- UF/IFAS fertilization and liming recommendations are advisory in nature and emphasize efficient fertilizer use and environmentally sound nutrient management without losses of yield or crop quality.
- It is assumed the nutrients will be supplied from purchased commercial fertilizer and the expected crop yields and quality will be typical of economically viable production.
- Growers should consider UF/IFAS recommendations in the context of their entire management strategy, such as return on investment in fertilizer and the benefits of applying organic soil amendments.
- Indicated fertilizer rates plus the nutrients already in the soil will satisfy the crop nutrient requirement for this cropping season. Excessive fertilization has been shown to reduce vegetable quality.
- On soils that have not been in vegetable production within the past 2 years, or where micronutrients are known to be deficient, apply 5 lb Mn, 3 lb Zn, 4 lb Fe, 3 lb Cu, and 1.5 lb B/A. Use soil testing to monitor micronutrient status every 2 years to avoid micronutrient toxicity, because some micronutrients can build up in the soil. When deciding about micronutrient applications, consider micronutrients added to the crop via fungicides.
- Up to 40 lb/acre Mg might be needed when soil test is medium or lower in Mg. Mg can be supplied in fertilizer or from dolomitic limestone, when liming is recommended. Calcium concentrations are typically sufficient in most soils used continuously for vegetable production or where the Mehlich-3 Ca index is >300 ppm. Calcium is added during liming activities and from calcium carbonate present in irrigation water drawn from aquifers in Florida. These sources should be considered in the determination of Ca fertilizer needs.
Fertilizer Timing and Placement
For drip irrigation
|1Nutrient injection rate (lbs/ac/day)
|2Time period in the growing season
1Based on double-row cultural system with beds on 4-ft centers, with no preplant N or K.
2Planting date of October 1 and end-of-harvesting date of April 30. Totals may increase or decrease, depending on length of season. Strawberries can be planted as early as 25 September and harvested as late as the end of April in west-central Florida, depending on cultivars and market prices.
3These are the recommended total seasonal N and K2O rates. Some growers on high-organic matter soils may do well with less than 175 lbs N/acre, and other growers on sandy soils, prone to leaching, may require slightly more, but rarely more than 200 lbs/acre. Extra seasonal N applications should depend on plant leaf or petiole sap testing, leaching rainfall, or extended-season needs. K2O injection ranges shown are typical for soils testing low to medium in Mehlich-3 extractable K and no K applied preplant; the total of 150 lbs/acre K2O is for soils testing low in K.
4Some growers may choose to omit N fertilization until 2 weeks after turning off the watering-in irrigation system, and some growers who double-crop may elect to cease fertigation late in the spring when the strawberry plants are removed, resuming fertigation when the double-crop is planted.
5Strawberry cultivars have differing N requirements early in the season. Growers should choose N rates within the ranges shown in the table for the different periods in the season, that are appropriate for the particular cultivar, and that will target 175 lbs N/acre for the season. The lower N amounts in the range are adequate for those cultivars with moderate N demand and would easily become too vegetative with excessive N. Other varieties have a greater N demand, especially early in the season. Rarely is more than 0.5 to 0.75 lbs/acre/day N required in the last 60 days of the season when too much N can reduce fruit firmness and shipping quality under the warmer growing conditions.
For overhead irrigation
- Broadcast all the P2O5 and micronutrients, if any, and 25% of the N and K2O into the bed.
- Band remaining N and K2O in center of bed 3 inches deep
For subsurface irrigation
- Incorporate 10 to 20% of the N and K2O, plus all the P2O5 and micronutrients, if any, into the bed.
- Apply the remainder of the N and K2O 2 to 3 inches deep in one or more bands about 6 to 10 inches from the plants.
For management systems where both subsurface and drip irrigation are used
- Apply no more than 20% of the N and K2O, plus all of the P2O5 and micronutrients, if any, into the bed.
- Apply the remainder of the N and K2O periodically through drip tubes according to the rate of crop growth.
- Supply 25% to 50% of the N in the nitrate form if soils were treated with multipurpose fumigants or if the soil temperature will stay below 60°F for up to one week following transplanting or germination.
- 25 to 30% of the N may be supplied from slow-release N sources, such as sulfur-coated urea, polymer-coated fertilizers, or isobutylidene-diurea (IBDU).
- Fertilizer and water management are linked. Maximum fertilizer efficiency is achieved only with close attention to water management. Supply only enough irrigation water to satisfy crop requirements. Excess irrigation may result in leaching of N and K, creating possible plant deficiencies.
- For subsurface irrigation, maintain a constant water table between 18 (at planting) and 24 inches (near harvest) below the top of the bed. Monitor water table depth and do not fluctuate to avoid fertilizer loss below the root zone.
- AE354, “Automatic Irrigation Based on Soil Moisture for Vegetable Crops,” https://edis.ifas.ufl.edu/publication/AE354
- AE500, “How to Determine Run Time and Irrigation Cycles for Drip Irrigation: Tomato and Pepper Examples,” https://edis.ifas.ufl.edu/publication/AE500
- AE260/CV107, “Principles and Practices of Irrigation Management for Vegetables” https://edis.ifas.ufl.edu/publication/CV107
- Fertilizer rates suggested are for the first crop. Squash and cucumber following other crops on the same mulch may not need substantial additional fertilizer. If fertilizer is needed for the second crop, apply fertilizer using a liquid-injection wheel or via drip irrigation. Apply no more than 30 to 40 lbs/acre N and/or K2O in any single injection wheel application.
- Transplants may benefit from application of a dilute, soluble starter fertilizer, especially at cool soil temperatures. Starter solution rates of N and P2O5 need not exceed 10 to 15 lbs/acre each.
Circular 1141/CV003, “Fertilization of Strawberries in Florida,” https://edis.ifas.ufl.edu/publication/CV003