Hiller E. & Jurkovič Ľ., 2020: Soil sorption and degradation of Agritox herbicide formulation containing Na-K-DMA MCPA salt as an active ingredient. Acta Geologica Slovaca, 12, 1, 35–42.

Soil sorption and degradation of Agritox herbicide formulation containing Na-K-DMA MCPA salt as an active ingredient

Edgar Hiller & Ľubomír Jurkovič

Department of Geochemistry, Faculty of Natural Sciences, Comenius University in Bratislava, Ilkovičova 6, 842 15 Bratislava, Slovakia; edgar.hiller@uniba.sk

Abstract

This study deals with the evaluation of soil sorption and degradation of Agritox herbicide formulation, which contains Na-K-DMA MCPA salt (dimethyl ammonium-potassium-sodium salt of (4-chloro-2-methylphenoxy)acetic acid) as an active ingredient. It is important to quantify these two processes as they are crucial for the migration of undesirable organic compounds into surface- and groundwater. Three agricultural soils were tested using column experiments to determine the sorption of MCPA salt and incubation batch experiments to measure its dissipation kinetics. The sorption of MCPA salt in these soils was relatively low with Freundlich constant values between 0.33–4.87 mg^l–1/ⁿ×l^1/n/kg. Despite the small number of soil samples tested, the effect of clay and organic carbon content on MCPA salt sorption was demonstrated. This herbicide was subject to rapid degradation in soil with half-lives of 4.5–7 days and degraded most rapidly in the soil with the highest microbial activity. Due to its rapid degradation, MCPA salt could be classified as a non-leacher into groundwater.

Key words: degradation, geochemical behaviour, MCPA, pesticide, soil, sorption

Manuscript received: 2020-03-24

Revised version accepted: 2020-05-19