SO4 Sulfur Rate Calculator
Estimate sulfur need from crop uptake, yield goal, and organic matter, then convert that requirement into a recommended SO4 Rate. Soil test sulfate-S is not used in this web version due to limited reliability in practice. Crop sulfur demand is based on values from Ward Labs.
Inputs
Crop sulfur demand
36.0 lb S/acre
Organic matter credit
7.5 lb S/acre
Total sulfur needed
28.5 lb S/acre
Recommended SO4 Rate
168 lb/acre
Based on crop sulfur demand minus organic matter credit, the calculator estimates total sulfur needed and converts that to a recommended SO4 Rate using 17% sulfur.
Calculation breakdown
▼
Calculation breakdown
▼Crop sulfur demand
200 bushels/acre × 0.18
= 36.0 lb S/acre
Organic matter credit
2.5 × 3
= 7.5 lb S/acre
Sulfur needed
36.0 - 7.5 - 0.0
= 28.5 lb S/acre
SO4 Product Rate
28.5 × (100 ÷ 17)
= 168 lb/acre
Soil test sulfate-S is fixed at 0 in this web version.