exchangeable acidity & BS

HEY!! I just had a quick question about exchangeable acidity and BS. Since exchangeable acidity is the acid cation on CEC and BS is about the base cations on CEC. Does it mean when exchangeable acidity is high, BS is low? (They are opposite?)

Yes, that is correct. High base saturation (BS) implies that there will be a high number of base-forming cations (Ca, Mg, K, and Na) on exchange sites, and it also means that number of acid-forming cations (Al and H) will be low on those same exchange sites.