SBIR-STTR Award

In the U.S. there are over 24,753 acres of containergrown nursery plants. Reported annual rates of application of nitrogen (N) fertilizer range from 1036 to 4730 pounds of N per acre. Determinations of the environmental fate of the applied nitrogen shows that only 5-8% of the applied nitrogen is incorporated into the plant. The U.S. annual production of 24,753 acres of container-grown woody nursery plants with nitrogen applied at the rate of 1500 pounds per acre yields 37 million pounds of N per year. If 6% of the applied nitrogen is retained by the plant, then over 34 million pounds of N remain as a potential pollutant Over 48% is leached from the plant container and discharged in the effluent from the container production area. ffigh growth rates of nursery plants are associated with root matrix solutions containing 80-500 mg N/liter; nitrogen concentration of effluent from the root matrix with "best management7 practices exceeds 282 mg N as nitrate/liter. The Public Health Service considers 10 mg N03-N per liter to be potentially hazardous. The fertilizer "conserver' is designed to protect fertilizer under an invemd, impermeable cup from the mass flow of surface-applied irrigation water or precipitation. The objective of this project is to evaluate the technical feasibility of the fertilizer "conserver" to eliminate fertilizer discharge from a container production system. Proposed experiments are designed to evaluate materials and size of the fertilizer "conserver" that would eliminate fertilizer discharge and yet produce quality plants. The simplicity of the "fertilizer conserver" and anticipated elimination of fertilizer discharge from a container operation suggests rapid acceptance by the greenhouse and nursery industry worldwide.