California Fertilization Guidelines
These guidelines have been written by scientists from the University of California, Davis with support from CDFA-FREP. The guidelines are based on research results from studies carried out in California and elsewhere. For an optimal fertilization program, site-specific information needs to be taken into account. Discussion about site-specific adjustments can be found here.
Field crops and vegetables
The California Department of Food and Agriculture (CDFA) Fertilizer Research and Education Program (FREP) and the University of California Davis (UCD) Department of Land, Air and Water Resources (LAWR) are working collaboratively to develop fertilization guidelines for major crops grown in California. The guidelines are uploaded on a flow basis and will be available to growers and crop advisors through this web-based platform.
The CDFA FREP and UCD LAWR are addressing the increasing grower and crop advisor demand for accurate, timely, efficient and effective crop nutrient information across the state, but specifically in the San Joaquin Valley's Tulare Lake Basin and the Salinas Valley in the Central Coast region. These two regions collectively represent a high degree of nitrogen sensitivity relative to drinking water quality and supplies. The guidelines, which are a synthesis of peer reviewed journal articles and research reports, serve two co-equal goals. The first is to facilitate awareness of what nutrients are needed for crops and their demand throughout the crop life cycle, and the second is to reduce the impact of nutrients to both the air and water resources.