California Naturalist
California Naturalist
California Naturalist
University of California
California Naturalist

Posts Tagged: nitrogen

The public is invited to the California Nitrogen Assessment’s Stakeholder Review Process

California farmers are seeing new nitrogen monitoring requirements they must implement in the years ahead. The state of California continues discussion on how growers can improve nitrogen use efficiency and how California can best respond to increasing concerns about nitrogen's movement through our environment. Nitrogen continues to be a pressing topic for California agriculture.

Lettuce field near Salinas, CA
Dairy manure management process

As part of that discussion, members of the public are invited to participate in the Stakeholder Review of the California Nitrogen Assessment (CNA), a comprehensive examination of the existing knowledge on nitrogen science, policy, and practice in California. Researchers have collected and synthesized a large body of data to analyze overall patterns and trends in nitrogen imports, exports, internal flows and storage throughout the state.

The CNA was designed to respond to stakeholder needs, and many scientists affiliated with UC Agriculture and Natural Resources were involved in the writing and review of the document. The review process is an opportunity to hear from stakeholders to understand how well the assessment meets those needs and what improvements can be made to the CNA before its publication. This approach aims to move beyond academic “business as usual” to more effectively link science with action and to produce information that informs both policy and field-level practice.

The Agricultural Sustainability Institute at UC Davis, the CNA's convening institution, is hosting a chapter-by-chapter public review process to allow stakeholders an opportunity to comment on the document before its final release. 

On Friday, June 12, UC SAREP hosted a webinar of Chapter 8: “Responses: Policies and Institutions.” View the webinar here. The webinar includes an introduction to the chapter by its lead author, Ken Baerenklau, associate professor of environmental economics and policy at UC Riverside, and instructions for how stakeholders can submit comments on the chapter.

Chapter 8, “Responses: Policies and Institutions,” provides an overview of available policy instruments for nonpoint source pollution control and examines outcomes from the implementation of these policies in previous cases to control nitrogen pollution in practice.

This is the fourth in a series of webinars and stakeholder review periods to discuss the California Nitrogen Assessment, which includes:

  • Identification of underlying drivers (e.g., regulations, population growth) and direct drivers (e.g., fertilizer use and soil management, fuel combustion) that affect stocks and flows of nitrogen in California agriculture.
  • Calculation of a mass balance to examine how nitrogen moves through California agroecosystems and the state as a whole (including agriculture, sewage, industry and transportation).
  • Evaluation of the state of knowledge about nitrogen's impacts on ecosystem health and human well-being. 
  • A series of scenarios, or "plausible stories about the future," that provide insights about nitrogen issues that will require attention over the next 20 years.
  • A suite of practices and policy options and the potential effects each would have on agriculture, the environment and human health.

Stakeholder comments for Chapter 8 will be accepted until June 26, 2015. The comment period for Chapter 7, “Responses: Technologies and Practices” is still open, with comments due by June 15, 2015. The webinars for all stakeholder presentations done to date are available on the California Nitrogen Assessment's website.

For more information about the stakeholder review process and to access the chapters currently available for review, visit the California Nitrogen Assessment's website.

Posted on Wednesday, June 10, 2015 at 5:00 PM

Nitrogen management training to be offered in 2015

A metered injection pump is one tool used by farmers to apply nitrogen precisely.
The UC Division of Agriculture and Natural Resources and CDFA are offering classes in three locations early in 2015 for certified crop advisers (CCAs) to receive nitrogen management certification. The training is open to CCAs who did not attend the nitrogen management certification training in 2014.

CCAs are individuals who have completed rigorous coursework and passed exams on nutrient, soil, water and pest management, enabling them to help growers produce crops economically and in an environmentally sound manner. Nitrogen management certification prepares CCAs to work with farmers to comply with new state regulations for tracking and reporting nitrogen inputs on farms, efforts that are aimed at minimizing the leaching of nitrogen into the underground aquifer.

The 2015 training sessions are sponsored by the UC California Institute for Water Resources, a statewide program that develops research-based solutions to water-related challenges in California.

“Over the next two years, our focus will be on groundwater quality and quantity,” said Doug Parker, director of the institute. “Our role is to provide policy makers and agricultural practitioners the best science possible on managing and protecting California groundwater.”

The nitrogen management training curriculum was developed by a group of UC ANR faculty, specialists and advisors. The first day is a general session with presentations on the nitrogen cycle in crop production systems, nitrogen sources, irrigation and nitrogen management, and nitrogen budgeting. The second morning will have concurrent sessions on annual and permanent crops and will include nitrogen planning practices.

CCAs must attend both days of the training to receive nitrogen management certification and 11 hours of continuing education credit units. (No DPR credit units will be given.) The registration deadline is Jan. 2. To register, go to the California Association of Pest Control Advisors Education website (CAPCA ED) Registration is online only; no on-site registration will be available. The registration fee is $160.

Nitrogen management training will be offered at the following locations:

Fresno – Jan. 13-14, 2015
Ramada Inn Fresno (University) – Shaw Rooms A, B, C
324 E. Shaw Ave., Fresno, CA 93710
Register online - Fresno

San Luis Obispo – Feb. 24-25, 2015
Courtyard by Marriott – Grand Ballroom
16-5 Calle Joaquin Rd., San Luis Obispo, CA 93405
Register online – San Luis Obispo

Sacramento – March 10-11, 2014
Sacramento Scottish Rite Temple – Bruno Room
6151 H St., Sacramento, CA 95819
Register online - Sacramento

For more information, contact the CDFA Fertilizer Research and Education Program at (916) 900-5022,

Posted on Monday, December 8, 2014 at 9:11 AM
Tags: nitrogen (3)

Nitrogen and water: What's being done now

Drinking water is a commodity often taken for granted in the United States. When we turn on the tap, we assume the water streaming out is at least safe, if not always up to our individual taste. We expect that problems with our drinking water are isolated, temporary and newsworthy. Which may be one reason why a report released yesterday by UC Davis made headlines.

According to the report, one in 10 people living in California’s most productive agricultural areas is at risk of exposure to harmful levels of nitrate contamination in their drinking water.

You can read “Addressing Nitrate in California’s Drinking Water” online in its entirety, or one of the shorter summary documents. This report was commissioned by the California State Water Resources Control Board in 2010 and is the first comprehensive scientific investigation of nitrate contamination in the Tulare Lake Basin and the Salinas Valley.

"The report defines the extent and costs of the problem, for the first time, and outlines how we can address it," said the report’s co-author Thomas Harter, UC Cooperative Extension specialist in the Department of Land, Air and Water Resources at UC Davis, in a UC Davis press release. "We hope it provides the foundation for informed policy discussions."

For the report, scientists examined data from wastewater treatment plants, septic systems, parks, lawns, golf courses and farms. The authors found that more than 90 percent of human-generated nitrate contamination in these regions’ groundwater is from agricultural activity—including applications of synthetic fertilizer and animal manures.

In their California Water Blog post on the topic (and a related op-ed), the report authors highlighted three key challenges for going forward, including this one:

“Nitrate discharges to groundwater and the degradation of underground water supplies are a chronic problem. Do the economic benefits of groundwater degradation outweigh the negative effects of degraded groundwater? Will it be cheaper, and better for all, to pay for the treatment of small water systems and preserve agricultural jobs? Would such an approach threaten long-term groundwater salinization from some of the same sources? Who will bear these costs of source reduction?”

While yesterday’s report looked directly at drinking water contamination, another—the California Nitrogen Assessment, currently under way—will evaluate existing information to gain a comprehensive view of nitrogen flows in the state, with a particular focus on the roles agriculture can play. The Agricultural Sustainability Institute's Tom Tomich gave an update to CDFA earlier this month about the progress of the California Nitrogen Assessment, which has brought stakeholders (including farmers) together to evaluate potential future scenarios in relation to nitrogen management and California agriculture.

These two reports apply science to define problems, evaluate costs and benefits, suggest solutions, compare options and otherwise serve to help guide decision makers throughout the state.

Richard Smith, UC Cooperative Extension advisor in Monterey County, samples soil for nitrogen.
In fields in the meantime, UC Cooperative Extension researchers have been working with growers on ways to improve fertilizer management, irrigation efficiency and other farming practices that can—according to the UC Davis report—significantly affect drinking water sources.

Here are some highlights of current UC ANR projects that aim to help reduce fertilizer contamination of groundwater:

  • Nitrogen management in vegetable crops: With trials in lettuce fields, UCCE advisors in Monterey County have demonstrated effective ways to reduce nitrogen inputs, save money and provide water quality benefits while maintaining equivalent yields, using a combination of weekly nitrate testing and scheduled irrigation management.
  • Nutrient analysis via leaf sampling for nut trees: Though leaf sampling currently provides tree-crop growers with a threshold "critical value" of nutrient analysis, this team of researchers is working to establish more robust and useful leaf sampling protocols that could point to specific timing of applications, fertilizer rates or other "nutrient budget" details for nut trees, particularly almond and pistachio.
  • Tools for dairies to manage nitrogen and water discharge: UCCE specialists at UC Davis and UC Riverside have developed comprehensive resources to help dairy operators comply with regional water discharge requirements, including step-by-step instructions for sampling supply wells and subsurface drainage systems, solid manure, liquid manure and soil.

Find out more about how UC is working to ensure all Californians have access to healthy crops and safe water including details of projects like these, peer-reviewed publications and experts, by visiting

Posted on Wednesday, March 14, 2012 at 11:12 AM
Tags: nitrogen (3), water quality (1)
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