不同施氮水平条件下烤烟对氮素的利用研究

大田中设置盆栽试验，采用１５Ｎ示踪法对不同施氮水平条件下的烤烟的氮素吸收、肥料氮素的利用和土壤ＡＮ值进行研究．试验结果表明，烤烟全生育期吸收的氮素主要来自于土壤可利用性氮．随着氮肥用量的增加，烤烟对肥料氮的吸收量增加，对土壤氮的吸收量减少，土壤对肥料氮素的固定和氮肥损失量增加．ＡＮ值有随氮素用量的增加而逐渐减小的趋势，但以处理４的（６７．５ｋｇ氮素／ｈｍ２）最小．肥料中的氮素利用率以处理４最高，达到５２．３％。

Study on Utilization of Nitrogen by Flue-Cured Tobacco at Different Nitrogen Fertilizer Levels.

A pot culture experiment in field was conducted. The nitrogen absorption, the utilization of nitrogen fertilizer by flue-cured tobacco and the AN Value of the soil at different application rates of nitrogen were studied with the method of (15)N tracer. The adults showed that the nitrogen absorbed by tobacco in the whole growth stage was mainly from the available nitrogen of soil. With the rising in nitrogen fertilizer level,nitrogen absorption by tobacco from the fertilizer increased and from the soil decreased, the rate of nitrogen fixed by the soil and the loss of nitrogen both from the fertilizer increased, and the AN value of the soil declined gradually, but the AN value of treatment 4 (67.5kg N/hm2) was the lowest in the all treatments.The utilization rate of nitrogen in fertilizer of treatment 4 was 52.3% and that was the highest in the all treatments.