Bacteriological Assessment of Soil Treated with Pesticide and Herbicide in Birnin Kebbi Metropolis of Kebbi State, Nigeria

Abstract

The present study was carried out on the effect of pesticides on soil microorganisms at half (x0.5) recommended rate (x1.0), and one and a half (x1.5). One commonly used insecticide Sniper as pesticide and herbicide Glyphosate were used on some physicochemical parameters and microbial populations. The mean value of pH for Sniper (x0.5) was 7.0; Sniper (x1.0) was 6.9; Sniper (x1.5) was 6.8; Glyphosate (x0.5) was 6.9; Glyphosate (x1.0) was 6.8: Glyphosate (x1.5) was 6.8 and for control soil was 7.3 respectively. The conductivity was ranged with a mean of 308.1 mS for Sniper x0.5, 410.3 mS for Sniper x1.0, 388.1 mS for Sniper x1.5, 197.8 mS for Glyphosate x0.5, 117.4 mS for Glyphosate x1.0, 223.85 mS for Glyphosate and 185.7 mS for the control soil. The soil organic matter was taken immediately after the treatments, and after the four weeks of treatment, the values were 1.50 g at week 0 and 0.72 g at week 4 for Sniper x0.5; 1.35 g at week 0 and 0.42 g at week 4 for Sniper x1.0; 1.71 g at week 0 and 0.50 g at week 4 for Sniper x1.5; 1.21 g at week 0 and 0.75 g at week 4 for Glyphosate x0.5; 1.05 g at week 0 and 0.86 g at week 4 for Glyphosate x1.0; 1.67 g at week 0 and 1.01 g at week 4 for Glyphosate x1.5 and 1.90 g at week 0 and 1.45 g at week 4 for the control soil. A total of 8 bacteria species were identified, such as Bacillus spp (50%), Lactobacillus spp (8.3%), Proteus spp (5.6%), Staphylococcus spp (11.1%), Actinomycetes spp (8.3%), Micrococcus spp (2.8%), Pseudomonas spp (8.3%) and Flavobacterium spp (5.6%). The effect of these findings shows that pesticides might be affecting the soil microbial load by reducing it.