Nutritional Status and Productive Components of Maize Fertilized With Sewage Sludge

The response of crops to the application of biofertilizers in the soil is not yet well established. Therefore, we carried out this study with the objective of evaluating the productive potential of maize fertilized with doses of sewage sludge, comparing with the use of mineral fertilizer over four agricultural seasons. The experiment was conducted in a Red Dystroferric Nitosol (Ultisol) in a randomized block design and repeated measures in time. The treatments consisted of five doses of sewage sludge and one treatment using nitrogen, phosphorus and potassium in formulation. All fertilizations were carried out at maize sowing at four planting times (summer and 2nd crop of 1st agricultural year and, summer and 2nd crop of 2nd agricultural year) and replicates. The results showed a cumulative increase in the P, Ca, Mg and Zn leaf concentrations over the four seasons crops, when the sewage sludge was used in the 30 and 40 Mg ha-1 doses. However, reductions in plant height, weight and maize cob diameter, mass and grain yield were observed at the end of the last harvest. The treated sewage sludge is a viable alternative for maize fertilization in the first harvest, provides increases in grain yield in the order of 1.35 Mg ha-1 and can be recommended instead of NPK mineral fertilizers in built-up fertility soils.