ABSTRACT The continuous demand for water in the agricultural sector has encouraged researchers worldwide to find alternatives to optimize this resource. The use of wastewater in irrigation is promising in this scenario, especially to produce tree seedlings. The growth, quality, and water productivity of Dalbergia nigra seedlings cultivated with sewage sludge were determined when irrigated with urban supply water (W1) and cattle wastewater (CWW) treated for 1 h (W2) and 2 h (W3) of ozonation, considering four irrigation depths and shading levels (0 % (C1), 37.6 % (C2), 49.4 % (C3), 75.8 % (C4)). The height, stem diameter, biomass, and the Dickson Quality Index (DQI) were evaluated. The largest volumes of water applied in each experiment were 2.342 L per plant in W2C1, 2.114 L per plant in W1C3 and 1.556 L per plant in W3C1. The CWW provided satisfactory seedling growth, especially W2, highlighting a DQI of 0.47 obtained in C1 and better water productivity (3.8 g L–1) in W2C1, with full depth. Using alternative inputs in the seedling production of tree species is a promising strategy and indicates benefits for waste disposal, such as sewage sludge and wastewater. resource scenario growth quality W1 W (W1 (CWW W2 (W2 W3 (W3 ozonation 0 ( C1, C , (C1) 376 37 6 37. C2, C2 (C2) 494 49 4 49. C3, C3 (C3) 758 75 8 75. C4. C4 . (C4)) height diameter biomass (DQI evaluated 2342 342 2.34 W2C1 WC 2114 114 2.11 W1C 1556 556 1.55 W3C1 047 47 0.4 3.8 38 3 (3. L–1 L1 depth disposal (W (C1 (C2 (C3 7 (C4) 234 34 2.3 W2C 211 11 2.1 155 55 1.5 W3C 04 0. 3. (3 L– (C (C4 23 2. 21 15 5 1.