Recommendations for controlled-release fertilizer use from positive research trials says growers should customize their fertilization programs.

A recent three-year research trial into the use of controlled-release fertilizer (CRF) saw many positives for the use of CRF in citrus and a recommendation: one size does not fit all. According to a Citrus Industry article by Tripti Vashisth, an assistant professor at UF/IFAS CREC, the study tested different CRF and elevated micronutrient blends at two different sites, and found that a “constant supply and soil application of macronutrients and micronutrients can improve the health and productivity of HLB-affected citrus.” However, the results for each site were different, beyond showing that the CRF and micronutrient blends increased health and productivity. This led to recommendations for growers to customize their approach to using CRF and micronutrient blend applications. See them below.

Controlled-Release Fertilizer Recommendations

Vashisth gave the following tips for a ‘successful nutrition program;’

  • “The goal of a nutrition program should be a continuous availability of all nutrients to the tree year-round.
  • Right source, right rate, right time and right place are key for fertilizer application.
  • A nutrition program should be a combination of soil- and foliar-applied nutrients. Do not rely solely on foliar application for any nutrient.
  • Soil-applied nutrients are taken up by the plant with the water uptake; therefore, irrigation scheduling is important.
  • The placement of fertilizer (right place) is critical. It should be placed in the wetted zone since the uptake of nutrients occurs in a solution form.
  • Frequent leaf nutrient analysis is essential for an effective nutrition program as it helps in ensuring that the fertilizer program is meeting tree requirements.
  • The focus of a nutrition program should be on leaf nutrient levels and not on the rate of nutrient applied.
  • Optimal soil pH is critical for making nutrients available to the tree; the soil pH needs to be in the right range at the time of nutrient application.
  • If soil pH adjustments are made periodically, the fertilizer application should be coordinated to occur after the pH adjustment.”

Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions or concerns about your farm or pasture, contact us and one of our team will be in touch.