Evaluating Drip Irrigation for Rice Cultivation: A Case Study in Northeast Italy

Abstract In response to increasing water scarcity affecting rice production worldwide, this study presents a field case study evaluating the feasibility of cultivating rice under aerobic soil conditions using surface drip irrigation. The experiment was conducted on a commercial farm in Veneto, northeastern Italy, during the 2021 growing season, where traditional flood irrigation was compared with drip irrigation on two adjacent clay soil plots of approximately <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="5,000 normal m squared" display="inline" overflow="scroll"> <mml:mn>5,000</mml:mn> <mml:mtext> </mml:mtext> <mml:msup> <mml:mrow> <mml:mi mathvariant="normal">m</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:math> each. Three dripline spacings (1.0, 1.25, and 1.5 m) were tested to assess their influence on soil wetting patterns and crop performance. The potential effect of irrigation water oxygenation, achieved by air injection through Venturi ejectors, was also evaluated. In addition to irrigation water consumption, four main crop parameters were measured: number of grains per panicle, plant height at the tillering stage, 1,000-seed weight, and grain yield at harvest. Results showed a yield reduction of approximately 40% in the drip-irrigated plot compared with flood irrigation, mainly due to increased weed competition. However, estimates based on yield components suggest that the potential yield reduction attributable to the irrigation method itself may be closer to 10%. Drip irrigation reduced water consumption by approximately 50% compared with the submerged system. The introduction of air into the irrigation water increased root system density, suggesting potential improvements in water and nutrient uptake efficiency. Although these findings highlight the potential of drip irrigation as a water-saving alternative for rice cultivation under the conditions examined, further research is required to address agronomic constraints and optimize system management.