耕作深度对烤烟生长、养分吸收及产量、质量的影响

通过田间试验研究了移栽前不同耕作深度(20、30和40 cm)对烟株农艺性状、根系发育及分布、干物质累积和养分吸收以及烟叶产量、产值和品质的影响。结果表明，不同耕作深度处理烟株前期生长无明显差异，但到打顶时烟株根系发育和分布则有显著差异。在0~10 cm土层内, 根系数量及根干重均随耕作深度增加而下降；而10~20 cm、20~30 cm两土层内根系数量及干重与耕作深度间的关系则与0~10 cm相反，20 cm处理与其余两处理间差异显著，耕作深度为40 cm处理明显有更多的根系。各处理烟株烟叶叶面积系数及最大叶面积、整株干物质累积和氮磷钾养分吸收均随耕作深度增加而增大, 且这种趋势随生育期发展而愈加明显。烤后烟叶产量、产值以耕作深度为40 cm处理最高, 30 cm处理次之, 20 cm处理最低, 前者与后两者间有显著差异；而评吸质量以耕作深度为30 cm处理各部位和40 cm处理上部叶相对更好。综合考虑, 建议烤烟生产中土壤耕作深度以30~40 cm为宜。

Effect of Tilling Depth on Growth,Nutrient Uptake,Yield and Quality of Flue-Cured Tobacco Plant

Deeper tillage has been commonly thought having positive effect on plant growth, but what depth for tillage is better is not clearly in tobacco production. A field experiment was conducted to investigate the effect of tilling depth (20, 30, and 40 cm, respectively) on the growth, root distribution, dry matter accumulation, nutrient uptake, yield and quality of flue–cured tobacco plant in Shilin county, Yunnan. The results showed that tobacco plant growth was significantly affected by the tilling depth from topping to harvesting except the early stage. The number and dry weight of roots decreased with increasing tilling depth at the 0–10 cm soil layer, but increased at the 10–20 cm and 20–30 cm soil layers, and more roots were found for the treatment with tilling depth at 40 cm. Leaf area index, maximum leaf area, dry matter accumulation and uptake of nitrogen, phosphorus and potassium increased in the plant with deepening tilling depth. The highest yield and economic value of flue-cured tobacco leaves were obtained at 40 cm of tilling depth. Moreover, the 30 cm of tilling depth was also better for higher yield and higher quality of leaf. It suggested that 30 to 40 cm was the optimum tilling depth for flue-cured tobacco.