A field study on persistence and mobility of metsulfuron-methyl in three tropical agricultural soils

Abstract

Studies on the persistence and mobility of metsulfuron-methyl in 3 soil types (Lating, Sungai Buluh, and Serdang Series) were conducted under field conditions. Two weeks after treatment (WAT), metsulfuron-methyl applied at 30 g/ha leached downward to the lowest depth of the soil profile of 30–40 cm in the Sungai Buluh and Serdang soils, but not in the Lating soil. At the recommended treatment rate (15 g/ha), no metsulfuron-methyl residue was detected in the lowest depth for the Lating series soil studied. At 1 WAT, a high percentage of the metsulfuron-methyl residue had accumulated in the top layer of the Lating soil compared with the other 2 soil types studied. The residue in the upper layer decreased as the period from application increased. The dissipation rate of metsulfuron-methyl was greater at the recommended rate than at double the recommended rate. The half-life of metsulfuron-methyl, at the application rate of 30 g/ha, was shorter in the Lating (approximately 8.2 days) than in the Sungai Buluh and Serdang soils (13.4 and 13.4 days, respectively) for the whole profile. However, the half-life of metsulfuron-methyl when applied at the recommended rate was shorter than when applied at double the recommended rate.