تحديد مستوى التدفق الصفري و التدفق التبخري حقليا تحت تناوب استعمال مياه ري عذبة و جوفية

الملخص EN

To study the effect of alternate use of fresh water(F) and ground water(G) irrigation as a common farming practice in Iraq, on location of Zero Flux Plane (ZFP), and evaporative flux (EF), two field plot experiments were performed at Al-Rasheed district.

Each plot was subjected to three alternate cycles as fallows: fresh water-ground water-fresh water(FGF) and ground water-fresh water-ground water (GFG) for the first and second plots respectively.

At the end of the second cycle soil moisture sensors installed at 2.5, 5, 10, 15, 20, 30, 40, 50 and 60 cm below soil surface to determine water content change as a function time for 14 days (336 hours).

Water potential was calculated from the parameters of the fitted van Genuchten equation to soil moisture characteristic curve data.

The results indicated high rate of decrease in water content (θ) and water potential(ψ) for the surface depths especially during early evaporation stage compared with sub surface depths (30-60cm).

ZFP was found at a depth of 5cm after 0.5 and 2 hours for FGF and GFG respectively.

At the end of each experiment plots 336 hours, ZFP was located at 50 and 40 cm depths for FGF and GFG respectively.

rare of EF after 336 hours ware 8.08×10-4 and 4.57×10-4 cm h-1 for FGF and GFG respectively.