Greetings James. Greetings Amit and Travis.
I came in here to post last night (before RedHawk had posted his reply)...unfortunately, the computer I use for internet did its crashing thing.
Posting this now while things seem to be working -
"My speculation is that the data has not been collected, as I think it would be quite costly and labor intensive to gather tens of thousands or more samples and then run the tests."
I guess that makes the most sense....it's just an empty value set. Confusingly (if this is the case), they included an option in the database to "Interpret nulls as zero". Even when this option is left
un-selected, the values returned for the above parameters are 0 (or 0.0).
Greetings RedHawk,
"The missing data you listed is data that would come from a "complete" analysis, not the normal testing that most people are satisfied with, that is why items show 0.00, there isn't any data from the soil test."
Aha - then, the data for these parameters is obtained from
local soil-testing. That would lead me to believe that these data may only be available for areas where Order of Soil Survey is listed as either 2 (Intensive) or 1 (Very intensive), and zero-values can otherwise be disregarded.
"Most folks don't want to spend the extra money for complete testing and for most folks it really isn't necessary for their needs."
Well, being that I'm a relative newbie to soils-related stuff, I wasn't sure if these parameters were among the most important ones to consider when evaluating
land - except I can see that one of them has a bearing on the salinity of the soil, which sounds like it could be an important variable to pin down.
Thanks for shedding light on the matter for me.
[Edited for clarity]