Variability of solute transport in field lysimeters

Solute transport at the field-scale is inherently influenced by the spatial variability of soil properties. Lysimeter studies in undisturbed soils are subject to same variability as that encountered in field soils. In this pa per, we present an experiment to assess the variability of solute transport within lysimeters. Bromide was applied to a series of lysimeters of 61 and 122 cm depth containing undisturbed, homogeneous sandy soil, and leached w ith two different flow rates of 30 and 60 mm d(-1) under non-steady state c onditions. There was substantial variability among the bromide breakthrough curves in the 61-cm lysimeter for both flow rates and in the 122-cm lysime ter for the lower flow rate. The variation of solute transport decreased wh en the lysimeter depth and the flow rate were increased. All breakthrough c urves showed a prolonged tailing, indicating that there was a stagnant wate r zone present in the soil.