Automated Irrigation Based on Soil Moisture Tension Reduces Run-off and Increases Productivity and Quality of Greenhouse-grown Cut Flower Roses

Abstract

Conventional irrigation practices of cut-fl ower greenhouse crops may result in application of excess water, resulting in runoff which may pollute the environment and contaminate drinking water supplies. A computerized irrigation control system based on soil moisture tension, originally designed for potted plants, was adapted for use in cut flower production. Tensiometers equipped with a high-fl ow ceramic tip and pressure transducers were effective in monitoring the soil moisture in the root zone of plants grown in ground beds and responded to rapid changes in soil moisture. The irrigation control system using these sensors, a computer, and custom-written software continuously monitored the moisture condition of the soil, initiated irrigation when the soil dried to a specific level, and turned off the water when an adequate amount was applied. When the system was installed in a greenhouse producing roses, water use decreased while productivity (stems harvested/m2) and stem length increased substantially. The observed increases in productivity and quality can result in significant increases in profitability for commercial rose producers.