Potassium sulfate SOP on 20 m² — 400 g for 10 g/m² of K₂O
To put 10 g/m² of K₂O on 20 m² with Potassium sulfate SOP, spread 400 g — that is 20 g per m². At 50% content it is simply the 200 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.
- K₂O 5 g/m² · 10 g/m²200 g
- K₂O 10 g/m² · 20 g/m²400 g
- K₂O 15 g/m² · 30 g/m²600 g
- K₂O 20 g/m² · 40 g/m²800 g
- Fertilizer
- Potassium sulfate SOP (0-0-50)
- Area
- 20 m²
- Nutrient matched
- K₂O
- Content
- 50%
- Nutrient needed
- 200 g
- Per m²
- 20 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 Potassium sulfate SOP goes on 20 m²?
At 10 g/m² of K₂O, 400 g — that is 20 g per m². It is the 200 g of nutrient needed divided by the 50% content.
Q. If I double the target, do I double the fertilizer?
Yes. Target and fertilizer weight are directly proportional — 5 g/m² takes 200 g and 20 g/m² takes 800 g. Area behaves the same way: twice the area, twice the fertilizer.
Q. What else goes in along with it?
Potassium sulfate SOP carries only K₂O, so nothing else comes along. The other nutrients have to be supplied by separate fertilizers.