Nutrition in Soil and Water from Feeding

Application of different types of feeds, fertilizers or food based nutrients in ponds results in the accumulation of high levels nitrogen, phosphorous and organic carbon in water and bottom soil. Farmers can use pond water as an irrigation source while soil as a fertility source of agriculture.In this study of nursery reared tilapia fingerlings in aforementioned earthen ponds using two different composition of commercial fish feeds varying crude protein content (24% and 35%) from initial about 6-8% organic carbon, 23-35% total nitrogen, 22-45% total phosphorous stored in pond sediments while 10-20% of available potassium and 2-3% of C/N ratio depleted from it. About 16-20% available nitrogen, 7-10% available phosphorous stored in pond water while about 8-9% dissolved organic carbon, 3-18% available potassium and 2-5% C/N ratio were depleted from it. Nutrient enrichment of pond water and soil during aquaculture production is insufficient to meet crop nutrient demand but fertilizer recommendations for crops should be altered.