Abstract: [Objective] This paper was to explore the effects of nitrogen before transplanting on nitrogen distribution and utilization efficiency in the rhizosphere soil of rice , and to give guidance for application of nitrogen fertilizer . [Method] The effects of nitrogen before transplanting application rate on spatio-temporal distributing of available nitrogen , utilization and yield were studied with Ningjing-2 utilizing the environment of breeding seedling through plastic-plate and transplanting with soil. [Result] The results showed that nitrogen before transplanting could markedly improve nitrogen content in the rhizosphere soil of rice . Along with the days after transplanting adding , nitrogen content in soil that 1 cm apart from plant was falling . But , which of 4 , 7 cm apart from plant was first increasing then falling . The results also showed increasing nitrogen application rate increased total nitrogen accumulation and nitrogen utilization efficiency , but the yield wasn’t linear increased . Yield of NM(310.5 kgN /ha) was highest . [Conclusion] The results suggested that 310.5 kgN /ha in seedling field could increase nitrogen content in the rhizosphere soil of rice ,accelerate tiller’s developing and enhance the rate of effective tiller . Nitrogen utilization efficiency and grain yield both were markedly increased .

Key words: Rice, Plastic-plate dotsow, Fertilizer before transplanting, Nitrogen use efficiency, Yield