In 2022, state funding finally allowed the UF/IFAS Nutrient Management Program (NMP) to respond to the long-standing request from Florida citrus growers for updated recommended fertilizer rates for citrus. Florida citrus growers have long been calling for updated science-backed fertilizer rates that reflect the realities of the current citrus industry concerning citrus greening, also known as HLB. Growers have been concerned that long-ago established rates did not take into consideration the challenges created by citrus greening (HLB) as the rates were established prior to the arrival of the disease.
The UF/IFAS NMP has been conducting the research to create updated fertilizer recommended nutrient rates for 14 Florida crops for the past two years, and the science is starting to yield results. All in all, more than 60 scientists have been working on 19 research projects in the Sunshine State. The research will have an array of benefits for Florida ag and Florida citrus growers, including aligning with the 4Rs.
Details of the Research
The research is being conducted at an array of locations, both at private locations with privately owned machinery and at UF/IFAS research facilities; it’s a purposeful action to have as many different sites as possible to get an array of data.
Researchers are studying the application rates for the key macronutrients nitrogen, phosphorus, and potassium in order to create nutrient recommendation rates. Citrus is not the only crop that is being researched; other crops include corn, cotton, potato, watermelon, snap beans, tomato, peaches, limpograss, and hemp.
Benefits of Updated Nutrient Rates
The benefits of the research to create updated fertilizer rates are numerous. Firstly, as mentioned for citrus, the nutrient rates will take the challenges created by citrus greening (HLB) into account. Nutrients have been found to be an important component in combating the decline in infected citrus trees that is seen with citrus greening (HLB) infection. The current recommended nutrient rates are based on citrus cultivation prior to the arrival of citrus greening, and they just don’t reflect the realities of the Florida citrus industry anymore.
Additionally, the new recommended nutrient rates are also being crafted with an eye towards precision fertilizing using precision application machinery, using controlled-release fertilizers, and reducing runoff and leaching of excess nutrients into the surrounding soil and waterways; these efforts align with the 4Rs of nutrient stewardship—using fertilizers from the Right source, at the Right rate, at the Right time, and in the Right place—to be economically, socially, and environmentally beneficial when using nutrients. The 4Rs are technically part of Florida’s citrus Best Management Practices, though they are not named as such. Coincidently, the research for updated nutrient rates for citrus also coincides with plans to update the state’s best management practices (BMPs) manual for citrus.
Lastly, the new recommended nutrient rates will also address another citrus grower concern: that recommended rates don’t take into account the differences in groves based on location, soil type, row spacing, seed varieties, irrigation practices, planting densities, and more.
Finding Out MoreUF/IFAS is also holding outreach seminars to growers and other invested parties to create transparency, educate, and inform. There is one seminar a month from September to December. Those interested can register at https://clue.ifas.ufl.edu/fertilizer-rate-studies-seminar-series/ and also find recordings of past seminars.
