Nutrient Optimization and Yield Intensification of Major Cereal Systems of Eastern India

India is the second largest producer of rice in the world with a production of 100 million t in 2010-11. However, it's current productivity is far below it's attainable yield level. Introducing hybrid rice into the predominant cropping system of eastern India and changing the blanket fertilizer recommendations for high yielding varieties (HYV) for rice to site-specific fertilizer recommendations can help boost rice productivity. Therefore, we started this project to optimize fertilizer recommendations in a HYV rice–hybrid rice–pulse cropping system by using the omission plot technique to assess rice responses to NPK application. The trials are being conducted in five farmer fields each in Burdwan and Birbhum districts as well as one experiment at the research farm of Visva Bharati University, West Bengal. The treatments being used include: T1) Ample dose of N+P+K+S+Zn; T2) P+K+S+Zn (-N); T3) N+K+S+Zn (-P); T4) N+P+S+Zn (-K); T5) N+P+K+Zn (-S); T6) N+P+K+S (-Zn); T7) Local variety under the unfertilized check; T8) Local variety under ample fertilizer treatment; and T9) Control (without any fertilizer, but plant protection measures will be taken). The ample N, P, K, S, and Zn rates were determined based on nutrient requirements for a predetermined yield target of each crop. Other deficient nutrients were applied as needed.

After the first season of the experiment, the maximum yield of HYV rice (> 5.5 t/ha) was achieved with T1 at all locations. Omission of individual nutrients reduced crop yields. Interestingly, the yield of HYV under control or no fertilizer application was reduced by almost 3 t/ha, compared with the fully fertilized treatment. This reinforces the observation that high yielding varieties cannot reach their potential without proper fertilizer application.