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

Ranchi is one of the two centers of the Global Maize Project in South Asia. The overall objective of the project is to improve the productivity of the maize-wheat cropping system over the farmers' existing fertilizer application practice (FFP). The experiment in Ranchi compared the effect of practicing ecological intensification (EI) over the FFP. Hybrid maize was grown during kharif 2014 and the crop was grown as rainfed crop. The EI dose for NPK was 180-90-100 kg/ha, while FFP received 5 t farmyard manure/ha along with fertilizer N at the rate of 40 kg/ha. During 2014-15 cropping cycle, the average maize grain and straw yields in EI plots were 6.9 and 7.6 t/ha, while that of FFP were 1.0 and 1.4 t/ha. After harvest of maize, wheat was grown as an irrigated crop during winter/rabi season. The average wheat grain and straw yield were 4.8 and 5.7 t/ha in EI while that of FFP were 0.9 and 1.3 t/ha, respectively.

Two supportive studies along with this project are going on at the same location with additional experimental treatments. In one of these studies, the effect of rate and time of N applications were determined. In the case of maize, N was applied at the rate of 160 kg/ha in three splits that were based of a leaf color chart (LCC), and observed a maximum yield of 7.0 t/ha for maize. In the case of wheat, N application at the rate of 150 kg/ha, also in three split doses based on the LCC, resulted in highest grain yield of 5.1 t/ha. In the third study, the experiment was conducted in the plots receiving ample NPK (250-120-120 kg/ha), omission of specific nutrients and doses calculated as site-specific nutrient management (SSNM) at 200-90-100 kg/ha during maize cultivation in kharif. During the rabi season, the treatments were ample NPK (150-110-100 kg/ha), omission of specific nutrients and doses calculated as SSNM (120-70-60 kg/ha). During kharif, wheat straw was incorporated in each treatment in half of plot, while in the other half of the treatments the residue was completely removed (traditional method). The highest maize yield of 7.6 t/ha was observed in treatment plots with incorporation of wheat straw along with application of ample NPK (250-120-120). In the case of wheat, a similar pattern was followed where maize straw was incorporated instead of wheat straw in half of the each plot. The highest wheat yield (5.1 t/ha) was observed in the plot receiving ample NPK with incorporation of maize straw.

Overall, this present study highlights that practicing EI in a maize-wheat rotation significantly improved yields over existing farmers' fertilizer practices.