Nitrogen and Phosphorus Concentrations in Fertilized and Unfertilized Farm Ponds in Central Missouri

Abstract

The limnology of six typical Missouri farm ponds, where fish growth rates had been determined, was investigated. Particular emphasis was directed toward a measurement of the important nutrient elements, nitrogen and phosphorus, in an effort to evaluate the processes associated with fertilization and establish nutrient factor or factors most clearly related to fish production for Missouri ponds.Comparison of the physical and chemical data for these fertilized and unfertilized ponds suggests that the limiting factor in productivity was soluble phosphate. Yearly mean concentrations of phosphate at the surface ranged from 0.016 to 0.028 p.p.m. in the fertilized ponds and from 0.010 to 0.016 p.p.m. in the unfertilized ponds. Daily phosphorus analyses showed good correhtion between concentrations of phosphate and plankton production. Each addition of fertilizer was followed by a rapid settling out which resulted in bottom phosphate concentrations which, in one pond, were as much as 10 times as great as the surface concentrations. This phosphate is confined to the bottom by a stable summer stratification in Missouri. Phosphorus added as fertilizer was found to be utilized within one week and on occasion within 24 hours depending on the degree of biological activity.The occurrence of fihmentous algae was correlated with increases in light penetration and soluble phosphate. A pond with filamentous algae showed a much lowered response to fertilization suggesting a removal of nutrients due to absorption by the algal mat.Nitrogen was not limiting for algal growth in these ponds. Unfertilized ponds showed higher concentration of inorganic nitrogen than did the fertilized ponds. This increased concentration of nitrogen was attributed to the presence of the legume Lespedem cuneata (sericea lespedeza) on the watershed of the unfertilized pond. Quantitative data on nitrogen inflow from the watersheds carrying growths of sericea lespedeza show significantly higher concentrations of inorganic nitrogen in the runoff water.

Ammonia Dynamics in Fertilized Fish Ponds Stocked with Nile Tilapia

“…High concentrations of TAN that are released after nitrogen fertilizer applications often decline quickly (Zeller 1953;Boyd 1974). Reduction of TAN from pond water occurs through several pathways: uptake as a nutrient by microflora (Murphy and Brownlee 1981;Lara and Romero 1986), adsorption on sediments (Kuznetsov 1968), volatization to the atmosphere (Bouldin et al 1974;Galloway 1980), and nitrification and denitrification (Isirimah et al 1976).…”

Effect of high phosphate fertilization rate on pond phosphate concentrations, chlorophyll a, and fish growth in carp polyculture

“…The level of phosphorus in water quickly falls within a short period after its application (Maskey and Boyd 1986). Concentrations of soluble orthophosphate usually decline by 90% within one or two weeks after fertilizer application (Nisbit 1951;Zeller 1952;Hepher 1958). Although some of the decrease is a result of phosphate uptake by phytoplankton, macrophytes, and bacteria (Rigler 1956(Rigler , 1964Hayes and Phillips 1958), most of the phosphate decline is usually the result of adsorption of phosphate by sediments.…”