Purdue engineer receives major USDA AFRI Award
Caitlin Proctor will use the $650,000 grant to study ways of improving hydroponic growing systems
Hydroponics – growing crops in nutrient-enriched water instead of soil – is a growing area of agriculture that presents special challenges for growers. Bacteria and biofilms (aggregations of microorganisms) in the systems can sicken and kill plants, reducing yield and costing farmers millions of dollars.
Purdue College of Agriculture engineer Caitlin Proctor, who recently received a major grant from the USDA’s Agriculture and Food Research Initiative (AFRI), is studying potential solutions to these problems.
“We think of hydroponics as super-controlled,” Proctor, an assistant professor in agricultural and biological engineering and sustainability engineering and environmental engineering, says. “But we still struggle to control bacteria within these systems. If you have a pathogen that gets in, it can spread quickly compared to conventional agriculture. We saw an opportunity to improve how we measure and monitor these microbes to develop early warning systems.”
Proctor will work with Purdue Agriculture faculty Roland Wilhelm, assistant professor of agronomy, and Celina Gomez, associate professor in horticulture and landscape architecture, and Soledad Benitez Ponce, a plant pathology associate professor at Ohio State University, to improve sampling procedures, develop biofilm capture devices, and create methods of using ‘good’ bacteria to outcompete bad bacteria.
To sample biofilms within a hydroponics system, researchers must currently swab the tanks’ “nooks and crannies.” There are no established guidelines for these measurements, and results are often inconsistent. Proctor wants to develop more reliable procedures, testing various sampling methods. One method involves using coated magnetic beads that can be distributed throughout the system and easily extracted. These beads were developed by Wilhelm with other Purdue scientists.
To determine effective methods for seeding good bacteria into hydroponics systems, Proctor and her team will test different ways of adding these so-called microbial inoculants. They’re typically introduced to systems as a liquid that must be added several times throughout the growing process. But Proctor plans to experiment with biofiltration systems that have been pre-seeded with bacteria; in theory this could be a simpler, more efficient method.
Proctor observes that more people are eating food grown hydroponically than they realize. “The project will benefit growers by helping them understand their microbiome and be proactive rather than reactive,” Proctor says. “And it will benefit consumers by creating more resilient food systems.”
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