Monitoring Environmental Conditions and Substrate Water Content for More Efficient Irrigation In Nurseries

Excessive irrigation in greenhouses and nurseries leads to nutrient leaching and runoff.  Obstacles to implementing more efficient irrigation practices include determining when plants need to be irrigated and how much water should be applied.  We have deployed wireless sensors networks in commercial nurseries to provide growers with real-time information concerning the environmental conditions and substrate water content of specific crops.  Growers can access this information through an on-site computer, while the researchers can access that same computer over the internet.  This allows for frequent communications and feedback between the growers and researchers concerning irrigation management.  The soil moisture sensors are used to determine when crops need to be irrigated, while rain gauges can provide valuable information about how much irrigation water is applied.  In data obtained in 2010/2011 trials, a significant change in substrate water content following irrigation was seen, clearly allowing growers to estimate leaching.  A rapid decrease in substrate water content following irrigation suggests that water is running out of the containers, thus allowing growers to determine whether they are leaching.  Having easy access to this information allows growers to make adjustments in their irrigation practices, changing either the volume and/or duration of application.  Real time charts allow growers to see the impact that that these changed practices have.  The next step in improving irrigation is the use of wireless dataloggers that not only monitor a crop, but that can make irrigation decisions as well. Growers will be able to enter specific irrigation set points, and the datalogger can then use those set points to irrigate crops as needed. The issues involving installation of this system will be discussed.