Calculate application rates for gypsum, elemental sulfur, and organic matter based on current and target soil values.
Select amendment type, enter current and target values, area, and purity to get required rate and total quantity.
Gypsum = |Target − Current| × 500 lb/acre
Sulfur = |Target pH − Current pH| × 300 lb/acre
Organic Matter = |Target − Current| × 2000 lb/acre
Adjusted = Base × (100 ÷ Purity%)
Lower pH 7.2→6.5 with 90% sulfur on 5 acres: Base = 0.7×300 = 210 lb/acre. Adjusted = 210×1.11 = 233 lb/acre. Total = 1,167 lb = 0.58 tons.
1. Select amendment. 2. Current soil test value. 3. Target value. 4. Area and purity. Calculate.
Amendments correct specific soil limitations: gypsum for sodic soils/calcium, sulfur to lower pH, organic matter for structure and water holding.
Applying sulfur without retesting (takes months). Using gypsum to raise pH (it's neutral). Over-applying fresh organic matter (N immobilization).
✓ Expert Reviewed: This calculator and its content have been reviewed by agricultural experts. Formulas are based on standard extension service recommendations.