Practical Training on Nitrogen Management in Organic Production of Vegetables & Strawberries: Part 1 of 3

Online Three-Part Workshop: Tuesdays, March 2nd, March 9th and March 16th All sessions: 9:00 to 11:00 am on Zoom Habrá traducción al Español

Registration Link:

Must enroll in all 3 sessions and class is limited to 50 participants

Cost: $30

Earn 6 hours CCA credits

About this workshop: In this 3-part series, participants will learn how to estimate nitrogen release from diverse organic sources and understand the role of these sources in supplying N to crops. Over the 3 sessions, we will discuss sources of nitrogen and their roles in organic soil fertility and in the nitrogen budget of crops. Sessions will have group instruction followed by discussions to allow participants the opportunity to ask questions and discuss their particular questions.

Who should enroll? Growers, CCA’s, PCA’s and other agricultural professionals who are interested in learning about nitrogen management in organic production are encouraged to enroll.

Part 1: Tuesday, March 2, 2021

Estimating Nitrogen Contributions from Cover Crops and Soil Organic Matter and the Role of Soil Microbes in Providing Plant-Available Nitrogen

Presenters: Margaret Lloyd, Daniel Geisseler and Louise Jackson

There will be an overview of the sources, transformations and fates of sources of organic nitrogen in soil, and discussions the release of available nitrogen for crop growth from cover crops and soil organic matter. There will be a discussion of the use of nitrogen budgets to better understand the sources and proportions of available nitrogen for crop growth.


Part 2: Tuesday, March 9, 2021

Estimating Nitrogen Release from Organic Amendments and Irrigation Water

Presenters: Patricia Lazicki, Margaret Lloyd and Michael Cahn

This session will focus on estimating nitrogen release from compost and estimates of nitrogen release from different organic amendments and organic nitrogen fertilizers. There will be a discussion of how much nitrogen is available from irrigation water of different nitrate contents.


Part 3: Tuesday, March 16, 2021

Putting it all Together: Nitrogen Management in Strawberries and Vegetables and Discussion of New Concepts in Organic Nitrogen Nutrition

Presenters: Joji Muramoto and Richard Smith

In this session, we will address specific aspects of organic soil fertility management in strawberries and cool season vegetables. Discussions will include crop nitrogen demand and strategies to supply demand. Specific references will be made to strategies for complying with forthcoming regulations being developed by the Central Coast Regional Water Quality Control Board. We will conclude with a discussion on new frontiers in organic nitrogen management.


About the Presenters:

Daniel Geisseler is an associae Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis. Daniel's research and outreach focuses on nutrient turnover and plant nutrition in agricultural systems. He is interested in the effects that different management practices have on nutrient use in California crops and how nutrient use efficiency can be improved, particularly with nitrogen.

Patricia Lazicki is a Ph.D. candidate in Soil Science at UC Davis. Previously, as a soil science researcher, she worked to develop the nitrogen guidelines for crops throughout California. Her research continues to focus on soil health and fertility in organic cropping systems.

Margaret Lloyd is the Small Farms Advisor for Yolo, Solano and Sacramento Counties. Her research and outreach focus is on the needs of organic vegetable farms. She has spent several years working to develop nitrogen guidelines for organic fresh market tomato production while working on other aspects of nitrogen management for organic growers.

Joji Muramoto is an assistant Cooperative Extension organic production specialist based at UC Santa Cruz. His research and extension focus on fertility and soilborne disease management in organic vegetables and strawberries. With his statewide responsibility for research and extension in organic production, he is networking organic systems researchers across the state to better serve organic communities throughout California.

Richard Smith is Vegetable Crops and Weed Science Farm Advisor in Monterey, Santa Cruz and San Benito Counties with the University of California Cooperative Extension. Richard conducts a research and education program on nutrient management in cool season vegetables to help growers improve efficiency of applied nitrogen. He is interested in practices and tools that help growers obtain economic yields while reducing the risk of nitrate leaching.

Louise Jackson is an emeritus Professor and Cooperative Extension Specialist from the Department of Land, Air and Water Resources at UC Davis. She worked for many years researching nitrogen cycling and how soil microbes affect nitrogen availability to plants.  Her research covered both cool and warm season vegetable farming systems in the Salinas and Sacramento Valleys.

Michael Cahn is the Irrigation and Water Resources Farm Advisor in Monterey, Santa Cruz and San Benito Counties with the University of California Cooperative Extension. Michael has conducted extensive research on improving nitrogen use efficiency through precise irrigation management. He developed the on-line irrigation and nutrient management decision program, CropManage.


For more information, contact Richard Smith @ 831-759-7357, email:

The University of California prohibits discrimination or harassment of any person in any of its programs or activities. (Complete nondiscrimination policy statement can be found at Inquiries regarding the University’s equal employment opportunity policies may be directed to Affirmative Action Contact and Title IX Officer, University of California, Agriculture and Natural Resources, 2801 2nd Street, Davis, CA 95618, (530) 750-1397;

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