macronutrients, with Mg being a minor macronutrient as well. Struvite can be produced from urine by adjusting pH (often just by waiting for urease-producing bacteria to work) and adding magnesium. There is considerable interest in the utility of urine-derived struvite as a fertilizer in austere situations. References External links Website of the European Phosphorus Platform about Phosphorus Recovery Ammonium minerals Magnesium minerals Phosphate minerals Orthorhombic minerals Minerals in space group 31 Struve family