Journal or Publishing Institution: Pest Management Science
Study: http://onlinelibrary.wiley.com/doi/10.1002/ps.842/abstract
Author(s): Strange‐Hansen, R., Holm, P.E., Jacobsen, O.S. and Jacobsen, C.S.
Article Type: Peer Reviewed Study
Record ID: 2228
Abstract: Sorption, mineralization and mobility of glyphosate were studied in six substrates: the five types of gravel most frequently used as surfacing in Denmark and a sandy agricultural soil from Simmelkær that served as a reference soil. Cumulative mineralization of [methyl‐14C]glyphosate in batch studies was highest in coarse gravel, amounting to 14% after 4 days at 30 °C and 32% after 31 days. Mineralization was slowest in the sandy reference soil, amounting to only 2% after 31 days. The adsorption coefficient (Kd) of glyphosate in gravel ranged from 62 to 164 litre kg−1, while that in the sandy reference soil was 410 litre kg−1. The results indicate that the relatively low Kd in gravel allows a relatively high rate of glyphosate mineralization by the biomass. When Kd is high, in contrast, mineralization is slow. Lowering the temperature to 10 °C decreased mineralization by 50% in one of two gravels. The leaching of glyphosate was screened in simple columns of gravel or soil in which precipitation events (20 mm over a 2‐h period) were simulated on three occasions, starting either immediately after or 2 days after application of glyphosate. [14C]Glyphosate was applied as a tracer mixed with the commercial product Roundup® Garden at the recommended rate of 2.4 kg glyphosate ha−1, equivalent to 1 µg g−1 soil. The highest concentration of [14C] compounds (expressed in terms of glyphosate concentration) in leachate from the columns exceeded 1300 µg litre−1, and was detected in rounded gravel after the first rain event. No glyphosate was detected in leachate from the sandy reference soil.
Keywords: Adsorption, Biomass, Carbon Isotopes, Denmark, Environmental Monitoring, Geologic Sediments, Glycine, Herbicides, Kinetics, Soil Pollutants, Temperature, Chemical Water Pollutants, Chemistry, Analogs & Derivatives, Analysis, glyphosate, soil transport processes, sorption, sandy soils, gravel, mineralization, leachates, herbicide residues, soil pollution, Sweden
Citation: Strange‐Hansen, R., Holm, P.E., Jacobsen, O.S. and Jacobsen, C.S., 2004. Sorption, mineralization and mobility of N‐(phosphonomethyl) glycine (glyphosate) in five different types of gravel. Pest Management Science: formerly Pesticide Science, 60(6), pp.570-578.
