Posted 12/5/2012 15:47 (#2734543 - in reply to #2734124) Subject: RE: strange soil test results
Little River, TX
Really you have an advantage on the Lab in that you know the history of your soil. So when you see an anomalies you can question the results.
The first thing when you see an unusual result. send them an E-Mail or call and ask if they could check their results.
They do not want you having a question as it may loose them future business.
I would also go out and re sample, as close as you can, for a second analysis if you are really worried.
Now it is a not a secret that soil has considerable variability.
Oklahoma did a study with 7 by 70 foot plots of bermudagrass. They divided the plots into one foot sub plots, Their results for pH, phosphate as well as grass dry matter yield varied dramatically. Which is why we probe 4 to 20 times for each sample. To average out the natural variability.
Ohio did something similar using 8 inch squares.
I believe it was Bill Moyer who sampled the same hole using different diameter probes and got different results.
Midwest has done my soil and plant analysis for maybe 10 years. They were a great help. They suggested I have my samples also analyses for free lime, (My soil is calcareous and has a good bit of free lime)
They also suggested I have measured CEC analysis run. The nice thing is CEC and free lime does not change unless you move a lot of dirt.
A good 30 years ago DR Dale Pennington at the TAMU Lab told me not to pay any attention to a Lab's recommendations but for me to decide my self on my fertility needs. He was very politely telling me to get off my sitter and learn for my self what my soil really needs.
Most honest advise I have received. Dr Coleman at A & L Plains alsop said he could provide accurate analysis of the samples I send, but he has no yield data on my soil.
So now I know what the free lime does to any phosphate fertilizer, and what a high CEC, high shrink clay soil effects any and all cations.
After all that is said and done, NOW I rely more on plant analysis than soil analysis to monitor fertility.
I know the Ammonium form of N does not leach out of this soil. Period.
I know it requires 35 of so pounds of phosphate fertilizer to accomplish the same results as 10 pounds does in other soils. +
I know that I really need between 400 and 500 ppm K (ppm not pounds of K2O) for my crops to have available a reasonably adequate supply of potassium.
I also know this soil from time to time needs some Cu & Mo inspite of what the text books say.
Nothing that I know applies in the soils of East Texas. Probably does not apply to some other parts of the Texas Blacklands, ether.
As you might guess I seldom sit down to watch TV on an evening.