Effects of Carbon/Nitrogen/Phosphorus Ratio on Mineralizing Bacterial Population in Aquaculture Systems

Abstract

Abstract The ratio of major fertilizing elements carbon, nitrogen, and phosphorus have immense importance in mineralization and aquatic productivity. It influences microbial activity of soil and water and, thereby, affects the rate of release of nutrients from organic manures. The effects of C/N/P ratio on different mineralizing bacterial populations were tested for six months in outdoor cement cisterns (180 L). Four isophosphorus (5 g P/m2/year) fertilization systems were adopted, namely cow dung, poultry litter, urea-single superphosphate, and a mixture of these fertilizers. The response of bacterial population with C/N and N/P ratio was established irrespective of treatment. Most of the groups of bacteria revealed an inverted curvilinear relationship with C/N and N/P ratio. The maximum abundance of these mineralizing bacterial populations was observed at C/N ratio of 8-14:1 for soil and 28-29:1 for water. The optimum N/P ratio for better bacterial abundance was exhibited between 3-7:1. The population of denitrifying and phosphate solubilizing bacteria decreased with increasing C/N and N/P ratio, respectively.