Academic research from across the US has shown that the response of biological products to improve plant function has potential to improve soybean yield in certain soil types. This project aims to quantify the yield benefits of planter in-furrow and foliar applied biological products in coastal plain soils. Up to 15 products will be tested in a replicated block design. Final yield will be analyzed to determine the potential benefits the products. The economics will be shared with farmers at grower meetings, DE Ag Week, Mid-Atlantic Crop School, in print and online.

1. Evaluate yield benefits of biological technologies that claim to improve the crops ability to process nutrients.
2. Disseminate the research results to Mid-Atlantic farmers.

An intensive study will be conducted to determine the response of corn to the use of biological products applied at planting. Each product will be tested in replicated blocks and will be conducted under a variable rate two tower linear irrigation (VRI) system located on the University of Delaware’s Warrington Irrigation Research Farm in Harbeson, DE. The entire study area will be treated identically for all production inputs except biological product applied. A high yield potential variety suitable for irrigated production will be selected. Fertilizer will be applied based on the University of Delaware recommendations for irrigated soybean production at 80 bu expected yield.
A maximum of 15 biological products plus a control will be applied with the planter via an in-furrow liquid injection system or foliarly with a broadcast spray. Each product will be mixed with water for a carrier to avoid the mixing or bacteria survival issues possible with fertilizer solutions.
This study will be harvested using a plot combine measuring test weight, moisture and yield for each plot.

Updated January 2, 2025:
Evaluating Soybean Yield Response to In-Furrow & Foliar Biologicals
Final Report
Principle Investigator: James Adkins -UD


Abstract:
Research across the U.S. has shown that biological products may enhance plant function and improve corn yields in specific soil types. Similarly, applications of carbon and other microbe “food sources” are theorized to stimulate native soil biology and produce comparable yield gains. This study evaluated the yield impacts of in-furrow and foliar-applied biological and supplemental products in coastal plain soils. Eight products(one with varied application timings) for a total of 10 treatments were tested in randomized 600-foot strips using a 6-row JD 7200 planter equipped with an in-furrow liquid application system. No statistically significant yield differences were observed in the rainfed or irrigated plots.

Procedure:
This study assessed the effects of soil biology-enhancing products on soybean yields under controlled conditions at the University of Delaware’s Warrington Irrigation Research Farm. Products were tested in replicated blocks with irrigation rates applied perpendicular to planting patterns (Images 1 & 2). Uniform inputs were used across the study, with variations limited to biological product applications. A Gleaner K2 combine with a Harvest Master system was used to collect plot weights, moisture, and test weight data from 270 plots under lateral move overhead irrigation (Image 3). The plots were no till planted behind last year's corn crop without cover crops.


Image 1: Infurrow product randomization Image 2: Perpendicular 90’ Irrigation Zones

Table 1. Field Operations, nutrient and pesticide applications.
April 24 VRT Dry Spread Potash & MAP 0-315lbs/a
May 16 Pre-emerge Herbicide Broadaxe & Metribuzin 22 oz/ac
June 12 Plant 6 row JD 7200 Axis 4513E 140k seeds/a
June 19 Post Emerge Herbicide Gly & Liberty 32 oz/a
June 19 Early Foliar Application Terramar + Radiate 1 qt/a
July 2 Late Foliar Application Terramar + Radiate 1 qt/a
Oct 7 Corn Harvest Gleaner K2




Image 3: 2024 Harvest of 270 Biological Plots Image 4: Aug 23 Imagery showing Irrigation

Results:



Figure 1. Soybean Yield by Treatment Figure 2. Soybean Yields by Irrigation
Note: Yield differences not statistically significant. Note: 28.7 bu/a Rainfed vs 71.7 bu/a Irrigated


Figure 3. Irrigated Yield by Product

Figure 4. Rainfed Yield by Product
The 2024 season was unusually dry requiring a total of 10.5 inches of irrigation from May 24 through September 20th. The rainfed plots were extremely stressed with dramatic differences in NDVI values between the irrigated and non-irrigated areas in the weekly aerial imagery. No differences were distinguishable between the individual products at any point throughout the season.
Conclusions:
This study demonstrated no yield benefit from using biological products under the tested conditions. Although none of the products hurt yields, none of the products showed a statistically significant impact on yield. Given these findings, farmers are unlikely to achieve positive returns from these products, even if they are cost-free. Results suggest that the efficacy of biological enhancements remains highly dependent on specific environmental conditions and cannot be generalized across broader applications.

This study demonstrated no yield benefit from using biological products under the tested conditions. Although none of the products hurt yields, none of the products showed a statistically significant impact on yield. Given these findings, farmers are unlikely to achieve positive returns from these products, even if they are cost-free. Results suggest that the efficacy of biological enhancements remains highly dependent on specific environmental conditions and cannot be generalized across broader applications.

The constant bombardment of advertising and aggressive marketing of biological products have made it very difficult for farmers to measure the benefits. This project aims to determine the real economic return for biological technologies for corn production in the Mid-Atlantic.
This project has the potential to increase farm profitability through enhanced yield and reduced fertilizer costs. Additional environmental and soil health benefits are possible but beyond the scope of this project.