Assessing Potential Water Savings Implementing Variable Rate Sprinkler Irrigation in a Maize Farm in Northern Italy

In recent agricultural seasons, many areas of the Po plain have experienced periods of water scarcity; to cope with this situation, farmers are introducing water saving technologies which would be more effective if supported by appropriate tools. Specifically, agro-hydrological models and soil moisture probes can support farmers in the irrigation management. In this study, an agro-hydrological model and soil water content measurements were used to optimize the water management in two irrigation sectors characterised by different soils under a center-pivot in a maize farm. When compared to the management operated by the farmer, a water use reduction of 17 and 23% was achieved in the coarse and fine soil sectors, respectively; this water saving was obtained respecting the constraints imposed by the farmer. The same modelling approach, applied to simulate variable rate irrigation for all the sprinkler systems of the farm (covering about 300 ha) in the period 2016–2020, resulted in an average water saving of 18%. This translates to a proportional energy saving at the farm level.