Vol. 5, Issue 6 (2017)
Leaching behavior of metribuzin and pretilachlor
Author(s): Ramprakash T and Madhavi M
Abstract: A lab experiment was conducted for two years (2012 and 2013) in red and black soils to study leaching behavior of pretilachlor and metribuzin with soil columns (PVC tubes of 10 cm diameter and 65 cm length). Soils were collected horizon wise and were filled into the column and pre-conditioned. Pretilachlor and metribuzin were applied to the column surface at recommended (X dose-500 g/ha and 350 g/ha, respectively) and double doses (2X) equated to surface area of the column and water was added to the column surface. After 7 days, soil samples were collected from each 5 cm blocks and analyzed for herbicide residues. Herbicide residues were determined using GC-ECD. Pretilachlor recovery varied from 89.2 to 96.4% in soil with LOQ of 0.025 mg/kg. Recovery of metribuzin in the soil varied from 92.4 to 94.8% and with LOQ of 0.015 mg/kg.
In red soils, pretilachlor leached up to 10-15 cm in both X and 2X doses. Depth wise distribution showed that, 46.2% and 50.6% of the total herbicide was detected in the top 0-5 cm layer in X and 2X doses. In 5-10 cm layer, 32.6% and in 10-15 cm layer 14.1% of residues were detected. In 2X dose, herbicide detection was 50.6% in 0-5 cm layer, 36.5% in 5-10 cm layer and 12.9% in 10-15 cm layers. In black soils, pretilachlor leached up to 10 cm and 15 cm depth in X and 2X doses, respectively. In X-dose, 72.55% was detected in the top 0-5 cm layer and 27.44 in the 5-10 cm layer. At 2X dose, 73.35%, 19.90% and 6.74% the herbicide detected in the top 0-5 cm, 5-10 and 10-15 cm soil layers, respectively.
Metribuzin could be detected upto 15-20 cm and 20-25 cm layer in X and 2X doses respectively in red soils,. Highest concentration of the herbicide could be detected in 05-10 cm layer in both doses (38.25% 32.59% in X and 2X doses respectively). In black soils, highest concentration of the leached herbicide could be detected in the 05-10 cm layer in both X and 2X doses (39.05% and 37.53%). Leaching of metribuzin was restricted upto 15-20 cm layer in both doses in black soils.
Pages: 1584-1587 | 869 Views 78 Downloads
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How to cite this article:
Ramprakash T, Madhavi M. Leaching behavior of metribuzin and pretilachlor. Int J Chem Stud 2017;5(6):1584-1587.
