University of California (UC)-Davis researchers will receive $2.8 million in new grants to study the use and impacts of nitrogen, a hero of the agricultural revolution that is increasingly viewed as a worrisome source of water and air pollution and potent greenhouse gases.
“This is one of the most important and least publicized environmental issues we face: Escaped nitrogen from agricultural production affects the quality of our air, water, and soil and has huge potential to contribute to climate change,” said Tom Tomich, director of the Agricultural Sustainability Institute at UC-Davis.
“Many members of the public and politicians are unaware of the scope of this challenge. And many farmers are unaware that nitrogen management can save them money.”
Nitrogen is a chemical element that occurs naturally in Earth’s air, water and soil. It is essential to life, and cycles through all plants, animals and people. 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 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.
Those environmental impacts are not fully documented, Tomich said.
“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,” he said.
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.
“It’s urgent that we know how much nitrous oxide and other greenhouse gases are released during irrigation and fertilization of farm lands in California,” Six said. “The good news is we know that it is economically feasible to reduce these emissions. The first step is quantifying the necessary reductions.”
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 U.S. 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.