African Journal of Soil Science

ISSN 2375-088X

African Journal of Soil Science ISSN 2375-088X Vol. 7 (2), pp. 001-004, February, 2019. © International Scholars Journals

Full Length Research Paper

Effect of two commonly used herbicides on soil microflora at two different concentrations

Ayansina A. D. V. 1* and Oso, B. A.2

1Department of Biological Sciences, Bowen University, P. M. B. 284, Iwo, Osun State, Nigeria.

2Department of Botany and Microbiology, University of Ibadan, Ibadan, Nigeria.

Accepted 21 November, 2018

Abstract

The effect of two commonly used herbicides (atrazine and atrazine + metolachlor) on non-target soil microflora was investigated over a period of 8 weeks. One kilogram soil samples each from maize farm were treated with the herbicides separately at company recommended and one and half (X1.5) recommended rates. Effects of the herbicides on soil pH and percentage organic matter were also investigated. Significant changes in soil pH and percentage organic matter were observed only in atrazine treated soils (P < 0.05). Herbicide treatments at both recommended and X1.5 recommended rates resulted in decreases in microbial counts. Higher concentrations of herbicides treatments resulted in much lower microbial counts compared to soils treated with recommended herbicide does. Herbicide treatments also resulted in the elimination of some microbial species. Pseudomonas sp. and Bacillus sp. were the most frequently isolated bacteria from herbicide treated soils. While A. niger, A. Flavus, Penicillium sp and Trichoderma sp were the most frequently isolated fungi from herbicide treated soils.

Key words: herbicides, microflora, atrazine, metolachor, concentrations.