Yield Formation and Nitrogen Use Efficiency of Rice in Northern Liaoning Province and Its Responses to Nitrogen Regulation

Using‘Tiejing 9'as experimental materials, the yield formation and nitrogen use efficiency and its responses to nitrogen regulation in northern Liaoning Province were studied. The results showed that while the same ratio for basic, tiller and ear fertilizer, as amount of nitrogen increased, the effective panicle number and total nitrogen content increased, 1000-grain weight and nitrogen physiological efficiency and harvest index decreased, nitrogen recovery rate was higher in middle nitrogen. In same nitrogen rate, the effective panicle number, 1000-grain weight, yield, total nitrogen uptake, nitrogen recovery and harvest index increased, nitrogen physiological efficiency decreased as the application of nitrogen delayed. Nitrogen application 210 kg/hm2 and the ratio 4∶3∶3 for basic, tiller and ear fertilizer was the best nitrogen regulation mode, and the yield increased by 0.6%~10.6% compared to the other nitrogen treatments and it reached up to 9494.8 kg/hm2. Suitable amount of nitrogen and application at late growth stage can coordinate the yield components and enhance the yield, improve nitrogen use efficiency, reduce cost and increase benefit.