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Little River, TX | The 100 ppm K on a field moist sample probably does not have a good mix to be representative.
The air dry would appear to be logical, but they still have to grind it to make a powder that can be mixed. At 400+/- ppm it is well above the favored 150 ppm K for sufficiency. The grinding process (Crushing is the favored term) to powder the sample will release the K atoms and molecules from the clay and they will appear to be available in the test result.
The Oven Dried releases even more potassium from the clay lattice to appear to be available.
This is why some soils people have come up with a correction factor to adjust the desired potassium level up to the same area the testing is reporting.
Please note I am referring to potassium, but any and all the cations are effected the same way.
We here in TX have a soils man with a mission to develop an extract that will report the true availability of cations to the crop. We all wish him luck.
I was hoping a number of our Montana Contributors would shine some enlightenment on the subject. I have seen from a moving vehicle Montana soil but have no knowledge of it's characteristics.
My solution is to multiply the measured CEC value by a magic factor. This provides me with an adjusted goal. I use this goal as a guide and measure the effectiveness of the fertilizer program using plant analysis. Plant analysis can also be strange but is simple compared to soil testing.
Some years ago I heard a soil advisor who adjusted the reported VH to Excessively High ppm K levels to the same scale as those used by NY, PA, IN, MO, & others. Reading slides while in a dark room and no proceedings provided is not condusive to complet understanding. | |
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Montana, soil, Comments from Montana?
