Impact of 2,4-D and Glyphosate on Soil Enzyme Activities in a Resistant Maize Cropping System

Crop varieties resistant to multiple herbicides have been developed provide better control of weed populations in row-crop fields where glyphosate resistance has become common. These new include lines maize (Zea mays) both and 2,4-dichlorophenoxyacetic acid (2,4-D). As these the potential impact microbial communities soil, there is concern that their co-application may a greater effect on activities linked soil nutrient cycling than if they were applied individually. To investigate this possibility, field study was conducted 2,4-D+glyphosate-resistant determine 2,4-D alone 2,4-D+glyphosate extracellular enzyme activity bulk rhizosphere soil. Maize treated at V2 V8 developmental stages. Changes small magnitude inconsistent between timepoints. 2,4-D+glyphosate-treated plots had higher beta-glucosidase, cellobiohydrolase, phosphatase activities, but only after application first year study, while no significant effects observed rhizosphere. Enzyme more impacted by organic matter herbicide treatments. results suggest that, when label rates, will not adversely affect activities.