Received: 28th March, 2024; Accepted: 28th May, 2024

Abstract

One of the major causes of low nitrogen use efficiency in rice is the application of fertilizer nitrogen (N) more than crop requirement at times when it is not required by plant during late sown conditions. This experiment was conducted at Rajendranagar farm of ICAR-Indian Institute of Rice Research, Hyderabad during kharif2021. The experiment was laid out in split plot design with three replications. Main plots consisted of three short duration rice varieties DRR Dhan-44, MTU 1010, MTU 1156 and four nitrogen management practices (sub-plots) recommended dose of nitrogen (RDN) @ 120 kg N ha-1, Silicon coated urea (SCU) @ 90 kg ha-1, Leaf Colour Chart based N application (LCC)@105 kg N ha-1, Soil test crop response based N application (STCR) @ 114.5 kg N ha-1. Among the varieties highest energy input (13.22 GJ ha-1) was recorded in DRR Dhan-44 but energy output (172.6 GJ ha-1) and energy use efficiency (10.26 GJ ha-1) were recorded in MTU 1156. Among the N management practices highest energy input (13.94 GJ ha-1) was recorded in RDN@ 120 kg N ha-1 and energy use efficiency (10.38 GJ ha-1) was recorded with Leaf colour chart based N application@105 kg Nha-1.
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