Determination of exchangeable cations and residual concentration of herbicide treated soils and analysis of the in-vitro biodegradation of the herbicides

Abstract

This study determined the effect of Atrazine, Xtravest, Gramoxone and Glyphosate on exchangeable cations and also analysed the in-vitro biodegradation of this herbicides as well as assayed for their residual concentration in soils. Exchangeable cations were analysed in atomic absorption spectrophotometer. Utilisation of herbicides was determined while herbicide degradation and residual concentration of herbicide were analysed using Gas Chromatography. K+, Ca2+, Mg2+, and Na+ declined while Fe2+ and Zn+ accumulated significantly. Bacteria and fungi significantly utilised herbicides as carbon source resulting in herbicide degradation. The lowest herbicide concentration of 118.55 ppm was obtained from atrazine inoculated with bacteria, while the highest herbicide concentration of 449.23 ppm was obtained from xtravest inoculated with fungi. Bacteria and fungi such as: B. subtilis, P. aeruginosa, P. florescences, P. putida, Actinomyces viscous, A. niger, A. tamarii, F. oxysporum, and P. chrysogenum were isolated in all the herbicide treated soils. Continuous herbicide treatment should be avoided because of their ability to persist in soils hence limiting essential nutrients available to plants. Indigenous microorganisms can be employed to remediate soils polluted by herbicides.