TY - JOUR
T1 - Sorption, mineralization and mobility of N-(phosphonomethyl)glycine (glyphosate) in five different types of gravel
AU - Strange-Hansen, Rikke
AU - Holm, Peter E.
AU - Jacobsen, Ole S.
AU - Jacobsen, Carsten S.
PY - 2004/6
Y1 - 2004/6
N2 - 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 (K
d) 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 K
d in gravel allows a relatively high rate of glyphosate mineralization by the biomass. When K
d 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 (20mm 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
-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.
AB - 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 (K
d) 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 K
d in gravel allows a relatively high rate of glyphosate mineralization by the biomass. When K
d 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 (20mm 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
-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.
KW - Glyphosate
KW - Gravel
KW - Mineralization
KW - Mobility
KW - N-(phosphonomethyl)glycine
KW - Sorption
UR - http://www.scopus.com/inward/record.url?scp=2542540686&partnerID=8YFLogxK
U2 - 10.1002/ps.842
DO - 10.1002/ps.842
M3 - Article
SN - 1526-498X
VL - 60
SP - 570
EP - 578
JO - Pest Management Science
JF - Pest Management Science
IS - 6
ER -