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_-_-_-_-_-,.-,.-:4 -~.~.~.~.~.~.~.. ,....-e-..~..~..<e..<e.<e.<: ..... ... ~'... ... ~ ... . ... " Hydraulic, weighing-type lysimeter used as the control Data Collection and Analysis Iysimeter is pennanently installed flush with the ground surface and sod is allowed to grow over the lip. The annular to surface area ratio is 0.06 for this lysimeter. A 0.15-m filter pack similar in design to that in the large Iysimeter was placed in the bottom of the smalllysimeters and the soil was packed above this to a bulk density of 1.3 g/cm3. The study included four soil types chosen for their infiltration and water holding characteristics: a sandy loam, a loam, and a clay loam acquired from sites in the City of Colorado Springs, and a loam soil obtained from Fort Collins. Three replications of the sand, loam, and clay were placed in nine small weighing Iysimeters and this was repeated for nine small drainage Iysimeters. Fort Collins loam was placed in the large Iysimeter and in three small weighing and three drainage Iysimeters. As such, there were a total of twelve small weighing Iysimeters and twelve small drainage Iysimeters. The amount of water application, deep percolation and the change in soil moisture content were measurell for four summer seasons (1992-95). Data for the large Iysimeter were collected daily except on the ,weekends. The change in soil moisture (CSM) was found by subtracting the day's Iysimeter weight from the previous day's lysimeter weight measurement. Deep percolation water (DP) was pumped out and measured, and the amount of water applied during each irrigation (I) was measured by using catch cans. Precipitation (P) was measured in a tipping bucket gauge and was assumed to be uniform over the entire study site. From these data, daily evapotranspiration (ET) was calculated frok a volume balance equation, ET = 1 + P - DP - CSM 10 (3)