Economic Use of Water in Drip-Irrigated Maize in Semi-Arid Region of Brazil

The objective of this study was to determine the economic level of drip irrigation for the crop of maize in the region of backwoods of Alagoas in Brazil, aiming at a sustainable production and economically viable. For this, the hybrid AG7088 was submitted to five irrigation levels (40, 80, 120, 160 and 200% of ETc) in an experiment developed at the Federal Institute of Alagoas/Campus Piranhas, with a randomized block design and four replications. Harvesting was carried out 98 days after planting, where grain yield with 12% moisture reached 2.1 and 11.8 Mg ha-1 and water use efficiency of 181.8 and 55.3 mm Mg-1 in treatments with 40 and 160% of ETc, respectively. The maximum a physical productivity estimated by the production function was 11.3 Mg ha-1, obtained with 919 mm of irrigation water. The maximum economic yield was 11.1 Mg ha-1, obtained with level of 841 mm (160% ETc).