Research & Project Database

Fertilizer Research And Education Program

Research and Project Database

Since 1990, FREP has funded research on many of California’s important and environmentally sensitive cropping systems. This database aims to make the wealth of information contained in FREP research projects available, understandable, and convenient for growers to implement. See the Crop Fertilization Guidelines for tips on how to improve nutrient management, based on information gleaned from research.

Current Projects

The following is a list of FREP projects that are currently being conducted. Each title links to the project's approved proposal and scope of work. Summaries of many of these projects are featured in previous FREP Conference Proceedings.

Copies of interim and annual project reports are available by contacting FREP at (916) 900-5022 or

  • 2019 FREP-funded projects
  • Development of Nutrient Management Budget and Nutrient Demand Model for Nitrogen Management in Cherry
    Patrick Brown, Douglas Amaral and Pedro Lima
  • Irrigation and Nitrogen Management, Monitoring, and Assessment to Improve Nut Production while Minimizing Nitrate Leaching to Groundwater
    Thomas Harter, Patrick Brown and Isaya Kisekka
  • Achieving Efficient Nitrogen Fertilizer Management in California Wheat
    Mark Lundy et al.
  • Developing a Nitrogen Mineralization Model for Organically Managed Vegetable Farms on the Central Coast
    Joji Muramoto, Richard Smith and Mike Cahn
  • Next Generation N Management Training for Certified Crop Advisors
    Doug Parker et al.
  • Immobilization of Nitrate in Winter-Fallow Vegetable Production Beds to Reduce Nitrate Leaching
    Richard Smith, Michael Cahn, Joji Muramoto and Daniel Geisseler
  • Promoting the Adoption of CropManage to Optimize Nitrogen and Irrigation Use through Low-Cost Data Loggers and Cellular Modems for Spanish-Speaking Growers in Santa Cruz and Monterey Counties
    Gerry Spinelli
  • 2018 FREP-funded projects
  • Assessing Drip Irrigation and Nitrogen Management of Fresh Onions Produced in California Low Desert (18-0592)
    Jairo Diaz, Roberto Soto, and Daniel Geisseler
  • Pima Cotton Nitrogen Management, Uptake, Removal - Impacts of Varieties, Subsurface Drip and Furrow Irrigation (18-0597)
    Robert Hutmacher
  • Understanding Influences on Grower Decision-Making and Adoption of Improved Nitrogen Management Practices in the Southern San Joaquin Valley (18-0596)
    Patrick Brown, Mark Lubell, and Sat Darshan Khalsa
  • Improving Nitrate and Salinity Management Strategies for Almonds Grown under Micro-irrigation (18-0549)
    Patrick Brown
  • Promoting the Adoption of Soil Nitrogen Quick Tests by Spanish-Speaking Operators on Strawberry Ranches in Santa Cruz and Monterey Counties (18-0535)
    Gerry Spinelli
  • Efficient Water and Nitrogen Management Practices for Mixed Leafy Baby Green Vegetables in the Desert (18-0593)
    Charles Sanchez
  • 2017 FREP-funded projects
  • Evaluation of Nitrogen Uptake and Applied Irrigation Water in Asian Vegetables; Bok Choy, Edible Chrysanthemums, Garlic Chives, Moringa and Lemongrass (17-0515)
    Aparna Gazula
  • A system Nitrogen Balance for Container Plant Production (17-0516)
    Lorence Oki
  • Assessment of Harvested and Sequestered Nitrogen Content to Improve Nitrogen Management in Perennial Crops (17-0488)
    Casey Creamer, John Dickey and Ken Cassman
  • Training on Crop Management that Integrates Climate, Soil and Irrigation
    System Data to Minimize Nutrient Loss and Optimize Irrigation Efficiency
    Trina Walley
  • 2016 FREP-funded projects
  • Continuing Education Courses for Growers Who Completed the Nitrogen Training Course (16-0703)
    Parry Klassen
  • Soil Biochar Amendment to Improve Nitrogen and Water Management
    Suduan Gao
  • Evaluation of Biochar for On-farm Soil Management in California (16-0662)
    Sanjai Parikh
  • Evaluation of Certified Organic Fertilizers for Long-term Nutrient Planning
    William Horwath
  • University of California Nursery and Floriculture Alliance Fertilizers and Plant Nutrition (16-0678)
    Lorence Oki

Completed Projects

The following is a list of completed FREP projects. Each title links to a PDF of the project's final report. Summaries of many of these projects are available in the FREP Research Database andFREP Conference Proceedings. Some Project Leaders have published their results in academic journals. Reprints of the journal publications may be requested directly from the corresponding authors.