Steven, you live in Sacremento right next to UC Davis, one of the top ag schools in the country. That's where I think you should go before spending a fortune on soil tests. The soil in your area often goes over the top alkaline as I recall from long ago reading but I guess that answer is too obvious, you said you tested pH. But I recall something about salt build-up in the interior valleys there- not enough rain- and even the ground water is often contaminated with excess salt.
I bet a phone call to UC Davis to one of their soil gurus could straighten you out quick. The rest of us merely speculate.