Are you asking can you ignore the soil density because if you don't factor it into the test results you will not have to factor it into the amendments?
Well if you don't factor it in the test, then your ppms will be off, they will be lower than what they are on the test. So if you follow a ppm recommendation, like say 25 ppm Cu, then you will may be adding Cu when you actually don't need it.
Now if you are focusing on BCS%, those numbers are not effected by the density factor, however when you amend one of those cations, the factor does come into play. That is because you are assuming your soil is much heavier than what it really is, therefore you are adding more of the cations than what you need to.
lb/acre is simply a weight vs weight calculation in the end because we assume a furrow slice of an acre weighs 2million lbs, so essentially lb/acre is 1 lb/ 2 millions lbs.
So if you're trying to add 1000 lb acre of Ca, thats essentially 500ppm with standard soil, however with our soil that same 1000 lb per acre might mean up to 5000 lb per acre when looking at lb / acre as a weight / weight.
You see the lb/acre can be interpreted just as that, weight / area, for field soil because its the same when converted using field soil density. However when lb / acre, in a weight / area sense, can not be used with lighter peat based soils because it is not the same as its weight / weight. Adding 2 lbs to an acre of our soil is not the same as adding 1 ppm to that same soil.
I may have confused you as i repeated myself a little bit
I get it. But say my soil weghs 1/4 vs std. My tcec will be 1/4 of its true value right. So on bcs when figuring lbs/acre I am only figuring 1/4 of what my true tcec can hold.
I know it does not work for ppm. I tend to put micros in foliars and then let microbes sequester the exudates. A few grows and no mo micro shortage even though it does not show up on cec.