Growing Indica and Aus Type Rice till Maturity in Hydroponics under N-Optimum and N-Stressed Condition: A Detailed Account

Abstract

The optimal utilization of nitrogenous fertilizer in agriculture is essential for reducing nitrogen (N) induced pollution and minimizing production costs. While studies have been conducted on the performance of rice genotypes under N-stresses, there remains a lack of detailed protocols for screening them during both seedling and maturity stages without absolute control of N, which is conveniently possible in hydroponics. Here we report a detailed protocol for growing of rice plants till maturity under N-stress (as well as N-optimum condition) in the hydroponics system. This protocol provides comprehensive details on requirements, experimental setup, media, growing conditions, parameters to be observed, and management practices for the hydroponics system and troubleshooting. Apart from the growing condition, we also detail the procedures for recording the observations during the growth phase of the plants. Two contrasting rice genotypes for nitrogen use efficiency (NUE), IR64 (Indica rice) and Nagina 22 (Aus type rice), were grown under optimum as well as N-stressed condition till the complete maturity of the plants for validation of this protocol. Significant differences (p < 0.05) between the two genotypes were observed on various parameters including the morphological parameters and N uptake, from seedling to maturity stages. We also observed the effect of aeration in the hydroponics system for rice and found that non-aerated conditions were preferable. This comprehensive protocol offers an efficient, easy, low-cost, and low-maintenance system for hydroponic studies under N stress conditions, enabling precise phenotyping and non-destructive examination of roots.