ABSTRACT

 Organic manure is organic matter that is used as organic fertilizer in agriculture. Most manure consists of animal feces; other sources include compost and green manure. Manures contribute to the fertility of soil by adding organic matter and nutrients, such as nitrogen, that are utilized by bacteria, fungi and other organisms in the soil. The study evaluated the effect of organic manure on soil microorganisms. The manure-soil samples were cultured on Nutrient Agar Medium, MacConkey, Sabouraud Dextrose Agar medium and Salmonella shiegella Agar using pour plate techniques. From the study, the bacterial isolates from the manure samples were identified by morphological characteristics, pigmentation on media, microscopy, biochemical and sugar fermentation methods. This reveals the major bacterial isolates to be Staphylococcus aureus, Escherichia co/i, Salmonella species, Kiebsiella species, Shigella species and Serratia species respectively, while the fungi species isolated include; Aspergillus niger, Aspergillus Jiawis, Rhodiorula species and Rhizopus stolon?fer respectively. The total bacterial mean count was found to be higher in Sample Al (soil + poultry manure) at (9.0 xlO3cfu/g), while the least bacterial count was recorded for sample A2 (soil + cowdung manure) at (1.4 x104cfu/g). From the findings in this study, it was observed that Staphylococcus aureus and Escherichia co/i are the most frequently occurring isolates with a percentage occurrence of 4(16.66%) each, followed by Pseudomonas aeruginosa 3(12.5%). Among the manure soil investigated for bacterial contaminants, sample Al (soil + poultry manure) had the highest number of bacterial isolates at 7(29.1%), when compare with soil without manure 4(16.6%). However, there were wide variations of fungi population in the manure-soil samples. with Aspergillus ,flavus and Aspergil/us niger, being the most predominant and frequently occurring isolates on the manure-soil samples at 2(8.33%) each. It was also observed in this study that poultry manure soil amendment (66cm) is a better option than cow dung manure soil amendments (64cm) followed by compost manure soil amendments (62cm) and soil without amendments (47cm) as revealed in the physical growth of maize plant treated with different manure. This study also revealed that the mineral composition of soil without amendments was found to be lower in nitrogen (O.11ml/l0Og), phosphorus (4.21m1/loog), and organic carbon (O.21m1/loog) when compared with soil with manure treatment. Conclusively, this study has proven that the soil amendments had significant effect on microbial population as well as its physico-chemical parameters as compared to soil without amendments and it also had great capacity to give atmosphere for microbial growth.