Design, construction, and field evaluation of a lysimeter system for determining turfgrass water use

Abstract

Lysimeters are often used in turfgrass and plant water-use studies; however, no detailed description exists for a lysimeter system of moderate volume allowing for rapid, direct measurement of evapotranspiration on a number of replicates. A lysimeter was developed using 250-mm diameter and 330-mm long polyvinvyl chloride piping resulting in a lysimeter volume of 15.5 L. These lysimeters were installed in the field by constructing a plastic soil-retention sleeve that was placed in the soil. The sleeve was matched to the lysimeter diameter so that there was only a 6-mm air gap between the lysimeter and the sleeve. After turf had filled in around lysimeter edges, there was no detectable difference in measured soil temperatures between lysimeters and surrounding plots at the 15-cm depth; however, volumetric soil moisture content of lysimeters was ~3% higher than that of surrounding soil. The lysimeter was weighed in the field by positioning a tripod hoist over the lysimeter. A load cell was installed in the hoist cable assembly so that when the lysimeter was lifted free of the soil-retention sleeve the weight of the lysimeter could be recorded. The system was shown to provide highly reproducible weight measurement data based on paired t-test analysis of repeated weighing data.