Gypsum Calcium Sulfate Soil Calculator
Calculate gypsum calcium sulfate product per acre to supply calcium and sulfur or to improve soil structure, with total pounds and bulk tons.
How This Calculation Works
Gypsum is usually applied by total pounds or tons per acre rather than by a single nutrient analysis, because it supplies both calcium and sulfur. Product pounds per acre equals the target rate directly, and total product is that figure times acres. Dividing by 2,000 gives bulk tons.
Field Calibration & Rate Reference Chart
| Analysis | Nutrient % | Target lb/ac | Product lb/ac |
|---|---|---|---|
| 46-0-0 Urea | 46 | 100 | 217 |
| 46-0-0 Urea | 46 | 120 | 261 |
| 34-0-0 AN | 34 | 100 | 294 |
| 28-0-0 UAN | 28 | 120 | 429 |
| 18-46-0 DAP | 46 | 60 | 130 |
| 11-52-0 MAP | 52 | 60 | 115 |
| 0-0-60 Potash | 60 | 80 | 133 |
| 10-10-10 | 10 | 60 | 600 |
| 19-19-19 | 19 | 80 | 421 |
| 6-4-0 Milorganite | 6 | 48 | 800 |
Common Questions
What does gypsum do for soil?
Gypsum supplies calcium and sulfur and can improve the structure of sodic or high-clay soils by displacing sodium. It does not raise pH, so it is not a lime substitute. It is most useful where calcium is needed without a pH change.
How much gypsum should I apply per acre?
Rates range widely from a few hundred pounds for sulfur nutrition to several tons per acre for sodic-soil reclamation. Base the rate on a soil test and the specific goal. For structure improvement, higher rates and incorporation work best.
Does gypsum lower soil pH?
No, gypsum is neutral and does not change soil pH. It supplies calcium and sulfur without the acidifying or liming effect of other amendments. Use lime if the goal is to raise pH.
Can I apply gypsum to lawns?
Yes, gypsum is sometimes used on lawns to supply calcium and sulfur or to loosen compacted clay. Apply at the rate on the product label and water it in. It will not replace a proper liming program where pH is low.