Leaching behaviour of metsulfuron in two texturally different soils

Abstract

Nowadays, herbicides are applied large ly in India, creating the need to evaluate potential leaching of herbicides. Thus leaching potential of metsulfuron in sandy loam and clay loam soils conditions was evaluated under laboratory conditions with simulated rainfall of 318-mm. Metsulfuron-methyl was applied at 4 and 8 g a.i. ha(-1) on soil columns, respectively. Maximum concentration of metsulfuron was recovered from 0-20 cm depths in both the soils. Results indicated high mobility of metsulfuron under continuous saturated moisture condition that may be significant in terms of ground water contamination.

Potencial de lixiviação e efeito residual de diuron + hexazinone + sulfometuron-methyl em solos de textura contrastante

“…Em solos cujo pH é inferior ao pKa, que, no caso, corresponde a 5,2 (Senseman, 2007), este herbicida predomina na forma neutra e, em condições de pH acima de 5,2, passa a apresentar-se na forma dissociada. Por consequência, à medida que o pH se eleva, aumenta a possibilidade de lixiviação, já que apresenta alta solubilidade em água (1.627 mg L -1 ) em pH 7,0 (Sondhia, 2009). Neste contexto, o pH dos solos arenoso e argiloso utilizados neste trabalho corresponde a 4,0 e 4,8, respectivamente.…”

“…Segundo Sondhia (2009), a solubilidade do sulfometuron-methyl se eleva com o aumento do pH do solo, sendo de 1.627 mg L -1 em pH 7,0. A meia-vida deste herbicida varia entre 30-120 dias, e pode ser degradado tanto por hidrólise quanto por biodegradação (Oliveira, 2001).…”

Determination of imazethapyr residues in soil and grains after its application to soybeans

“…Long-term imazethapyr carryover has been observed in soil that is below a pH of 6.5, resulting in significant sugar beet damage. 16) Selectivity in soybeans is attributed to a rapid detoxification via hydroxylation and glycosylation in the course of days [1][2][3][4][5][6]31) and the persistence of the imazethapyr herbicide in the soil is very long in soils with low pH. 30) In another study conducted in soils with a high pH (alkaline, cracking clay, pH 8.6) no residue was found in the top 10 cm of soil; however, 0.6-1.6 ng/g of imazethapyr was reported at 20-40 cm soil depths after four months of imazethapyr application.…”

“…Longer persistence also increases the chance of contaminating surface and groundwater through leaching and runoff. 1,2) Imazethapyr, 5-ethyl-2-[(RS)-4-isopropyl-4-methyl-5-oxo-2-imidazolin-2-yl] nicotinic acid belongs to the imidazoline group that has a toxicity class of III and is used as a selective herbicide for the control of a broad spectrum of weed species. [3][4][5][6] Extremely effective weed control and good crop tolerance in pulses and other leguminous crops have contributed to an increase in the popularity of this herbicide.…”

Monitoring of metsulfuron-methyl and its residues in an artificial pond

“…Since metsulfuron-methyl has a high leaching potential, it could be transferred from the site of application to surface waters during and after application via either overland runoff or incorrect disposal of waste (Belfroida et al 1998;Fogg and Boxall 2004;Sondhia 2009). To understand the impact of possible spray-drift events and leaching of metsulfuron-methyl on aquatic environments, several methods have been used to study its toxic effects on aquatic animals and plants (Wei et al 1998;Cedergreen et al 2004;Moraes et al 2007).…”