Changes in microbiological activity in soil after glyphosate treatment

The effects of the herbicide glyphosate on the abudence of bacteria and actinomycetes, activity of enzyme β-glucosidase and microbial phosphorus biomass were examined. A laboratory bioassay set up on two types of soils differing in physicochemical properties (loam and sandy loam). The following concentrations were tested: 32.6, 65.2, 326.0 and 3260.0 mg a.i. kg-1of soil. Samples were collected 3, 7, 14, 30 and 45 days after treatment with glyphosate. The acquired date indicated that the effect of glyphosate on microbial activity of the soils depended on its application rate, duration of activity and tipe of soil, and the effect was either stimulating or inhibiting. However, the detected changes were found to be transient, indicating that there is no real risk of the compound disrupting the balance of biochemical processes in soil.