Global Maize Project in India: Ranchi, Jharkhand - Site Specific Nutrient Management in Maize-Wheat cropping system in Ranchi, Jharkhand

Optimal nutrient management strategies for maize-wheat system were initiated in the Western Plateau Region of Jharkhand. Three experiments were conducted during 2011 with wheat (variety DBW 17) in rabi (December 2010 to April 2011) and maize (Pioneer 30V92) during kharif (June to October, 2011).

Highest grain yield of maize (7.0 t/ha) and wheat (4.1 t/ha) were obtained with application of N: P₂O₅:K₂O at 180: 90: 100 kg/ha for maize and 130: 70: 60 kg/ha for wheat under the ecological intensification (EI) treatment in the long-term system evaluation of EI and farmers’ fertilization practices (FFP), Maize and wheat grain yields were 2.27 and 2.2 t/ha, respectively, under the FFP treatment. The EI treatment recorded 104.6 % higher maize equivalent yield over FFP.

Studies on the effect of rate and time of N application on maize-wheat system yield showed that application of N in maize at 240 kg/ha produced maximum grain yield (7.5 t/ha) that was at par with yield obtained (7.1 t/ha) with N application at 160 kg/ha in 3 splits on the basis of a leaf color chart (LCC). Nitrogen applied at 150 kg/ha in 2 splits in wheat resulted in highest grain yield (5.1 t/ha). Percent increase in yield of the maize-wheat system, over no application of N, was highest (254%) with the application of 240 and 150 kg N/ha in maize and wheat, respectively.

In the omission plot experiment, wheat yield was highest (4.8 t/ha) in the ample NPK (150:110:100) plot. Omission of N and P from the ample NPK treatment reduced yield by about 4 and 2.1 t/ha, respectively, with no reduction in yield due to K omission. In the following maize season, both ample NPK and omission plots were divided into two equal plots and residues of the previous wheat crop were retained in one plot and were completely removed from the other plot. Maize yield in the ample NPK (250:120:120) plots, with and without residues, were 8.36 and 8.28 t/ha, respectively. The lowest yield of maize (0.8 t/ha) was obtained in the N omission plot where wheat residues were retained while the yield was slightly higher (1.1 t/ha) in the N omission plot with no residues retained. Reduction in maize equivalent yield of the system due to nutrient omission, as compared to ample NPK plot, followed the order N (84.8%) > K (42.4%) > P (32.1%). IPNI-22