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

25 Mar 2015

2014 Annual Interpretive Summary


Now in its sixth year, this Global Maize Project has been comparing an ecological intensification system (EI) and farmers’ fertilization practice (FP) in a Vertisol at the experimental station of the University of Agricultural Sciences, Dharwad, Karnataka. The highest grain yields of maize (6.8 t/ha) and wheat (3.8 t/ha) were recorded with EI (180-90-100 kg N-P2O5-K2O/ha for maize and 130-70-60 kg/ha for wheat). The EI system recorded 65% higher grain yield of maize over FP. The higher grain yield in EI over FP may be attributed to higher uptake of N (162 kg/ha), P (72 kg/ha) and K (53 kg/ha), which were 19, 20 and 26% higher than the FP, respectively. Also, net returns of INR 64,850/ha were obtained in EI, which were 22% higher than the net returns obtained with FP (INR 53,000/ha), an improvement over the previous year by 19%. In another experiment on the effect of application rate and timing of N fertilization, the treatment that received N rate in maize at 240 kg/ha in three splits with application guided by the use of leaf color chart (LCC) recorded the maximum yield of 7.3 t/ha. In wheat, 150 kg N/ha application in three splits on the basis of LCC resulted in the highest grain yield of 3.9 t/ha. This information was used to decide the right rates of NPK application in the EI system.

Omission plot studies indicated ample NPK (250-120-120), compared to NPK rates derived through site-specific nutrient management (SSNM) (200-90-100) resulted in maize yields of 7.7 and 7.3 t/ha, respectively. Continuous omission of nutrients for six years showed that maize yield response due to application of N, P and K was 6.3, 0.7 and 1.0 t/ha, respectively. In wheat, ample NPK (150-110-100) compared to the SSNM rates (120-60-50) produced 3.9 and 3.8 t/ha. Yield response due to application of N, P and K was 2.8, 0.16 and 0.22 t/ha, respectively.

Considering the results reported so far, few changes have been considered for further improving the EI system. The NPK application rates were changed to 220-90-100 kg N-P2O5-K2O/ha, optimum plant population (60 x 20 cm spacing), continuous monitoring and management of pest and disease incidence, residue retention of maize after harvest, and inclusion of a grain legume within the maize-wheat-pulse cropping system were the other changes considered for improving the EI system.