Leaching of a Mixture of Hexazinone, Sulfometuron-Methyl, and Diuron Applied to Soils of Contrasting Textures

• Published in: Water, air, and soil pollution air, and soil pollution, 2016-08, Vol.227 (8), p.1, Article 268
• Main Authors: Mendes, Kassio Ferreira, Inoue, Miriam Hiroko, Goulart, Michael Ortigara, Pimpinato, Rodrigo Floriano, Tornisielo, Valdemar Luiz
• Format: Article
• Language: English
• Subjects: Atmospheric Protection/Air Quality Control/Air Pollution; Calcium chloride; Carbon; Chromatography; Clay; Climate Change/Climate Change Impacts; Diuron; Earth and Environmental Science; Environment; Environmental monitoring; Environmental perception; Experimental design; Floods; Food processing industry; Herbicides; High performance liquid chromatography; Hydrogeology; Leachates; Leaching; Liquid chromatography; Loam soils; Sandy loam; Sandy soils; Soil Science & Conservation; Soil sciences; Soil texture; Sugarcane; Water Quality/Water Pollution
• ISSN: 0049-6979; 1573-2932
• DOI: 10.1007/s11270-016-2954-4

The increasing use of herbicides in sugarcane production has increased environmental concern regarding the fate of these compounds, especially when they are used in mixtures. Among the various processes that determine the behavior of molecules in the environment, leaching stands out. In this context, the aim of this study was to evaluate the leaching of a mixture of hexazinone, sulfometuron-methyl, and diuron in soils with contrasting textures. A completely randomized experimental design containing three replications in a 2 × 6 factorial arrangement was used, with two soils (alfisol–Paleudult, sandy clay texture and ultisol–typic Hapludalf, sandy loam texture) and six depths (0–0.05, 0.05–0.10, 0.10–0.15, 0.15–0.20, 0.20–0.25, and 0.25–0.30 m). Three glass columns of 50 cm were used for each soil. The dose used was 391.0 + 33.35 + 1386.9 g a.i. ha −1 of hexazinone, sulfometuron-methyl and diuron, respectively. After applying the mixture to the top of each column, rainfall simulation with 200 mm of 0.01 mol L −1 CaCl 2 solution was applied for 48 h. The leachates were collected at 6, 12, 24, 36, and 48 h. The chromatographic determinations of the herbicides were performed by high-performance liquid chromatography (HPLC) with a UV-Vis detector. For hexazinone, the highest percentage recovery in the soil with a sandy clay texture occurred at a depth of 0.10–0.15 m, with 40 % recovered, while in the soil with a sandy loam texture, the most part was recovered at a depth of 0.25–0.30 m. Diuron demonstrated little mobility in the soil and was detected in most cases only in the surface layer (up to 0.10 m) in both soils. Sulfometuron-methyl, in soil with a sandy clay texture, was detected to a depth of 0.15–0.20 m with the highest concentration found at a depth of 0–0.05 m, while in sandy loam soil, a higher concentration was found at a depth of 0.10–0.15 m; this herbicide was detected down to 0.25–0.30 m. These results show that the soil texture directly influences the leaching of hexazinone, sulfometuron-methyl, and diuron.