In recent years, sweet corn production has gained momentum in the Suwannee Valley and Gilchrist County, as rising costs in South Florida have pushed growers north and local producers look to diversify beyond traditional staple crops such as watermelon, peanuts, and field corn. As new crops move into the region, especially in environmentally sensitive areas like the areas surrounding the springs of Gilchrist County, so do new nutrient management challenges. Sweet corn, a high nitrogen user, requires close attention to fertilizer application methods, timing, and placement to minimize nitrogen loss in the sandy soils and protect water quality.
One of the region’s largest sweet corn producers is helping lead the way in exploring ways to more efficiently use nitrogen. Located near the well-known Ginnie Springs and within a Priority Focus Area designated under Florida’s Basin Management Action Plans (BMAPs), this grower has worked closely with UF/IFAS Extension, Gilchrist Soil and Water Conservation District (GSWCD), Florida Department of Agriculture, Office of Ag Water Policy (FDACS-OAWP, Suwannee River Water Management District (SRWMD), and industry partners to conduct a series of on-farm fertilizer trials. This farmer’s efforts show how technical support, conservation partnerships, and equipment upgrades can work together to reduce nitrogen losses while maintaining crop productivity.
Extension Support Drives On-Farm Change
The collaboration began in 2022, when conversations between the producer and Gilchrist County Extension Agent Tyler Pittman laid the foundation for an on-farm demonstration focused on improving nitrogen management in sweet corn. With support from UF/IFAS Extension, the GSWCD, FDACS-OAWP, and the SRWMD, the grower began exploring practical ways to enhance fertilizer efficiency and protect water quality in a region known for its vulnerable springs.
In the spring of 2023, the grower participated in an 18-acre demonstration trial testing a controlled-release fertilizer (CRF) product developed in collaboration with GSWCD and an industry manufacturer. CRF is designed to release nitrogen slowly over time, better lining up with crop uptake and reducing leaching into groundwater. The initial application was made pre-plant using the farm’s existing side-dress equipment, but it became apparent that the applicator wasn’t ideal for banded granular CRF applications. The product was being broadcast too far into the row middles, failing to deliver nutrients close enough to the plant. That spring season crop required supplemental fertigation later in the season, and ultimately, the original trial plans were abandoned so to not lose the crop’s quality.
Instead of calling it quits, the grower and project partners saw it as an opportunity for further improvement and research. With support from SRWMD’s cost-share program, the grower retrofitted their side-dress applicator with coulters, allowing for more precise fertilizer placement by banding the fertilizer directly into the soil alongside the plant. This targeted application not only reduced the risk of nutrient losses but also eliminated the need for one of the three side-dress passes the grower would typically apply, saving time, labor, and fuel.
The upgraded equipment was first used with the grower’s conventional fertilizer program to validate its effectiveness. Encouraged by the improved placement and reduced input costs, the team moved forward with a second small CRF trial in the fall 2023 season on another 18-acre block. This time, the CRF was applied two weeks after planting using the upgraded applicator, improving both timing and placement. As a result, the crop required little supplemental fertigation, yielded similarly to the farm’s standard program, and used roughly 100 pounds less nitrogen per acre than was previously
used prior to any trial work! Motivated by the trial’s success, the grower extended this new placement approach across their entire 400-acre fall crop of sweet corn, lowering conventional nitrogen fertilizer rates and relying on the upgraded applicator for all fertilizer applications.
By the spring of 2024, the grower had expanded the CRF trials to 30 acres and applied the reduced nitrogen rates using conventional nitrogen sources across the rest of their 470-acre spring sweet corn crop using the same targeted application method. In addition to fertilizer efficiency, the operation began testing additional best management practices (BMPs), such as planting cover crops during the off-season and implementing strip-till and no-till planting practices, setting them up for long-term improvements in soil health and nutrient use efficiency.
Though CRF has not yet been adopted by this farm due to increased cost, the combination of upgraded equipment, better fertilizer placement, and adjusted nitrogen rates have shown impressive results. The 2023 CRF trials alone reduced nitrogen inputs by 2,520 pounds across 36 acres. The equipment upgrades also allowed for reductions of 60 pounds of nitrogen per acre in the spring and 80 pounds per acre in the fall, resulting in an estimated nitrogen savings of 50,960 pounds across both seasons. These changes also translated into financial savings in fertilizer for the grower totaling nearly $81,000!
Successful BMP Adoption in Sweet Corn
This demonstration highlights the importance of collaboration among producers, Extension agents, conservation districts, departments of agriculture, and water management agencies when it comes to adopting BMPs. While sweet corn has been a part of the region’s agricultural makeup for many years, its growing popularity makes the results from these trials especially valuable for growers facing today’s nutrient management demands. In areas where water quality is closely tied to agricultural practices, especially near vulnerable springs, the shift to more targeted fertilizer approaches is both beneficial and essential. With Extension support, financial cost-share assistance, and a willingness to try something new, this grower has shown that real, measurable nitrogen reductions are not only achievable, but profitable too.
Authors: Sydney Williams, Tyler Pittman, Joel Love, Bob Hochmuth, and Taite Miller
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