SIMULATION OF WINTER WHEAT WATER BALANCE WITH CROPWAT AND ISAREG MODELS

This paper presents the results of water balance simulations on winter wheat production in the area around Bijelo Polje. Winter wheat production over three years and on two soil types has been simulated with the CROPWAT and ISAREG models. The simulated results have proved variations between the two models and the measured yield. Crop evapotranspiration ranges between 304.5 to 463.3 mm. The relative yield obtained after the simulations is very similar to the relative yield obtained on a measured basis, except in the 2008/2009 season. Net irrigation requirements (NIR) to obtain the maximum yield are higher at 49-116 mm in the simulations with the CROPWAT model. The total NIR to maximize yield ranges between 84-300 mm depending on the season and model. Water use efficiency ranges from 0.82 to 1.28 kg/m^3. The obtained results verified both models as good tools for determining winter wheat water balance and indicated that winter wheat yields could be improved with irrigation.