基肥(^(15)N)施用时间对烤烟生长、烟碱含量及氮素来源的影响

Effects of Application Time of Base Fertilizer(^(15)N) on Growth,Nicotine Content and Nicotine-N Resources of Flue-cured Tobacco

采用大田试验,应用15N同位素示踪技术,研究了3种基肥施用时间(从移栽日期开始计算分别提前0,15和30 d)对烤烟生长发育、烟碱含量及氮来源的影响。结果表明,烤烟干物质累积量和烟碱含量均随生育期的推进而逐渐增加。打顶前烟碱含量随着叶位上升而下降,打顶后则相反。提前施用基肥有利于提高烤烟地上部干重。提前施用基肥不影响上、中部烟叶烟碱含量,但提高了下部烟叶的烟碱含量。烤烟各部位烟叶烟碱氮中来源于肥料氮的比例随着生育期的推进和叶位上升均逐渐下降,基肥施用时间对烟碱氮中来源于肥料氮的影响不明显。适当提前施用基肥有利于促进烤烟生长发育而对烤烟品质无不良影响。

A field experiment with 15N isotope tracing was carried out to study the effects of application time of base fertilizer（0,15,30 d before transplanting） on the growth,nicotine content and nicotine-N resources of flue-cured tobacco.The results showed that both dry matter accumulation and nicotine concentration in flue-cured tobacco increased with the growing of tobacco plants.The concentration of nicotine decreased with the elevation of stalk position before topping,while it was on the contrary after topping.The dry matter weight above ground was increased by early application of base fertilizer,which also promoted the nicotine contents in lower leaves,while those in upper or middle leaves were not affected.The proportion of nicotine N sourced from N fertilizer decreased with the growing of plants and the elevation of stalk position;but not significantly affected by the time when the base fertilizer was applied.It suggested that properly earlier application of base fertilizer would benefit tobacco growth at no expense of its quality.