2013 ASHS Annual Conference

Non-weighing lysimeters were used to measure seasonal water use of mature ‘Emerald’ southern highbush blueberry plants grown in pine bark beds and in pine bark amended soil in north-central Florida. In the absence of rain, irrigation was applied daily with microsprinklers at approximately 150% of reference evapotranspiration as either one or two applications. The lysimeter dimensions were 1.2 m across the row by 0.9 m in the row by 0.5 m deep. A section of 25.4 cm diameter PVC pipe attached to the bottom of each lysimeter was used to collect leachate. Leachate was collected and its volume determined from each lysimeter at about weekly intervals throughout the study. Soil moisture was monitored with TDR sensors at three depths in representative lysimeters and changes in soil moisture content across measurement periods were negligible since irrigation or rainfall occurred daily. Water use, expressed as liters per plant, was calculated as the difference between the amount of irrigation/rain added to lysimeters and the amount of leachate collected from lysimeters during each measurement period. Average daily water use was calculated for monthly intervals beginning in April, 2010 and ending in August, 2012. Water use increased rapidly during spring foliation and peaked during the final stages of fruit ripening and harvest (May) and again during late summer (August and/or September). A temporary decline in water use was observed immediately following postharvest pruning during early summer. Few significant differences in water use were observed between soil management or irrigation treatments. Monthly averages for daily water use during the 29-month period ranged from 1.6 L/plant in January to 8.2 L/plant in August.