0? Huh? 7.0 is neutral. What do the recommendations say like add lime or sulfur? There is no known acid to my knowledge with a PH of 0. If it were possible your feet would catch on fire if you stepped on the yard. :-)

That wouldn't make walking through the yard much fun. Although, maybe it would discourage some of the squirrels from digging so many holes. :-)

I don't think it is referring directly to the PH of the soil. The test results list the PH as 7.0. I found the following on the University of Missouri Extension site.

"A routine soil fertility test (pH, neutralizable acidity, phosphorus, potassium, calcium, magnesium, organic matter, and cation exchange capacity) is recommended under the following circumstances:"

But, it does not go on to explain what neutralizable acidity measures. I guess I should give them a call.

I can certainly be wrong, but perhaps they're referring to the amount of pH buffering agents in the soil? If I recall correctly it's used to calculate how much lime would be needed to alter the pH of the soil while accounting for how much pH buffers are currently present.

:shrug:

Seems to make sense to me though because compost and other types of organic matter tend to help buffer the soil against random swings in pH so the addition of these materials could be why that value has risen...

Neutralizable Acidity

"Technicians add a buffer solution to the sample used for salt pH analysis to estimate the neutralizable acidity of the soil. Neutralizable acidity is a measure of the exchangeable hydrogen within soil. It is used to calculate the pounds of effective neutralizing material necessary to lime the soil to the proper salt pH range."

Thanks morpheuspa. Guess I need to learn to search a little better. I swear I searched the site for a definition. Oh well. Thanks for the info.

I was happy with most of what I saw, especially the percentage of organic matter. It jumped from 2.4% in 2006 to 4.8% now. I mulch mowed the grass and leaves the second half of last year. That plus the compost top-dressing on the front lawn has obviously made a big difference. Even the back yard, which did not receive any compost and was tested separately, jumped from 2.4% to 4.4%.

Lets see, you got basically the same improvement in the front and back regardless of the use of compost. This is exactly the point I have been trying to make for several years now. It doesn't matter whether you top dress with compost or not, the cultural practices (mulch mowing) make more difference in your soil's organic matter. Please tell me that you water infrequently and you are mowing at or near your mower's highest setting.

Of course this does not mean that I suddenly trust soil tests. I am absolutely convinced that both of your soil tests were wrong. But since they demonstrate my point about compost, can I use them as a reference in the future ;-O

I am absolutely convinced that both of your soil tests were wrong.

Hopefully they were both wrong in the same direction and by the same amount. If done by the same lab, that's probably reasonably close within their tolerance.

You may not be able to rely on them absolutely for a good answer, but the relative change tells us much.