Determination of Half-Life of Ametryn on Red-Yellow Latosol and Red-Yellow Ultisol with Different pH Values

作者：Andrade S R B; Silva A A; Lima C F; Queiroz M E L R; Franca A C; D'Antonino L

来源：Planta Daninha, 2010, 28(2): 375-383.

DOI：10.1590/S0100-83582010000200017

• persistence
• soil characteristics
• HPLC
• bioassay

The objective of this study was to determine the half-life (t1/2) for the herbicide ametryn in Red-Yellow Latosol (LVA) and Red-Yellow Ultisol (PVA) with different pH values. Thus, plastic pots coated inside with plastic film were filled with 330 g of samples from the soils under study (LVA with pH values adjusted to 4.4, 4.9 and 5.8, and PVA pH 5.9), collected in degraded pastures without herbicide application. Ametryn was applied on these soil samples at a dose of 5.0 ha L(-1). Twelve hours after application, the first soil samples were extracted from the pots to determine the concentration at zero time, and every five days new samples were removed from the other pots (two per time) to determine ametryn concentration over time. Ametryn extraction from the soil matrix was performed by Solid Liquid Extraction with Partition at Low Temperature (SLE-PLT) and quantified by liquid chromatography. A biological test for indirect determination of herbicide persistence was also carried out. Results indicated that ametryn half-life (t1/2) on the soils evaluated was 26, 19, 12 and 11 days in LVA soil pH 4.4; pH 4.9; pH 5.8 and PVA pH 5.9, respectively. Both methods (chromatography or bioassay) used to evaluate ametryn persistence in soils showed that degradation of this herbicide is strongly influenced by soil pH and organic matter content.

• 出版日期2010-6