The experimental design was a 3 × 3 factorial with the three soil types and three rates of glyphosate application: 0 (control), 1 (59 μg ae g−1 dry soil), and 2 (118 μg ae g−1) times the maximum recommended field application rate. For both glyphosate concentrations, the herbicide was diluted in 1 mL of deionized water to improve evenness of application.