Andrew J. Aubin

Degradation of 14C-glyphosate in saskatchewan soils

Glyphosate is a non-volatile herbicide that is relatively immobile in soil, with little potential for leaching (Torstensson 1985). Its degradation in soil is due to microbiological processes (Sprankle et al. 1975; Nomura and Hilton 1977; Rueppel et al. 1977; Moshier and Penner 1978). The major soil metabolite of glyphosate has been identified as aminomethylphosphonic acid which also undergoes breakdown in the soil (Nomura and Hilton 1977; Rueppel et al. 1977). Chemical analysis of residues in soils is both complex and time consuming. Consequently, most laboratory degradation studies have been conducted with 14C-glyphosate with the rate of 14CO2 evolution being used as an indication of herbicide breakdown (Torstensson 1985). A summary of such studies has revealed half-life values ranging from 3 days to 22.8 years (Torstensson 1985)

Persistence studies with the herbicide clopyralid in prairie soils at different temperatures

Mesure en laboratoire de la vitesse de degradation biologique du clopyralid (acide dichloro-3,6 picolinique) dans trois sols du Saskatchewan a differentes temperatures (10,20,30 o C)