I think heritage gave a number to look at. It is not to be taken in isolation, but it is a good start. I stop picking apart the messenger and actually read the message. The private labs have done me well. Using their numbers has enabled me to go beyond putting more organic matter on soils already over 5%, and aerating grease.
They who can give up essential liberty to obtain a little temporary safety, deserve neither liberty nor safety.
Benjamin Franklin 1775
Sell not virtue to purchase wealth, nor Liberty to purchase power.
Benjamin Franklin Poor Richard's Almanac1738