General information
- UF/IFAS fertilization and liming recommendations are advisory and promote efficient fertilizer use and environmentally sound nutrient management, all without sacrificing yield or crop quality.
- Recommendations assume nutrients come from commercial fertilizers, with expected crop yields and quality typical of economically viable production.
- Recommendations presume the use of straight fertilizers (single-nutrient sources). If multi-nutrient fertilizers are used, the analysis should match the recommended nutrient ratio rates.
- Consider UF/IFAS recommendations within the broader nutrient management strategy. Evaluate fertilizer rates, timing, placement, and sources for efficiency, and weigh the return on fertilizer investment.
- When applying organic soil amendments, understand and include their nutrient contributions and other benefits of adding organic matter.
- For optimal results, follow these guidelines entirely. The UF/IFAS recommendation is a comprehensive approach combining fertilizer rates with nutrient management practices, including irrigation.
- Growers should incorporate UF/IFAS recommendations into their overall farm plan, considering fertilizer costs and the benefits of adding organic materials to the soil.
Corn production in Florida requires careful nutrient management tailored to the state's sandy soils and climate. The following recommendations encompass soil testing, pH management, and fertilization strategies for field corn's nitrogen, phosphorus, potassium, secondary nutrients, and micronutrients. Emphasis is given to the new interim UF/IFAS nitrogen recommendation of 1.37 lb N required per bushel of corn (approved September 3, 2025) for high-yield irrigated corn. These guidelines will help maximize yield while maintaining environmental stewardship.
Fertilizer Rates
Table 1. Soil test-based fertilizer rates for corn (lb/acre/year).
|
Irrigated corn |
Target pH |
N |
P2O5* (Low) |
P2O5* (Medium) |
P2O5* (High) |
K2O** (Low) |
K2O** (Medium) |
K2O** (High) |
|
For 30,000 plants/acre |
6.5 |
See the table 2 below |
175 |
70 |
0 |
175 |
70 |
0 |
*Low, medium and high P2O5 indicates ≤25, 26-45 and >45 mg P/kg soil, respectively
**Low, medium and high K2O indicates ≤35, 36-60 and >60 mg K/kg soil, respectively
Source: 1. Mylavarapu, Obreza, Morgan, Hochmuth, Nair, and Wright. 2014. Extraction of Soil Nutrients Using Mehlich-3 Reagent for Acid-Mineral Soils of Florida. https://edis.ifas.ufl.edu/ss620
- Mylavarapu, R., Wright, D., & Kidder, G. (2021). UF/IFAS standardized fertilization recommendations for agronomic crops (SS163/SL129, rev. 10/2021). Soil, Water, and Ecosystem Sciences Department, UF/IFAS Extension. https://doi.org/10.32473/edis-ss163-2021
Table 2. Yield goal-based nitrogen recommendations for corn production in Florida.
|
Yield potential (bushels/acre) |
N Rate (lbs /acre)*** |
|
100 |
137 |
|
150 |
206 |
|
200 |
274 |
|
250 |
343 |
***Indicates nitrogen rates expected to satisfy the crop's seasonal nitrogen requirement. Excessive nitrogen applications do not increase yield. Other nutrients should be applied on a soil-test basis for balanced fertilization.
Corn in Florida needs 20-30 lb sulfur/acre, applied as sulfate and often supplied by N sources. Zinc and manganese may be used at 2-3 lb /acre only if soil tests indicate a need (avoid excess zinc if rotating with peanuts). Boron should be applied at 1 lb /acre in split doses with N. See Field Corn Production Guide (https://edis.ifas.ufl.edu/publication/AG202) for more secondary nutrient guidance.
Fertilizer Timing and Placement
Phosphorus and Potassium: Apply all the phosphorus as a starter fertilizer. Potassium is generally broadcast preplant or in pre- and post-plant applications. Broadcasting is less labor-intensive and efficient on medium-fertility soils, but research shows that banding P and K can reduce rates by about 25% while maintaining or improving yields.
Nitrogen: Apply nitrogen in split applications (equal to or more than 7 splits total). A portion of N (approximately 30 lb N/acre) may be applied at planting as a starter fertilizer, placed two inches below and two inches to the side of the seed ("2×2 placement"), which typically supplies about 10-15% of the corn's total N requirement. If N is applied through the irrigation system, use the same amount, i.e., 30 lb/acre at planting, then make a side dress of 30 lb N/acre when the corn is 12-15 inches tall. The remainder should be injected through the irrigation system weekly or biweekly, depending on the crop growth stage, and divided into 5-8 applications, with all N applied by tassel emergence (VT). Splitting N fertilizer through the vegetative period improves N use efficiency and reduces leaching risk in Florida's sandy soils.
Water Management
Corn requires about 20-24 inches of water per season (rain + irrigation), with demand peaking at tasseling and grain fill. The crop is most vulnerable to moisture stress from tasseling through the dough stage, when even brief droughts can cause 20-50% yield loss, making timely irrigation essential. If excessive rainfall leads to nitrogen leaching, growers may apply a supplemental 30 lb N/acre rescue application under FDACS Office Agricultural Water Policy BMP guidelines (https://www.fdacs.gov/Agriculture-Industry/Water/Agricultural-Best-Management-Practices). Using a soil moisture sensor could help manage water in the soil profile, along with better N management.
Interim Recommendation: Nitrogen (N)
Based on UF/IFAS yield trials, corn requires about 1.37 lb of N per bushel of expected yield. For field corn in Florida, the UF/IFAS Plant Nutrient Oversight Committee (PNOC) has approved an interim recommendation of 1.37 lb of N needed per bushel of corn (2025) (see Table 2 for your potential yield target and N requirement). Applying rates above this level offers no yield gains and increases the risk of leaching and unnecessary costs.
Footnotes 104 and 124 in UF/IFAS Standardized Fertilization Recommendations for Agronomic Crops (https://edis.ifas.ufl.edu/publication/SS163) still apply.
References
Wright, D., Small, I., Mackowiak, C., Grabau, Z., Devkota, P., & Paula-Moraes, S. (2020). Field corn production guide (SS-AGR-85). University of Florida, IFAS Extension. https://edis.ifas.ufl.edu/publication/AG202
Mylavarapu, R., Wright, D., & Kidder, G. (2021). UF/IFAS standardized fertilization recommendations for agronomic crops (SS163/SL129, rev. 10/2021). Soil, Water, and Ecosystem Sciences Department, UF/IFAS Extension. https://doi.org/10.32473/edis-ss163-2021
Mylavarapu, Obreza, Morgan, Hochmuth, Nair, and Wright. 2014. Extraction of Soil Nutrients Using Mehlich-3 Reagent for Acid-Mineral Soils of Florida. https://edis.ifas.ufl.edu/ss620