Understanding the complexities in glyphosate and ametryn interactions: Soil retention and transformation as influenced by their applications alone and mixture

Author(s)

Alves, Paulo Alexandre de Toledo ; Munhoz-Garcia, Gustavo Vinicios ; Nalin, Daniel ; Mendes, Kassio Ferreira ; Tornisielo, Valdemar Luiz

• Document type: Journal article
• Source: CROP PROTECTION; v. 184, p. 10-pg., 2024-06-25.

Abstract

The use of herbicide mixtures is widely adopted by farmers in agriculture worldwide. Glyphosate and ametryn are herbicides commonly applied in tank mixtures, increasing the spectrum of weed control in sugarcane crops. After application, herbicides can reach the soil layer, which is susceptible to retention, transport, and degradation processes. Herbicide interactions in mixtures may affect their bioavailability and persistence in soil, leading to different behavior in the environment compared to when applied alone. This study evaluated the sorption-desorption and transformation of C-14-glyphosate and C-14-ametryn in soil when applied alone or in a tank mixture. The sorption of C-14-ametryn in soil was increased by 25% when mixed with glyphosate (C-14-ametryn + glyphosate). This increase in sorption was not evident for C-14-glyphosate when mixed with ametryn (C-14-glyphosate + ametryn). The amount desorbed of C-14-ametryn (20%) applied alone was higher than in a mixture (10%). Both herbicide's mineralization half-live time (MT50) was influenced when applied in mixtures. C-14-glyphosate applied alone showed lower MT50 (55 days) compared to C-14-glyphosate + ametryn (119 days). C-14-ametryn also showed lower MT50 when applied alone than when applied with glyphosate (>120 days in both cases). These results suggest that the presence of ametryn in mixture with glyphosate decreases the desorption and mineralization of both herbicides, potentially affecting their bioavailability for weed root absorption and degradation in environment. (AU)

• FAPESP's process: 09/13357-9 - Behavior of ametryne and glyphosate herbicides applied in association in soils of cultivation of sugar cane
• Grantee: Paulo Alexandre de Toledo Alves
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 22/00718-8 - Glyphosate carrier nanosystems: from development to application in weed management
• Grantee: Gustavo Vinícios Munhoz Garcia
• Support Opportunities: Scholarships in Brazil - Doctorate
• FAPESP's process: 22/16554-4 - Application of radiometric techniques to characterize the retention, mobility, toxicity, and degradation of herbicide nanocarrier systems in the environment
• Grantee: Valdemar Luiz Tornisielo
• Support Opportunities: Regular Research Grants