Crop water requirements represent the amount of water to be supplied to a field to recover the losses occurred by evaporation and transpiration. Crop water requirements are used for (i) a day‐to‐day on‐field irrigation scheduling, (ii) determination of seasonal water needs of an existing irrigation scheme (i.e. seasonal irrigation planning), and (iii) estimation of water volumes to be supplied to newly irrigated areas (i.e. during the irrigation project design and definition of irrigation network hydraulic characteristics).
Irrigation scheduling is a process used by irrigation managers to determine the correct frequency and duration of watering, i.e. when to irrigate and how much water to apply. It is usually focusing on a specific crop cultivated in an area with homogeneous (representative) weather, soil, and irrigation system characteristics. Irrigation scheduling aims to optimize use of water, nutrient, and energy, while achieving the maximum economic benefits of agricultural production, reducing environmental impacts, and ensuring the provision of ecosystem services. The soil–water‐balance method for irrigation scheduling is described together with a practical example of irrigation scheduling strategy. Moreover, the application of innovative technological solutions that integrate field data, sensors, and models in smartphone Apps for control and automation of irrigation process is illustrated.