Plant Part and Time: | Sample leaves in late June and later (until early August) if needed to allow nutritional monitoring. Sample trees randomly within uniform soil areas by taking three to five leaves per tree until 100 leaves are combined for the analysis. |
Element and Sufficiency Range | Interpretation and Recommendations |
---|---|
Nitrogen (N) 1.5-2.0% | Deficiency due to inadequate or ineffective N fertilization. Generally, a total of 80 to 100 pounds of N per acre are needed for high density plantings (600 trees per acre) with half applied at the initiation of spring growth and the other half by mid May. If N is less than 1.4% N, apply an additional 20 to 30 pounds of N per acre. |
Phosphorus (P) 0.1-0.3% | Deficiency may be due to low soil P, inadequate P fertilization, or poor root development. If P is less than 0.1% and soil test P is low, apply 25-50 pounds P2O5 in next year's fertilization program. If P is between 0.1 and 0.3% and soil test P is medium or higher, application of P fertilizer may be omitted the following year. |
Potassium (K) 0.8-1.2% | Deficiency due to low soil K, inadequate K fertilization, and/or heavy crop load. If leaf K is less than 0.7% K, apply an additional 25-40 pounds K2O per acre. Otherwise, continue with present K fertilization practices. If the K level is greater than 1.0% K, application of K2O may be reduced in next year's fertilization program. |
Calcium (Ca) 1-2% | If soil pH is in the recommended range (6.0 - 7.0), low Ca levels are unlikely. |
Magnesium (Mg) 0.1-0.3% | Deficiencies may occur at very low soil test Mg levels. If leaf Mg is less than 0.1%, apply 15-25 pounds of Mg per acre as magnesium sulfate or other forms of soluble Mg. If lime is needed to raise soil pH, use dolomitic lime to supply magnesium instead of magnesium sulfate. |
Sulfur (S) 0.1-0.25% | If the S level is less than 0.10%, apply a sulfate source of S at 10 pounds of S per acre. Sulfate sulfur sources may be gypsum, ammonium sulfate, potassium sulfate, or others. |
Boron (B) 20-75 ppm | Low levels of B may occur on very sandy and low organic matter soils (less than 1% OM). If the B is less than 20 ppm, soil apply 1/2 pound of actual B per acre. |
Copper (Cu) 5-10 ppm | If the Cu level is less than 5 ppm, apply copper sulfate to the soil at a rate of 4 pounds per acre (one pound of Cu per acre) each year until tissue levels improve. |
Manganese (Mn) 20-100 ppm | Low Mn levels are unlikely under Georgia conditions. |
Zinc (Zn) 20-50 ppm | Low zinc levels may occur on very sandy low organic matter soils. If the Zn level is less than 20 ppm, soil apply 10 pounds of zinc sulfate per acre. |