Q.Growing cypress trees
How to correct too much alkaline or too much acidity in soil?
The best way to adjust soil pH is by soil test and amending with nutrients based on actual deficiencies found. Balancing of the major minerals and incorporating soil organic matter (compost) will automatically bring the pH into best balance.
It is common for gardeners to shortcut the best management practices by directly addressing high pH (alkalinity) with soil sulfur, and low pH (acidic conditions) with lime. But this is a very short-sighted practice and can throw other important factors out of balance.
In the Imperial Valley you undoubtedly have good lab and agronomist resources for soil testing and recommendations for Rx amendments.