Study clarifies crop input confusion

Every time Fred Below and Connor Sible meet with Illinois farmers, they get the same question. “What’s the story with these biologicals? Do they work?”

The University of Illinois Urbana-Champaign crop scientists and Illinois Extension specialists are happy to share what they know about the natural growth stimulants, informed by dozens of trials and published research. But with new products constantly being added to the market — and a muddled regulatory landscape — it’s not always clear what farmers are even asking.

“We do a lot of Extension talks, and we started to notice a disconnect. Farmers and companies call these products biologicals, but the scientific literature and regulatory bodies call them biostimulants,” said Below, professor in the department of crop sciences, which is part of the College of Agricultural, Consumer and Environmental Sciences at the University of Illinois. “When we started looking into it, we realized the terminology is not only confusing, these very different products are all regulated the same, if they’re regulated at all.”

The realization prompted Sible, Below and colleague Juliann Seebauer to embark on a deep dive into the world of biologicals and biostimulants, publishing their commentary in Agricultural and Environmental Letters.

First, just what are those products? In the most basic sense, they are live microbial inoculants and non-living naturally derived chemicals or extracts applied to soil, seeds and plants to improve growth in some way. That can be through enhancing fertilizer efficacy, reducing crop stress, improving soil health or other mechanisms.

Sible, research assistant professor in crop sciences and University of Illinois Extension specialist, said, “The original biological was soybean inoculum. That’s been around for decades, if not a century. But then the humic and fulvic acids [from decomposing organic matter or mineral deposits], hydrolysates [from plant and animal byproducts], and alginates [from seaweeds] came along, and were mostly applied in specialty crops. In those systems, anything you can do to improve the quality of your crop — the difference between a good juicy tomato and a small dry one, for example — goes a long way.”