Effect of Organic Production of Maize on soil Microbial Population and Activities on Alfisol in Abeokuta, Southwestern Nigeria

The study investigated the effect of organic production of maize on soil microbial population and activities. In this study, different fertilizers such as compost, neem fertilizer, poultry manure, green manure, NPK, organo-mineral fertilizer, were applied to the soil for maize production and soil samples were collected and taken to the laboratory for analysis. The effect of the different fertilizers on growth of maize was determined. The soil samples were analyzed for microbial biomass nitrogen, carbon and phosphorus; total viable count and total fungi count; phosphorus mineralization and organic matter level. Results of the analysis showed that compost and NPK gave significantly higher numbers of leaves, plant height and leaf area than other fertilizers. Poultry manure and organo-mineral fertilizer gave significantly higher microbial biomass carbon and nitrogen relative to other fertilizers but organo-mineral fertilizer gave significantly higher microbial biomass phosphorus. Neem fertilizer gave a significantly higher viable count while NPK gave a significantly higher total fungi count compared to other fertilizers. Organo-mineral fertilizer gave significantly higher inorganic phosphorus and organic matter production shortly after application (3 WAP) whereas neem fertilizer gave higher levels at 6 WAP. Conclusively, the use of composts should be encouraged in the organic production of maize to enhance yield and improve the soil quality.