Measuring Nitrate in Leachate During Greenhouse Production of Philodendron ‘Green Princess’: Comparing Analysis Methods and Evaluating Results

Nutrient runoff from excess fertilizer during commercial plant production may cause significant environmental damage while also posing a human health hazard. Determining effective and affordable methods of measuring nutrient leachate may help growers reduce nutrient waste while also reducing production costs. The main objective of this study was to compare the efficacy of several application rates of three different controlled release fertilizers during a six-month commercial production cycle for a Philodendron ‘Green Princess’ crop. Nitrogen is often considered to be the most important component of commercial fertilizers and we attempted to match the nitrogen sources and percentages in the fertilizers evaluated. Using the standard pour-through method, leachate was collected throughout the production cycle and evaluated for various nutrients. This portion of the project aimed to identify methods for measuring nitrate that were equally accurate and practical for growers to implement to reduce nitrate runoff. There were no visible symptoms of nitrogen deficiency on the Philodendron ‘Green Princess’ crop during the production cycle with any of the control release fertilizers tested. Numerous leachate samples contained substantial quantities of nitrate ions on some collection dates. Both destructive and non-destructive chlorophyll analyses were conducted on the crop and no chlorophyll deficiencies were discovered.