67-12 Mini-Lysimeter Systems to Monitor Transpiration and Control Drought Stress.



Monday, October 17, 2011: 4:00 PM
Henry Gonzalez Convention Center, Room 213A, Concourse Level

Bruce Bugbee, plants soils and climate department, Utah State University, logan, UT and Julie Chard, 4820 Old Main Hill, Utah State University, Logan, UT
Methods for the precise control of drought stress have been a holy grail of plant biology research.  Here we describe a five-container growth chamber system and a 16-container greenhouse system, each of which uses load cells to precisely monitor and control the mass of a soil/plant system.  The calibration and signal conditioning necessary to quantify transpiration over 10 minute intervals is described. Evaporation can be reduced to less than 1% of the transpiration rate by covering the container surface. Procedures for quantifying and correcting the effect of temperature on load cell output are described. Each system can be programmed to maintain a steady-state reduction in transpiration compared to well-watered control plants, and can continuously monitor whole-plant stomatal conductance. Mini-lysimeters are also useful for quantifying physiological water use efficiency, whole-plant stomatal oscillations, and plant-available water in the root-zone. Example data for each of these parameters is provided.
See more from this Division: ASA Section: Climatology & Modeling
See more from this Session: Soil-Plant-Water Relations: Modeling and Measurements