Competition for limited available water for crop production is an ever-increasing issue for
farmers due to increasing demand of irrigation water worldwide. Due to high energy cost
in operating pressurized irrigation systems, energy-efficient low-pressure wick irrigation
systems can play important roles for smallholder greenhouse crop production by ensuring
higher water use efficiency than most traditional approaches. The objectives of this study
were to investigate HYDRUS 2D-simulated water distribution patterns in soil and soilless
growing media, and to evaluate water balance in these media under capillary wick irrigation
system. To accomplish these objectives, eggplants (Solanum melongena L.) were grown
in potted peatgro and sandy clay loam in a greenhouse experiment, water distribution was
simulated by using HYDRUS 2D software package and compared with the measured
values, and water uptake by the plant roots was determined for water balance calculation.
The wetting pattern was found axially symmetric in both growing media (peatgro and
soil) under the wick emitters. The simulated
water distribution in both growing media
revealed dependency of spatial extent of the
wetted zone on water application period and
hydraulic properties of the media. The mean
absolute error (MAE) in water content over
depth varied from 0.04 to 0.10 m3 m−3 and the root mean square error (RMSE) varied from 0.04 to 0.11 m3 m−3. Deviations between the
measured and simulated water contents in the peatgro medium were larger over depth than
over lateral distance. In contrast, the model criteria matched well for the sandy clay loam
and provided MAE of 0.01 to 0.02 m3 m−3 and RMSE of 0.01 to 0.03 m3 m−3, indicating
good agreement between the measured and simulated water contents.