2026 Projects: New York Soil Test Conversion Program
How to derive Cornell Morgan P, K, Ca, and Mg equivalents from Mehlich-3 results?
Background: Use of Soil Tests
Soil testing for soil nutrients including soil phosphorus (P) generally consists of conducting a chemical extraction followed by filtration and either ICP or colorimetric quantification of nutrients in the extraction solution (see Agronomy Fact Sheet 15 for more details). To comply with the CAFO Farm Permit and the NY 590 Conservation Standard, farmers must follow Cornell University nutrient guidelines which are derived using Morgan-extractable nutrient values.
In 2001, NMSP and PRO-DAIRY nutrient management staff worked with consulting firms and extension educators to collect soils samples of relevance for New York agriculture and develop conversion equations for a number of university and commerical laboratories. With new soil testing labs marketing and offering services to CAFO Permitted farms in New York, in partnership with state agencies NYSDEC, NYSAGM and NY NRCS, the NMSP is working on 2026 New York Soil Test Conversion Program for existing and new laboratories to further collaborate on developing conversion equations to Cornell Morgan equivalents for
nutrient management planning via the NRCS-NY 590 conservation practice standard.
For more information about this project, contact Quirine Ketterings (qmk2@cornell.edu or 607-255-3061). You can also write to: Quirine Ketterings, Nutrient Management Spear Program, Department of Animal Science, Cornell University, 323 Morrison Hall, Ithaca NY 14853.
Goals
Development of new Mehlich 3 or Modified Morgan to Cornell Morgan soil test conversions.
Funding Sources
This project is funded by the New York Department of Environmental Conservation as well as New York Department of Agriculture and Markets and Elanco.
Additional Resources
- Soil Sampling Project Description (PDF)
- Soil Sampling Project Description (PPT)
- Soil Sampling Field History Form (PDF)
- Soil Sampling Field History Form (DOC)
Farmer Impact Stories
Fact Sheets
- Agronomy Fact Sheet 15: Phosphorus Soil Testing Methods
- Agronomy Factsheet #110: The New York Phosphorus Index 2.0.
Extension Articles
- Czymmek, K.J., Q.M. Ketterings, M. Ros, S. Cela, S. Crittenden, D. Gates, T. Walter, S. Latessa, G. Albrecht (2020). New York Phosphorus Index 2.0. What's Cropping Up?
- Ketterings, Q.M. and K.J. Czymmek (2002). Phosphorus Soil Testing and Nutrient Management Planning in New York. What's Cropping Up? 12(4): 1-3.
- Ketterings, Q.M., B. Bellows, K.J. Czymmek, W.S. Reid, and R.Wildman (2001). Conversion Equations Part 1: Do Modified Morgan and Mehlich III P Have a Morgan Equivalent? What's Cropping Up? 11(3): 2-3.
- Ketterings, Q.M., B. Bellows, K.J. Czymmek, and W.S. Reid (2001). Conversion Equations Part 2: Do Mehlich-III K, Ca and Mg Have Morgan Equivalents? What's Cropping Up? 11(4): 4-5.
Journal Articles
- Ketterings, Q.M., K.J. Czymmek, W.S. Reid and R.F. Wildman (2002). Conversion of modified Morgan and Mehlich-III soil tests to Morgan soil test values. Soil Science 167(12): 830-837.