Researchers at the University of California, Davis, have found a way to reduce the amount of nitrogen fertilizers needed to grow a grain crop. The discovery could save farmers in the United States billions of dollars annually in fertilizer costs while also benefiting the environment.
The research stems from the lab of Eduardo Blumwald, a distinguished professor of botany who has discovered a new route for grains 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 problems. The study was published in the journal Plant Biotechnology.
Nitrogen is key to plant growth, and agricultural operations rely on chemical fertilizers to increase productivity. But whatever is planted is lost, mixed with soil and groundwater. Blumwald’s research could make for 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 aside, but there are also the harmful effects of nitrogen on the environment.”
A new route to natural fertilizer
Blumwald’s research centers enhance the conversion of nitrogen gas in the air to 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 such as rice and wheat do not have that ability and must rely on taking up inorganic nitrogen, such as ammonia and nitrate, from fertilizers in the soil.
“If a plant can produce chemicals that fix atmospheric nitrogen gas to soil bacteria, we can modify plants to produce more of these chemicals,” Blumwald said. “These chemicals will induce soil bacterial nitrogen fixation and the plants will use up the ammonium, reducing the amount of fertilizer needed.”
Blumwald’s team used chemical investigations and genomics to identify compounds in rice plants that enhanced the bacteria’s nitrogen-fixing activity.
They then identified the pathways that produced the chemicals and used gene editing techniques to increase the production of compounds that stimulate biofilm formation. Those biofilms contain bacteria that enhance nitrogen conversion. As a result, the nitrogen-fixing activity of the bacteria increased, as did the amount of ammonium in the soil for plants.
“Plants are incredible chemical factories,” he said. “What it can do is provide a sustainable alternative agricultural practice that minimizes the use of excessive nitrogen fertilizers.”
The route can also be used by other plants. A patent application on the technology has been filed by the University of California and is pending.
Dawei Yan, Hiromi Tajima, Howard-Yana Shapiro, Riedmond Fong and Xavier Ottaviani of UC Davis contributed to the research paper, as did Lauren Kline 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 this topic.
material provided by University of California – Davis, Original written by Emily C. Dooley. Note: Content can be edited for style and length.