Leaching behaviour of four herbicides in two soils of Kerala

• Published in: Indian journal of weed science 2015-04, Vol.47 (2), p.193-196
• Main Authors: Devi, K.M. Durga, Abraham, C.T, Upasana, C.N
• Format: Article
• Language: English
• Subjects: 4-D; Butachlor; Leaching; Oxyfluorfen; Pretilachlor
• ISSN: 0253-8040; 0974-8164

The present study was conducted to find out the extent of leaching of butachlor, pretilachlor, 2,4-D and oxyfluorfen in two soil types, viz. Type I [coarse textured low organic matter soil (Mannuthy–Ultisol] and Type II [fine textured high organic matter soil (Alappad-Inceptisol]. Intact soil columns were collected from the paddy fields after the harvest of second crop. Butachlor, pretilachlor, 2,4-D and oxyfluorfen were applied in moist soil columns at the recommended rate of application. Soil samples from different depths up to 10 cm (top 5 segments of 2 cm each) and the leachate at 30 and 60 cm depths were analyzed for herbicide residues using gas chromatography. Among the four herbicides tested, 2,4-D registered highest level of residue in the leachate (0.20 ppm at 60 cm depth). Pretilachlor and butachlor followed the same trend in the pattern of movement of residue through the soil columns. However, the leachate of pretilachlor registered much lower quantity of residue (0.006 ppm). Fine textured organic matter rich soil recorded lower residue levels compared to the soil with coarse texture and poor organic matter. It could be attributed to the high adsorptive power of the soil, especially at the top layers with high organic matter content. Oxyfluorfen residues could not be detected in the leachate, because of its poor water solubility.