15N示踪探究烤烟氮素吸收分配规律

摘要

通过大田试验,利用15N示踪研究了烤烟大田各生育期对肥料氮的吸收分配规律.结果显示:烟株偏向吸收硝态氮,且吸收的硝态氮主要分布在叶片和茎中；烟株吸收的追肥氮占吸收肥料氮的比例随生育期的推进而不断增加；成熟叶片中肥料氮占总氮的比例不足两成,且随叶位上升而不断下降.%Nitrogen absorption and distribution patterns in flue - cured tobacco at different growth stages were studied through 15N - labelled field experiment. The results showed that the tobacco plants absorbed more nitrate nitrogen than ammonium nitrogen, and the absorbed nitrate nitrogen was mainly accumulated in leaves and stems. The ratio of the absorbed top dressing nitrogen to the absorbed total nitrogen fertilizer gradually increased with the advance of growth period. The ratio of nitrogen fertilizer to total nitrogen in mature leaves was less than 20% , and it continued to decline with the rising of leaf position.