Impact of land preparation on water saving in border irrigation

Border irrigation is still the most widely surface irrigation technique used for watering row crops worldwide, including the Padana Plain where it is mainly used to irrigate forage crops. Observations in the Lombardy Padana Plain show that a considerable amount of water, up to 3000 m³/ha, is used during each irrigation event, often resulting in excessive irrigation. This practice is unsustain-able in the long term due to declining surface water supplies. Research suggests that improved management of irrigation timing and land preparation can lead to significant reductions in water use. This work investigates the potential water savings that could be achieved by op-timising land preparation on a 2 ha irregular boundary field traditionally irrigated at 2300 m³/ha per irrigation event. Using detailed topographic data and the Irri-Surf2D model, scenarios such as using laser levelling to improve slopes, intro-ducing ridges and adjusting irrigation timing were investigated. The results showed that effective land preparation could save up to 47% of water per irriga-tion event. These results show how it is possible to increase the sustainability of border irrigation while keeping this technique alive in the Padana plain.