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.

Atlantic Forest; sewage sludge; ozonation; automated irrigation; biometric parameters