University of Maryland: (John Lea-Cox, David Ross and Andrew Ristvey )
In Maryland , we have been living with State Regulations for nutrient management since the Water Quality Improvement Act was passed in 1998, mandating that virtually every agricultural producer in the state writes and implements a Nitrogen and Phosphorus-based management plan.
As such, our team's research over the past six years has focused predominantly on reducing N and P runoff from intensive ornamental operations, and providing growers with the best BMP information possible to achieve these goals.
You would think that we actually knew a lot about optimizing water and nutrient applications to container plants. Well, we do in part, but what we don't know is how efficient those practices are in a real-world scenario.
What we have found is that water management is the key to controlling both nitrogen and phosphorus runoff in container nurseries. However, nutrient uptake efficiencies by two woody perennials (Holly and Azalea) were very low (often less than 20%), but increased when nutrient applications were better timed to match active growth periods, and when irrigation applications were carefully managed.
Our current water management research program is focused on using capacitance probes to accurately sense the water content of diverse variety of soilless substrates, using Decagon Ech 2 0 capacitance probes and a wireless network capability developed by the Carnegie Mellon Robotics Institute. Being able to accurately sense the plant-available water in real-time using these networks would allow growers to more accurately apply water to their plants, reducing water applications and conserving nutrients in the root zone of the plant.