Effects of Snail Farming On Soil Microbial Spectrum and Physicochemical Properties.
The study was undertaken to determine the effect of snail farming on soil microbial spectrum and physicochemical properties. This was investigated using standard chemical analytical procedures and cultural techniques. Snail soil samples were collected from two locations within Owerri, including, Nekede and Irete. Snail species reared in the farms were Achatina achatina and Archachatina marginata. The pH changed from neutral to alkaline. The temperature also increased slightly. Phosphate, sulphate, nitrate and total organic matter showed similar increase in the snail farm soil samples than in the test control sample with the differences being statistically significant. (P = 0.05).Sodium and potassium ions increased slightly while calcium and magnesium ions increased more. Thirteen bacterial species isolated from the snail farm soil samples were Bacillus, Pseudomonas, Aeromonas, Staphylococcus, Shigella and Flavobacteria, Nitrobacter, Escherichia coli and Klebsiella, Proteus, Enterobacter, Micrococcus and Salmonella species. The most prevalent was Bacillus species which had 100% occurrence. The total heterotrophic bacteria (THB) had the highest counts in both snail farm soil samples and controls. Further bacteriological analysis of the snail shell bacterial loads showed the same trend as in the soil analysis. The values of the enzymatic activities estimated in both snail farm and control soil samples showed that dehydrogenase had the highest activities. These changes are attributable to the contents of the wastes and their metabolism by microorganisms. The snail wastes could serve as increased additional source of micro-organisms to the soil while the left-over food items served as added nutrient for microbial growth. Most metabolic reactions are exothermic and the cumulative effect was the slight increase in soil temperature observed in this study. Similarly, the breakdown of the protein content of the wastes caused the release of ammonia which dissolved in the soil moisture to cause the increased pH values observed.