Jay Capasso, Vivek Sharma, Paulette Tomlinson, and Erin Dasher
Introduction
North Florida’s Suwannee Valley is an agriculturally productive region for crops, including corn, peanuts, watermelon, and carrots. The region is also home to the highest concentrations of freshwater springs in the world, which serve as major tourist and recreational sites.
The region has very sandy soils, so water and the nitrates dissolved in it percolate quickly through the root zone, making it difficult to keep nutrients available for crops and out of the groundwater. Meeting water quality targets, such as those established through basin management action plans for the Santa Fe and Suwannee River, has become an important issue for the agricultural industry and state regulators.
UF/IFAS scientists at the North Florida Research and Education Center–Suwannee Valley launched in 2018 the Sod-Based Rotation Project, funded by the Florida Department of Agriculture and Consumer Services. Over 16 years, the study will compare five zones under a center-pivot irrigation system. Each zone follows a distinct crop rotation, ranging from the conventional peanut-corn cycle to a peanut-corn-carrot rotation. Two of the rotations also include a two-year phase of bahiagrass pasture with cattle grazing before the rotation returns to row crops.
By tracking soil nitrogen at multiple depths, plant uptake, yields, and modeling results, the project will demonstrate how much a sod rotation and the implementation of best management practices increase yield and conserve nitrate in the root zone.
After just a single 4-year cycle, the rotations including 2 years of sod are already demonstrating improvement to the soil at the project site (Acharya & Sharma, 2025):
- Increased water-holding capacity: in the top six inches of soil. In North Florida’s quick-drying sandy soils, that added water-holding capacity means moisture from rainfall and irrigation events last longer in the soil, increasing the field’s drought resilience.
- Higher aggregate stability: a key indicator of physical soil health.
- Evidence of less deep percolation: suggests less nitrate leaching potential.
The project has just entered Phase Two, where best management practices, including split nitrogen applications, controlled-release fertilizers, efficient fertilizer placement methods such as banding, and soil moisture sensor-guided irrigation, are included in each rotation.
Take Away for North Florida Farmers
Sod-based rotations provide many benefits, including reducing plant disease and pest pressure on row crops, thereby boosting yields. Perennial grasses also have deep roots that can build soil organic matter over time, increasing soil water-holding capacity and nutrient content. Grazing offers additional advantages for soil health by increasing rooting, cycling nutrients, and enriching the land’s microbial diversity. Growers should take into consideration that perennial grasses produce considerable residue and are challenging to kill. Generally, it is recommended to apply herbicide to the Bahia grass and overseed with a winter cover crop in the fall before transitioning to a row crop, such as peanuts or corn. These steps will allow time for the Bahia grass residue to break down.
The Dry Corners
The research sites “dry corners” refer to the areas surrounding the center pivot irrigation system that do not receive irrigation. They have become valuable sites for extension forage demonstrations. Local County Extension agents Paulette Tomlinson from UF/IFAS Extension Columbia County and Erin Dasher from UF/IFAS Extension Suwannee County have led several educational field day events to teach producers about forage, grazing, weed, and nutrient management.
References
1
