behaves when in contact with the soil. Thus, the objective of this research was to evaluate the transport of atrazine via leaching with the addition of mineral oil in a soil agricultural under laboratory conditions. To quantify the concentration of the herbicide along the profile of the very clay soil column (30 cm), 14C-atrazine (ring-U-14C) was used with 16,667 Bq of radioactivity per column in volume of 200 mL solution and 0 (control), 1, and 2% mineral oil (v/v) was added in the application volume. Atrazine was applied at the highest commercial dose recommended for sugarcane (4 kg ha-1). After simulation of a precipitation of 200 mm for 48 h, each column was sectioned into six parts of 5 cm and the analytes of each soil sample and the leachate were quantified by liquid scintillation spectrometry. The atrazine remained in the superficial layer of the soil, between 0 and 10 cm of depth, independent of the addition of mineral oil. No atrazine residues were detected in the leachate solution (> 30 cm) in any evaluated treatment. The addition of mineral oil at the time of application of pre-emergence atrazine did not interfere with the transport of this herbicide in the soil profile agricultural via leaching; therefore, the adjuvant may have positive effect only in the herbicide-plant relationship.

Understanding the Environmental Behavior of Herbicides: A Systematic Review of Practical Insights

“…On the other hand, adjuvants such as mineral oils are widely used in herbicide application to reduce drift and droplet evaporation, as well as to enhance herbicide absorption by the plant. Thus, the addition of mineral oil (1 and 2% v/v) at the time of pre-emergence atrazine application did not interfere with the transport of this herbicide in the arable soil profile via leaching; therefore, the adjuvant may have a positive effect only on the herbicide-plant relationship [68].…”

Manejo químico de caruru-roxo (Amaranthus hybridus) com herbicidas aplicados em pré e pós-emergência

“…A atrazine e [atrazine + simazine] demonstraram redução de controle a partir dos 30 DAT, o que pode ser atribuído a perda de residual do herbicida no solo (Tabela 2). Esse fato pode decorrer pelo processo de lixiviação, uma vez que as unidades experimentais receberam irrigação constante e, o grupo das triazinas apresenta alto potencial de perdas por lixiviação (Mendes et al, 2019). O tratamento com metribuzin atingiu valores de controle acima dos 80% até 21 DAT, nas demais avaliações apresentou perdas drásticas de controle, chegando aos 60 DAT com resultado somente superior a testemunha sem herbicida.…”

Leaching potential of S-metolachlor in a medium-textured Oxisol soil with bioindicator plants

“…The downward movement of herbicides in the soil or along the soil water is called leaching or percolation (Mancuso et al, 2011;Franceschi et al, 2019;Mendes et al, 2019). It is known, for instance, that the leaching potential of herbicides such as the S-metolachlor can be influenced by natural precipitation and/or artificial irrigation or by soils that have large pores or are poor in organic matter.…”