California's land-grant extension doesn't use a one-size-fits-all number — it uses a published method. Combined source: lime + nutrients (UC ANR 8292) in california_uc_anr v1.1. Enter your soil-test values in the free calculator and Zone Forge returns tons of CaCO₃-equivalent per acre, ECCE-adjusted, with the citation.
Need lime: North Coast, Sierra foothills, coastal North/Central CA. Do NOT need lime: Sacramento Valley, San Joaquin Valley, Imperial Valley, Salinas Valley, most of Southern CA.
Published source: California — UC ANR / CDFA-FREP / UC Davis Nutrient Management (Olsen-P calibration + commodity manuals)
It depends on your soil's buffer/acidity reading and your target pH — California publishes a method, not a single number. Combined source: lime + nutrients (UC ANR 8292) in california_uc_anr v1.1. Enter your values in the free Zone Forge lime calculator for tons of CaCO3-equivalent per acre, with the citation.
Combined source: lime + nutrients (UC ANR 8292) in california_uc_anr v1.1. Source: California — UC ANR / CDFA-FREP / UC Davis Nutrient Management (Olsen-P calibration + commodity manuals).
Zone Forge computes every California recommendation from that state's own published land-grant method — lime, soil-test fertilizer, and full variable-rate prescriptions. See the science →