Biochar, Filter-Cake, and Polymer-Based Special Fertilizers for Maize Cultivation

This investigation assessed the effects of special fertilizers on maize. The experiment was performed according to a randomized block design, with four replications in a 7 × 4 + 1 factorial scheme, representing seven sources (filter-cake-based organic compound, biochar-based organic compound, organic-mineral (OM) filter-cake, OM biochar, OM filter cake + humic substances (HS), mineral fertilizer with polymers, and conventional mineral) and four fertilizer levels based on the nitrogen (N) contents (60, 120, 180, and 240 kg/ha). An absolute control, without any fertilizer application, was used. At 60 days after sowing (DAS), the plant growth parameters, nutritional status, and residual nutrients in the soil were evaluated. The mineral fertilizer with polymers and OM filter-cake + HS showed better results for the dry matter of the shoot of the plant and plant height. When considering the leaf area, the OM filter-cake and OM filter-cake + HS fertilizers stood out. The accumulation of N and potassium (K) in the shoot of the plants was higher when the OM filter-cake + HS and mineral fertilizer with polymers were applied. With respect to the accumulated phosphorus (P), treatment with the OM filter-cake, OM filter-cake + HS, and mineral with polymers showed better results. On the other hand, for the analysis of P and residual K in the soil, the treatments based on filter-cake and biochar organic compost were better. Treatment with the OM filter-cake + HS and mineral with polymers stood out when considering the plant growth parameters and nutritional aspects of the maize crop.