Accelerated transformation of the fumigant methyl isothiocyanate in soil after repeated application of metham-sodium

Properties of Soil Fumigants and Their Fate in the Environment

“…The major metabolites are 3-chloroallyl alcohol, 3-chloroacrylic acid, and carbon dioxide. The degradation rates of the 1,3-D isomers were mostly reported to be similar in soils (Leistra et al, 1991;Smelt et al, 1989;van Dijk, 1980;van der Pas and Leistra, 1987), with relatively greater degradation of trans-1,3-D than cis-1,3-D in enhanced soil (Dungan and Yates (2003). The half-life of 6-7 days was typically observed in sandy loam soils at 20°C and with a soil water content of 10% (Kim et al, 2003;Wang et al, 2000).…”

Conversion of metam sodium and emission of fumigant from soil columns

“…The rate of decomposition depends strongly on soil temperature, soil texture, and soil moisture. The efficiency of conversion in soil is reported to be very high, ranging from 87% to 95% (Turner and Corden, 1963;Smelt et al, 1989;Wales, 2000), but most of these studies investigated high metam sodium application rates (Turner and Corden, 1963;Smelt and Leistra, 1974;Gerstl et al, 1977). Less emphasis has been given to the conversion of metam sodium at application rates representative of typical contemporary fumigant usage in fields.…”

Impact of fumigation with metam sodium upon soil microbial community structure in two Japanese soils

“…Metam sodium is rapidly hydrolysed in soils to methyl isothiocyanate (MITC), the active biocidal compound (Smelt and Leistra 1974). Whilst previous studies have revealed the fate of met am sodium and MITC in soil (Lloyd 1962;Smelt and Leistra 1974;Smelt et al 1989), little is known about the toxicity of MITC in the environment in terms of human health or natural resources (Taylor, Jr. et al 1996). In addition, there are few reports on the effects of metam sodium fumigation on soil microorganisms.…”