Nitrogen-based fertilizers help California farmers produce more than 400 agricultural commodities—vegetables, fruits, meats and dairy products—worth $36 billion a year. But excess nitrogen is emitted from soils, seeps into groundwater and runs off into surface waters. Wastes from cattle, chickens and other livestock include nitrogen. Farm machines burning oil, gasoline and diesel release nitrogen to the air.

The resulting known environmental impacts include:

• Trapped solar radiation in the atmosphere, contributing to the "greenhouse effect" that is changing the Earth's climate;

• Decreased high-altitude ozone, which allows more solar radiation to reach Earth's surface, causing skin cancer and adding to the greenhouse effect;

• Increased smog and ground-level ozone, which can cause or worsen respiratory diseases such as asthma and viral infections such as the common cold;

• High concentrations of nitrates in groundwater, which can cause methemoglobinemia, or "blue baby disease," and possibly bladder and ovarian cancers; and

• Nitrogen runoff in bays and coastal areas, where it makes algae numbers spike then crash, drawing oxygen from the water and leading to dead zones—areas that cannot support finfish, shellfish or most other aquatic life.

These environmental impacts are not fully documented, according to Tom Tomich, director of the Agricultural Sustainability Institute at UC Davis.

With this new funding, we can start to fill in those blanks, and improve management of nitrogen, carbon and water to help move agriculture toward sustainability in significant ways.

—Tom Tomich

Data on agricultural nitrogen pollution are limited, and some nitrogen pollution forms are difficult to monitor. Measurements can be labor-intensive and expensive and are influenced by variables such as weather conditions, irrigation timing and method, and crop-specific fertilization practices. The new studies should improve data-collection methods, said Agricultural Sustainability Institute researcher Johan Six, a professor in the Department of Plant Sciences.

The new Agricultural Sustainability Institute grants and objectives include:

• $1.5 million from the David and Lucile Packard Foundation for a statewide assessment of existing scientific evidence on nitrogen use in conventional and alternative farming systems, and relevant practices and policy options. Also: a program to improve communication about nitrogen concerns among California farmers, ranchers, extension advisors, environmental and community groups, agribusiness (including the fertilizer industry) and government agencies (including California Department of Food and Agriculture and US Environmental Protection Agency). This grant is to the Agricultural Sustainability Institute, in collaboration with the University of California Agricultural Issues Center, Kearney Foundation for Soil Science, and the UC Sustainable Agriculture Research and Education Program.

• $500,000 from the California Energy Commission and $350,000 from the David and Lucile Packard Foundation to Johan Six for new research on nitrous oxide emissions in various farming systems.

• $300,000 from the California Air Resources Board to Will Horwath, professor in the UC Davis Department of Land, Air and Water Resources, for research on practical ways to reduce nitrous oxide emissions in California agriculture.

• $150,000 from the California Department of Food and Agriculture’s Fertilizer Research and Education Program to Horwath, Six and David Goorahoo, an assistant professor at the Center for Irrigation Technology at California State University, Fresno, to measure nitrous oxide emissions from cotton, corn and vegetable cropping systems.

Established in 2006 by the UC Davis College of Agricultural and Environmental Sciences, the Agricultural Sustainability Institute includes the University of California’s statewide Sustainable Agriculture Research and Education Program (SAREP), the Student Farm at UC Davis, and the Russell Ranch Sustainable Agriculture Facility at UC Davis, as well as programs at other campuses across California.