Precision in Fertilizer Placement

Definition; Precision fertilizer placement means applying the right type, right dose, at the right place and time (4R Nutrient Stewardship) using advanced techniques to maximize nutrient use efficiency (NUE), reduce losses, and increase yield.

Need for Precision Fertilizer Placement

• Fertilizer use efficiency is very low in India: N (30–50%), P (15–20%), K (50–60%), S & micronutrients even lower.
• Blanket broadcasting leads to nutrient losses through leaching, volatilization, fixation.
• Imbalanced use of NPK (excess N, low P & K) → soil fertility decline.
• Rising cost of fertilizers → need for efficient placement.

Techniques of Precision Fertilizer Placement

• (i) Band Placement; Fertilizer is applied 2–5 cm below and beside the seed row. Minimizes fixation (P, Zn). Common in maize, sugarcane, cotton.
• (ii) Deep Placement; Urea Deep Placement (UDP): Urea briquettes (1–3 g) placed 7–10 cm deep in transplanted rice. Reduces N losses by ~30–40%, increases yield.
• (iii) Seed-cum-Fertilizer Drill; Ensures simultaneous sowing + fertilizer placement in moist soil zone. Improves germination & uniformity.
• (iv) Fertigation (Precision via Irrigation); Water-soluble fertilizers applied through drip or sprinkler irrigation. Nutrients supplied in small, frequent doses → high efficiency.
• (v) Site-Specific Nutrient Management (SSNM); Based on soil testing, GPS, remote sensing, crop sensors (GreenSeeker, SPAD meter). Ensures nutrient supply based on soil & crop demand.
• (vi) Smart Technologies; Variable Rate Technology (VRT): Fertilizer applied at variable rates across the field using GPS maps. Nano-fertilizers: Improve uptake efficiency (e.g., Nano-Urea from IFFCO).

Advantages

• Increases fertilizer use efficiency (NUE can go up to 70–80%).
• Reduces fertilizer cost by 20–40%.
• Improves crop yields by 10–25%.
• Decreases nutrient losses to air and water → less pollution.
• Maintains long-term soil fertility & sustainability.

Facts for ASRB NET

• Average fertilizer consumption in India = ~135–140 kg/ha (2023).
• UDP technology (Bangladesh & Eastern India) → saves 30–35% N, increases rice yield by 15–20%.
• SSNM concept developed under IRRI and promoted in rice–wheat system.
• Precision fertilizer placement can cut greenhouse gas emissions (N₂O) by 15–20%.
  4R Nutrient Stewardship: Right Source, Right Rate, Right Time, Right Place.