Salinity and SAR Management Calculator

Use this calculator to estimate gypsum requirements, irrigation water needs, reclamation water depth, and sodium adsorption ratio. Enter values from soil or water test reports when available.

Note: Results are estimates for planning purposes. Consult a qualified Extension specialist or crop advisor for site-specific recommendations.

Before you calculate

All fields in the selected calculator are required="". Use numbers only. Percent fields should be entered as whole percentages, such as 75 for 75%.

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Gypsum Requirement

Enter soil values
Depth of soil to be reclaimed.
Average bulk density of the soil to be reclaimed.
Use the CEC value from the soil lab report when available.
Initial sodium adsorption ratio in the soil depth to be reclaimed.
Target sodium adsorption ratio for the soil.

About this calculation

Leaching alone with heavy irrigation is not an effective reclamation practice in sodic soils because sodium can reduce soil infiltration capacity. Gypsum supplies calcium, which can help displace sodium from clay-binding sites so sodium can be leached with irrigation water.

View Managing Saline and Sodic Soils article (opens in a new window)