International Science Community Association International Research Journal of Biological Sciences 2278-3202 11 1 2022 02 10 Effects of an organophosphate (glyphosate) and a quaternary ammonium (paraquat) herbicides formulation on soils’ culturable bacterial and fungal populations 40 53 EN Nnenna Omorodion 1 University of Port Harcourt Department of Microbiology PMB 5323 River state Nigeria Nwatu Ifeanyichukwu 2 University of Port Harcourt Department of Microbiology PMB 5323 River state Nigeria Emmanuel Munyaneza 1 Museum of Environment, Rwanda Cultural Heritage Academy, Rwanda Elias Bizuru 2 University of Rwanda, Rwanda Jérôme Degreef 3 Fédération Wallonie-Bruxelles & Botanic Garden Meise, Belgium Tiwari Saurabh K. 1 Polymer Synthesis & Catalysis Group, Reliance Research and Development Center, Reliance Industries Limited, Navi Mumbai-400701, India Gaikwad Mahadev 2 Germplasm & Cultivation Group, Reliance Research and Development Center, Reliance Industries Limited, Navi Mumbai-400701, India Nagle Vinod 3 Germplasm & Cultivation Group, Reliance Research and Development Center, Reliance Industries Limited, Navi Mumbai-400701, India Dasgupta Santanu 4 Germplasm & Cultivation Group, Reliance Research and Development Center, Reliance Industries Limited, Navi Mumbai-400701, India Gupta Virendrakumar 5 Polymer Synthesis & Catalysis Group, Reliance Research and Development Center, Reliance Industries Limited, Navi Mumbai-400701, India Kalita Pankaj 1 Department of Chemistry, Arya Vidyapeeth College, Guwahati, Assam, India Patro Krishna Raju 1 Regional Plant Resource Centre, Bhubaneswar 751015 Odisha, India Gupta Nibha 2 Regional Plant Resource Centre, Bhubaneswar 751015 Odisha, India K.E. Olasuyi 1 Department of Forestry and Wood Technology, Federal University of Technology, P.M.B 704, Akure, Ondo State, Nigeria O.M. Boboye 2 Department of Forestry and Wood Technology, Federal University of Technology, P.M.B 704, Akure, Ondo State, Nigeria Aborisade Wakili Tope 1 Department of Biosciences and Biotechnology, Kwara State University, Malete, Nigeria Atuanya Ernest Ikenna 2 Department of Microbiology, Faculty of Life Sciences, University of Benin, Edo State, Nigeria > Research Paper 2021 11 13 2022 02 10 Herbicides play significant roles in weed management and contribute immensely to increase in productivity in agronomy system. However, its continuous application could have some dire effect on non-target soil microbiota. Therefore, this study assessed the impact of glyphosate and paraquat herbicides on soil culturable bacterial and fungal population. The loamy composite soil samples of forest reserve, Owena, Ondo State, Nigeria were used for the experiment. Each of the herbicide formulation was applied at the concentration rates ranged from half of the field recommended rate (0.5FR), the recommended rate (FR), two, four, and eight times the recommended rate (2, 4 and 8) FR respectively. The treatments were replicated thrice and arranged in complete randomized design, while the untreated soil samples serve as control. The standard pour plate technique was used for the enumeration of bacterial and fungal colonies after 5, 10, 15, 20, 25, 30 and 35 days of exposure. The findings showed that the glyphosate pesticides formulation applied at concentration range of 0.5 to 2FR significant stimulate bacterial populations of the soil samples while the fungal populations was not affected at the same concentration. However, the treatments at higher doses (4FR and 8FR) significantly reduced the number of bacterial and fungal counts of the soil samples. For paraquat treated soils, the treatment rate below the double recommended field rate did not have any significant effect (p > 0.05) on both bacterial and fungal populations. While the increases in inhibitory effect were observed with corresponding increases in paraquat application rates in the soil samples. Copyright@ International Science Community Association