RUBBER NEWS

Fertilization for Mature Rubber Plantations (Business Stage)

Posted on by content02.vinahugo
13
Oct

Inorganic Fertilization for Mature Rubber Trees

Proper fertilization management during the business phase is essential for maintaining latex yield, extending tree lifespan, and ensuring soil fertility.

  • Priority: Fertilizer application should be based on regional nutrient diagnostics to optimize both economic and technical efficiency. Where diagnostics are unavailable, apply fertilizers according to Table 12.

  • Application Period: From the first tapping year until the end of the harvesting cycle, following the company’s technical regulations.

  • Fertilizer Type:

    • On flat land: use compound NPK 16-8-16.

    • On slopes or contour lines: use NPK 16-8-16 or blends recommended by local nutrient analyses.

    • May combine inorganic and organic fertilizers to improve soil balance.

  • Application Frequency: Apply once per year at the beginning of the rainy season when the soil is moist. Do not fertilize during heavy or continuous rain.

Table 12. Inorganic Fertilizer Rates for Mature Rubber Trees

Soil Class N (kg/ha) P₂O₅ (kg/ha) K₂O (kg/ha) NPK 16-8-16 (kg/ha) Urea (kg/ha) Fused Phosphate (kg/ha) KCl (kg/ha)
I 45 22 45 281 97 137 75
II 50 25 50 312 108 156 83
III 55 27 55 343 119 168 91

*When soil pH (H₂O) ≥ 6, replace fused phosphate with superphosphate.

Fertilization Techniques

  • Flat Land:

    • Mix and spread fertilizer evenly in 1.0–1.5 m wide bands between rubber rows or into humus pits.

    • Mechanized fertilizer application is encouraged in flat plantations.

  • Sloped Land:

    • Apply fertilizer through trenches or multi-purpose pits as used during the immature (KTCB) stage after canopy closure.

Adjusting Fertilization in Mature Plantations

Fertilizer regimes may be adjusted to ensure cost-efficiency, stable yield, and soil sustainability based on real conditions.

  • Adjustment Principles:

    • Fertilizer quantity and composition may vary depending on soil condition, yield level, or tree health.

    • Prioritize fertilization for high-yielding and younger trees:

      • Tapping years 1–5 > 6–10 > 11–18.

    • For sandy soils (>50% sand), rocky soils, or those with low organic matter (<2.5%), apply at least 50% organic fertilizer (by investment value) in combination with inorganic fertilizers.

  • Cases to Suspend Fertilization:

    • Plantations undergoing final tapping before replanting (exhausted trees).

    • Extensive plantations with poor productivity due to factors other than soil fertility (e.g., low tapping density, unsuitable clones, poor bark condition).