Biodegradation in soil of enhanced efficiency fertilizers based of poly(vinyl alcohol) and starch microspheres

• Grant number: 21/14234-0
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: March 01, 2022
• End date: February 29, 2024
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Inorganic Chemistry
• Principal Investigator: Roselena Faez
• Grantee: Rodrigo Ragazzi dos Santos
• Host Institution: Centro de Ciências Agrárias (CCA). Universidade Federal de São Carlos (UFSCAR). Araras , SP, Brazil

Abstract

Enhanced efficiency fertilizers (EEFs) appear as an alternative for the more efficient application of fertilizers, as they attenuate environmental impacts and keep the nutrients needed for the stages of plant growth available for longer. A current major challenge is the development of EEFs from materials that degrade in the environment after fulfilling their nutrient release function. Thus, it is essential to develop biodegradable materials and understand the biodegradation processes. This work aims to evaluate and establish a soil biodegradation profile of an EEF consisting of poly(vinyl alcohol), PVA, and starch/micronutrient microspheres. The microspheres will be prepared by spray drying and the composite PVA/microspheres by processed in an internal mixing chamber. The biodegradation will be evaluated by the Bartha respirometry method, and the microbiota will be characterized macroscopically through growth in plates and counting of colony-forming units and microscopically using optical microscopy. The materials will be structurally, morphologically, and thermally characterized before and after the biodegradation process by Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffractometry (XRD), Scanning Electron Microscopy (SEM), Differential Scanning Calorimetry (DSC), and thermogravimetric analysis (TGA). It is expected to establish a biodegradation profile of the material and correlate it with possible structural changes and their influence on the soil microbiota.(AU)