Soil test conversions for New York.
(S08-ketterings968972-poster)
Authors:
Q.M. Ketterings* - Cornell University K.J. Czymmek - Cornell University
Abstract:
In New York State, the Morgan soil test is used as the basis for phosphorus fertilizer recommendations and the P runoff index. Private laboratories servicing NY typically use the Mehlich-III solution as their basic soil test extractant. To meet NRCS standards for nutrient management in the state, accurate conversions from Mehlich-III and Modified Morgan to Cornell Morgan soil tests were needed. A study was conducted to: 1) derive and assess the accuracy of models that convert Mehlich-III and (modified) Morgan P, K, Ca and Mg soil tests other laboratories to Cornell Morgan equivalents; and 2) assess the need for laboratory specific models. Four commercial laboratories and four university laboratories in the NE participated in the study that involved 232 soil samples representative for New York’s agricultural region. Morgan and Mehlich-III extractable K, Ca, and Mg were linearly correlated although slopes we laboratory dependent. For P, the best model fit was obtained using pH, Mehlich-III P, Ca, and Al as independent variables. Test results showed that laboratory specific models were needed for accurate conversions. We conclude that conversion equations can be used to derive accurate Morgan
equivalents but that results need to be verified based on land use history and conversions need to be laboratory specific.
Speaker Information: Quirine Ketterings, Cornell University, Department of Crop and Soil Sciences, 817 Bradfield Hall, Ithaca, NY 14853; Phone: 607 255 3061; E-mail: [email protected]
Session Information: Tuesday, November 4, 2003, 2:30 PM-4:30 PM Presentation Start: 2:30 PM (Poster Board Number: 1435) Keywords: phosphorus; soil testing; high P soils; environment
