Wireless sensors networks for optimization of irrigation, production, and profit in ornamental production

With increasing interest in sustainable horticulture, growers require new tools to help them make better production decisions. Wireless sensor technology has become available in agriculture, and can be used to provide real-time information regarding environmental conditions. Wireless sensor network (WSN) systems with soil moisture and EC sensors can provide real-time information about the moisture and general nutrient status of soilless substrates, and help growers make more informed irrigation and fertigation decisions on a daily basis. We are using WSN systems that not only can monitor irrigation and nutrient status of the substrates, but can also automatically implement irrigation protocols specified by growers, based on either sensor- or modelbased algorithms. We analyzed the production and economic benefits of using substrate-moisture sensors to automate irrigation in two commercial production settings. In a container-nursery environment in Georgia (USA), set-point irrigation using substrate-moisture sensors reduced water usage by a hydrangea crop by as much as 83%, without any negative impact on plant growth or quality. Sensorcontrolled irrigation prevented root disease in Gardenia jasminoides production, while shortening the production cycle. We conservatively estimate that the combination of lower plant mortality and faster production resulted in a net economic profit of $ 10/m2 over a nine-month production period. A greenhouse cut-flower producer in Maryland (USA) reduced irrigation applications by 50% using substrate set-point control with a WSN (Decagon Devices, Inc.), while producing better quality snapdragon flowers with higher yield. WSN systems also saved time and labor costs for growers managing large operations. Based on our findings, WSN systems pay for themselves in less than one year.