Triple superphosphate TSP on 5 m² — 108.7 g for 10 g/m² of P₂O₅
To put 10 g/m² of P₂O₅ on 5 m² with Triple superphosphate TSP, spread 108.7 g — that is 21.74 g per m². At 46% content it is simply the 50 g of nutrient you need divided by that figure.
Fertilizer to spread
Urea is only 46% nitrogen, so putting 10 g of N down means spreading 10 ÷ 0.46 = 21.74 g of urea. Multiply instead and you get 4.6 g, a number that looks plausible enough to pass unnoticed. Whenever the content is below 100%, the fertilizer weight is always larger than the nutrient weight — that is the fastest check that you have the division the right way round.
- P₂O₅ 5 g/m² · 10.87 g/m²54.3 g
- P₂O₅ 10 g/m² · 21.74 g/m²108.7 g
- P₂O₅ 15 g/m² · 32.61 g/m²163 g
- P₂O₅ 20 g/m² · 43.48 g/m²217.4 g
- Fertilizer
- Triple superphosphate TSP (0-46-0)
- Area
- 5 m²
- Nutrient matched
- P₂O₅
- Content
- 46%
- Nutrient needed
- 50 g
- Per m²
- 21.74 g
Nearby cells
Same fertilizer, other areas
Same area, other fertilizers
Worth knowing
- Fertilizer to spread = nutrient needed ÷ (content ÷ 100). It is a division, never a multiplication.
- Nutrient needed = area × target rate, so twice the area means twice the fertilizer.
- A fertilizer with half the content takes twice as much for the same nutrient — inverse proportion.
- With a compound, matching one nutrient drags the other two in at their content ratio.
Common questions
Q. How much Triple superphosphate TSP goes on 5 m²?
At 10 g/m² of P₂O₅, 108.7 g — that is 21.74 g per m². It is the 50 g of nutrient needed divided by the 46% content.
Q. If I double the target, do I double the fertilizer?
Yes. Target and fertilizer weight are directly proportional — 5 g/m² takes 54.3 g and 20 g/m² takes 217.4 g. Area behaves the same way: twice the area, twice the fertilizer.
Q. What else goes in along with it?
Triple superphosphate TSP carries only P₂O₅, so nothing else comes along. The other nutrients have to be supplied by separate fertilizers.