U.S. Growers Cautiously Optimistic About Biostimulants

Across the globe, farmers growing corn, wheat, soybeans and other row crops are increasingly using biostimulants in their efforts to increase yields — and makers of biostimulant products hope farmers will catch on.

Signs are positive. In April, for example, Monsanto and Novozymes announced the test of a new inoculant on Monsanto’s corn hybrid seeds sold in the U.S.


There are challenges. Biostimulants work differently than traditional crop inputs. A product that works for one farmer might not help another.

The USDA has recruited The Ohio State University and the University of Tennessee to test certain biostimulant products, to teach farmers how to evaluate products, and share that information with the industry.

U.S. Growers Cautiously Optimistic About Biostimulants


“We’re trying to cut through the noise and arrive at some consistently applicable practices, tools, and guidelines that growers can use when evaluating biostimulant material,” says OSU Professor Dr. Matt Kleinhenz, who is leading the USDA study.

Biostimulants also lack regulation. The EPA is drafting long-promised guidelines that manufacturers hope will more clearly define biostimulants, distinguish them from biofertilizers and biopesticides, and bring legitimacy and acceptance.

“There is a lot of snake oil in the biostimulant arena,” says Justin Smith, executive vice president of sales and field services for Huma Gro, the agricultural division of Bio Huma Netics, in Gilbert, Arizona. “A new regulatory framework would weed out companies doing that.”

Good Experiences
David Beaudreau, Jr., executive director of U.S. Biostimulant Coalition, a nonprofit that addresses regulatory and legislative issues related to biostimulants, says biostimulant adoption rates for corn, soybean, wheat, and cotton in the American Midwest have risen over the past five years.

According to a 2013 study by MarketsandMarkets, a global research firm, the amount of land containing row crops treated with biostimulants was expected to grow globally from 6.52 million hectares in 2011 to 12.745 million hectares in 2018, and in North America from 1.31 million hectares to 2.56 million hectares.

“It’s a matter of time before biostimulants come into more widespread use,” Beaudreau says. “The industry has been able to demonstrate the products work, and they work well.”

Marcus Meadows-Smith, CEO of BioConsortia Inc. in Davis, California, says his firm develops biostimulants using solid science. It grows plants in different soil types and under various stresses, including lack of water. Then the company identifies high-performing plants and isolates microbes that help them overcome adversity and thrive generation after generation.

Since it was founded three years ago, Meadows-Smith says, BioConsortia has tested biostimulants on pasture, corn, and several other crops in New Zealand, and realized yield increases in the 5% to 7% range. BioConsortia is now testing on corn, soybean, and sorghum in the Midwest.

Carlos Kee, research agronomist with Agricultural Sciences Inc. in Dallas, says his company produces biostimulant products from nonliving plant extracts. The products have been used on corn, wheat, and soybeans in South America. Kee believes biostimulants are just beginning to gain popularity in the U.S.

“A lot of people felt that if biostimulants didn’t bump yield up significantly, it wasn’t worth spending on them,” Kee says. “That’s a narrow look. If you can improve plant and soil health, you might not increase yield this year, but you’re saving yield down the road.”

Caution Remains
A collection of peer-reviewed academic articles, provided by Biostimulant Coalition, finds biostimulants help plants respond better to stress, prevent soil erosion, decontaminate soil and water, and improve yields. However, in some cases, research was done in labs, not in fields.

A study in Amman, Jordan determined that biostimulants applied to wheat crops from 1999-2003 in Saudi Arabia produced significant yield increases. A 2007 look at biostimulants used on turfgrass and ryegrass, presented by Crop Science Society of America, came up with positive results but nevertheless recommended caution when using certain biostimulants.

A January article published by Frontiers in Plant Science recommends additional study into biostimulants, adding that “commercial entities” will likely lead the way. The article says future studies and advancements wouldn’t happen if biostimulants were “not considered legitimate.”

Allen Philo, vice president of fertilizer sales and operations at BioStar Systems LLC in Overland Park, Kansas, is skeptical of biostimulants. Although his company specializes in fertilizer products, Philo gives lectures on soil biology and crop fertility. He spoke at the 2017 Midwest Organic and Sustainable Education Service conference.

Philo says some biostimulants — like cytokinins, which strengthen roots — have been well-researched and proven effective. In other cases, the same class of biostimulants that promote root health can kill a plant. The difficulty is finding the right dosages, which come in parts per billion.

“To try to get the right measure over an entire field could be a problem,” Philo says. “There have been successes, but there have been failures, too. Biostimulants are never a replacement for good, solid agronomy.”

Meadows-Smith knows some biostimulant companies fail to field-test products thoroughly in various soils.

“That’s where the next generation of biostimulants will have a big impact, as far as increased efficiency and yields,” Meadows-Smith says. “Already there are companies out there with products, and you will see more with better formulations.”

Empowering Farmers
In the study conducted by the USDA, which started last year and will end in August 2019, researchers will work exclusively with organic farmers to test the effectiveness of just six or seven microbe-containing biostimulants on tomatoes, butternut squash, lettuce, spinach, and carrots. The methods farmers learn to evaluate biostimulants can carry over to conventional growers and other types of crops and biostimulants, Kleinhenz says.

Further, the USDA study aims to form a network of farmers, manufacturers, scientists, educators, and consultant who will share information they glean about various biostimulant products.

Kee says government research will show that biostimulants can benefit row crops.

Meanwhile, Smith says the long-awaited EPA guidelines will guarantee that products have been reviewed, certified, and legally registered.