Location: National Soil Erosion ResearchTitle: Nitrogen, phosphorus, calcium, and magnesium applied individually or as a slow release or controlled release fertilizer increase growth
|COLE, JANET - Oklahoma State University|
|SMITH, MICHAEL - Oklahoma State University|
|CHEARY, BECKY - Oklahoma State University|
|CONAGHAN, KELLEY - Oklahoma State University|
Submitted to: Scientia Horticulturae
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/16/2016
Publication Date: 10/12/2016
Citation: Cole, J.C., Smith, M.W., Penn, C.J., Cheary, B.S., Conaghan, K.J. 2016. Nitrogen, phosphorus, calcium, and magnesium applied individually or as a slow release or controlled release fertilizer increase growth. Scientia Horticulturae. 211:420-430.
Interpretive Summary: In an effort to reduce nutrient pollution and improve the efficiency of animal waste management, animal manure has been used to create slow release fertilizers as a beneficial reuse. The goal of this study was to compare a recycled manure-based slow release fertilizer rich in magnesium ammonium phosphate (MAP), to a commercially available slow release fertilizer and conventional chemical fertilizer. Tomatoes were grown in order to compare the different nutrient sources, and the nutrient release timing was also measured among the different fertilizers. In year one of the study, the manure-based slow release fertilizer performed the same as the commercially available slow release fertilizer. In the second year of the study, the manure-based fertilizer performed the same as conventional chemical fertilizer. The results of this study showed that agricultural wastewater can be reused to create a beneficial by-product fertilizer material that performs as well as conventional chemical fertilizers and slow release fertilizers, for growing tomatoes.
Technical Abstract: The U.S. Environmental Protection Agency (USEPA) has restricted concentrated animal feeding operation(CAFO) release of waste products into U.S. waters. These waste products must be disposed of using best management practices. Most of the waste is spread on cropland, but some operations have found other creative uses for waste products. Use of a phosphorus (P) reduction system to remove P from wastewater results in magnesium ammonium phosphate (MAP), a slowly soluble fertilizer. Using a P reduction system will not eliminate the need for land application of manure and wastewater, but it reduces the nutrient load in the waste that is applied thereby making compliance with regulations easier. In the first year of this study, MAP was compared to a controlled release fertilizer (CRF) with a similar nutrient ele-ment ratio on plant growth, fruit yield, nitrogen (N), P, potassium (K), calcium (Ca), magnesium (Mg),iron (Fe), manganese (Mn), and zinc (Zn) concentration in tomato (Solanum lycopersicum L. ‘MountainFresh Plus’) plant parts. Plant growth and fruit production were similar with the two fertilizers, but the number of tomato culls was greater with either fertilizer than on control plants. Foliar N, P, Ca, and Mg concentration did not differ regardless of fertilizer treatment. Plants fertilized with CRF had a greater leaf K concentration than those fertilized with MAP, but foliar K concentration did not differ between fertilized and nonfertilized plants. Iron and Mn concentration in above-ground vegetative plant parts (stems and leaves) did not differ regardless of fertilizer treatment, but Zn concentration increased linearly as CRF increased. In the second year, MAP, each of the essential elements contained in MAP separately,and a hand mixture of each of these elements was tested for their effect on tomato plant growth, fruit yield, and tissue N, P, K, Ca, Mg, Fe, Mn, and Zn concentration and content. Magnesium ammonium phosphate and the hand mixture of fertilizer resulted in greater above-ground biomass excluding fruit stem weight and fruit yield than any of the individual nutrient treatments. Calcium sulfate resulted in a greater number and weight of tomatoes harvested than MAP. Nitrogen concentration did not differ among thefertilizer treatments for roots, stems, or leaves, but N content was greater in red fruit with the hand mixof fertilizer than with no fertilizer or with ammonium sulfate or Mg oxide. In immature green fruit at termination of the study, N content was greater with no fertilizer or Ca sulfate than with MAP or triplesuperphosphate (TSP). Phosphorus, K, and Ca concentrations did not differ among fertilizer treatments for any tissue tested. Magnesium concentration in green tomatoes differed among fertilizer treatments such that Mg concentration of green tomatoes from plants fertilized with TSP was greater than Mg concentration of green tomatoes fertilized with ammonium sulfate or Mg oxide. Phosphorus and K content of green fruit differed among fertilizer treatments with P and K concentration highest in green fruit from plants fertilized with Ca sulfate and lowest in green fruit from plants fertilized with MAP or TSP.