Study on the Rational Application Ratio of Nitrogen Fertilizer in Rice in High Latitudes Areas

[Objective] To study the rational application ratio of nitrogen fertilizer in rice in high latitudes areas.[Method] An experiment was carried out with randomized complete block design consisted of four treatments,the proportions of base nitrogen fertilizer,tiller fertilizer and panicle fertilizer were 4∶2∶4(treatment 1),4∶3∶3(treatment 2) and 5∶3∶2(treatment 3) respectively,non-nitrogen fertilization(Treatment 4) was the control.[Result] The application ratio of nitrogen fertilizer had certain effect on the ratio of grain to straw,the lower the ratio of base fertilizer to tiller fertilizer,the higher the grain-straw ratio;N absorptron of per hundred kilograms economic output showed no big difference,and the average N application amount was 1.21 kg;the nitrogen use efficiency of treatment 1 was close to that of treatment 2,while that of treatment 3 was very low of 25.86%;the yield of treatment 1 was the highest with the phenomenon of unfavorable-delayed senescence appeared in 2007,then followed by treatment 2 and treatment 3.[Conclusion] The rational application ratio of base fertilizer,tiller fertilizer and panicle fertilizer for rice in the high latitudes areas in North China was 4∶3∶3,it could be popularized for rice production.