Abstract: In order to clear effects of nitrogen management on rice yield and lodging resistance of the third accumulative temperature belt in Heilongjiang Province.The two main cultivated rice cultivars was used in this study,and the nitrogen was applied as the base,tiller,spike and grain nitrogen application ratio to 10 : 0,8 : 2,6.5 : 3.5,5 : 5 at three N levels as 0,115,161 kg/ha. The results showed that when the nitrogen application was up to 161 kg/ha and the base,tiller-spike,grain nitrogen application ratio turned to 6.5 to 3.5,rice yield increased.The main reason resulting in higher yield was that increase of the spike-grain nitrogen ratio could increase grain number per panicle,panicles number and sink capacity in the population.Increase of nitrogen application rate made plant height increase,bending moment increase,bending force reduce,and lodging index increase.Decrease of the spike-grain nitrogen ratio at late growth stage made rice stem bending force increase,lodging index decrease.Induce of nitrogen application rate or increase of the spike-grain nitrogen ratio at late growth stage could made 2nd internode and its leaf sheath length decrease,area of cross section enlarge,internode dry weight increase,culms wall thicken.Physical properties of rice stem improved.

Key words: Nitrogen management, Rice, Lodging, Yield

CLC Number: 

• S143.1