Fertilizer Source Affects Iron, Manganese, and Zinc Leaching, Nutrient Distribution, and Geranium Growth#

Abstract

The effect of various sources of iron (Fe), manganese (Mn), and zinc (Zn) on growth and visual quality of geranium (Pelargonium X hortorum L. “Orbit Red”) seedlings, nutrient leaching, and nutrient distribution in the growing medium was determined in two experiments. In the first experiment, Fe, Mn, and Zn were applied as a commercially formulated water‐soluble fertilizer (WSF), granular incorporated fertilizer (GIF), or no micronutrient (NOM) fertilizer was applied. In the second experiment, the commercially formulated GIF was applied, but WSF was specially formulated to apply the same amount of each element from the same chemical sources as the GIF. Also a 50% GIF and 50% WSF (50 GIF/50 WSF) treatment was included. In both experiments, shoot relative growth rate (RGR) tended to be greater when WSF was applied than when GIF was used. Plant visual quality did not differ regardless of fertilizer used in either experiment, but plants receiving NOM fertilizer were of lower quality than plants receiving any micronutrient fertilizer. The amount of Fe, Mn, and Zn leached from the medium was greater with GIF than with WSF or 50 GIF/50 WSF when the same amount of each element was applied regardless of fertilizer source. Analysis of the growing medium at the end of each experiment revealed higher amounts of Fe, Mn, and Zn in the upper portion than in the middle or lower portions of the medium with WSF. The micronutrients studied were evenly distributed throughout the medium when applied as a GIF. #Approved for publication by the Director, Oklahoma Agricultural Experiment Station. This research was supported by project H‐2324.