施氮水平对甘蔗苗期氮磷钾吸收与分配的影响

Effects of nitrogen levels on absorption and distribution of nitrogen,phosphorus and potassium of sugarcane in early growth stage

以新台糖22号（ROC22）为试材，采用网室微区盆栽试验方法，基肥设^15N标记尿素0．75、1．5、2．25g／盆3个施氮水平，研究了施氮水平对甘蔗苗期氮磷钾吸收与分配的影响。结果表明：甘蔗吸收的氮素15．18％～16．77％来自施用的氮肥，83．23％～84．82％来自土壤和种茎；甘蔗氮肥利用率为1．76％～3．44％。随施氮水平的提高，甘蔗幼苗干物质、N、P、K积累，以及来源于肥料氮素比率呈增加趋势，但氮肥利用率显著下降；N与P、K表现出一定的协同作用。施氮水平主要影响氮磷钾尤其是肥料N在甘蔗地下部分器官的分配。

In this micro-plot experiment, sugarcane varieties ROC22 was used as experimental materials, and three nitrogen levels were desiged with 0.75 g, 1.5 g and 2.25 g 15N-labeled urea/pot at sowing time respectively, to study the influences of nitrogen levels on absorption and distribution N, P, K of sugarcane in early growth stage. The results showed that 15.18%-16.77% nitrogen of sugarcane accumulation was derived from nitrogen fertilizer, and 83.23%-84.82% was from soil and seed-stem. The nitrogen utilization rate of sugarcane was 1.76%-3.44%. The dry matter accumulation, nitrogen accumulation, phosphorus accumulation, potassium accumulation and the proportion of N from nitrogen fertilizer in sugarcane plant showed a increasing trend with the increase of nitrogen fertilizer, while nitrogen utilization rate of sugarcane decreased significantly. N showed a synergy relationship with P and K. The nitrogen levels had influenced on N, P and K, especially fertilizer-nitrogen distribution in sugarcane roots.