Americas and Oceania Group - International Plant Nutrition Institute

of mineral nutrients in wheat grain and straw, were 0.78, 0.78, and 0.16 respectively for N, P, and K. This
suggests that there is a high potential of K export from field with harvested straw. Such high removal/mining
of K with straw needs to be compensated with external application, unless a large portion of the straw is
returned back to the field. Analysis of soil and plant samples from rice and maize experiments are in progress.
These data will be used to develop SSNM strategies for the three major cropping systems under study.
India-017
Global Maize Project in India: Ranchi, Jharkhand
Project Leader: Rakesh Kumar, Birsa Agricultural University Department of Soil Science & Agricultural Chemistry,
Kanke Ranchi, Jharkhand. E-mail: rkssacbau@rediffmail.com
Project Cooperators: A.K. Sarkar and S. Karmakar
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: P 2 O 5 :K 2 O
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 v
92 IPNI Interpretive Summaries