v1.2 (2026-06-21) · Adams-Evans buffer pH method for low-CEC, kaolinitic Coastal Plain Ultisols. The method was originally calibrated by Adams & Evans at Auburn University (1962) and is the canonical lime-requirement test across the Southeast Coastal Plain. This source serves five states whose land-grant labs use Adams-Evans or an Adams-Evans-equivalent calibration: Delaware (UDel, classical AE with p-nitrophenol), New Jersey (Rutgers, classical AE), South Carolina (Clemson, Moore-Sikora variant — non-toxic chemistry with AE-equivalent calibration within 0.03 pH units), Florida (UF/IFAS, classical AE), and Alabama (Auburn, Modified AE with Huluka 2005 reagents — published rates match classical AE within 0–500 lb/ac). The published tables assume 67% ECCE agricultural-grade limestone; the engine converts to the user's product ECCE downstream. This is a soil-fertility lime source; nutrient recommendations (P/K/Mg/etc.) for each of the five states should still be drawn from that state's published nutrient handbook, not from this source.
This source publishes a state method — its crop-specific rate tables are maintained in the extension bulletin rather than a fixed crop list, so Zone Forge doesn't claim a crop set here.
Lime calculator. Zone Forge computes this source's published lime rates in-app and cites the method.
Yes — Zone Forge's calculators are free and need no signup. This page shows the states and crops Coastal Plain Adams-Evans lime method (University of Delaware calibration) covers so you can verify the source behind your recommendation.
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