Capture of Sprinkler Irrigation Water by Container-grown Ornamental Plants

Abstract

The capacity for container-grown plants to capture sprinkler irrigation water plays a critical role in adjusting irrigation rates to deliver required amounts of water to the container substrate. The capture factor (CF) used to describe this capacity was defined as the amount of water captured with a plant relative to the amount captured without a plant. A wind-sheltered, irrigation test area was established to measure CF as affected by plant species, plant size, container size, container spacing, and sprinkler type. CF values for 11 marketable-sized, commonly grown plant species ranged from 1 to 4 with highest values exhibited by plant species with an upright, spreading growth habit. CF values increased as plant size increased. Close container spacings (less than one container diameter between adjacent containers) reduced CF when the allotted area outside the container limited the potential amount of water that could be captured. Compared with impact sprinklers, wobbler sprinklers increased irrigation capture 7% for Ligustrum japonicum grown in 27-cm-diameter containers but not in 16-cm-diameter containers. Results showed that CF is a dynamic parameter that depends on canopy size, container size, container spacing, and sprinkler type. A working knowledge of CF is crucial for determining irrigation requirements to maximize sprinkler irrigation efficiency in container nurseries.