Sorption-desorption of glyphosate and its metabolite aminomethylphosphonic acid in floodplain soil

• Grant number: 18/09345-4
• Support Opportunities: Scholarships abroad - Research Internship - Scientific Initiation
• Start date: June 29, 2018
• End date: August 24, 2018
• Field of knowledge: Agronomical Sciences - Agronomy - Plant Health
• Principal Investigator: Kassio Ferreira Mendes
• Grantee: Felipe Gimenes Alonso
• Supervisor: Harry Vereecken
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: Forschungszentrum Jülich, Germany
• Associated to the scholarship: 17/20497-8 - Relationship between carryover and persistence of quinclorac in soils, BP.IC

Abstract

Soil is the final fate of the herbicides applied in weed control in crops, so the study of the soil-herbicide interaction is essential for the comprehension of its behavior. Glyphosate is an herbicide non-selective, applied in post-emergence and have a broad-spectrum, being the most widely used in the world. The aminomethylphosphonic acid (AMPA) is one of the primary degradation products (metabolite) of the glyphosate and because of it's high toxicity there is great concern about the damage that can be caused to the environment. However, knowledge about the glyphosate and AMPA behavior in floodplain soils still unknown. Based on this, the objective of the study will be to evaluate the sorption-dessorption process of glyphosate and AMPA in floodplain soils. Soil samples will be collected from the superficial layer (0-10 cm) and the sorption-desorption will be performed with the 14C-glyphosate by using liquid scintillation counting (LSC) and the AMPA will be analyzed by HPLC equipped with a UV. Although scarce, experiments involving herbicides behavior in floorplain soils are critical for assessing the efficiency of weeds control in various crops, so more studies are necessary to provide the information that is missing on the literature about this subject and optimize its use in the agriculture. (AU)