The study has shown that the Florida harvester ant,Pogonomyrmex badius(Latreille) (Hymenoptera: Formicidae) causes phosphorus and potassium to accumulate at the surface of colony sites in abandoned fields and along road shoulders. Soil samples from the crater surface of 5 harvester ant colonies contained 10.4±1.0 ppm phosphorus and 16.5±3.9 ppm potassium. Soil samples from control areas not associated with an ant colony contained 6.2±0.5 ppm phosphorus and 6.6±1.0 ppm potassium. The growth (height) of buttonweed,Diodia teresWalt, seedlings was greater in soils from ant mounds than in soils from control areas. The accumulation of nutrients is caused by the deposition of debris and waste products (seed covers, dead ants, feces, and other metabolic wastes) around the crater rim. The soil enrichment increases the standing crop of plants immediately surrounding the colony crater. The gradual mineralization of nitrogen and other inorganic nutrients is responsible for the continued greater growth of plants at sites abandoned for several years.Colonies are long-lived and may move to new locations several times during a period of years. The increased plant growth could possibly reduce the foraging radius of the workers by increasing local seed production.