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 as well as previous FREP Conference Proceedings. These findings have not been subjected to independent scientific peer review. Some Project Leaders have published their results in academic journals. Reprints of the journal publications may be requested directly from the corresponding authors.

2013

Dairy Cattle Entry Requirements Developing Testing Protocols to Assure the Quality of Fertilizer Materials for Organic Agriculture (13-0223-SA)
W.R. Horwath and S.J. Parikh
Phosphorus and Boron Fertilizer Impacts on Sweetpotato Production and Long-Term Storage (13-0266-SA)
C. Scott Stoddard

2012

Fertigation Education for the San Joaquin Valley (12-0390-SA)
William Green and Kaomine Vang

2011

Remediation of Tile Drain Water Using Bioreactors (11-0462-SA)
T.K. Hartz, Richard Smith, Mike Cahn, and Laura Tourte
California Certified Crop Advisor FREP Educational/Outreach Project (11-0470-SA)
Dan Putnam
Survey of Nitrogen Uptake and Applied Irrigation Water in Broccoli, Cauliflower, and Cabbage Production in the Salinas Valley (11-0558-SA)
Richard Smith, Mike Cahn, and T.K. Hartz
Optimization of Organic Fertilizer Schedules (11-0456-SA)
David M. Crohn and Marsha Campbell Mathews
Management Tools for the Fertilization of the 'Hass' Avocado (11-0437-SA)
Richard Rosecrance and Carol J. Lovatt

2010

Relationship of Soil K Fixation and Other Soil Properties to Fertilizer K Rate Requirement (10-0012-SA)
G. Stuart Pettygrove
Development of a Nutrient Budget Approach to Fertilizer Management in Almond (10-0039-SA)
Patrick Brown
Nitrogen Research & Groundwater Management Education Program (10-0011-SA)
Renee Pinel
Adjustable-Rate Fertigation for Site-Specific Management to Improve Fertilizer Use Efficiency (10-0004-SA)
Michael Delwiche
Chemistry, Fertilizer, and the Environment – A Comprehensive Unit (10-0010-SA)
Judy Culbertson, Shaney Emerson, and Lyn Hyatt
Development of Leaf Sampling and Interpretation Methods for Almond and Pistachio (10-0015-SA)
Patrick Brown
European Pear Growth and Cropping: Optimizing Fertilizer Practices Based on Seasonal Demand and Supply with Emphasis on Nitrogen Management (10-0105-SA)
Kitren Glozer and Chuck Ingels

2009

Citrus Yield and Fruit Size Can Be Sustained for Trees Irrigated with 25% or 50% less Water by Supplementing Tree Nutrition with Foliar Fertilization - Comparison of Conventional Irrigation and Partial Root Zone Drying at the Same Reduced Irrigation Rates Supplemented with Equal Foliar Fertilization (09-0581)
Carol J. Lovatt and Ben Faber
Developing Testing Protocols to Assure the Quality of Fertilizer Materials for Organic Agriculture (09-0582)
W.R. Horwath and S.J. Parikh
Improving Pomegranate Fertigation and Nitrogen Use Efficiency with Drip Irrigation Systems (09-0583)
James E. Ayars and Claude J. Phene
Towards Development of Foliar Fertilization Strategies for Pistachio to Increase Total Yield and Nut Size and Protect the Environment: A proof-of-concept project (09-0584)
Carol J. Lovatt

2008

Development of a Comprehensive Nutrient Management Web site for the California Horticultural Industry (08-0629)
T.K. Hartz
Evaluation Low-Residue Cover Crops to Reduce Nitrate Leaching, and Nitrogen and Phosphorous Losses from Winter Fallow Vegetable Production Fields in the Salinas Valley (08-0628)
Richard Smith and Michael Cahn
Western Fertilizer Handbook Turf & Ornamental Edition (08-0007)
Renee Pinel and Pamela Emery

2007

California Certified Crop Adviser FREP Educational Project (07-0352)
Dan Putnam
Can a Better Tool for Assessing 'Hass' Avocado Tree Nutritional Status Be Developed? A Feasibility Study (07-0002)
Carol J. Lovatt, Richard Rosecrance, and Ben Faber
Comparing the Efficiency of Different Foliarly-Applied Zinc Formulations on Peach and Pistachio Trees by Using 68Zn Isotope (07-0669)
R. Scott Johnson
Development and Implementation of Online, Accredited Continuing Education Classes on Proper Sampling and Application of Nitrogen/Crop Nutrients (07-0223)
Renee Pinel, et al.
Development of Certified Crop Adviser Specialty Certification and Continuing Education in Manure Nutrient Management (07-0405)
Stuart Pettygrove
Evaluation of Humic Substances Used in Commercial Fertilizer Formulations (07-0174)
T.K. Hartz
Fertilizer Education Equals Clean Water (07-0120)
Kay Mercer and Kevin Peterson
New Standard for the Effectiveness of Foliar Fertilizers (07-0667)
Carol J. Lovatt
Optimizing Nitrogen Availability in Cherry Growth to Obtain High Yield and Fruit Quality (07-0666)
Kitren Glozer, Gregory Lang, and Joe Grant

2006

2004

Detecting and Correcting Soil Calcium Limitations (04-0701)
T.K. Hartz, Richard Smith, and Mike Cahn
Fertility Management in Rice (04-0704)
Chris van Kessel and Bruce Linquist
Fertilization Technologies for Conservation Tillage Production Systems in California (04-0808)
Jeff Mitchell, et al.
Improving Water-Run Nitrogen Fertilizer Practices in Furrow and Border Check – Irrigated Field Crops (04-0747)
Stuart Pettygrove

2003

Hiring a Landscape Company - What You Should Know Before You Start (03-0654)
Valerie J. Mellano
Improving the Procedure for Nutrient Sampling in Stone Fruit Trees (03-0652)
R. Scott Johnson
Increasing Yield of the 'Hass' Avocado by Adding P and K to Properly Timed Soil N Applications (03-0653)
Carol J. Lovatt
Potassium Fertility Management for Optimum Tomato Yield and Fruit Color (03-0651)
Tim Hartz
Precision Fertigation in Orchards: Development of a Spatially Variable Microsprinkler System (03-0655)
Michael Delwiche, et al.
Reevaluating Tissue Analysis as a Management Tool for Lettuce and Cauliflower (03-0650)
T.K. Hartz
Soil-Solution Partitioning of Trace Elements in Cropland Soils of California (03-0088)
Andrew C. Chang, Weiping Chang, and Albert L. Page

2002

Determination of Nursery Crops Yields, Nutrient Content, and Water Use for Improvement of Water and Fertilizer Use Efficiency (02-0651)
Richard Y. Evans and Linda L. Dodg
Evaluation of Polyacrylamide (PAM) for Reducing Sediment and Nutrient Concentration in Tail Water from Central Coast Vegetable Fields (02-0781)
Michael Cahn, Husein Ajwa, and Richard Smith
Practical Soil Test Methods for Predicting Net N Mineralization (02-0653)
W.R. Horwath and G.S. Pettygrove
The Effect of Nutrient Deficiencies on Stone Fruit Production and Quality (02-0691)
R. Scott Johnson

2001

California State Fair Farm Upgrade Project (01-0640)
Michael Bradley, Joe Brengle, and Teresa Winovitch
Crop Nitrate Availability and Nitrate Leaching under Micro-Irrigation for Different Fertigation Strategies (01-0545)
Blaine Hanson and Jan W. Hopmans
Development of a Leaf Color Chart for California Rice Varieties (01-0510)
Randall G. Mutters
Development of BMPs for Fertilizing Lawns to Optimize Plant Performance and Nitrogen Uptake While Reducing the Potential for Nitrate Leaching (01-0508)
Robert Green, et al
Development of Lime Recommendations for California Soils (01-0511)
Robert O. Miller, Janice Kotuby-Amacher, and Nat Dellavalle
Effects of Cover Cropping and Conservation Tillage on Sediment and Nutrient Losses to Runoff in Conventional and Alternative Farming Systems (01-0473)
William R. Horwath, et al.
Efficient Phosphorus Management in Coastal Vegetable Production (01-0509)
T.K. Hartz
Evaluating the Impact of Nutrient Management on Groundwater Quality in the Presence of Deep Unsaturated Alluvial Sediment (01-0584)
Thomas Harter, et al.
Fertilization Technologies for Conservation Tillage Production Systems in California (01-0123)
Jeff Mitchell and Willi Horwath
Site-Specific Variable Rate Fertilizer Nitrogen Application in Cotton (01-0507)
Richard E. Plant, et al.

2000

Ammonia Emission Related to Nitrogen Fertilizer Application Practices (00-0515)
Charles F. Krauter
Can We Predict K Fixation in the San Joaquin Valley from the Soil Texture and Mineralogy?
M. Murashkina, et al.
Effect of Different Rates of N and K on Drip-Irrigated Beauregard Sweetpotatoes (00-0507)
Scott Stoddard and Bob Weimer
Evaluation of Slow Release Fertilizers for Cool Season Vegetable Production in the Salinas Valley (00-0506)
Richard Smith and Tim Hartz
From the Ground Up: A Step-By-Step Guide to School Gardening (00-0072)
Jennifer Lombardi
Improving the Diagnostic Capabilities for Detecting Molybdenum Deficiency in Alfalfa and Avoiding Toxic Concentrations for Animals (00-0516)
Roland D. Meyer, Daniel B.Marcum, and Steve Orloff
Location of Potassium-Fixing Soils in the San Joaquin Valley and a New, Practical Soil K Test Procedure (00-0508)
G. Stuart Pettygrove and Randal J. Southard
Long Term Rice Straw Incorporation: Does It Impact Maximum Yield? (00-0651)
Chris van Kessel and William R. Horwath
Minimizing Nitrogen Runoff and Improving Nitrogen Use Efficiency in Containerized Woody Ornamentals through Management of Nitrate and Ammonium-Nitrogen (00-0509)
Donald J. Merhaut and Richard Y. Evans
On-Farm Monitoring and Management Practice Tracking for Central Coast Watershed Working Groups (00-0071)
Kelly Huff
Precision Horticulture: Technology Development and Research and Management Applications (00-0497)
Patrick H. Brown
Reducing Fertilizer Needs of Potato with New Varieties and New Clonal Strains of Existing Varieties (00-0514)
Ronald E. Voss
Residual Soil Nitrogen and Nitrogen Management for Alcala Cotton (00-0604)
R.B. Hutmacher, et al.
Seasonal Patterns of Nutrient Uptake and Partitioning as a Function of Crop Load of the 'Hass' Avocado (00-0621)
Richard Rosecrance and Carol J. Lovatt
Site-Specific Variable Rate Fertilizer Application in Rice and Sugar Beets (00-0505)
Richard E. Plant, et al.
Teach the Teachers: Garden-Based Education about Fertility and Fertilizers (00-0070)
Peggy Sears Perry

1999

Evaluating and Demonstrating the Effectiveness of In-Field Nitrate Testing in Drip- and Sprinkler-Irrigated Vegetables (99-0756)
Marc Buchanan
Nitrogen Budgeting Workshops (99-0757)
Molly Johnson and Gwen Huff
Pajaro Valley Nutrient Management Education & Outreach Project (99-0764)
U Win and Frank Shields
The Role of Inorganic Chemical Fertilizers and Soil Amendments on Trace Element Contents of Cropland Soils in California (99-0533)
Andrew C. Chang

1998

Air Quality and Fertilization Practices: Establishing a Calendar of Nitrogen Fertilizer Application Timing Practices for Major Crops in the San Joaquin Valley (98-0471)
Jack King, Jr.
Demonstration of Presidedress Soil Nitrate Testing as an N Management Tool (98-0513)
Tim Hartz
Effect of Cover Crop or Compost on Potassium Deficiency and Uptake, and on Yield and Quality in French Prunes (98-0422)
Richard Rosecrance, P. A. Delwiche, and Fred Thomas
Efficient Irrigation for Reduced Non-Point Source Pollution from Low Desert Vegetables (98-0423)
Charles. A. Sanchez, Dawit Zerihun, and Khaled. M. Bali

1997

Agricultural Baseline Monitoring and BMP Implementation: Steps Towards Meeting TMDL Compliance Deadlines within the Newport Bay/San Diego Creek Watershed (97-0365 M99-01)
Laosheng Wu and John Kabashima
Agriculture and Fertilizer Education for Grades K-12 (97-0361)
Pamela Emery, Richard Engel, and Judy Culbertson
Development and Demonstration of Nitrogen Best Management Practices for Sweet Corn in the Low Desert (97-0365 M98-02)
Jose L. Aguiar, et al.
Development and Testing of Application Systems for Precision Variable Rate Fertilization (97-0365 M97-06A)
Ken Giles
Development of an Educational Handbook on Fertigation for Grape Growers (97-0365 M99-07)
Glenn McGourty
Development of Fertilization and Irrigation Practices for Commercial Nurseries (97-0365 II M99-03)
Richard Y. Evans, Carmen Garcia-Navarro, and Linda L. Dodge
Development of Irrigation and Nitrogen-Fertilization Programs on Tall Fescue to Facilitate Irrigation-Water Savings and Fertilizer-Use Efficiency (97-0365 M97-07)
Robert L. Green, Grant J. Klein, and Victor A. Gibeault Thomas
Development of Nitrogen Best Management Practices for the "Hass" Avocado (97-0365 M98-01)
Carol J. Lovatt
Drip Irrigation and Fertigation Scheduling for Celery Production (97-0365 M97-02) T.K. Hartz
Nitrogen Mineralization Rate of Biosolids and Biosolids Compost (97-0365 M99-10)
Tim Hartz
Interaction of Cotton Nitrogen Fertility Practices and Cotton Aphid Population Dynamics in California Cotton (97-0365 M98-04)
Larry D. Godfrey and Robert Hutmacher
Long-Term Nitrate Leaching Below the Root Zone in California Tree Fruit Orchards (97-0365 M97-04)
Thomas Harter, et al.
Nitrogen Budget in California Cotton Cropping Systems (97-0365 M97-09) William Rains, Robert L. Travis, and Robert Hutmacher
Nitrogen Fertilization and Grain Protein Content in California Wheat (97-0365 M99-04)
L.F. Jackson
Potassium Responses in Rice Fields as Affected By Straw Management Practices (97-0365 M99-08)
Chris van Kessel, et al.
Relationship between Fertilization and Pistachio Diseases (97-0365 M99-06)
Themis J. Michailides and Patrick Brown
Soil Testing to Optimize Nitrogen Management for Processing Tomatoes (97-0365 M97-03) Don May and Jeff Mitchell
Uniformity of Chemigation in Micro-irrigated Permanent Crops (97-0365 M97-008)
Larry Schwankl and Terry Pritchard
Water and Fertilizer Management for Garlic: Productivity, Nutrient and Water Use Efficiency and Postharvest Quality (97-0207)
Marita Cantwell, et al.
Winter Cover Crops Before Late-Season Processing Tomatoes for Soil Quality and Production Benefits (97-0365 M99-11)
Gene Miyao, Paul Robins, and Mike Cahn

1996

Development of a Nitrogen Fertilizer Recommendation Model to Improve N-Use Efficiency and Alleviate Nitrate Pollution to Groundwater from Almond Orchards (96-0367)
Patrick H. Brown
Fertilizer Use Efficiency and Influence of Rootstocks on Uptake and Nutrient Accumulation in Winegrapes (96-0399)
Larry E. Williams
Improving Fertilizer Practices of SE Asians in Fresno and Tulare Counties (96-0405)
Richard Molinar and Manuel Jimenez
Management of Nitrogen Fertilization in Sudangrass for Optimum Production, Forage Quality and Environmental Protection (96-0400)
D. Putnam
Nitrogen Management in Citrus under Low Volume Irrigation (96-0280)
M.L. Arpaia and L.J. Lund
Survey of Changes in Irrigation Methods and Fertilizer Management Practices in California (96-0371)
John Letey, Jr.

1995

Avocado Growers Can Reduce Soil Nitrate Groundwater Pollution and Increase Yield and Profit (95-0523)
Carol J. Lovatt
Best Management Practices (BMPs) for Nitrogen and Water Use in Irrigated Agriculture: A Video (95-0463)
Larry Klaas and Thomas Doerge
Determination of Best Nitrogen Management Practices for Broccoli Production in the San Joaquin Valley (95-0520)
Michelle Le Strange, Jeffrey P. Mitchell, and Louise E. Jackson
Development and Promotion of Nitrogen Quick Tests for Determining Nitrogen Fertilizer Needs of Vegetables (95-0582)
Richard Smith and Kurt Schulbach
Diagnostic Tools for Efficient Nitrogen Management of Vegetables Produced in the Low Desert (95-0222)
C.A. Sanchez
Effects of Irrigation Nonuniformity on Nitrogen and Water Use Efficiencies in Shallow-Rooted Vegetable Cropping Systems (95-0519)
Jeff Mitchell, Laosheng Wu, and Blake Sanden
Evaluation of Controlled Release Fertilizers and Fertigation in Strawberries and Vegetables (95-0418)
Warren E. Bendixen
Evaluation of Pre-Sidedress Soil Nitrate Testing to Determine N Requirements of Cool Season Vegetables (95-0583)
T.K. Hartz, Warren Bendixen, and Kurt Schulbach
Guide to Nitrogen Quick-Tests for Vegetables with the 'Cardy' Nitrate Meter (95-0582)
Kurt Schulbach, et al.
Irrigation and Nutrient Management Conference and Trade Fair (95-0419)
Danyal Kasapligil
Relationship between Fertilization and Bacterial Canker Disease in French Prune (95-0478)
Steven Southwick, Bruce Kirkpatrick, and Becky Westerdah
Site Specific Farming Information Systems in a Tomato-Based Rotation in the Sacramento Valley (95-0518)
Stuart Pettygrove, et al.
Using High Rates of Foliar Urea to Replace Soil Applied Fertilizer in Early Maturing Peaches (95-0214)
R. Scott Johnson and Richard Rosecrance

1994

Best Management Practices for Tree Fruit and Nut Production: A Video (94-0463)
Thomas Doerge and Larry Klaas
Education through Radio (94-0517)
Patrick Cavanaugh
Effects of Four Levels of Applied Nitrogen on Three Fungal Diseases of Almond Trees (94-0513)
Beth L. Teviotdale
Effects of Various Phosphorus Placements on No-Till Barley Production (94-0450)
Michael J. Smith
Improvement of Nitrogen Management in Vegetable Cropping Systems in the Salinas Valley and Adjacent Areas
Stuart Pettygrove
Nitrogen Management through Intensive on-Farm Monitoring (94-0362)
T.K. Hartz
Nutrient Recommendation Training in Urban Markets: A Video (94-0463)
Wendy Jenks and Larry Klaas

1993

Citrus Growers Can Reduce Nitrate Groundwater Pollution and Increase Profits by Using Foliar Urea Fertilization (93-0530)
Carol J. Lovatt and Joseph G. Morse
Drip Irrigation and Nitrogen Fertigation Management for California Vegetable Growers: Videotape
Timothy K. Hartz
Educating California's Small and Ethnic Minority Farmers: Ways to Improve Fertilizer Use Efficiency through the Use of Best Management Practices (BMPs)
Ronald Voss
Nitrogen Efficiency in Drip-Irrigated Almonds (93-0551)
Robert J. Zasoski
Western States Agricultural Laboratory Proficiency Testing Program (93-0568)
R.O. Miller and J. Kotuby-Amacher

1992

Crop Management for Efficient Potassium Use and Optimum Winegrape Quality (92-0627)
Mark A. Matthews
Determination of Soil Nitrogen Content In-Situ (92-0575)
Shrini K. Updahyaya, Sayedahmed Shafii, and William J. Chancellor
Establishing Updated Guidelines for Cotton Nutrition (92-0589)
Bill Weir, et al.
Impact of Microbial Processes on Crop Use of Fertilizers from Organic and Mineral Sources (92-0639)
Kate M. Scow
Optimizing Drip Irrigation Management for Improved Water and Nitrogen Use Efficiency (92-0629)
Timothy K. Hartz
Potential Nitrate Movement below the Root Zone in Drip-Irrigated Almonds (92-0631)
Roland D. Meyer
The Use of Composts to Increase Nutrient Utilization Efficiency in Agricultural Systems and Reduce Pollution from Agricultural Activities (92-0628)
Mark Van Horn

1991

Demonstration Program for Reducing Nitrate Leaching through Improvements to Irrigation Efficiency and Fertilizer/Cover Crop Management (91-0654)
Stuart Pettygrove, et al.
Field Evaluation of Water and Nitrate Flux through the Root Zone in a Drip/Trickle-Irrigated Vineyard (91-0556)
Donald W. Grimes
Influence of Irrigation Management on Nitrogen Use Efficiency, Nitrate Movement, and Groundwater Quality in a Peach Orchard (91-0646)
R. Scott Johnson and Claude J. Phene
Nitrogen Management for Improved Wheat Yields, Grain Protein and the Reduction of Excess Nitrogen (91-0485)
Bonnie Fernandez

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Sacramento, CA 95814
916-900-5022
Fax: 916-900-5349
Email: frep@cdfa.ca.gov

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FREP Research Database Crop Fertilization Guidelines Annual Conference Competitive Grant Program

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