Web-based tool for calculating field-specific nutrient management for rice in India

Area of Science:

• Agricultural Science
• Agronomy
• Soil Science

Background:

• Uniform fertilizer application is common in rice production.
• Site-specific nutrient management (SSNM) offers a tailored approach.
• Existing methods may not optimize nutrient use for individual fields.

Purpose of the Study:

• To develop and evaluate a web-based decision support tool, Nutrient Manager for Rice (NMR), for site-specific nutrient management in rice.
• To compare NMR recommendations with blanket fertilizer recommendations (BFR) and farmer's fertilizer practices (FFP).

Main Methods:

• Developed NMR tool based on SSNM principles for calculating N, P, and K fertilizer rates.
• Conducted on-farm trials in 74 irrigated rice fields over three seasons.
• Compared NMR with BFR and FFP for grain yield, fertilizer rates, cost, and financial risk.

Main Results:

• NMR resulted in higher grain yield (0.6-0.7 Mg ha⁻¹) than FFP in two seasons with comparable or lower fertilizer costs.
• NMR achieved comparable yield to BFR but reduced N and P rates and total fertilizer cost.
• Switching to NMR reduced the likelihood of financial loss from 31% (FFP to BFR) to 18% (FFP to NMR).

Conclusions:

• NMR effectively facilitates field-specific nutrient management (N, P, K) for rice.
• NMR enhances fertilizer use efficiency without compromising rice yield.
• NMR presents a viable, cost-effective, and lower-risk alternative to uniform fertilizer application strategies.