Influence of nitrogen levels, organic amendments and foliar nutrition on growth and yield performance of rice (Oryza sativa L.) in the Cauvery Deltaic Zone

Nitrogen (N) is an essential macronutrient vital for crop growth and development and its replenishment in agricultural soil is indispensable for sustainable food production and preventing nutrient depletion. Despite extensive research, there remain significant knowledge gaps in understanding the complex interactions between root-soil interfaces for efficient nitrogen uptake, the root-shoot interaction mechanisms for nitrogen utilization and the development of integrated management strategies to minimize the rice root system for high yield and efficient nitrogen use. The field experiment was conducted during the cropping season using a Randomized Block Design (RBD) with nine treatment and replicated three. The observations on plant growth parameters, physiological indices, biomass production and yield attributes were recorded following standard agronomic procedures. The treatment receiving the 100% recommended dose of fertilizer (120:40:40 kg ha⁻¹) recorded the highest values for plant height (102.67 cm), no. of tillers (402 m⁻²), LAI (5.41), DMP (10,985 kg ha⁻¹), CGR (5.74 g m⁻² day⁻¹), AGR (0.0861 g plant⁻¹ day⁻¹), grain yield (4,978 kg ha⁻¹) and straw yield (7,126 kg ha⁻¹). This was closely followed by the integrated nutrient treatments, with T₆ performing statistically on par with T₄. The combined use of organic with chemical fertilizers and foliar Zn and B significantly improved NUE and minimized nutrient losses. INM practices demonstrate strong potential to reduce dependence on urea, enhance soil health and improve long-term nitrogen-use efficiency in rice production systems. The study provides practical evidence supporting the adoption of sustainable nutrient management strategies in intensively cultivated rice ecosystems.Graphical abstract