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Nutrient Management Program

Nutrient Management Program


General information

  • 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.
  • Recommendations assume that nutrients will be supplied from commercial fertilizer and expected crop yields and quality will be typical of economically viable production.
  • Recommendations assume straight fertilizers (single nutrient sources) will be used to apply nutrients. If multi-nutrient fertilizers will be used, the fertilizer analysis should align with recommended nutrient rate ratios.
  • Consider UF/IFAS recommendations in the context of the overall nutrient management strategy. Evaluate fertilizer rates, timing, placement, and source for efficiency and consider return on fertilizer investment.
  • If organic soil amendments are applied, understand and account for nutrient contributions and other benefits of adding organic matter.
  • For best results, follow these recommendations in their entirety. The UF/IFAS recommendation is a holistic combination of fertilizer rates plus nutrient management aspects including irrigation.

Fertilizer rates

Crop Plants/acre Target pH lbs/acre/cropping season


P2O5 K2O
        Low Med High Low Med High
Hemp for fiber 300,000 6.25 - 7.5 50 30 15 0 50 50 50
750,000 6.25 - 7.5 150 30 15 0 100 100 100
Hemp for seed 100,000

6.25 - 7.5

50 30 15 0 50 50 50
300,000 6.25 - 7.5 150 30 15 0 100 100 100
Hemp for flower 3,000 6.25 - 7.5 150 30 15 0 50 50 50
15,000 6.25 - 7.5 150 30 15 0 100 100 100
  • Maximum uptake of vigorous hemp crops has been demonstrated in trials outside of Florida to be 225 lbs N, 50 lbs P2O5, and 300 lbs K2O per acre (Kaur et al., 2023). Uptake of N at rates above those listed in the table have been demonstrated to be excessive under Florida conditions and result in a plateau or decline in plant production and crop quality.
  • Fertilizer applications of sulfur, calcium, magnesium, and other micronutrients may be identified through soil or leaf tissue tests. If sulfur is required, apply 15-20 lbs S/acre.

Fertilizer timing

  • Apply all the P2O5, 30% of the K2O, and 30% N in a preplant or at-planting application.
  • Apply the remaining K2O and N in one or two more side-dressings, spaced approximately 4 weeks apart.
  • Liquid fertigation can also be applied in weekly dosing for flower production under plasticulture up to 150 lbs N /acre equivalent.

Fertilizer placement

  • Consider banding the P2O5 next to the plant row.

Fertilizer sources

  • N applications have been studied as granular fertilizer, though operation efforts have been deployed in other trials involving enhanced efficiency (controlled release) fertilizer. Use of liquid fertilizer has also been effective (Anderson et al, 2021).
  • Apply S as sulfate (e.g., gypsum, ammonium sulfate, magnesium sulfate, potassium sulfate, potassium magnesium sulfate) because elemental S will convert to sulfate too slowly to supply the sulfur needs of the current crop.
  • Apply Mg using potassium magnesium sulfate or magnesium sulfate.

Water management

  • Seeds and transplants require adequate moisture at planting for optimum establishment.
  • Well-drained soils are preferred for hemp cultivation. Flooding exceeding 12-18 hours may substantially damage the crop and further expose it to disease.
  • Based on operational experience, ½- to 1-inch irrigation per week is appropriate for fiber and seed crops by overhead and flower crop through drip. Consider using a soil moisture meter and increasing irrigation as needed per plant growth and soil moisture.


Anderson, S.L. II, B. Pearson, R. Kjelgren, and Z. Brym. 2021. Response of essential oil hemp (Cannabis sativa L.) growth, biomass, and cannabinoid profiles to varying fertigation rates. PLoS ONE 16(7): e0252985.

Kaur, N., Z. Brym, L. A. M. Oyola, and L. K. Sharma. 2023. Nitrogen fertilization impact on hemp (Cannabis sativa L.) crop production: A review. Agronomy Journal, 00, 114.

Other Resources

SL476 “Hemp Fertilization: Current knowledge, gaps and efforts in Florida: A 2020 Report.” (