Research HighlightsPioneering Protein Biostimulant Research in Soybeans
In this article, you’ll find details on:
- Biostimulants include categories of products comprised of biological components intended to stimulate growth or health responses in plants.
- Very little academic research has been done in the U.S. on protein hydrolysate biostimulants, made of protein waste from animal, fish or plant protein processing, especially on row crops.
- Greenhouse and research plot trials in Virginia provide the initial investigation into the potential for these biostimulants to impact soybean yield or protein content.
By Laura Temple
Biostimulants sound natural and trendy in agronomics. Biological components should promote plant growth or health. But do such applications actually stimulate plant growth to improve yield or composition?
That question intrigues Guillaume Pilot, an associate professor focused on plant molecular physiology at Virginia Tech. His basic research investigates how plants make, sense and use amino acids, the building blocks of protein that carry out plant functions.
“I started researching biostimulants after learning more about them from a colleague in France who was doing research on specific products for a company based in Spain,” Pilot says. “I learned that very little academic research has been done on these products in the U.S. Papers have been written about them on greenhouse crops like tomatoes and lettuce, but I decided to explore if they work in row crops.”
That decision makes him a pioneer, setting out into this unknown field. After starting work with corn in 2022, support from the Virginia Soybean Board allowed him to include soybeans for 2023, 2024 and beyond.
Pilot is collaborating with Carol Wilkinson, associate professor at the Virginia Tech Agricultural Research and Extension Center in Blackstone, Virginia. Wilkinson manages field plot trials, while Pilot focuses on greenhouse work and analysis. They are also working with Lori Snyder, an associate professor at North Carolina State University, who has been looking at biostimulants and seed quality, including germination and protein content. Together, they aim to learn if biostimulants can impact soybean yield and protein content, and if so, when and how they are most effective.
Types of Biostimulants
Biostimulants include a variety of categories.
- Microbial products include concentrations of live beneficial bacteria or fungi. Many of these naturally live in soils, but these products increase the concentration of specific species of microbes.
- Humic or other organic acids result from the extraction of soil organic materials. They promote plant growth through unknown mechanisms.
- Seaweed extracts contain concentrations of plant hormones, intending to promote plant growth and health.
- Protein hydrolysates come from waste proteins of animal, fish or plant protein processing.
Pilot’s team focuses on protein hydrolysate biostimulants, which naturally tie to his amino acid research. In the creation of these products, either chemical or enzymatic hydrolysis breaks down some of the chemical bonds to break the proteins into smaller pieces.
“The idea is that applying amino acids in the form of these biostimulants to a plant could affect or disturb how it senses the amount of nitrogen it has in a way that may make it distribute nitrogen better or extract more nitrogen or other nutrients from the soil,” he explains. “We’ve learned that amino acids are produced in veins rather than leaves, so adding them to the leaves could change communications within the plant and stimulate new responses.”
Plus, these products handle and store more easily than microbial products that contain living organisms.
“This also could become a way to upcycle food industry protein waste,” Pilot adds.
Starting from Scratch
Because no studies have been published about this category of biostimulants in U.S. row crops, Pilot and Wilkinson consider a wide range of factors as they develop greenhouse and small plot trials in Virginia.
Each year, their trials include four to seven diverse protein hydrolysate biostimulants with different ratios of amino acids, depending on their source. Products include a few developed from soybean meal, one from fish processing and one that was developed from slaughterhouse waste.
The products are all foliar, but application timing and method have not been exact or consistent, as they experiment with various options.
“We’ve focused on applying the products in a way that is compatible with current systems,” Pilot says. “We’ve made two applications in soybeans at various vegetative and reproductive growth stages, and up to three applications in corn.”
In addition to monitoring yield results, they are testing nitrogen content of plant stems, leaves and pods during both vegetative and reproductive stages. These analyses will indicate if applications improve nitrogen uptake or use efficiency. At the same time, Pilot has been looking at how the products influence soybean protein content in growth chamber conditions.”
“We didn’t see any yield or nitrogen content differences between treatments in 2023, but that was an ideal growing season for soybeans,” he reports. “We are still analyzing data from 2024, but we may see differences under less-than-optimal growing conditions.”
Pilot and Wilkinson saw lots of variability in the small plot trials, which may also have cloaked results. He says that they hope to include split field trials with grower cooperators during 2025, which may show any results better.
“We plan to continue this research for a few more years to explore different possibilities for application timing, various growing conditions and more,” he says. “We also plan to test whether biostimulants can help soybeans withstand drought. This is an emerging topic in the research on biostimulants, and, if successful, it could really help growers during dry years.”
Because this is such a new area to study, there is much to learn and share with others.
Additional Resources:
- Mid-Season Management from Science for Success – SRIN article
- Biological Seed Treatments: The Big Picture – SRIN article
- Meet the Principal Investigator on this project: Guillaume Pilot
Published: Dec 6, 2024
The materials on SRIN were funded with checkoff dollars from United Soybean Board and the North Central Soybean Research Program. To find checkoff funded research related to this research highlight or to see other checkoff research projects, please visit the National Soybean Checkoff Research Database.
