【作者】 汪璇；

【导师】 谢德体； 魏朝富； 刘洪斌；

【作者基本信息】 西南大学 ， 农业资源利用， 2009， 博士

【摘要】 产地对作物品质的形成和影响具有非常重要的作用。依据良种的生物学性状,选择最适宜的地区进行区域化栽培是现代化农业的重要特征。作物生态适宜性评价是认识和掌握一定地域内作物生长发育对各生态因子的需求与该地域实际可提供的生态条件相互吻合程度,从而因地制宜地开发利用区域生态资源、优化种植总体布局的最有效方式。目前的作物生态适宜性评价研究主要集中在指标体系和评价方法等方面。指标体系的选择和构建大多源自影响作物生长的光、温、水和土壤基本理化性状,而作物品质和产量是立地条件特别是土壤地球化学背景和气候综合作用的结果。评价方法则大多是从线性角度建立作物品质与环境因子之间的定量关系,较难反映出生态条件对作物品质的复杂影响。现有较成功的作物生态适宜性评价也主要局限在一些试验点上,而在区域层面,较多的存在着“以点代面”或者在不同地形地貌区域方法泛化的现象。随着人为措施日益标准化,可以认为,作物的品质在一个足够小的地理栅格单元范围内是相似的;同一品种作物的品质在相似的环境要素组合下是相似的,环境因子组合越相似,作物的品质也越相似。因此本研究以50m栅格为基本单位,以重庆烤烟区烟叶品质和烟区生态环境为研究对象,引入在处理复杂非线性系统方面具有较大优势的计算智能技术,综合运用空间分析、数理统计等方法,从区域层面系统研究地理条件复杂的重庆烤烟区气候、54种土壤地球化学元素(指标)、地形地貌等空间分布特征及其对烟叶品质的影响,在GIS平台下对烤烟区气候适宜性、土壤地球化学适宜性、地形地貌适宜性和烤烟生态综合适宜性进行细网格定量评价,并通过烟叶等级指标和综合品质评分对评价结果进行验证,在此基础上提出重庆烤烟种植适宜性区划。主要结果如下:1、重庆烤烟烟叶品质特征及综合评价(1)重庆烤烟烟叶品质特征分析。以重庆13个烤烟区县2004～2007年270件定点监测的烟叶样品为材料,分析重庆烤烟烟叶化学成分的总体特征,发现重庆烤烟总糖、还原糖、钾含量较高,氯含量低,碱、氮含量均在适值范围内。在表征烤烟化学成分协调度指标方面,糖氮比、糖碱比、钾氯比偏高,氮碱比偏低。烟叶总体具有燃烧性好,气味清香的特点,但酸碱关系一般。(2)烤烟烟叶品质综合评价体系的构建。以烟叶化学成分作为评价烟叶品质的主要标准,采用不基于先验知识的粗糙集属性约简算法,筛选出影响烤烟烟叶品质的主要指标:还原糖、总植物性碱、氯、钾、氮、钾氯比、糖碱比和氮碱比。在此基础上以国内外公认的优质烟叶最适宜范围为满分,高或低于该最适宜范围依次降低分值,构建烤烟烟叶化学成分综合评价体系。(3)重庆烤烟烟叶品质综合评价。采用熵权法对重庆不同烤烟区县270件烟叶样品进行综合评价,并根据综合评价结果利用层次聚类法将重庆烤烟品质分为4个类别。不同级别烤烟化学成分的统计结果表明:Ⅰ类烟叶具有总糖、还原糖、总植物性碱、总氮、钾含量充分、适宜,氯含量低,可燃烧性好的特点;烟叶化学成分中钾氯比、糖碱比、氮碱比均在优质烟叶最适范围内,具有良好的协调性。Ⅱ类烟叶具有总糖、还原糖、总植物性碱、总氮含量充分、适宜,氯含量低,可燃烧性好的特点;化学成分中糖氮比、钾氯比、氮碱比均在优质烟叶最适范围内,具有良好的协调性;但该类烟叶糖碱比偏高,钾含量偏低,酸碱平衡关系一般。Ⅲ类烟叶具有总植物性碱、总氮含量充分、适宜,可燃烧性好的特点;烟叶化学成分中糖氮比、钾氯比均在优质烟叶最适范围内,具有良好的协调性;但该类烟叶总糖、还原糖、钾含量偏低;糖碱比、氮碱比偏高,酸碱平衡关系较差。Ⅳ类烟叶具有总植物性碱、总氮含量充分、适宜,可燃烧性好的特点;钾氯比、氮碱比也均在优质烟叶最适范围内;但烟叶钾、氯含量低;糖氮比、糖碱比均偏高,酸碱平衡关系差。从不同区县烟叶样品的统计来看,渝东南黔江、武隆、酉阳、彭水样品中Ⅰ类最多;南川、巫山、巫溪、奉节、涪陵次之;而綦江、秀山样品中Ⅰ类较少,其中綦江所采集的3件样品化学成分综合评价均为Ⅳ类,烟叶品质总体较差。2、气候要素对烟叶品质的影响针对重庆烤烟区地形地貌复杂,立体气候明显,小气候类型多样的特点,将经度、纬度、海拔高度、坡度、坡向和地形遮蔽度等地形因子引入到烟区气候空间模拟中,在GIS平台下采用基于DEM的小网格法和多因子日照模拟法分别对烟叶大田期的光、温、水分布进行区域化模拟,研究和分析了烤烟生长季内气候资源的地理分布及其规律;深入分析区域气候条件与烟叶品质的关系,并在此基础上采用模糊数学和层次分析相结合的方法对重庆烤烟种植气候适宜性进行了细网格定量评价:(1)在大田生长期内,烤烟区均温的空间分布比较一致,呈现出中部偏北地区较高,向东南和东北地区逐渐降低,中部的石柱和东北巫溪部分区域热量最低的趋势;降水量总体十分丰富,但在不同生长期内时空分布差异较大;日照时数在435.9771h～912.596h之间,且不同地貌条件下的日照差异比较明显,在巫山、巫溪、奉节等海拔较高地区可以获得较长的日照,而在彭水、酉阳、黔江等地势相对较低的地方获得的日照时数则相对较短。(2)统计分析重庆大田期不同时间段及整个大田期热、水、光条件对烟叶化学成分及协调度影响,表明烤烟大田期气候条件与烟叶化学成分、协调度有着密切的关系。在热、水、光总量基本满足烤烟经济种植要求的前提下,重庆烤烟区热、水、光在大田期的时段分布和匹配比其大田期总量对烟叶化学成分和协调度的影响显著。平均气温对烟叶总糖、还原糖和糖碱比的影响显著,对总植物性碱、氮及其它化学成分和协调度的影响不显著;降水量和日照时数对烟叶中绝大部分化学成分含量的影响均达显著水平。(3)影响重庆烤烟生长的主要气候指标为还苗伸根期均温、旺长期均温、成熟期均温、还苗伸根期降水量、旺长期降水量、成熟期降水量、成熟期日照时数和大田期日照时数。(4)重庆市烤烟种植气候高度适宜区主要集中在渝东南,尤其是黔江、酉阳、秀山、武隆、涪陵的大部分区域;石柱、丰都、南川、綦江一些区域的适宜度有所下降;渝东北烤烟区适宜度则总体相对偏低,其中部分地区适宜度值不足0.3,已不适宜烟叶的生长。3、土壤地球化学背景对烟叶品质的影响土壤地球化学元素在母岩-土壤-植物系统中迁移对农产品内在品质具有特殊影响,将土壤地球化学背景引入到作物生态适宜性评价中,充分考虑到烤烟区地形地貌复杂的特性以及土壤类型差异对于土壤元素(指标)含量的影响,集成回归克里格法和普通克里格法在GIS平台下对烤烟区土壤地球化学元素(指标)分布进行了区域化模拟,系统分析了区域土壤植物营养元素特征,探寻地球化学元素(指标)对烟叶品质的影响,进而对重庆烤烟区土壤地球化学适宜性进行了细网格评价,取得的结果如下:(1)研究区土壤养分分布具有富磷、富钾和氮适中的特点。除奉节北部、丰都、涪陵以东和綦江地区氮含量相对缺乏外,其它地区均处在适度和富足级。磷含量呈渝东南大于渝东北的趋势,总体含量均较富足。除酉阳以东,巫溪部分地区钾含量适中外,其它地区都呈较富足或很富足状。总体来看,烤烟区大量营养元素分布比较均匀。(2)烤烟区土壤Ca和Mg含量在区域分布上表现出一定的相似性,其整体呈现出渝东北高于渝东南的趋势,Ca的高值区主要集中在渝东北奉节东部,而Mg主要集中在渝东北巫溪地区,此外在渝东南綦江、南川也有部分高值。土壤S则呈现出明显的渝东南高于渝东北的趋势,其中渝东南武隆、彭水、黔江含量最高。(3)烤烟区土壤微量营养元素Mn、Cu、Zn、Mo、B、Cl在空间分布上表现出较强的相似性,其整体表现出渝东南大于渝东北的趋势,总体上高值区域具有较为明显的斑块状分布特点,主要分布在东南武隆、彭水、黔江、酉阳一带;Fe的空间分布情况则不太规则,总的趋势并没有表现出带状的分布格局,东北部巫山,东南部彭水、武隆、南川部分地区具有高值,但总体含量与其它地区差异并不明显。(4)烤烟区54.83%的地区土壤有机质含量在1.5～3%之间,且主要分布在石柱、南川、涪陵以东,丰都南部以及除秀山外渝东南大部分地区;有机质含量＜1.5%的面积为18413.01km~2,占整个烤烟区面积的45.16%;只有零星的地区土壤有机质含量超过3%,烤烟区土壤有机质含量比较丰富。(5)整个烤烟区土壤总体呈弱酸性至中性,绝大部分土壤pH都能满足烟叶生长的要求。从空间分布来看,渝东南主要烤烟区武隆、丰都、石柱和南川的个别地区土壤出现较为明显的酸化特征;不同土壤类型植物营养元素含量丰、缺依次是:黄棕壤、黄壤、石灰土、紫色土、水稻土。(6)影响烤烟区烟叶化学成分及协调度的土壤地球化学元素(指标)有:土壤pH值、土壤有机质、N、P、K、Cl、Ca、Mn、Cu、Mg、Fe、B、Zn、REE。(7)重庆市烤烟种植土壤地球化学高度适宜区主要集中在渝东南武隆、彭水、黔江、酉阳、南川以南地区;渝东北巫山、奉节以北地区适宜度逐渐下降;丰都、涪陵以西、奉节西部以及綦江大部分区域土壤地球化学的适宜度都较低。4、地形地貌对烟叶品质的影响采用曲线估计法研究和分析了研究区地形地貌对烟叶品质的影响,进而结合模糊数学和层次分析法对烤烟区地形地貌适宜性进行了细网格定量评价:重庆烤烟区地势起伏大,层状地貌明显,主要包括中山、低山、高丘陵、中丘陵、低丘陵、缓丘陵、台地和平坝等8大类。海拔高程分布特征为,大部分地区位于海拔1200m以内,其中海拔400m以下地区占总面积的10%;海拔400m～800m和800m～1200m区域分别占总面积的37.60%和30.57%;海拔1200m以上区域占总面积的21.83%;且总体呈现出渝东北普遍高于渝东南的趋势。从坡度组成来看,烤烟区适宜农业耕作的平地与缓坡地(坡度＜15°)的面积占全区土地总面积的37.08%;可以部分用于农业生产的中坡地(15～25°)面积占土地总面积的31.85%;而不适宜农业生产的陡坡地(＞25°)面积为12885.66km~2,占土地总面积的31.07%,其中有10.70%的土地坡度在35°以上,主要分布在巫溪以北的中低山区。烤烟区海拔高程和坡度对烟叶化学成分均有影响,以海拔900m～1200m范围内,＜10°地区种植的烤烟品质较为优良。烤烟区地形地貌适宜度最高的地区主要集中在渝东南尤其是酉阳中部、黔江东部、石柱中部、涪陵和南川西部等地区;秀山、酉阳东部、綦江地区适宜度逐渐下降;渝东北烤烟区适宜度总体相对偏低,巫溪部分地区适宜度值甚至不足0.1,已完全不适宜烟叶的种植。5、基于计算智能的烤烟生态适宜性综合评价及烟叶种植区划(1)烤烟生态适宜性综合评价指标体系的构建。从可持续发展理论出发,以大生态系统观为指导,综合考虑气候、土壤地球化学因素和地形对烟草生长的影响,构建了重庆烤烟生态适宜性综合评价指标体系,整个指标体系由目标层、准则层、指标层三大部分构成,涵盖了影响重庆烟叶生长最重要的20个生态因子:还苗伸根期均温、成熟期均温、旺长期降水、成熟期日照、大田期日照、海拔、坡度、土壤有机质、土壤pH值、N元素、P元素、K元素、Cl元素、Ca元素、B元素、Ree稀土元素、Zn元素、Mn元素、Fe元素、Mg元素。(2)针对烟叶种植生态适宜性综合评价具有典型非线性动力学特征以及各评价指标之间的模糊性和渐变性,将模糊逻辑、人工神经网络和智能优化技术相结合构建了烟叶种植生态适宜性智能评价模型。模型将专家知识定量化,充分利用神经网络良好的非线性映射能力,通过对已有样本的学习来探寻烟叶种植生态适宜性级别与生态指标之间的内在规律,在GIS平台下完成了重庆烤烟生态适宜性综合评价并对结果进行了检验,符合率为82%,整个烤烟区生态适宜性综合评价结果良好。(3)重庆市烤烟区生态适宜性综合评价结果说明,最适宜级别5379.41km~2,占整个烤烟区面积的13.15%,主要分布在石柱、丰都以东、武隆、彭水西北,黔江、酉阳中部等地区,南川、綦江、秀山和奉节等也有零星分布;适宜级别13022.89km~2,占整个烤烟区面积的32.20%,主要分布在涪陵南部,南川、奉节北部,秀山东部地区,酉阳、彭水、黔江、巫山和巫溪也有零星分布;次适宜级10529.01km~2,占整个烤烟区面积的22.62%,主要分布在酉阳以东,秀山北部,彭水中部,綦江南部等地区,奉节南部和巫山的部分地区也有零星分布,占整个烤烟区面积的26.03%;不适宜级别9148.48km~2,,主要分布在丰都以西、南川东南、綦江北部,奉节、巫山南部,巫溪西北,此外渝东南石柱、武隆等个别地区也有零星分布;另有2430.15km~2的土地为居民点、滩涂等,属于烤烟种植的屏蔽区域。(4)整个重庆烤烟区可以划分为渝东南重点发展区、渝东北重点发展区、渝东南稳定发展区、渝东北稳定发展区、渝东南限制种植区和渝东北限制种植区共6种类型。其中重点发展区包括黔江、酉阳、彭水、武隆、石柱、南川大部分地区以及丰都东部、涪陵、綦江和秀山个别地区和奉节北部、中部,巫溪南部和巫山的部分地区;稳定发展区包括秀山大部、酉阳东部、涪陵中西部和黔江、彭水、綦江、南川、武隆的零星地区以及巫山中部、巫溪、奉节的少部分地区,烤烟生产可在区域内规模化种植或者土地通过技术措施加以改良,作为烟草种植的扩大发展预留地;限制发展区包括丰都、涪陵以西,武隆北部,石柱西部和秀山、彭水、南川东南、綦江的个别地区以及奉节、巫山南部,巫溪西北,巫山东北部分地区,这些区域土地不适宜于烟草种植,应严格限制其烟草种植面积。综上所述,本文利用54种土壤地球化学元素(指标),结合气候、地形要素从区域层面系统研究重庆烤烟区生态环境对烟叶品质的影响,明确了影响和制约重庆烤烟烟叶品质的生态指标,并针对生态环境对作物品质非线性、非确定复杂影响的特点,集成不同计算智能技术,在GIS平台下对重庆烤烟种植进行了生态适宜性评价,不仅进一步丰富和完善了生态适宜性评价的体系和方法,也为有效利用区域生态资源,合理开展烟草布局提供了最基本的依据。本次研究主要集中于对农产品品质有主导影响的生态环境方面,但社会经济因素对作物品质仍有较为重要的作用,未来应进一步量化其对作物种植适宜度的影响,并与生态适宜性评价相结合,从而更好地应用到种植实践中。更多还原

【Abstract】 Habitats have a great effect oncrops growth and quality.Modern agriculture management aims to optimally allocate crop planting through measuring the coupling of designating crop to given land, and Crop ecological suitability evaluation is therefore hold the most effective means to assess coincidence degree between crops growth requirements for ecological environments and available ecological features.Nowdays crops ecological suitability evaluation research mainly focuses on the selection of evaluation indices as well as the assessment methods application.And the hierarchy of evaluation index is mostly built by selecting climatic factors and several soil physical and chemical features.However,crop quality is determined by site conditions,especially the comprehensive influence of soil Geochemistry and climatic elements.Evaluation methods mostly concentrate on building linear relationship between crops quality and ecological factors,which rather hardly can depict ecological environment actual consequence.Meanwhile,available successful crops ecological suitability evaluation cases just limit on some trial points and in regional level,more just use the result of a selected point to replace the situation in the entire area or simply apply single interpolation technology regardless of topography difference..With the standardization of artificial measures has been widely practiced,it is hold that the crop quality could be similar within a detailed geography grid unit and that the same cultivar quality could be similar with almost the same similar ecological environment.The more similar ecological environments,the more similar the crop quality is.Based on this premise,in this study,50m grid was chosen as basic unit,and a GIS-based decision support system was built for evaluating flue-cured tobacco ecological suitability in flue-cured tobacco-planting areas,Chongqing,China.This was done by integrating computational intelligence technology which is of strong strength in dealing with complex nonlinear relationship, spatial analysis and mathematical statistics.The spatial distribution of Climatic factors,54 soil geochemical elements as well as terrain and their influences on flue-cured tobacco quality were given detailed analyses.And climate suitability,soil geochemistry suitability,topography suitability and ecological comprehensive evaluations were punitively calculated in detailed grid scale.The results are summarized as follows:1.Flue-cured tobacco leaves quality characteristic and comprehensive evaluation(1)Flue-cured tobacco leaves quality characteristic analysis.270 flue-cured field monitored tobacco leaves from the year of 2004-2007 were chosen as samples and chemical compositions were given detailed analyses.The results showed that the concentrations of total sugar,reducing sugar and potassium are slightly higher while the concentration of chlorine is very low.The concentrations of total alkaloid,nitrogen are in fitting value range.In terms of tobacco leaves chemical compositions coordination degrees,sugar/nitrogen,sugar/alkaloid and potassium/chlorine are all slightly higher whereas nitrogen/alkaloid is slightly low.Generally,Chongqing flue-cured tobacco leaves are of good combustibility,the aroma type of flue-cured tobacco is light but the acid alkali balance is under normal.(2)The comprehensive quantitative evaluation system of flue-cured tobacco leaves quality.In this study,chemical compositions were used to assess tobacco leaves quality.Indices that influence leaves quality were selected as follows:reducing sugar,total alkaloid,chlorine,potassium,nitrogen, potassium/chlorine,sugar/alkaloid and nitrogen/alkaloid through rough sets attributes reduction.The flue-cured tobacco leaves comprehensive quantitative evaluation system was constructed by setting scoring standards for selected indexes.(3)Flue-cured tobacco leaves quality comprehensive evaluation.270 samples were scored by entropy-weight method and the evaluation results show that Chongqing flue-cured tobacco quality can be classified into 4 types.For typeⅠ,the concentrations of total sugar,reducing sugar,total alkaloid and total nitrogen as well as all chemical compositions coordination degrees all fall into fitting value range,and the concentration of chlorine is low.Leaves that belong to typeⅡcontain sufficient total sugar,reducing sugar,total potassium and total nitrogen.Sugar/nitrogen, potassium/chlorine,nitrogen/potassium all are in fitting range.However,the concentration of potassium is a bit low and sugar/potassium is a bit high.For typeⅢ,although the concentrations of total alkaloid,total nitrogen and sugar/alkaloid as well as potassium/chlorine are in fitting range,but the concentrations of total sugar,reducing sugar,potassium are on the low side,sugar/alkaloid, nitrogen/alkaloid are on the high side.Leaves that were classified as type TV contain sufficient alkaloid and total nitrogen,potassium/chlorine as well as nitrogen/alkaloid also are the fitting range, however,the concentrations of potassium,chlorine are on the low side and sugar/nitrogen, sugar/alkaloid are on the high side.In terms of regional distribution,the samples from the areas of Qianjiang,Wulong,Youyang and Penshui which all locate in the southeast of Chongqing contribute to moreⅠtype,followed by Nanchuan,Wushan,Wuxi,Fengjie and Fuling.Leaves of type I leaves from samples of Qijiang and Xiushan are almost unavailable.2.Climatic factors influence on flue-cured tobacco leaves qualityDue to distinct tri-dimensional climate character in Chongqing flue-cured tobacco planting area, the integration of GIS,multi-factors sunshine hours simulation and small grid simulation methods which consider the topographic elements including elevation,slope,aspect,hill shade,latitude and longitude was applied to simulate climatic factors spatial distributions.The characteristics of regional distribution and influences on leaves quality were given detailed analyzed.Based on analysis results,climate suitability detailed were conducted by combing fuzzy mathematics and AHP. The results are depicted as follows:(1)The spatial distributions of average temperatures within tobacco growth season show similar trend,that is,the temperature of the area of the north-central is relatively high,and then gradually decreases toward southeast and northeast,and in the areas of Sizhu and Wuxi,the average temperature are found lowest.Globally,rainfalls of the whole fields season are quiet sufficient but within different growth stages,the spatial distribution difference is obvious.The whole sunshine hours of the fields growth season range from 435.977h to 921.586h,and appear strong positive correlation with elevation element.(2)The statistics of climatic factors influences on tobacco chemical compositions from the whole fields growth season and different stages show that climatic factors have a strong relationship with tobacco chemical compositions and coordination degrees.Compared with the climatic factors from the whole fields growth season,the climatic factors within different growth stage contribute to more influence.On the whole,average temperature has more influence on tobacco total sugar,reducing sugar and sugar/alkaloid but less impact on total alkaloid,nitrogen and other chemical compositions while rainfalls and sunshine hours have an obvious impacts on most leaves chemical compositions.(3)The climatic factors on flue-cured tobacco quality of Chongqing include the following indicators:the average temperature of transplant shock and root extending period,the average temperature of fast growing period,the average temperature of maturing period,the rainfalls of transplant shock and root extending period,the rainfalls of fast growing period,sunshine hours of maturing period and the sunshine hours of the whole fields period.(4)The result of Chongqing flue-cured tobacco climate suitability evaluation indicated that highly suitable area locates in southeast,especially the area of Qiangjiang,Youyang,Xiushan, Wulong and Fuling.In some areas of Shizhun,Fengdu,Nanchuan and Qijiang,the suitable indices are relatively lower and in the northeast part,the suitable indices are the lowest typically in some regions,where the suitability values are even below 0.3.3.Soil geochemistry influence on flue-cured tobacco leaves qualityIn this dissertation,54 soil geochemiscal elements are investigated to judge flue-cured tobacco planting ecological suitability.Considering the complex terrain feature of research area and the influences from different soil types on soil elements contents,regression kriging and ordinary kriging were integrated to predict soil geochemiscal elements regional distribution.Their spatial characteristics as well as impacts on tobacco leaves quality were given detailed analyses.Soil geochemistry suitability of flue-cured tobacco planting area were finally evaluated.The conclusions can be draw as follows:(1)For the tobacco-planting soils,the contents of total P,total K are rich and the N are medium. In terras of spatial distribution,besides the north of Fengjie,the east of Fengdu and Fuling as well Qijiang,the contents of soil N are in rich or sufficient level.Compared with the northeast of Chongqing,the contents of soil total P are richer.(2)The contents of soil Ca and soil Mg of tobacco-planting area show similar spatial distribution pattern.However,the high value of soil Ca contents were found in Wuxi whereas the high value of soil Mg were found in Wuxi.For the spatial distribution of soil Scontents,it rather has opposite trend.(3)In the 54.83%of tobacco-planting areas,the contents of soil organic are ranged from 1.5-3%,and most are found in Shizhu,Nanchuan,the east of Fuling,the south of Fengdu and most Chongqing southeast regions.The acreage of areas that the contents of soil organic are below 1.5% is 18413.01km~2,which accounts for the 45.16%of the whole tobacco-planting area.Only 0.01% area,the contents of soil organic excess 3%.(4)For most tobacco-planting areas,the soil pH condition can satisfy tobacco leaves growth needs.In terms of spatial distribution,only very few areas of Wulong,Fengdu,Shizhu and Nanchuan were found obvious soil acidification.According to the abundance of soil nutrients contents,Soil types were ranked by yellow brown soil,yellow soil,lime soil and paddy soil.(5)Soil pH,soil organic,soil total nitrogen,soil potassium,soil phosphorous,soil chlorine,soil calcium,soil manganese,soil copper,soil magnesium,soil iron,soil boron,soil zinc as well as soil REE are the soil geochemical indicators that affect Chongqing flue-cured tobacco leaves quality.(6)Soil geochemistry suitability evaluation of Chongqing flue-cured planting area showed that the high suitability values concentrate on Wulong,Penshui,Qianjiang,Youyang,and the south of Nanchuan.In the area of Wushan and the north of Fengjie,the suitability values tended to decreased and reached low level in Fengdu,the west of Fuling and Fengjie as well as Qijiang.4.Topography influence on flue-cured tobacco leaves qualityCurve estimation method was used to analyze topography influence on tobacco leaves quality of the study area,and then Fuzzy mathematics and AHP were combined to evaluate topography suitability in detailed grid.The results can be concluded as follows:(1)There are many various terrains in the study area,which includes middle rolling mountain, small rolling mountain,great rolling hilly,middle rolling hilly,small rolling hilly,gentle hilly,mesa and level land.In terms of elevations,most areas are below 1200m,among which the areas that below 400m account for 10%while the areas that are between 400m and 800m,between 800m and 1200m account for 37.60%,30.57%respectively.The areas that are above 1200m only account for 21.83%.On the whole,the northeast of the study area is of higher elevation than that in the southeast.(2)In terms of slope,37.08%lands of the study area are suitable for agricultural cultivation (slope＜15°),lands that are partly suitable for cultivation account for 31.85%(slope ranges from 15 to 25°).31.07%lands(slope＞25°) are not suitable for cultivation,which account for 31.07%of the whole area and covers 12885.66 km~2.10.70%of them which are located in the small and mille rolling hillys of Wuxi are even above 35°(3)Elevation and slope both show correlation with flue-cured tobacco leaves chemical compositions.In the areas where the elevation ranges from 900m to 1200m and the slope is below 10°,the flue-cured tobacco leaves can obtain better quality.(4)Topography suitability evaluation result showed that the high suitability areas mostly locate in the center of Youyan and Shizhu,the east of Qiangjiang,Fuling and the west of Nanchuan.In the are of Xiushan,Youyang east and Qijiang,suitability level gradually decreases;the suitability of the northeast of Chongqing is relatively low,where Wuxi’s suitability even cannot reach 0.1.5.Computational intelligence-based flue-cured tobacco comprehensive ecological suitability evaluation and planting planning(1)The building of the hierarchy of Chongqing flue-cured tobacco leaves growth ecology comprehensive evaluation.The whole hierarchy is composed of target level,criteria level and indexes level,which covers 20 ecological indicators that mostly influence tobacco leaves growth of study area.The 20 ecological indicators include the average temperature of transplant shock and root extending period,the average temperature of maturing period,the rainfalls of fast growing period, sunshine hours of maturing period,the sunshine hours of the whole fields period,elevation,slope, soil organic,soil pH,soil total nitrogen,soil potassium,soil phosphorous,soil chlorine,soil calcium, soil manganese,soil magnesium,soil iron,soil boron,soil zinc as well as soil REE.(2)Combining with fuzzy logic,artificial neural network and intelligent optimization technology, the model of tobacco ecology comprehensive intelligent evaluation was built.It can quantize expert experiences while using nonlinear mapping of ANN,and search interior laws between ecological suitability and ecology indicators without human interruption.The results showed that the accuracy rate is 82%.(3)Comprehensive ecological suitability evaluation results indicated that the areas that belong to the highest suitable gradation account for 9820.79 km~2,which mainly distributed in Shizhu,the east of Fengdu,Wulong,the westnorth of Pengshui,Qijiang and the middle Youyang.Some of areas of Nanchuan,Qijiang,Xiushan and Fengjie also are also found high suitability value.The areas that belong to the high suitable gradation-including the south of Fuling,the north of Nanchuan,Fengjie, and the east of Xiushan as well as some of areas of Youyan,Pengshui,Qiangjiang,Wushan and Wuxi.The total acreages are about 11148.49km~2.The areas that belong to the normal suitable gradation,the lowest suitable gradation and the worst level account for 13807.42km~2,5645.20km~2 respectively.(4)The whole study area can be divided by six different planting areas according to the suitability evaluation result.And the key development regions include most areas of Qianjiang,Youyang, Penshui,Wulong,Shizhu,Nanchuan,eastern Fengdu,eastern Fuling,odd lots of Qijiang and Xiushan,northern Fenjie,middle Fengjie,southern Wuxi and odd lots of Wushan,in which the value of suitability is above 0.85.Stable development regions include most of areas Xiushan,eastern Youyan,midlle-west Fuling and odd lots of Qianjiang,Pengshui,Qijiang,Nanchuan,Wulong as well as middle Wushan,few areas of Fengjie and Wuxi.In these areas,scale planting can be employed and for some lands,after improvements by technological measures,they can be kept as future potential key development areas.The areas whose suitability value below 0.6,in this dissertation, is hold as limited development region.Western Fengdu,western Fuling,northern Wulong,western Shizhu,odd lots of Xiushan,Pengshui,southeast Nanchuan as well as southern Fengjie,southern Wushan,northwest Wuxi and northeast WushanTo sum up,in this dissertation,54 geochemical elements combined with climatic factors,terrain are investigated to research the influence on the flue-cured tobacco quality of Chongqing,from the view of regional level.Major ecological indices that affect flue-cured tobacco quality were confirmed.An intelligent evaluation model by integrating different computational intelligence technologies for preciously depicting nonlinear and fuzzy relationship between ecology environments and crops quality was proposed.It was conduced to evaluate comprehensive ecological of Chongqing flue-cured tobacco planting area and achieved satisfying results.The whole research results not only contribute to enriching and improving crops ecological suitability evaluation indices and methodology,but can provide fundamental support for regional tobacco planning.However,crops planting suitability is a complex system which also need to consider the influence from social,economical factors.How to evaluate their influences in quantitative way and integrate with ecological evaluation results would have to been paid more attention by multidisciplinary.更多还原