The 2007-2009 numbers look to me like a consistent trend of acid soil being corrected (using lime annually ?). The 2010 numbers can't be compared for several reasons - different area, and different reporting method (direct concentration vs. CEC calculation).

On soil sampling and analysis about the best you can expect year-to-year is +/- 5% relative variation, and +/- 10% would not be uncommon.

Perhaps more important for a long-term view is your choice of labs and the methods they use. Your soil is acidic, and the test methods should be those optimized for your regional conditions. That should influence your choice of appropriate soil labs. Using TAMU, which has adapted methods for TX alkaline soils, for testing the acidic soils such as those of the northeast would not be the preferred approach, and vice versa. In which state are you located?

This post was edited by TXEB on Wed, Aug 14, 13 at 7:33

Where are you located, what are you trying to grow, and what sort of difficulties are you having with your garden?

That low pH is the first thing you need to take care of...trying to get at minimum of 5.8...though 6.5 is more ideal for most vegetable production.

Taking care of that will shift your nutrient use/balance to an entirely different level, too.

CEC's are generally lab measured in relation to a 7.0 buffered soil, so highly acidic soils will give high readings that are a bit overestimated. A lot depends on the type of lab measurement used, but most use a 7.0 buffered ammonium acetate test.

I imagine your BS (base saturation, if listed) is rather low to non-existent.

BTW - after my chirping about the right lab for the soil based upon regional norms, I should add that a basic soil pH test should largely be the same regardless of lab - it is a simple water extraction. Results for the other ions depends appreciably upon the extraction method used. So your pH measurement should be sound, across the board.

Which raises the question - how has the soil in the garden area been treated differently over time? Was it tilled deeply, or amended/treated in some way differently than the lawn soil? Has it been irrigated the same? What was the sampling depth in the lawn areas?

I have tilled o. M. In the garden. The soil was sampled around 6 inches. I used your run of the mill organic ferts from big box stores.
The lawn has been fed with feed store products like sbm and cgm. It was probably sampled at similar depth. And I have spike aerated yearly.

My concerns came when I read some rants about stopping liming and peoe on here saying if you fix you ca/mg ratio then the pH will fix itself.

Ca/Mg ratio is one (of quite a few) things that is hyped up, but really needs to go away. It's of very little importance as long the soil contains adequate Ca and Mg.

Adjusting Ca/Mg ratio will not fix your pH issue. Adjusting soil pH up from where you're currently at will help plants uptake Ca and Mg easier, though.

As I recall West is in Tennessee, his 2nd favorite forum is Tennessee Gardening. Why he is not using the University of Tennessee for soil testing is unknown, and I think he is trying very hard to make a mountain out of a mole hill, The numbers are not that different, within range of normal lab tolerances.

Im actually just across the line, in KY. Resources for anything to do with gardening in Ky are scarce around here, all except for the soil tests. If I can find a place nearby that sends sample to UT then I'll do that, because UT has a pretty extensive agriculture program. But for now, it's the UK county extension office and the co-op store in Tennessee sends the samples to Memphis, I think.

I'm not really trying to overthink it. I just don't want to try to fix one thing, being the pH, and screw up one or several other things. And I think I will have another soil test done seeing how my last one was 3 years ago. I have done a small amount of lime applications since then.

I would like to have lime trucked in and spread, then i'm going to aerate, fertilize, and seed.

If you can, the U. Tenn lab is probably your best bet. They have the correlation studies to go with the methods they use. But, I suspect you may have to get used to some different numbers, along with different critical levels. I believe they stayed with Melich I extraction, while many other labs moved to the more aggressive III version. Will they take samples from KY residents? If that's not an option, then the A&L lab in TN is probably your next best option.

The CEC values are generally calculated from measured pH, Ca, Mg and K levels. Personally, I find the direct measures (ppm or lbs/acre) far more useful. As nc-crn noted, the Ca/Mg ratio is a relic that has been amply demonstrated and proven to be pretty much insignificant. Get the absolute levels to approprite concentrations, and you'll be fine.

Ok, thanks everyone. TXEB, I just looked at their website they do use the Mehlich 1 method, what is it (just out of curiosity)?

I'll be posting the results soon!

west - there are a number of standard soil extraction solutions used by different labs to extract the various analytes from the soil matrix. The most common ones are Modified Morgan, which is a dilute weak buffered acetate system used mostly on northeast acidic soils, Mehlich-1 that was developed primarily for use on acidic soils, and is a dilute unbuffered double acid system of both HCl and sulfuric acid, and Mehlich-3 which is the most aggressive of the 3 and was developed for use primarily on alkaline soils using ammonium fluoride, ammonium nitrate, EDTA, acetic acid and nitric acid. There are some others, but they tend to be used selectively for some specific analyses.

There have been numerous studies and models developed to try to relate the results of one extraction method to those obtained via another. But, in reality it depends largely on the soil type and characteristics. The best approach is to use a lab that has adopted methods and has developed the correlations with plant response for the soils of the type you're analyzing. That is typically best accomplished with a regionally oriented lab, often associated with one of the land grant universities.

A decent summary of which labs in the SE U.S. use which methods is available form U. KY via the link below. As you will see KY uses Mehlich-3, which is also what A&L uses (as do almost all private commercial labs), as does TAMU (the report linked is wrong about TX - they use Mehlich-3). That, in part, is why the KY and A&L results are pretty much consistent. If you change to Tenn. you'll get noticeably different numbers, but they along with the Tenn. correlations will probably be more meaningful for your soil conditions that those derived from Melcih-3 extractions.

Here is a link that might be useful: SOIL TEST EXTRACTANTS: MEHLICH-1 and MEHLICH-3

This post was edited by TXEB on Thu, Aug 15, 13 at 19:48

Ohio State University and Purdue in Indiana both list the University of Kentucky for soil tests they don't do.