Soil fertility has become an interconnected aspect of modern agriculture, incorporating factors such as nutrient availability from soil, and its revision has become necessary for ensuring sustainability. Therefore, to understand the solubility of nutrients from organomineral fertilizers pelleted with biosolids and sugarcane filter cake, and to evaluate the resulting chemical changes in soil from its use, an experiment was performed in a completely randomized design. The experiment was done with four replicates in a 3 × 5 +1 factorial scheme, using three fertilizer sources (mineral fertilizer, organomineral fertilizer pelletized with biosolids, and organomineral fertilizer pelletized with the filter cake); five doses (60%, 80%, 100%, 120%, and 140% of the recommended dose of fertilization for corn); and an additional control treatment (absence of fertilization). The formulation of the organomineral fertilizers was 5-17-10 with 10% total organic carbon. All fertilizer sources were packed in a microfiber cloth positioned 1 cm below the surface of the soil and incubated for 60 days. Subsequent evaluation of chemical attributes: pH H2O (1:2.5); pH SMP (Shoemaker-McLean-Pratt); and the content of exchangeable aluminum, phosphorus, potassium, calcium, magnesium, silica, and organic matter within the soil was done. Organomineral fertilizers pelleted with biosolids or filter cake do not acidify the soil, but they were found to reduce aluminum saturation and promote a slow release of nutrients, which allowed a more balanced base in the soil. This then ensured a better balance of nutrients, with greater cation exchange capacity, base sums, and base saturation. The use of these fertilizers can contribute to stabilizing the pH of the soil with fewer applications of acidity correctives

Pelletized organomineral fertilizers (OMFs) are a promising, sustainable alternative for eucalyptus fertilization, the most widely cultivated hardwood tree globally. However, little is known about the effects of OMFs on initial plant development and soil quality. We evaluated the effects of different doses of a pelletized OMF derived from sugarcane filter cake (0%, 50%, 100%, 150%, and 200% relative to the recommended phosphorus dose for cultivation) and a mineral treatment (mineral fertilizer at the recommended dose for eucalyptus), as well as the effects of time (30, 60, 90, and 120 days after transplanting), on the morphophysiological responses of eucalyptus plants (diameter at neck height, plant height, and chlorophyll a and b content) and soil pH, microbial biomass (MBC), and microbial activity (soil basal respiration [SBR]). Increases in fertilizer dose led to increased chlorophyll a values, but values decreased under the highest doses (150% and 200%). OMF addition led to an initial increase in soil pH, followed by a reduction. The highest values of plant height, stem diameter, and fresh and dry masses of leaves, stems, and roots were observed when the OMF dose of 50% was administered. MBC values were inversely proportional to the OMF dose, and the SBR and metabolic quotient (qCO2) values observed under the 50% and 100% treatments were equal to or better than those observed under the mineral fertilizer treatment. Pelletized OMFs derived from filter cake could potentially replace mineral fertilization in the early development of Eucalyptus urophylla × Eucalyptus grandis without damaging soil quality