Leaching of Pre-Emergent Herbicides in Clay Soil Under Different Rainfall Simulations

• Grant number: 25/08674-8
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: August 01, 2025
• End date: May 31, 2026
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Patrícia Andrea Monquero
• Grantee: Guilherme Toler Scavroni
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

Leaching is one of the main processes influencing the mobility of herbicides in the soil, affecting both their efficacy in weed control and their potential for environmental contamination. This study aims to evaluate the leaching of pre-emergent herbicides applied in sugarcane fields under different simulated rainfall intensities, using a bioindicator plant. The herbicides sulfentrazone, clomazone, and the combination of sulfentrazone + clomazone will be tested at commercially recommended rates for sugarcane cultivation. Applications will be performed on clay soil columns contained in 40 cm high PVC tubes. The experimental design will follow a 4 × 8 factorial scheme, with three herbicide treatments and one control (no herbicide), evaluated across eight soil depth layers (0-5, 5-10, 10-15, 15-20, 20-25, 25-30, 30-35, and 35-40 cm), under two simulated rainfall intensities (20 and 40 mm), with four replications. Seventy-two hours after rainfall simulation, the tubes will be opened longitudinally and seeds of the bioindicator plant Cucumis sativus (cucumber) will be carefully sown in a continuous line along the soil columns. Plants will be evaluated at 7, 14, 21, and 28 days after application (DAA) for phytotoxicity, as well as for shoot dry mass, height, and leaf area.