Triple superphosphate

TSP is manufactured by acidulating phosphate rock with phosphoric acid, which converts much of the rock’s relatively insoluble phosphorus into water-soluble monocalcium phosphate. Typical guaranteed analysis is around 0-46-0.

TSP supplies phosphorus as its dominant nutrient, in a form that is largely water-soluble and therefore accessible to roots soon after application, along with a secondary supply of calcium bound within the phosphate mineral.

• Phosphorus is the primary nutrient, at high concentration
• Calcium is supplied as a secondary nutrient
• No nitrogen, potassium, or sulfur is supplied in meaningful amounts

TSP is used as a concentrated, straight phosphorus source where a grower wants to supply phosphorus independently of nitrogen, such as when nitrogen is being managed separately, and as a component of blended and compound fertilizer products.

• High phosphorus analysis reduces bulk and handling cost per unit of nutrient
• Useful where phosphorus is needed without accompanying nitrogen
• Widely used as a phosphorus component in fertilizer blends

Because phosphorus is largely immobile in most soils, placement close to the developing root system is a general principle for maximising uptake efficiency, and soil pH strongly affects how much of the applied phosphorus remains available over time.

Phosphorus lost from fields through erosion and runoff, rather than leaching in most soils, is the main environmental pathway of concern, since even modest phosphorus loading can contribute to the eutrophication of lakes and rivers.