Evaluating soybean variety performance and response to deer grazing
Sustainable Production
Abiotic stressAgricultureLand Use Water supply
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Luke Macaulay, University of Maryland
Co-Principal Investigators:
Nicole Fiorellino, University of Maryland
James Lewis Jr, University of Maryland
+1 More
Project Code:
Contributing Organization (Checkoff):
Institution Funded:
Brief Project Summary:
Protecting soybeans from deer damage can be complex, due to great variation in fields, the environment and even deer behavior. However, bare spots along timberlines and yield maps provide plenty of evidence that damage from deer can be costly. Farmers should take an integrated pest management approach to protecting their crops from deer. IPM tools for deer management include fencing, repellants, vegetation management and hunting. This project explored more about how forage soybeans provide a vegetative management tool, including how and where they have the greatest potential to limit deer feeding on commodity soybeans.
Key Beneficiaries:
#agronomists, #Extension agents, #farmers, #hunters, #soybean breeders
Unique Keywords:
#deer, #deer management, #environmental stress
Information And Results
Project Summary

We will use a randomized complete block design on up to five soybean varieties in fields bordering forested areas with long-term historical deer grazing pressure. We will place a 5-10’ diameter hog-wire deer exclosure on each plot and use trail cameras to quantify deer grazing activity by varieties (Fig. 2). We will focus the experimental effort at the Wye Research & Education Center, and will provide demonstration seeds of forage varieties at a collaborating farmer’s fields in Caroline County, MD, and near Harrington, DE, to evaluate performance of these varieties in different soil types and with different deer populations, for a total of up to 25 acres of planting.

Project Objectives

1) what varieties of soybeans can produce the best yields under heavy herbivory,
2) what varieties can best withstand deer grazing,
3) what varieties can attract deer away from conventional crops, and
4) estimate the costs and potential benefits of using particular varieties to attract deer away from conventional crops.

Project Deliverables

Progress Of Work

We have planted randomized complete block trials in two fields at the Wye Research & Education Center, and provided seed to two farmers who have planted forage or late variety soybeans for individual testing. We have held a field day for the Wildlife Subcommittee of the Maryland Farm Bureau on 7/20/21 and presented a poster at the Maryland Commodity Classic on 7/22/21. We have flown drone imagery of the fields. Heavy deer herbivory is occurring on our plots as expected, and we are documenting plant growth with drone imagery, and deer activity with camera traps. Recent poster presentation at the Commodity Classic is attached.

View uploaded report PDF file

We have completed gathering data for the project and have analyzed the data and harvest and analysis of data and presented it to the Maryland Farm Bureau (~50 attendees), a webinar for Lower Shore farmers (~20 attendees, hosted by Meaghan Perdue), at the Talbott County Corn Club (~50 attendees) , and to the University of Maryland Extension monthly administrative meeting (~200 attendees).

I am attaching a brief presentation given to the Talbott Corn Club in late January 2022 that shows our high level results and conclusions. I am soliciting funding to continue this work for a second year to have greater certainty about our findings and to better understand deer preferences and increase demonstration seeding. I anticipated drafting a peer-review article on our findings after a second year's data has been gathered.

View uploaded report PDF file

Final Project Results

Please see attached report.

View uploaded report PDF file

We developed a more detailed understanding of the patterns of deer grazing on soybeans and how these patterns are influenced by precipitation, and gained better insights into yields that can be expected from 3 different forage soybean varieties and how they compared to two conventional soybean varieties. We found that group 5 soybeans produced the highest yields under moderate deer grazing, with the highest yields from a conventional 5.3 soybean, which yielded 54.1 bushels/acre, followed closely by a group 4.7 forage soybean. The latest maturing group 7 forage soybean yielded only 36.4 bu/acre, but may have served to attract deer away from other varieties when they would have been most vulnerable to yield losses from deer grazing. In terms of deer grazing patterns, we documented that 74% of grazing activity occurred at night, with 44% of all grazing activity occurring in just five days of June and July (fig. 2). Statistical analysis of precipitation patterns found that grazing was significantly affected by rainfall events, with decreased grazing activity during rainfall events, increasing grazing activity one day following rainfall, and even greater grazing activity the second day after rain (see table 2 and fig. 3).

Benefit To Soybean Farmers

Deer are the leading cause of crop damage by wildlife in Maryland, with most recent government estimates showing approximately $10 million in losses annually, with 77% of those losses attributable to deer (USDA NASS 2011). Maryland in particular faces greater challenges than many other soybean growing areas in the country due to smaller field sizes that are more often interspersed with and bordered by forested areas that provide refuge for deer, which emerge to graze highly palatable and nutritious soybeans. Farmers have regularly identified deer and wildlife damage as one of their top concerns, and frustrations by farmers are well documented in news media articles. Soybean yields in 2020 in certain fields at the Wye Research & Education Center in Queenstown, MD, were reduced by 20-30 bushels per acre in a field bordering a forested area (Fig. 1). While hunting and crop damage permits allow some farmers to reduce deer population densities, some locations are not amenable to this due to factors such as landowners or neighbors that do not allow hunting, nocturnal grazing activity, and time required to harvest sufficient numbers of deer. Past research has yielded promising early results of using forage soybeans as a kind of ‘biological fence’ around a field perimeter to reduce damage to crops. This project seeks to build upon that effort by focusing on evaluating deer preferences of different varieties of soybeans and those soybean variety’s ability to recover from grazing. With this effort we seek to draw deeper insights into the most economical approaches for growing soybeans in fields with high deer grazing pressure.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.