تأثير تناسق الارواء بمياه الري المالحة على الإنتاج تحت الري الناقص

Abstract

The study aimed towards developing a computer model to be used for evaluating the effect of water distribution uniformity of deficit irrigation with saline water on field crop production. The development of the model is based on the concept of water balance in the field. For the application of the model, corn crop (yellow maize) autumn season is selected using ready data on reference evapotranspiration at the selected field site (North Jazirah Project – Nineva). Moreover, published data on field sprinkler water distribution around sprinkler head of stationary system are used. The main assumption upon which the model is based is that, for a given case, irrigation water distribution and salinity are fixed for all irrigations during the season. The results of the study revealed that the deficit in the yield ratio increases with the increase in moisture depletion ration and water salinity, but decreases with the increase in the degree of irrigation uniformity. Furthermore, the effect of salinity on production is greater with deficit irrigation, therefore a balance should be sought between deficit irrigation level and water salinity on production under each case of irrigation non-uniformity. Finally, the study showed that the leaching fraction increases as the degree of irrigation uniformity deteriorates because deep percolation losses increase with the reduction in uniformity.