Effects of different factors on the adsorption–desorption behavior of Glyamifop and its migration characteristics in agricultural soils across China

Abstract

Rice weeds strongly inhibit the production of rice because they compete with rice. Glyamifop is a novel herbicide for controlling rice weeds and being tested in paddy fields. Based on our previous studies, Glyamifop offers excellent control for rice weeds and has no negative effects on rice plant growth as well as rice yields. However, the adsorption–desorption and migration behaviors of Glyamifop in paddy soils are still not well resolved. In this study, we investigated the adsorption–desorption and migration characteristics of Glyamifop in paddy soils collected from four provinces in China, using batch equilibrium, soil column leaching, and thin-layer chromatography tests combined with liquid chromatography–tandem mass spectrometry (LC-MS) analysis. The results showed that all the soils had a relatively high adsorption capacity for Glyamifop, and both Freundlich adsorption and desorption constants were positively correlated with soil cation exchange capacity, organic carbon content, and organic matter content (P < 0.05). Moreover, despite the initial solution pH, temperature, humic acids, and surfactants also had strong effects on the adsorption of Glyamifop in soil, while the leachability and mobility of Glyamifop were very low in most soils. Therefore, due to the relatively low leachability and mobility of Glyamifop as well as its high adsorption capacity in soil, Glyamifop can serve as an excellent herbicide for rice weeds and cause little pollution to the environment.