^15N示踪技术应用于甘蔗氮素吸收与分配的研究

采用田间微区方式,研究在施氮量相等的条件下,基肥、分蘖肥和攻茎肥分别施用20%、30%和50%15N标记尿素对甘蔗氮素吸收及分配的影响.结果表明,甘蔗不同器官从肥料中吸收的NDFF%和NDFF均表现为攻茎肥＞分蘖肥＞基肥;氮素在甘蔗根系和叶片的分配比率均为基肥＞分蘖肥＞攻茎肥,而在蔗茎中的分配比率则是攻茎肥＞分蘖肥＞基肥;不同时期施肥甘蔗对氮素的利用率表现为攻茎肥＞分蘖肥＞基肥.

Studies on nitrogen uptake and its distribution in sugarcane using 15N tracer technique

A micro-plot field experiment was carried out to study the effect of different application rates of ＇^15N- labeled urea on nitrogen uptake and its distribution at different growth stages of sugarcane. Three treatments included 20, 30 and 50% application of ^15N-labeled urea at sowing, tillering and elongation stages of growth, respectively. The rest of the urea used was unlabclled, and the total quantity of urea applied was kept the same in the ＇all treatments. The results indicated that both the NDFF% （^15N-percent derived from fertilizer） and NDFF （^15N-concentration derived from fertilizer） were the highest in different sugarcane parts in the third treatment （50% of ^15N-labeled urea） and the lowest in the first treatment （20% of ^15N-labeled urea）. Further, the ratio of N in sugarcane roots and leaves was found highest in the first treatment and the lowest in third treatment, while the ratio of nitrogen in sugarcane stalks showed contrasting results. The highest utilization rate of nitrogen by sugarcane was observed in the third treatment and the lowest one was observed in the first treatment.