以湘南烟区气候、土壤等生态因素和烟叶质量状况为基础数据资料，运用模糊数学隶属函数模型对该区的气候适生性、土壤适宜性和烟叶质量可用性进行了综合评价，合理地进行了该区植烟区域的划分。结果表明：1)湘南烟区的气候适生性指数（Climate feasibility index， CFI）为(79.59%±3.96%)，变幅为74.71%～83.98%；该区烟叶大田生长期气温适宜，日均温≥20 ℃持续天数较长，≥10 ℃活动积温较高，昼夜温差较小，降雨充沛，相对湿度较高，日照百分率较低。2 )湘南烟区的土壤适宜性指数（Soil feasibility index, SFI）为(43.92%±15.49%)，变幅为13.32%～82.82%；该区土壤具有较强的保肥能力，有机质、氮素、速效磷及多种微量元素含量丰富，但pH值中性偏碱，全磷和钾素含量难以满足烟株需求，且交换性钙镁比值不协调，有效硫含量偏高，有效硼缺乏。3)湘南烟叶外观质量指数（Appearance quality index, AQI）和感观质量指数（Sen sory quality index, SQI）分别为（86.65%±3.29%）和（63.08%±0.74%），烟叶成熟度较好，叶片结构疏松，香气质较好，杂气和刺激性相对较小。
Aims Southern Hunan is the largest flue-cured tobacco-growing area in Hunan, China, aided by climate and soil conducive to the growth and development of tobacco. Our objectives were to evaluate climate feasibility, soil fertility and tobacco quality, and provide a scientific basis for classifying southern Hunan tobacco-growing areas. Methods We obtained climate data for 30 years, including different growth and development periods and total sunlight hours during the field period, for the counties of Xintian, Yongxing, Jianghua, Jiangyong, Daoxian, Ningyuan, Guiyang, Jiahe, Hengnan and Lanshan from the Hunan Meteorology Bureau. We collected 1 225 soil samples from 2002 to 2003 and determined soil parameters, including pH, organic matter, nutrient elements and cation exchange capacity (CEC). We selected three or four flue-cured tobacco varieties from southern Hunan in 2004 and determined six appearance quality indexes and nine sensory quality indexes of 15 tobacco samples of C3F grades. We estimated climate feasibility index (CFI), soil feasibility index (SFI), appearance quality index (AQI) and sensory quality index (SQI) for tobacco by applying membership function and estimating weight values for each index by using principal components analysis. Important findings The CFI was (79.59%±3.96%) and ranged from 74.71% to 83.98%. The areas had feasible temperature, a long period with average daily temperature ≥20 ℃, high accumulated temperature of ≥10 ℃, small day-and-night temperature differences, abundant precipitation, high humidity, and low sunlight percentage during field periods. The SFI was (43.92%± 15.49%) and ranged from 13.32% to 82.82%. The soil had high nutrient storage capability and was rich in organic matter, total N, hydrolytic N, available P and most micro elements; however, pH was neutral to slightly alkaline and total P, total K and available K were insufficient for tobacco. Furthermore, the ratio of exchangeable Ca to Mg was unbalanced, available S was high and available B was lacking. The AQI and SQI were (86.65%±3.29%) and (63.08%±0.74%), respectively. Tobacco leaves had good maturity, open configuration and high quality of aroma; undesirable taste and biting taste were small.