三类稻作烟田的烤烟生长、物质积累分配及养分利用效率特征.

[Objective] The present study aimed to clarify the growth, material accumulation and distribution, and nutrient utilization efficiency of flue-cured tobacco in tobacco-rice rotation fields for Hunan. [ Method] The dynamic changes of root system, above ground agronomic characters, dry matter, nitrogen, phosphorus, potassium and nicotine accumulation and distribution, as well as the utilization efficiency of nitrogen, phosphorus and potassium in three types of tobacco-rice rotation fields were studied by using typical case investigation method. [Result] Tobacco plants in high yield fields had developed root system, large quantity, large absorption surface area, thick stem, large leaf area, and more accumulation of dry matter, nitrogen, phosphorus and potassium. 90 days after transplanting, the total dry matter, nitrogen, phosphorus, potassium and nicotine accumulation in high yield fields were 35. 08%, 33. 84%, 18. 18%, 28. 03% and 25. 24% higher than those in suitable yield fields, and 70. 4 1 %, 44. 51 %, 63. 53 %, 59. 94 % and 21. 81 % higher than those in safeguarding yield field, respectively. The harvest index of nitrogen, phosphorus and potassium were higher in suitable yield fields. [Conclusion ] The suitable soil types should be selected for tobacco production. Straw should be full returned to the field to improve soil organic matter. Early winter ploughing should be carried out to promote soil ripening. Attention should be paid to the cultivation of soil to improve soil aeration and soil temperature, so as to promote early growth and rapid development of flue-cured tobacco. [ABSTRACT FROM AUTHOR]