SINGH, PANKAJSAHOO, SANKET2023-07-052023-07-052021M/SS/358/2019-20https://krishikosh.egranth.ac.in/handle/1/5810197970‘A field experimentation was led at Dr. RPCAU Soil Science Research field, under A.I.C.R.P. project, during Kharif season of 2020-21 in a nitrogen deficient (mineralizable nitrogen = 198.9 kg ha-1) sandy loam calcareous soil to study about yield, nutrient uptake capacity and ‘nitrogen use efficiency’ of ten rice genotypes under different ‘levels of nitrogen’ and screening of nitrogen use efficient genotype. The experimental design was split-plot, assigning three levels of nitrogen (0, 60 and 120 kg N ha-1) to the main plot and ten rice varieties (CNN-1, CNN-2, CNN-3, CNN4, CNN-5, BCV-1, MTU-1010, Vardhan, Rasi, T1-93) to the subplots with three replications. Sub-plot size was 7.2 m2 and recommended doses of fertilizer was N : P : K :: 120 : 60 : 40 and ZnSO4 @ 25 Kg ha -1. The results of this investigation were found as, yield and nitrogen uptake of varieties increase linearly with nitrogen doses. But, yield and uptake between genotypes varies on the basis of their genotypic characteristics. The highest agronomic efficiency and physiological efficiency was attained by genotype CNN-5, while the highest apparent nitrogen recovery and utilization efficiency was attained by genotype TI-93, the highest Agro-physiological efficiency was attained by both CNN-5 and CNN-3. However, the highest ‘physiological efficiency index of nitrogen’ and ‘nitrogen harvest index’ was attained by CNN-3. On the basis of ‘Grain Yield Efficiency Index (GYEI)’ BCV-1, Vardhan, MTU-1010 and CNN-5 were found nutrient efficient genotypes, CNN-2 and Rasi were found nutrient inefficient genotypes and CNN-4, CNN-3, CNN-1, TI-93 genotypes were found moderately susceptible. On the basis of average yield of genotypes at low nitrogen level and average Physiological Efficiency Index of Nitrogen (PEIN) of genotypes, BCV-1 and CNN-5 were found efficient and responsive (ER), although both have different yield potential, Vardhan, MTU-1010 were found efficient and non-responsive (ENR), however only CNN-3 was non-efficient and responsive (NER) genotype and CNN-1, CNN-2, CNN-4, Rasi and TI-93 were non-efficient and non-responsive (NENR) genotypes. Among all genotypes under study, BCV-1 was found the best genotype in calcareous soil.EnglishThesis