WATER USE EFFICIENCY WITH RAPID WATERING OF POTTED PLANTS ON FLOODED FLOORS

Sub-irrigation for production of potted ornamental plants combats the waste of water and fertilizer inherent to traditional overhead watering systems used in green¬houses. Because current ebb and flow watering systems for flooded floors operate slowly, the root medium takes up water to near saturation during each irrigation event. We used a system that delivered and removed water rapidly, to restrict the water provided to the plants. We examined several parameters that vary between this partial saturation ebb and flow watering on a flooded floor compared to full saturation watering. Plants took up 20 to 30% less water and fertilizer. Biomass until flower development and bloom, and stem height, were reduced by 10 to 20% under partial saturation. This watering method did not affect flower development, or plant composition. Volumetric water content was the only parameter of the root medium that was affected by location on the flooded floor.