- Author: Emily C. Dooley, UC Davis
Discovery could reduce nitrogen pollution, save farmers billions
Researchers at the University of California, Davis, have found a way to reduce the amount of nitrogen fertilizers needed to grow cereal crops. The discovery could save farmers in the United States billions of dollars annually in fertilizer costs while also benefiting the environment.
The research comes out of the lab of Eduardo Blumwald, a distinguished professor of plant sciences, who has found a new pathway for cereals to capture the nitrogen they need to grow.
The discovery could also help the environment by reducing nitrogen pollution, which can lead to contaminated water resources, increased greenhouse gas emissions and human health issues. The study was published in the journal Plant Biotechnology.
Nitrogen is key to plant growth, and agricultural operations depend on chemical fertilizers to increase productivity. But much of what is applied is lost, leaching into soils and groundwater. Blumwald's research could create a sustainable alternative.
“Nitrogen fertilizers are very, very expensive,” Blumwald said. “Anything you can do to eliminate that cost is important. The problem is money on one side, but there are also the harmful effects of nitrogen on the environment.”
A new pathway to natural fertilizer
Blumwald's research centers on increasing the conversion of nitrogen gas in the air into ammonium by soil bacteria — a process known as nitrogen fixation.
Legumes such as peanuts and soybeans have root nodules that can use nitrogen-fixing bacteria to provide ammonium to the plants. Cereal plants like rice and wheat don't have that capability and must rely on taking in inorganic nitrogen, such as ammonia and nitrate, from fertilizers in the soil.
“If a plant can produce chemicals that make soil bacteria fix atmospheric nitrogen gas, we could modify the plants to produce more of these chemicals,” Blumwald said. “These chemicals will induce soil bacterial nitrogen fixation and the plants will use the ammonium formed, reducing the amount of fertilizer used.”
Blumwald's team used chemical screening and genomics to identify compounds in rice plants that enhanced the nitrogen-fixing activity of the bacteria.
Then they identified the pathways generating the chemicals and used gene editing technology to increase the production of compounds that stimulated the formation of biofilms. Those biofilms contain bacteria that enhanced nitrogen conversion. As a result, nitrogen-fixing activity of the bacteria increased, as did the amount of ammonium in the soil for the plants.
“Plants are incredible chemical factories,” he said. “What this could do is provide a sustainable alternative agricultural practice that reduces the use of excessive nitrogen fertilizers.”
The pathway could also be used by other plants. A patent application on the technique has been filed by the University of California and is pending.
Dawei Yan, Hiromi Tajima, Howard-Yana Shapiro, Reedmond Fong and Javier Ottaviani from UC Davis contributed to the research paper, as did Lauren Cline from Bayer Crop Science. Ottaviani is also a research associate at Mars Edge.
The research was funded by the Will W. Lester Endowment. Bayer Crop Science is supporting further research on the topic.
Editor's note: Blumwald is affiliated with UC Agriculture and Natural Resources through the Agricultural Experiment Station at UC Davis.
/h3>/h3>- Author: Jeannette E. Warnert
“The beauty of our proposal is that carbon dioxide emitted into the atmosphere as a byproduct of combustion of these bio-fuels would be captured again by tobacco plants and, through the natural process of photosynthesis, be converted back into fuel," said Anastasios Melis, professor in the Department of Plant and Microbial Biology at UC Berkeley.
Peggy G. Lemaux, UC Cooperative Extension specialist, Melis and Krishna Niyogi, Agricultural Experiment Station faculty in the Department of Plant and Microbial Biology at UC Berkeley, are lead researchers in the project.
For more information and a video growing biofuel in tobacco leaves, see the UC Green Blog.
Additional coverage:
Lemaux and Eduardo Blumwald, professor in the Department of Plant Sciences at UC Davis, were interviewed about biotechnology for a program that will air on the Bay Area’s KQED Channel 9 at 7:30 p.m. May 8. Lemaux and Blumwald will also participate in a "Google Hangout" at 11 a.m. May 8.
/span>- Author: Jeannette E. Warnert
These are problems that will be addressed by scientists and policymakers at the Climate-Smart Agriculture Global Science Conference at UC Davis this week.
For the story, Ortiz interviewed Eduardo Blumwald, professor in the Department of Plant Sciences at UC Davis, one of the conference speakers. Blumwald believes many of the problems of world food production can be addressed with genetically modified organisms.
"There is no other alternative," he said. "Our population is increasing. We'll be at 9 billion people by 2050, and food security is a big problem."
Eric Holt-Giménez, executive director of Food First, told the reporter he believes genetically modified crops are no silver bullet solution for salty and thirsty soil or for pest control.
"Building resilience into the ecosystem is the only way to address the problem," he said.
Alan McHughen, UC Cooperative Extension specialist in the Department of Botany and Plant Sciences at UC Riverside, said he is a proponent of the judicious use of GMO technology.
"We have to investigate it – it has to be treated with respect," he said. "There will be some products that come through that we don't want to be commercialized, and then there will be others that should be commercialized more rapidly."