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Little River, TX | You have a different problem than we have here. Here the computed CEC, which would relate to your adjusted CEC fluctuates all over the place, because they use one of the many equations to estimate the CEC value of the clay and organic matter, and the adding fertilizers will change their levels found in the soil test.
Your,
So, for extra dollars, the lab runs what they call a K-displacement test. (Don't ask - I don't know.) equates to my measured CEC Value. The amount of clay seldom changes so those values should be much more stable.
Don't fertilize for a few years with K, ammonium, or other cations and those elements will go down and the computed CEC will also go down. Spread a bunch of fertilizer and their soil test will go up and the computed CEC will go up. The clay stays the same & in your case is in the 15 meq/100g range.
That makes it easy. Here using soil test to determine available potassium I multiply the CEC by 8.07 & 10.44. I want my soil test to fall inside that range. You do not have that problem.
Something you may experience is, with your free lime you will need to add an additional 10 lbs of P2O5 for each percentage of free lime. This is to work around the lime in the soil tying up added phosphate fertilizer into one of calcium phosphates. You can also accomplish this by putting your phosphate down in a band behind a chisel shank. This concentrates the phosphates and delays the calcium's chemical reaction with the phosphate.
Just in case you have missed it, I have a rather poor opinion for soil testing's usefulness. I am an advocate for tissue testing. | |
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Soil Tests and knowing your soils
