• Soybean is a major crop in US and Virginia agriculture and it is prized for the
quality of its seeds, rich in protein. Soybean is therefore an important feed to
poultry and swine. Breeding efforts have shown that increasing seed protein
content has often negatively impacted yields but have managed to steadily
increase yields by 0.5 bu./acre/year for the last 30 years.
• Biostimulants are a diverse class of products that are claimed to increase plant
growth and productivity through a few applications during the growing season.
Protein hydrolysates are one class of biostimulants, and are produced by
breaking down proteins from both animal and plant waste through industrial
processes.
• One of those protein hydrolysates has been shown in split-field trials by our
collaborators at North Carolina State University to increase soybean yields by
60% and, for one of the fields, increase seed protein content from 38 to 40%.
• The goal of this project is to test whether five protein hydrolysates, obtained
from various suppliers, are able to similarly increase yield and possibly protein
content using controlled field trials. In parallel, we will apply these protein
hydrolysates on soybean grown in the greenhouse to test whether their effect
resides in the promotion of the growth of the root system and nutrient
absorption from the soil.
• If successful, this project will lay the foundation for follow-up field and in-farm
trials that will identify effective products, their application rates and regimes,
together with the expected increase in seed yields and quality.
• The results of these trials have the potential to increase the revenue of soybean
growers in Virginia and the USA by >20% at a cost of potentially $20/acre.

The immediate goals of this project are to identify the ability of five PH
biostimulants to increase soybean growth. The long-term goals of the project is
to identify the effective PHs and their application rate and time that will reliably
increase yields.
• Objective 1 - Evaluate the potential of five protein hydrolysates to increase
yield and seed protein content in field conditions. Samples will be taken during
the vegetative growth phase to evaluate the effect of the protein hydrolysate on
nutrient uptake. At harvest, biomass production and seed yield and quality will
be determined.
• Objective 3 – Identify the major effect of protein hydrolysates on plant growth
in greenhouse conditions. The plants will be grown in pots until seed production.
During the vegetative growth, the effect of the protein hydrolysates will be
evaluated by measuring plant growth and nutrient content. At the end of the
experiment, above- and under-ground biomass will be separated and analyzed
independently for nutrient content and weight. The goal is to test whether any
protein hydrolysates have a root-growth promoting effect, which have been
postulated in the literature. This will help understanding how PHs work and
guide us in future tests; this information will also be useful to make better
recommendations to the producers.

The results of this project will directly lead toward improved soybean yields that
can be applied in on-farm tests in the 2024 growing season, with later
optimization of the application regimes and rates. This work will provide data
that will be summarized by treatment, synthesized and analyzed, and a report
will be prepared that contains the potentials of each PH on crop yield. This
report will be posted on the Virginia Cooperative Extension web site, and will be
available to growers and general public free of cost. The results will be
disseminated to growers during one field day and two producer meetings. The
findings will be published in peer-reviewed journals. These findings will be
utilized by producer to decide applying or not PHs to their field in future
growing seasons.
Our collaborators at NC State University will repeat their trials this year, enabling
us to compare our results with theirs. In the eventuality that our treatments have
no effect and theirs show a remarkable improvement, we will carefully compare
the conditions, treatments, soybean accession, etc. to assess the issue and
correct for the following year. Even such a negative result will be informative,
because it will most likely allow identifying possible causes of the PH having no
effect, and address them for the producers.