Soil Water Evaporation in Irrigated Corn

Abstract

Three simulation models were evaluated for their ability to predict bare soil water evaporation in irrigated corn. The models were Ritchie, CERES-Maize, and EPIC. Soil water evaporation field data, collected in North Platte, Nebraska, were used to evaluate the models. Small lysimeters under the crop canopy measured soil water evaporation during the growing season. Mini-lysimeters excluded root growth, but soil water contents were adjusted to surrounding soil weekly. Micro-lysimeters were installed on a daily basis, which allowed for soil water extraction until the day of data collection. Soil water evaporation simulated by Ritchie and CERES-Maize models most closely matched evaporation measured by North Platte lysimeter data. EPIC predicted lower soil water evaporation rates during complete canopy cover. Keywords. Evapotranspiration, Transpiration, Soil evaporation, Model evaluation. Three simulation models were evaluated for their ability to predict bare soil water evaporation in irrigated corn. The models were Ritchie, CERES-Maize, and EPIC. Soil water evaporation field data, collected in North Platte, Nebraska, were used to evaluate the models. Small lysimeters under the crop canopy measured soil water evaporation during the growing season. Mini-lysimeters excluded root growth, but soil water contents were adjusted to surrounding soil weekly. Micro-lysimeters were installed on a daily basis, which allowed for soil water extraction until the day of data collection. Soil water evaporation simulated by Ritchie and CERES-Maize models most closely matched evaporation measured by North Platte lysimeter data. EPIC predicted lower soil water evaporation rates during complete canopy cover.