15. Salt and Water Dynamic of Potato Crop Under Irrigation with Low Quality Waters

In Tunisia, the scarcity of water for irrigation and the quality of available resources make it necessary to adopt strategies of water management aimed to increase water use efficiency. If from one side, choosing an appropriate irrigation system, like a well-designed subsurface drip system can ensure high values of water distribution uniformity, increasing water use efficiency requires that irrigation scheduling account for actual crop water requirement, depending on soil, plant, climate, and other local conditions. During the growing season (2014) to investigate the effects of low water quality and scheduling on water’s dynamic in soil (soil water content moisture distribution, water’s stock variation) and water use efficiency (WUE) to produce potato (Solanum tuberosum L.). Subsurface drip irrigation was used for two treatments T1 and T2; T2 was irrigated 50% of T1. During the crop season soil water During the crop season soil water content variation was more important at the end due to root uptake and hard climatic condition, treatment T2 had less water stock and best water use efficiency with 10.83 kg/ha than 5.85 kg/ha for T1.