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Little River, TX | In theory you can cross check one labs plant analysis results with any other, unlike soil analysis with all the squirrelly extractants that will not work with your particular soil.
Unfortunately this is not completely true. California at Davis likes to report with different scales. Some of their sample is supposed to be just the middle third of an alfalfa plant while the rest just the top third. I believe they also want some stems only and some leaves only. Try to compare that to Iowa results.
For the macro elements they. all but CA, will be within the standard variability. For the Minor elements the spread may be a little wider. For the Micro elements it is hard to say.
My gripe with all the Labs is when they see a wild looking result their QC people seldom re analyze the sample but almost never mention it in their report.
Had one, A & L Plains, lab report 150 ppm Moly, That should have set off alarm bells that could be heard in Newfoundland. When I called I got the it is a valid report as DR somebody checks all the reports.
Some will publish the plant analysis ratios for us, but they do not really do a DRIS analysis using the ratios.
Thirty years ago good DR Pennington at TAMU labs told me to do my own interpretation of soil analysis. He was honest enough to say that few have actual performance results with our soils. Unless they have done yield results with soil exactly like ours with our climate, they are just so much paper wasted.
Most have a computer program to do the recommendations.
Now Midwest Labs told me that if I expected to use CEC values I should use only Measured CEC results as the computed CEC results are subject to exaggerations.
Have a high pH soil? Maybe a Calcareous soil? Even using the Olsen chemistry, without having a Free Lime result you can not make valid phosphate recommendations. If I expect to adjust my tissue analysis phosphate levels I need to know the soil's free lime content.
When I contact Midwest Labs I have someone reasonably qualified to provide the answers. The Technicians are not students and the phone operator is not in their first job out of high school. | |
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Are all labs that do tissue testing the same?
