The run-off facility was constructed as a means to capture the liquid that runs out of the bottom of containerized plants in order to evaluate fertilizer use. Eighteen lines are set up with microirrigation stakes to precisely irrigate the plants that are a part of the experiment. Below the gravel that the potted containers are sitting on is grooved plastic that captures the liquid that comes through the containers. The captured liquid is sent through a system of pipes into a container at the north end of the facility. The liquid run off is sampled regularly and checked for nutrient levels with the equipment in our laboratory.
This year's research is examining a fertilizer product called Crystal Green® that is harvested from The Durham Advanced Wastewater Treatment Facility in Tualatin. This fertilizer product is a prilled mineral called struvite that contains phosphorus, ammonium and magnesium that is precipitated at the end of the treatment process. The production of struvite removes 90% of the phosphorus from the treated water and in turn provides a source of fertilizer for nursery crops. This experiment aims to quantify the efficiency of the fertilizer for containerized nursery plants.