Sullivan K, Valdes E. 2009. The effects of fertilization on nutrient content of pasture, soil and water in 3 savannahs at Disney’s Animal Kingdom Lodge. In Ward A, Treiber K, Schmidt D, Coslik A, Maslanka M, Eds. Proceedings of the Eighth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Tulsa, OK.
Historically, grass nutrient content at Disney’s Animal Kingdom Lodge (DAKL) has been observed to have high levels of potassium (> 4 %), a possible concerning factor in the development of hypomagnesemia in grazing hoofstock. There had been no fertilization of the savannahs at DAKL for 2 years prior to the current study, and potassium levels had reduced approximately by half (~ 2 %). In order to test the effects of fertilization on the grass nutrient content, water nutrient content and soil nutrient content at DAKL, a year long study was initiated. Two specific areas of each of the 3 savannahs with animals present at DAKL were fertilized in May 2008 with Nature Safe 8-3-5 Stress Guard Fertilizer (Griffin Industries, Cold Spring, KY). A pre-fertilization sample was also taken in both in the areas to remain unfertilized and each of 6 areas to be fertilized. Sampling began June 2008 on a monthly basis of all fertilized areas, unfertilized controls, and an unfertilized control without animal presence. Water and soil samples were also taken. Based on concerns of hypomagnesaemia and laminitis, the nutrients of most interest were magnesium, potassium, starch, sugars and soluble carbohydrates. In all cases, there were minimal to no significant differences in the grass content between fertilized areas and unfertilized areas in terms of these nutrients. There appeared to be some seasonal variation in the grass with potassium and magnesium lower during the winter months of January and February. Starch, sugar and soluble fiber did not show any clear patterns throughout the year. Potassium and magnesium levels in the water appeared to be low and steady throughout the year, with total dissolved solids slightly elevated in the first two months after fertilization but still within normal parameters. Soil samples also did not differ in nutrient content across time or by area. The lack of differences in nutrient content with fertilization indicates that the addition of mineral nutrients through the fertilizer used may not be directly responsible for changes in grass nutrient content.18_SullivanPasture.pdf     249 KB