Combined Effect of Elevated CO2 and Nitrogen Fertilizer Management on Wheat Yield in Sub-tropical India

Abstract. Field experiments to understand the effect of elevated CO₂ and the consequence of rising atmospheric temperature on wheat production is felt necessary to develop suitable adaptations. The objective of this study was to investigate the effect of CO₂ enrichment in combination with varying nitrogen management on yield of wheat in sub-tropical India. Wheat crop was grown inside open top chambers with ambient CO₂ (380 ppm) and elevated CO₂ (50% higher than ambient) environment under four N management in dry season of 2014-15 at Kharagpur, India. The N treatments were application of N at normal recommendation [N100(CF), i.e. 120 kg/ha], 50% higher than N100(CF), and SPAD-based management using chemical fertilizer (CF) and integration of CF with organics in the highest dose (180 kg/ha). With the elevation of CO₂ environment, the grain yield was increased by 11 to 26% and straw yield by 23 to 29%. The maximum increase was noted in high N dose management. This indicated that wheat crop can be benefited under elevated CO₂ environment with higher level of N fertilizer application in sub-tropical India.