Struvite-based composites for slow-release fertilization: a case study in sand

Author(s)

Valle, Stella F. ; Giroto, Amanda S. ; Dombinov, Vitalij ; Robles-Aguilar, Ana A. ; Jablonowski, Nicolai D. ; Ribeiro, Caue

• Document type: Journal article
• Source: SCIENTIFIC REPORTS; v. 12, n. 1, p. 14-pg., 2022-08-19.

Abstract

Struvite (St) recovered from wastewaters is a sustainable option for phosphorus (P) recovery and fertilization, whose solubility is low in water and high in environments characterized by a low pH, such as acidic soils. To broaden the use of struvite in the field, its application as granules is recommended, and thus the way of application should be optimized to control the solubility. In this study struvite slow-release fertilizers were designed by dispersing St particles (25, 50, and 75 wt%) in a biodegradable and hydrophilic matrix of thermoplastic starch (TPS). It was shown that, in citric acid solution (pH = 2), TPS promoted a steadier P-release from St compared to the pure St pattern. In a pH neutral sand, P-diffusion from St-TPS fertilizers was slower than from the positive control of triple superphosphate (TSP). Nevertheless, St-TPS featured comparable maize growth (i.e. plant height, leaf area, and biomass) and similar available P as TSP in sand after 42 days of cultivation. These results indicated that St-TPS slow P release could provide enough P for maize in sand, achieving a desirable agronomic efficiency while also reducing P runoff losses in highly permeable soils. (AU)

• FAPESP's process: 16/10636-8 - From the cell factory to the Biodiesel-Bioethanol integrated biorefinery: a systems approach applied to complex problems in micro and macroscales
• Grantee: Roberto de Campos Giordano
• Support Opportunities: Program for Research on Bioenergy (BIOEN) - Thematic Grants
• FAPESP's process: 18/10104-1 - Nanocomposites Preparation from Urea modified with Glycerol for optimization of Process of Controlled Release of Nutrients
• Grantee: Amanda Soares Giroto
• Support Opportunities: Scholarships in Brazil - Post-Doctoral