Assessment of soil quality around the vicinity of selected cement company in Benue State using physicochemical and biotic properties

Abstract

The aim of the study was to assess the level of quality of soil around the vicinity of Dangote Cement Company, Gboko, Benue State using physicochemical and biotic parameters, and compare the results with the control soil samples and available permissible limits. The experimental site was partitioned into 5 major locations (L1-L5). Each location was further partitioned into 4 plots. Both the topsoil (0-15cm) and subsoil (15-30cm) were collected. Sixteen (16) soil samples were collected from each location totaling 80 soil samples at the experimental site and 16 at the control location. Physicochemical parameters including particle distribution, soil pH, temperature, moisture, organic matter and electrical conductivity were determined. The total viable bacteria and fungi were obtained in cfu/g of soil samples following appropriate dilution and standard microbiological practices. Detritivores such as ants, termites and worms were physically counted per soil sample. The experimental site was largely composed of sand followed by silt and clay while the control soil collected from Annune market area in Tarka L. G. A. of Benue state was largely made up of silt followed by clay and sand. On average, percentage clay varied from 18.8±1.3to 22.0±1.2 in the experimental site while the control location had a higher amount of clay with a mean value of 30.9±0.3. The control location had a higher amount of soil moisture with a mean value of 52.8±1.7. The soil at the experimental site was largely acidic and it varied from 5.7±0.2 to 6.0±0.1 whereas the control location possessed fairly neutral soil (7.1±0.1). The soil temperature was reduced in the control location (31.1±0.4). All electrical conductivity (E.C) values except those of the control location exceeded permissible limits of 1 dS/m. Consequently, organic matter level was much reduced in all locations ranging between 8.2±0.5 and 9.1±0.7 in the study area whereas the control soil samples had higher values of 15.7±0.5 as the average O.M level and only this fell within the permissible range of <15% O.M for arable soil. The control sample (3.33 x 10⁸cfu/g) contained a higher quantity of bacteria and total detritivores than the experimental samples. Thus, the quality of soil at the experimental site was compromised in all parameters evaluated. This could be as a result of the environmental impact of the cement factory within the vicinity of the experimental site, hence a need for regulatory measure and full environmental audit of the impact assessment on a continuous basis for decision making.