[Terrapreta] Doing it in the dirt.

[Jim Joyner]

Richard,

Forgive me for taking so long to respond. I've been away and I had 
problems with Yahoo!.

I still intend to call you but I thought a little more discussion on 
your experiment might help me and others.

Do you know what the before-and-after percentages of base saturation you 
have in your soil for calcium, magnesium, potassium, hydrogen, and 
sodium? And the CEC? Have they changed since the application of charcoal?

My concern here is something typical of University Extension services. 
When they do experiments with various methodologies or practices, they 
typically will use crop response as the sole criteria for success.

There is certainly nothing wrong with looking a crop response, but 
without looking at the composition of the soil throughout the 
experiment, other variables are overlooked. Later, someone will try the 
same experiment in another soil and it gets completely different results 
-- and they go off scratching their heads.

The bigger point is that the "balance" (having calcium, 65 to 75%, 
magnesium, 10 to 15%, and potassium 2 to 5%. No need for hydrogen or 
sodium) is more important than nutrient levels. Some nutrients cannot 
properly be utilized without the balance. If the balance is somehow 
changed in the soil (or is changed by charcoal) then the results are 
misleading. (Often Extension will tell you that the pH influences the 
use of phosphorous. What they don't tell you is that the make up of the 
base saturation (the soup) is what gives you the pH reading)

My guess is that, while charcoal increases the CEC, it will bring some 
calcium and magnesium with it -- but it may not be enough. In which case 
it would throw off the balance and possibly give you a misleading crop 
response.

If, on the other hand, you know all this and are watching it, well, you 
can tell me to buzz off. But even so, the answers will help me

Thanks,

Jim