Water is destined to be the critical resource of our Century since the demand for fresh water will continue to increase while the supply dwindles. Irrigated agriculture is the primary user of diverted water globally, reaching a proportion that exceeds 70–80% of the total in the arid and semi-arid zones. Nevertheless, irrigated agriculture is still practiced in many areas in the world with complete disregard to basic principles of resource conservation and sustainability. Therefore, irrigation water management in an area of water scarcity will have to be carried out most efficiently, aiming at saving water and at maximizing its productivity. In the context of Mediterranean region, crops production is predominantly limited by water deficiency and inadequate management. Therefore, understanding how crops can increase the capture and the efficiency in using limiting resources, such as water, undertakes a strategic importance. Thus, the needs for improving water productivity (WP) in Mediterranean agriculture and for investigating WP behavior on legumes (such as faba bean) and root (such as potato) crops are evident. Accordingly this work focused in this issue.