MULTIVARIATE STATISTICS OF FERTILITY PARAMETER FLUXES IN CEMENT-DUST-POLLUTED SOILS IN MFAMOSING, NIGERIA: IMPACT ON AGRICULTURE

This study investigated the impact of cement-dust pollution on the fertility status of agricultural soils to ascertain their health and suitability for cropping. Relevant soil nutrients and enzyme activities were determined from 12 control soil, 12 NPK-treated polluted soil and 12 un-amended polluted soil samples, using standard soil analytical and biochemical procedures. Soil microbial biomass-carbon was quantified by chloroform-fumigation-extraction (CFE) method. Cultivable aerobic bacterial count was determined on Tryptic Soy Agar (TSA) while cultivable fungal quantitation was performed on Czapek-Dox agar. Corn (Zea mays) yield served to evaluate pollutant effect on tested parameters. Principal component analysis (PCA) extracted two components, PC1 and PC2, from nine studied dependent variables (DVs) which explained 68.33% variability about the data. Number and membership of extracted components were confirmed by two clusters obtained by agglomerative hierarchical cluster analysis (AHCA). Multivariate analysis of covariance revealed significant effect of soil type on the combined DVs when the effect of the covariate (planting period) was controlled. One-way analysis of covariance (one-way ANCOVA) revealed non-significant effect of planting period but a significant main effect of soil type on corn yield when controlling for the effect of the covariate. Relative to control soil, per cent loss in corn yield was 55.69% in cement dust-polluted soil but reduced to 36.07% in polluted soils treated with NPK. The research findings have shown that cement dust pollution significantly reduced corn yield and the stress may persist in agricultural soils amended with fertilizer.