Project Overview
Soil salinization due to saltwater intrusion threatens cotton production in eastern North Carolina, and high soil salinity due to other environmental stressors (e.g., drought, over fertilization) is increasingly impacting cotton producing regions globally. Although cotton is relatively salt-tolerant, moderate-high salinity levels have detrimental impacts on yield. Beyond conservation land management practices and crop selection, there are few short-term solutions available to farmers (NC State Extension Publication AG-439-89). Biostimulants, including beneficial microbial inoculants, are a promising class of agricultural inputs that may alleviate salinity stress and maintain crop yield. The goal of this project was to evaluate the performance of Concept Agritek biostimulant products on cotton production in salt-impacted fields in Hyde County.
Methods
Salinity Mapping
We identified a field site in Hyde Country that historically experienced high soil salinity due to saltwater intrusion for the trial. We used a DualEM sensor pulled behind an ATV to map ECa (apparent electrical conductivity). ECa mapping revealed two salinity ranges (Figure 1a); 0.063-0.68 decisiemens per meter (dS/m) (indicating low salt with no impact on plant growth) and 0.681-2.03 dS/m (indicating high salt with impact on plant growth). Across the field, values ranged from 0.047-1.156 dS/m with an average value of 0.518 dS/m. Standard soil salinity measurements for both fields are reported in Table 1 (average of 10 composite soil samples per field).
ECa map with green regions indicating no salt impact on plant growth (0.063-0.68 dS/m) and yellow regions indicating moderate salt impact on plant growth (0.681-2.03 dS/m). Red shapes are areas with highest salinity. Split-field design with alternating Treated and Untreated strips.
| Field | 1:2 EC (dS/m) | SSI | SAR | ESP |
|---|---|---|---|---|
| High Salinity | 1.47 | 147 | 1.78 | 31.4 |
| Low Salinity | 0.31 | 30.9 | 0.68 | 11.8 |
Field Trial Installation
Cotton (DP2211B3TXF treated with Acceleron insecticide) was planted (approximately 44,000 plants/acre) on 6/25/2025 using a split field (i.e., "high" salt and "low" salt field), strip trial design with alternating Treated and Untreated strips (Figure 1b). Each strip was four rows with 30” spacing between rows and 7’ spacing between strips. The high salinity field had 8 Treated and 7 Untreated strips, and the low salinity field had10 Treated and 10 Untreated strips.
Biostimulant treatment included a combination of Concept AgriTek products design to enhance crop performance in high salinity soils (Table 2). Products were applied at the manufacturer’s recommended rates and included Buncha Bugs DF (beneficial microbial consortia) at 1 oz per acre, Biovate XP (plant micronutrient) at 16 oz per acre, and SaltX (soil amendment) at 4 gallons per acre. Immediately prior to planting, 2 x 10 oz packages of Buncha Bugs DF were added to 2.5 gallon of BiovateXP. The solution was applied in furrow at 10 gallons per acre by mixing 10 gallons of water with 16 oz of biostimulant mixture. SaltX was applied 2 x 2 at 20 gallons per acre by mixing 16 gallons of water with 4 gallons of biostimulant.
| Product | Formulation | Description | Application Rate |
| Buncha Bugs DF | Bacillus mucilaginous (1.1x108 CFU/g); Bacillus subtilis (6.8x107 CFU/g); Bacillus megaterium (3.4x107 CFU/g); Bacillus licheniformis (3.4x107 CFU/g); Bacillus simplex (3.4x107 CFU/g); Glomus intraradices (95 ppg/g) | Beneficial microbial consortia |
1 oz/acre (planter); 2 oz/acre (fertigcation) |
| BiovateXP | Cobalt (Co) 0.01%; Manganese (Mn) 0.05%; Other water-soluble Mn (0.05%) | Plant micronutrient | 16 fl oz/acre (planter); 32 fl oz acre (broadcast or fertigation) |
| SaltX | Manganese (Mn) 0.05%; Humic Acid 12% (derived from earthworm castings) | Soil amendment | 0.5-4 gal/acre (broadcast) |
Results
Stand Count
Cotton emerged 5 days post-planting, and stand count was determined approximately 3 weeks post-planting. Stand count was significantly higher in the low salinity field (average 40,123 plants/acre) compared to the high salinity field (23,178 plants/acre) (p-value < 0.001), but within each field there was no difference in stand counts between Treated and Untreated strips (Figure 2). Since soil salinity was "patchy" in the high salinity field, for each strip we also determined stand count in a segment determined “salt-impacted” and a segment determined “salt-unimpacted.” While we observed higher stand counts between salt impacted (average 12,044 plants/acre) and unimpacted (average 34,311 plants/acre) segments (p-value < 0.001), biostimulant treatment had no impact (Figure 3).
Cotton Yield
At the trial conclusion, there was not enough biomass to harvest the high salinity plot. For the low salinity plot, Treated and Untreated strips were combined and harvested on 11/7/2025. Yield for Untreated was 367.5 lb/acre and Treated was 370.2 lb/acre.
Main Takeaways
- Fine-scale ECa field mapping can be an effective tool for crop rotation and variety selection decision making.
- Soil salinization resulted in significant reduction of cotton stand count and yield.
- Under the study conditions, the combination of Concept AgriTek biostimulant products (including a beneficial microbial seed treatment, plant micronutrient solution, and soil amendment) had no impact on cotton stand count compared to untreated controls.
- More data is required to determine if the combination of Concept AgriTek biostimulant products results in higher cotton yield in low salinity soils.
Acknowledgements & Disclaimers
The project was led by Dr. Mallory Choudoir, Dr. Matthew Ricker, and Andrea Gibbs. Additional collaborators include Isabella Borrero, Madaris Serrano Perez, Julia Janson, Rod Gurganus. This project was funded by the North Carolina Cotton Producers Association, Inc. and the growers and importers of upland cotton. We are extremely grateful to Tooley Farm for their collaboration and support. We would also like to thank Dark Water Enterprises, Inc. (Pantego, NC) for donating the products used in the trial.
The use of brand names and/or any mention or listing of specific commercial products or services herein is solely for educational purposes and does not imply endorsement by North Carolina State University or our partners, nor discrimination against similar products or services not mentioned.
