v1.0 (2026-05-23) · OSU Central Analytical Lab. EM-9585 (October 2025) is the most recently updated state lime table set in the U.S. Supports BOTH Sikora buffer (preferred, non-hazardous) AND SMP buffer (historical). Five published target-pH columns: 5.6, 6.0, 6.4, 6.8, 7.2. Western Oregon (Willamette, Coast Range, Cascades, Rogue/Umpqua) is heavy lime country. Eastern OR (Columbia Basin, dryland wheat) variable; many soils neutral-to-alkaline.
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 OSU Updated Lime Requirement Recommendations for Oregon (EM-9585, October 2025) covers so you can verify the source behind your recommendation.
Browse the full Coverage Explorer — every state, crop and source — or see the science →