The current world scenario shows increase in fertilizer price associate to the high Brazilian dependence of importation, which impacts in the final cost of food. Most efficient fertilizer usage, mainlymacronutrients (nitrogen, phosphorus, potassium - N, P, and K), is essential to obtain maximumproductivity of crops combined to the reduction of possible nutrients loss to the environment. Slow or controlled release fertilizers can contribute to the rational administration of these inputs. However, the high demand (tons per application) requires the maximization of nutritional contents, in simple production processes with high productivity and based on low-cost raw materials. Thus, here we proposedeveloping a class of nanocomposites with partially polymerized urea-based matrices (nutrient source of N) using bio-refinery residues, and modified with nanoparticles also source of nutrients, so that the microstructure and polymerization degree can synergistically modulate their release behavior. The polymer matrix will be based on the partial urea polymerization by condensation using di-isocyanates and glycerol, an abundant biodiesel byproduct, in which different degrees of polymerization will be investigated about its influence on the N-releasing process. The modification of properties will be donemainly using mineral sources of nutrients as nanoparticles (super phosphate triple, KCl, among others) where the dispersion degree and homogeneity will be investigated about their influence in each nutrient release. To satisfy the high demand (typical of fertilizers), the adequacy of these formulations for highproductivity processes, such as extrusion, will be investigated. Tests of nutrient release in aqueous medium will be carried out for prior determination of specific release rate, as well as tests of mineralization in incubated soil, composite biodegradability and greenhouse tests with test plants. The comprehension of the matrix' polymerization degree influence, the interaction with nanoparticles and aspects of materials' processing will contribute to the description of nutrient difusional process inpartially soluble structures, giving support for the design of new integrated fertilizer systems with extremely high nutrient contents and viable industrial production.
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