Classification of Rice Genotypes based on NUE under Changing Climate

In the event of high input agriculture, more emphasis on fertilizer use efficiency, especially nitrogen use efficiency (NUE) has to be given to safeguard the economic as well as environmental resources under rice production system.Though the nutrient use efficiency mainly depends on the efficient fertilizer management practices, the existing N use efficiency pattern under varied doses and the factors responsible for N use efficiency in existing fertilization application in various soil and crop varieties need to be studied for further improvement in N use efficiency.With this view field experiment was initiated to determine various classes of NUE at different N levels under the promising rice , varieties/genotypes by following split plot design.The genotypes were grouped as efficient & responsive (9), non-efficient & responsive (4), efficient & non-responsive (6) and non-efficient & non-responsive (13) genotypes.The efficient and responsive genotypes can be used for high input Agriculture.The lowest agronomic nitrogen use efficiency was observed under higher dose of 150 % recommended dose of nitrogen than other doses.The physiological nitrogen use efficiency of the genotypes decreased with increasing nitrogen fertilizer.