14th March 2012
Dear Mr Warren-thing,
As you said, after your own fashion:
“The significance of pH lies in it’s influence on availablity of soil nutriments, solubility of toxic nutrient elements in the soil, physical breakdown of root-cells, cation exchange capacity in soils whose colloids (clay/humus) are pH-dependent, and on biological activity.
“Acid soils are rare in semi-arid dryland areas of the world. Most soils in the Central and West Asia and North Africa region have pH values of 8.0-8.5.
“Air-dry soils may be stored for several months in airtight containers without affecting pH measurement.”
The available soil, as we understand it, is very high in organic matter at a 1:2 – 1:5 (soil:water) ratio.