15N示踪研究烤烟对氮的吸收及分配

采用盆栽试验，利用^15N示踪研究了烤烟对不同形态氮的吸收利用规律。结果表明，烤烟各部位叶片对氮素的积累量表现为中部叶〉上部叶〉下部叶；肥料氮进入的比例具有下部叶〉中部叶〉上部叶的规律。不同生育期肥料氮进入烟叶中的比例，以团棵期最高，之后肥料氮进入的比例减少，统计分析结果表明（5％水平），从现蕾期到成熟期之间差异不大。同位素^15N标记肥料施入土壤后约39％～53％被烟株吸收利用，约22％～41％损失，约20％～37％残留于土壤中。

Absorption and distribution of nitrogen of flue-cured tobacco with 15N tracer

With the development of the methods of planting in frame and isotope tracer technique, the absorption and distribution of N nutrients of the main variety Longjiang 911 of flue - eured tobaeeo of Heilongjiang province were eondueted. The results showed that the N aceumulations of flue - eured tobaeeo increased as the order of bottom leaves, topping leaves, middle leaves; on the eontrary, the proportion of fertilizer N absorbed by flue- cured tobaeeo increased as topping, middle, bottom leaves; the ratio of feltilizer N into tobacco leaves was highest in seedling stage and decreased gradually with the extension of growing period, but there were small differenees from budding to mature period by 5% level of statisties result, ^15N tracer showed that after the application of ^15N fertilizer in soil 39%- 53% of total N was utilized; 22%-41% lost; 20%- 37% residued in soil.