Global Maize Project in India: Dharwad, Karnataka - Site Specific Nutrient Management in Maize-Wheat cropping system in Northern Karnataka
This project was initiated to assess the short and long term effects of ecological intensification of maize production on productivity, environmental impact, and profitability of farmers growing maize in Northern Karnataka. This project also helps in understanding the yield potential of maize based cropping system in the region and helps develop long-term nutrient management strategies for sustaining improved maize productivity in the region.
IPNI-2009-IND-GM35
14 Feb 2011
2010 Annual Interpretive Summary
Evaluation of the maize-wheat cropping system under ecological intensification (EI) providing 180-90-100 kg N-P2O5-K2O/ha and FP (farmer practice) providing 115-52-45 kg/ha resulted in grain yields of 4.5 t/ha and 3.4 t/ha, respectively.
Higher net returns of INR 27,282/ha were realized with EI, which was 40% higher than FP. In wheat, the yield under EI (130-70-60) and FP (70-50-60) were 3.2 and 2.6 t/ha, respectively. Rate and application studies found 240 kg N/ha could generate 6.8 t/ha, which was higher than the 6.1 t/ha produced with 160 kg N/ha. Net returns and benefit-to-cost (B:C) ratios with 240 and 160 kg N/ha were INR 44,953 (3.61) and INR 40,019 (3.52), respectively. Application of N in three splits with and without the use of leaf color charts (LCC) resulted in equivalent maize yields of 5.3 and 5.1 t/ha, but these results were superior to N provided in two splits. Grain yields in the succeeding wheat crop were 3.7 and 3.2 t/ha using 150 and 100 kg N/ha, respectively. Significantly higher net returns and B:C ratios were realized at 150 kg N/ha (INR 32,981 and 3.26) compared to 100 kg N/ha (INR 27,970/ha and 3.03). Timing of N application had no effect on wheat yield.
Studies on indigenous soil nutrient supply indicated ample NPK (250-90-100) and NPK rates derived through site-specific nutrient management (SSNM) (200-90-100) resulted in maize yields of 7.1 and 6.4 t/ha, respectively. Yield response due to soil N, P, and K only was 3.8, 1.6, and 1.3 t/ha, respectively. In wheat, ample NPK (150-110-100) and SSNM rates (120-60-50) produced 3.6 and 3.1 t/ha. Yeld response due to indigenous soil supply of N, P, and K was 2.1, 0.7, and 0.5 t/ha, respectively.
Information was also collected on growth and yield parameters besides analyzing the soil and plant samples for nutrient uptake. Yield in the EI treatment (4.5 t/ha) with 180 kg N/ha was lower than that (6.2 t/ha) achieved with 160 kg N/ha. Researchers attribute this deviation to inferior soil fertility at the location where EI studies were conducted compared to where the N rate experiments took place. These deviations will be addressed in forth coming experiments. Results will be utilized to continuously improve the EI treatment for the development of guidelines of best management practices. IPNI-23