Rev. Bras. Ciênc. Solo.2025;49(spe1):e0240127.

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Struvite potential as a slow-release fertilizer for phosphorus sustainable management in Brazilian agriculture

Caio Teves Inácio , David Villas Boas de Campos , Fabiane Antes Goldschmidt , Rubia Mores , Airton Kunz , Gustavo Brunetto , William Natale , Lessandro De Conti , Paola Daiane Welter , Carina Marchezan , June Faria Scherrer Menezes , Ricardo de Castro Dias , Bruno José Rodrigues Alves

12/Sep/2025

DOI: 10.36783/18069657rbcs20240127

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ABSTRACT

Phosphorus in agriculture is an essential, limited, and strategic resource, and its sustainable management is a global challenge. Phosphorus (P) recovery as struvite (NH₄MgPO₄.6H₂O) from manures and municipal and agro-industrial wastewaters has been considered one of the most sustainable technologies, based on the circular economy, to face challenges regarding P reserves and its use for conventional fertilizer production. Struvite is a slow-release P-fertilizer (5 % N, 12 % P, 10 % Mg), which could significantly reduce the Brazilian dependency on fertilizer imports. We found a large number of recent studies that show its predominant application for temperate and Mediterranean regions. However, its potential as a fertilizer and better use for subtropical and tropical regions, such as Brazilian agriculture, is still unknown. We highlight that: (i) crop responses reported were quite variable with few field studies carried out; (ii) the crop yield expected may be on average 10 % below those in soluble P sources; (iii) a potentially high residual effect should be effectively measured; (iv) promising use of struvite mixed with soluble P-fertilizers to produce high yields; (v) higher efficiency than manure, composts or phosphate powder rocks. In fact, there is a lack of studies carried out on subtropical and tropical soils and climates; none were found in Brazil. Therefore, the lack of studies on Brazilian soils is a barrier to a precise evaluation of struvite as a fertilizer for Brazil’s agricultural systems, especially for acidic Oxisols and no-till systems. Finally, struvite production from swine wastewater can expand in specific states in the South, Southeast, and Midwest of Brazil, where the swine production is concentrated. truvite production technology might be easily adopted and affordable for medium- to large-scale confined swine operations, which could yield some 300,000 Mg of struvite per year.