Dosatron

Fertilization is essential for greenhouse production and is most commonly achieved using fertilizer injectors.  Since the fertilizer is applied with the irrigation water, excessive irrigation results in excessive fertilizer applications.  Much of the applied fertilizer can be lost by leaching.  Leaching fertilizer results in both an economic loss (the cost of the fertilizer) and potential environmental problems (runoff of nutrient rich water).  A team of researchers and extension personnel at the University of Georgia has been working on more efficient irrigation systems for greenhouses.  The approach is based on the use of wireless sensor networks and soil moisture sensors to determine when a crop needs water.  Findings so far indicate that leaching can be greatly reduced with this approach.  And now they are focusing on related questions: if growers irrigate more efficiently and leach less, can they use less fertilizer and reduce production costs? And if growers leach less, how much does that reduce the amount of fertilizer that gets leached from the pots?  Our previous research growing nursery crops and other greenhouse crops showed we can use 50-70% less water and much less fertility and still have a high quality crop.  The question is, does this technology work in a cost effective way with bedding plant production where EC levels are critical?

To answer these questions, UGA PhD student Alem Peter is working with professors Paul Thomas and Marc van Iersel on a study to quantify nutrient leaching under different irrigation regimes.  In this same study, they also hope to answer the question of whether fertilizer rates can be reduced when irrigation is more efficient.  For this study, the University of Georgia team needed fertilizer injectors that can operate with low flow rates and Dosatron USA donated two D14MZ2 – 14 GPM fertilizer injectors.  The Dosatrons will be used to fertigate a petunia crop with 100 or 200 ppm nitrogen.  These two fertilizer rates will be combined with 4 different irrigation approaches (ranging from no leaching to excessive leaching) to determine optimal practices for the production of high quality bedding plants.  Look for the experimental results by the end of  the 2012 summer season.