Closing the Water Balance with a Precision Small-Scale Field Lysimeter.

We developed a set of two precision, small-scale, water balance lysimeters to provide accurate measurements of bare soil evaporation. Each lysimeter comprises a soil tank, a balance assembly with load cell, a wicking drainage system, and a stilling well to measure drained water. Fiberglass wicks installed at the bottom of the soil tanks provide -60 cm of tension to the base of the soil column, and soil water drainage is quantified to close the water balance within the lysimeter.