云南多雨烟区增密减氮对烤烟产质量及养分利用率的调控效应

为明确增密减氮对烤烟产质量及肥料利用率的调控效应。以烤烟品种"云烟105"为材料,研究种植密度(13 890,15 150,16 665株/hm~2)和施氮水平(0,84,94.5,105 kg/hm~2)及其互作对烤烟产质量及养分利用效率的影响。结果表明:适度增密减氮能显著提高烤烟肥料利用率、产量和产值,使烟叶总糖、还原糖、钾含量显著升高,总氮、烟碱含量降低,对水溶性氯无显著影响,烟叶化学品质更加协调。烟叶化学成分协调性及烤烟氮磷钾利用率显著受年份、密度、施氮及年份×施氮、密度×施氮、年份×密度×施氮互作影响,其中施氮、密度及互作对烟叶化学成分含量效应分别为42.5%,27.3%,18.9%,而其对养分利用率的效应分别为38.2%,25.4%,23.8%。与当前烤烟种植模式相比,增密和减氮10%～20%组合对烤烟增产、提质和增效作用显著,最佳密度和施氮量分别为15 150株/hm~2和84.0～94.5 kg/hm~2。

The Regulatory Effects of Enhanced Density Combined with Reduced Nitrogen Fertilizer on Yield, Quality and Nutrient Use Efficiency of Flue-cured Tobacco in Rainy Areas, Yunnan Province

In order to clarify the regulation effects of enhanced density combined with reduced nitrogen fertilizer on yield, quality and fertilizer use efficiency of flue-cured tobacco, a field experiment which took flue-cured tobacco cultivar "Yunyan 105" was conducted in rainy areas for two years (2016 and 2018). Three plant densities (low density of 13 890 plants/hm², medium density of 15 150 plants/hm² and high density of 16 665 plants/hm²) and four nitrogen levels (0,84, 94.5 and 105 kg/hm²) were set, and the effects of planting density, reduced nitrogen and their interaction on yield, quality and nutrient use efficiency were studied. The results showed that compared with the conventional planting pattern, moderate density and reduced nitrogen fertilizer significantly promoted fertilizer use efficiency, yield and output, increased the contents of total sugar, reducing sugar and potassium, reduced total nitrogen and nicotine contents, but did not affect water-soluble chlorine significantly, resulting in the more harmonious tobacco chemical components. The chemical components usability index and NPK utilization in flue-cured tobacco were significantly affected by year, density, N application and their interactions, including the interaction of year and N rate, density and N rate, year both density and N rate. Meanwhile, the contribution of N fertilizer on chemical components usability and fertilizer use efficiency of flue-cured tobacco were 42.5%, 38.2%, and that of planting density were 27.3%, 25.4%, and that of the interaction of both planting density and N rate were 18.9%, 23.8%, respectively. Compared with the current cultivated pattern of flue-cured tobacco, the enhanced density combined with reduction of 10%~20% in nitrogen fertilizer significantly affected to yield, quality and NPK use efficiency of tobacco, and the optimal cultivated pattern of planting density and N rate should be 15 150 plants/hm² and 84.0~94.5 kg/hm², respectively.