Startups are developing genetically modified soil microbes to fix nitrogen for crops, potentially lowering the environmental impact and costs of traditional synthetic fertilizers.
Key facts
- •Synthetic fertilizer production accounts for roughly 2% of global greenhouse-gas emissions.
- •Switch Bioworks is testing a genetic switch that triggers ammonia production only when soil nitrogen levels are low.
- •Switch Bioworks is two to three years away from a commercial product, with early trials underway in six US states.
- •Pivot Bio has been operating since 2011 and has expanded its microbial fertilizer products to crops including cotton, wheat, and sorghum.
- •Current modeling suggests microbes can replace a maximum of about 50% of synthetic fertilizer usage.
Synthetic fertilizer production is responsible for approximately 2% of global greenhouse-gas emissions. To address this, companies like Switch Bioworks and Pivot Bio are developing engineered soil microbes capable of fixing nitrogen directly for crops. While these biological alternatives could reduce the need for chemical fertilizers, experts note that synthetic products will remain essential for the foreseeable future.
By the numbers
The Challenge of Nitrogen Fixation
Nitrogen fixation is an energy-intensive process for microbes, which often struggle to balance producing ammonia for plants with their own survival and growth. Switch Bioworks is addressing this by developing a genetic "switch" that allows microbes to establish healthy colonies in the soil before triggering nitrogen production only when soil levels drop sufficiently.
Field Trials and Market Outlook
Switch Bioworks is currently conducting trials across six US states, primarily focusing on corn. The company expects to be two to three years away from a commercial product, with initial models suggesting their microbes could replace about 25% of synthetic fertilizer usage. Meanwhile, Pivot Bio, founded in 2011, has already deployed its microbial products across millions of acres and expanded its offerings to include crops such as cotton, wheat, and barley.
Limitations of Microbial Solutions
Experts caution that microbial fertilizers are not a complete replacement for synthetic options. Modeling indicates that microbes may only be able to replace up to 50% of synthetic fertilizer at most. Consequently, researchers emphasize that other emissions-reduction strategies remain necessary to address the environmental impact of the agricultural sector.
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This article was independently rewritten by ManyPress editorial AI from reporting originally published by MIT Technology Review.
