Growing Pecans – Crop Nutrition 101

Key Nutrients:

Pecans require several macronutrients (N, P, K, Mg, Ca, S) and micronutrients (Zn, Fe, Mn, B, Cu, Ni) for optimal growth and fruit production. Nutrient deficiencies, especially nitrogen, potassium, and magnesium, are common in Georgia soils. Normal leaf concentrations should be: N 2.3 and 3.0%; K .75 – 1.75%.

• Nitrogen(N) is essential for tree growth, yield, and kernel quality and is the most limiting nutrient, and most likely to become deficient. Tell-tale signs of deficiency include poor growth, reduced yield, and pale leaves.
  • Fertilization Tips:
    • Soil Application: Apply in early spring or split applications in spring and late summer.
    • Foliar Application: Can be effective during early growth stages or during periods of deficiency.
    • Fertigation: Suitable for irrigated orchards, allows precise nitrogen application.
    • Techniques: Monitor soil moisture to optimize nitrogen uptake; avoid excessive application to prevent foliage shading.
• Potassium (K) facilitates carbohydrate movement, regulates osmosis, and enhances winter resistance and is the second most important nutrient in pecan production after N. Deficiencies can often be recognized by leaf scorch and reduced shoot growth.
  • Fertilization Tips:
    • Soil Application: Apply Polysulphate as an alternative to potassium chloride (muriate of potash) in early spring. Polysulphate contains important secondary macros, like calcium, magnesium and sulfur and is a low-chloride source of K.
    • Foliar Application: Beneficial during early growth stages or when deficiency symptoms appear, Nova FLOW and Nova PULSE are good examples, of potassium rich foliar solutions that also include key micronutrients like Zinc and Boron
    • Techniques: Maintain a balanced nitrogen-potassium ratio (2:1); adjust application based on leaf analysis.
• Micronutrients:
  • Pecan trees are heavy users of Zinc; it is essential for quality and yield. Zinc is often applied as a foliar spray to ensure quick uptake.
• Using fertigation solutions that contain a fully chelated micronutrient pack, and a balanced NPK supply can support integrated nutrient management. Depending on soil pH and water quality, Agrolution (non-acidifying) or Agrolution pHLow (ideal for alkaline soils/hard water) are powerful fertigation solutions that come in a range of analyses to meet crop and soil needs.

Nutrient Requirements:

Nutrient balance is key to quality yields. Based on lbs/acre, these are the essential nutrients requirements (Wells & Conner, 2007)

Element Sufficiency Range

• N(%) 2.5-3.0
• P (%) 0.14-0.3
• K(%) 1.3-2.5
• Mg(%) 0.35-0.6 Ca(%) 1.3-1.75
• S (%) 0.25-0.5
• Zn (ppm) 50-100
• Fe (ppm) 50-300 Mn (ppm) 100-800 B (ppm) 50-100
• Cu (ppm) 6-30

Role of Nutrients:

Key quality and yield parameters can be affected by different nutrients. See how they can influence your harvest.

+ = improving    – = decreasing    +/- = different results, depending on the rate of nutrient applied

Yield: N++, P+, K+, Mg+, Ca+, S+ Quality: N+, P+, K++, Mg+, Ca+, S+

General Tips for Fertilization:

• Leaf Analysis: Use foliar or leaf analysis to adjust nutrient application rates and timing.
• Timing: Apply nutrients during critical growth stages (e.g., early spring, kernel filling) to meet tree demands.
• Integration: Combine soil, foliar, and fertigation methods based on orchard needs and environmental conditions.
• Monitoring: Regularly monitor soil conditions, pH levels, and leaf nutrient status to optimize nutrient uptake and tree health.
• Balanced Approach: Maintain a balanced nutrient profile to prevent deficiencies and maximize pecan production.

Pecan trees have specific periods of high nutrient demand, such as during early spring foliage growth and kernel filling stages. Matching nutrient application timing with these demand periods is essential for optimizing tree health and nut production.