Grainswest - Spring 2022

Spring 2022 Grains West 10 THE FARMGATE BY MADELEINE BAERG • PHOTOS COURTESY OF THE UNIVERSITY OF MINNESOTA LONG CRITICIZED FOR ITS irrigation-clogging, livestock-endangering, dugout-deoxygenating properties, lowly pond scum is in the midst of an image makeover. Research carried out by teams at the University of Minnesota and the U.S. Agricultural Research Service indicates that, when applied to farm fields, cyano- bacteria (blue-green algae) offer a host of agronomic and environmental bene- fits. It may serve as an organic alternative to synthetic fertilizer that can increase soil organic matter and aggregation, support microbial populations and more. Cyanobacteria also has potential as a renewable, carbon-sequestering soil inoculant. “Cyanobacteria was identified 40 or 50 years ago as a natural source of nitrogen for rice, and some research was done in Southeast Asia, India and Russia,” said Adriana Alvarez, the study’s lead and PhD student at the University of Min- nesota’s Department of Bioproducts and Biosystems Engineering. “Here in North America, research [on cyanobacteria] has focused on biofuels and other applications but not so much on the agriculture aspect. We are excited about the potential for [its use in] agriculture. Cyanobacteria’s most obvious positive attribute is its ability to quickly absorb nitrogen during growth. It then slowly releases that nitrogen during decom- position. The study found soils treated with it had higher soluble nitrogen and phosphorus rates than untreated soils. In the team’s greenhouse-scale study, now awaiting peer review, wheat plants produced equally as much yield whether soil was treated with a conventional rate of synthetic urea fertilizer or a mixture of cyanobacteria and urea. The study also indicated treated soils had higher rates of soluble organic carbon, known to support plant growth-stimu- lating soil microbes. As well, it was less prone to erosion because the algae im- proved clumping and formed a biological crust on the soil surface. While the research confirms cyanobac- teria holds promise for agriculture, the concept is far from commercialization. Researchers will first need to identify the best bacterial strains for the job, which in itself is a complex undertaking. These strains may eventually be tailored to spe- cific crops and environmental conditions. Researchers must also determine how to scale up algal production and identify optimal application systems and rates. Though the microscopic algae lend them- Scumof theearth Researchers identify possible agricultural applications of algae Known as blue-green algae, cyanobacteria show promise as an organic fertilizer and may also offer several additional soil health benefits. A University of Minnesota study determined the algae prevented erosion because it improved clumping and formed a biological crust on the soil surface.