Soil Sampling Is Key to Cold-Hardy Citrus Fertilization

Soil sampling is one of two keys to building a good citrus fertilization program in North Florida and South Georgia, University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) researchers wrote recently. The authors are Muhammad A. Shahid, assistant professor of horticulture, and postdoc scholar Shahid Iqbal, both with the North Florida Research and Education Center.

Shahid and Iqbal offered the following suggestions for soil analysis in cold-hardy citrus regions:

• Soil samples should be taken at least once per year, preferably before a new fertilization cycle begins, typically in late fall or early spring.
• For newly established orchards, soil testing should be done before planting to make informed decisions on fertilizer applications.
• Divide the block into sampling areas that are uniform in soil type, management history or crop performance.
• Collect soil 8 to 10 inches deep using a soil probe or auger.
• Take soil from five different points for each sample.
• Mix the samples thoroughly in a clean bucket and fill a labeled soil sample bag with about 1 pint of soil.
• Send samples to the laboratory for analysis.

According to Shahid and Iqbal, the cold-hardy citrus regions of North Florida and South Georgia need precise and science-based recommendations regarding nutrient management due to their unique soil characteristics, fluctuating temperatures and emerging pest and disease pressures.

The authors noted that effective nutrient management is critical for encouraging plant growth, fruit quality and resilience to different biotic and abiotic stresses in citrus. Over- or under-fertilization can cause a serious reduction in yield, increase susceptibility to freeze damage and degrade soil health, they stated.

The other key to building a good citrus fertilization program in the cold-hardy region is leaf analysis, the researchers noted. “The most effective use of soil and leaf analysis is together,” they wrote.

Source: UF/IFAS