1997 Volume 41 Pages 61-66
With the increasing economic growth in the and regions, and with the growing need for new water resources, the demand of new water supply systems for irrigation are becoming high. One of the most water-safe method for irrigation is the trickle method. In this method, water for irrigation must be supplied just on root zone with the help of emitters. The problem associated with the trickle irrigation is the salinization, this leading to such problem as threatens irrigated agriculture, slow infiltration, water logging and crusting. Gypsum has been shown to be effective in reducing the sodium content in soil, but it is inconvenient for trickle irrigation and currently too costly. The dynamics of soil salinization is strongly affected by evaporated water and by plant water uptake. Therefore, any hydraulic solution for reducing the salinization needs a good understanding of the flow pattern and moisture content and their relationship with the evaporation and water uptake by plants under the use of trickle irrigation. The flow pattern and the moisture distribution under trickle irrigation was simulated numerically and experimentally. The hydraulic properties of the studied soils were estimated in this study. To maintain high water content in the upper part of the soil under trickle irrigation, a sub-layer was used beneath the top soil layer and its hydraulic properties were examined.
