Biossólido e torta de filtro na composição de fertilizantes organominerais para a cultura da cana-de-açúcar (saccharum sp)

Abstract

Sugarcane represents one of the crops of Brazil with the greatest energy potential, whether in the production of biofuels or electricity. Currently, the sugar-energy sector hopes to increase productivity without increasing the area planted, based on improvements in agricultural practices and new varieties. Thus, the use of urban and industrial waste as an organomineral fertilizer for sugarcane can be a correct way to dispose of this waste and also bring environmental and economic sustainability to the crop. In this work, the effects of the dosage and of two sources of organic residues (biosolids and filter cake) on the estimation of photosynthesis, biometric variables and chemical and technological variables, on sugarcane yield (Saccharum sp) were evaluated two crop cycles.The experiment was conducted in the experimental area of the Vale do Tijuco Plant (CMAA) located in the Rio Peixe, municipality of Prata, MG. The recommended fertilization for planting was 570 kg ha-1 of formulation 04-21-07 (NPK) and coverage of 570 kg ha-1 of 07-00-28 (NPK) + 0.7% of B. The experimental design was a randomized complete block design in a 4 x 2 + 2 factorial scheme with four concentrations of organomineral fertilization with a filter cake base and biosolid (50%, 100%, 150% and 200% of the recommendation for cover and cover), in addition to a positive control (100% of mineral fertilization) and a negative control (without fertilization), in four replicates. The analyzes of the physiological characteristics of the plants, liquid photosynthesis and stomatal conductance indicate that the organomineral fertilization maintains the same photosynthetic efficiency of the mineral fertilization. The use of biosolids and filter cake at a dose of 50% of the sugarcane recommendation was significantly superior to the mineral fertilization at the dose of 100% for the photosynthetic rates. The same occurs in the chemical-technological variables of sugarcane, brix, pol% cana, purity, fiber and ATR not altered by the application of mineral and organomineral fertilizer. However, there was an increase in total sugar produced per hectare (TAH) in the second year of cultivation of 10,25% through organomineral fertilization with biosolid when compared to the same nutrient dose with mineral fertilizer application. The application of organomineral fertilizers in sugarcane proved to be efficient and with gains in the evaluated variables. Therefore, it is recommended the use of biosolids and filter cake as a source of organic matter for the organomineral fertilization of sugarcane, combining environmental sustainability with cost reduction without loss of productivity.