Studies on Nitrogen Requirement of New Genotypes of Non-scented and Scented Rice

Abstract

A field experiment was conducted at the CCSHAU Rice Research Station, Kaul, during Kharif 2024 to evaluate the effects of nitrogen levels on productivity, nutrient uptake, and post-harvest soil fertility in scented and non-scented rice genotypes. Three nitrogen levels (75%, 100%, and 125% of the recommended dose of nitrogen [RDN]) and nine rice genotypes were evaluated. Nitrogen application had no significant effect on post-harvest soil pH, electrical conductivity or organic carbon; however, available soil nitrogen, phosphorus and potassium increased significantly, with the highest values under 125% RDN. Among the genotypes, Basmati CSR 30 maintained the highest post-harvest available nitrogen (173.27 kg ha⁻¹) and phosphorus (28.97 kg ha⁻¹), whereas HKR 48 recorded the highest available potassium (351.47 kg ha⁻¹). Application of 125% RDN produced the highest number of panicles (314.07 m⁻²), grains per panicle (126.93), test weight (24.73 g), grain yield (5734 kg ha⁻¹), and straw yield (7432 kg ha⁻¹). However, grains per panicle, test weight, and grain yield were statistically at par with those under 100% RDN. Grain nutrient concentrations also increased with nitrogen application. INGER 75 produced the highest grain yield (6159 kg ha⁻¹), whereas HKR 18-33 produced the highest straw yield (8883 kg ha⁻¹). Although 125% RDN maximized yield, nutrient concentration and residual soil fertility, 100% RDN achieved a comparable grain yield, indicating that the recommended nitrogen dose was adequate for efficient rice production under the study conditions.