Soil Humus Characteristics Of Yunnan Gold Corridor Tobacco Growing Areas

This study selected 73 samples of soil and flue-cured tobacco leaves from Yunnan Golden Corridor tobacco-growing areas,systematically analyzes the composition characters of soil humus in Yunnan Golden Corridor tobacco-growing areas and their realationships with the physiochemical characteristics of soil,soil nutrients and chemical compoent of tobacco leaves;using clustering and variance analysis method to study the composition characters of soil humus in Yunnan Golden Corridor tobacco-growing areas and their difference beween different soil types;using simple correlation and linear stepwise regression analysis method to study the realationship between soil humus with the physiochemical characteristics of soil and chemical compoent of tobacco leaves,The main results are as follows:1.The mean of the soil humus and its composition carbon concent in Yunnan Golden Corridor tobacco-growing areas : the humus 16.64g/kg,humus acid 5.15g/kg,humic acid 1.81g/kg,fulvia acid 3.35g/kg,humin 11.49g/kg,HA/FA ratio range for 0.19-2.06,the average is 0.54.Indicator for the humus and its composition carbon conten and the HA/FA ratio,the 10 city of Yunnan Golden Corridor tobacco-growing areas were divided into three categories,the Ⅰclasses include Kunming,Yuxi and Puer;the Ⅱclasses include Lincang,Qujing and Dali;the classes include Honghe,Ⅲ Chuxiong,Baoshan and Wenshan,the Ⅲclasses area’s soil humus and its compositions carbon concent were significantly higher than Ⅰclasses and class Ⅱ,HA/FA ratio had no obvious difference between the three regions.Soil humus and its composition carbon concent has a significant difference between different soil types,humus carbon content in purple soil was significantly lower,and other soil types were as follows(frow high to low): red soil>alluvial soil> paddy soil;HA/FA ratio was all less than 1 in four soil types,and it was as follows(frow high to low): alluvial soil > purple soil> paddy soil> red soil.2.Overall,soil humus carbon and its components had significant regression relationship with the soil p H,CEC and clay,had significantly positively correlated with the content of fine clay and cation exchange capacity,had negatively correlated with the p H of soil;soil fulvia acid,humic acid and humus acid had a close relationship with soil p H and clay,had positively correlated relationship with clay,had negatively correlated with the p H;soil humin carbon have very significant regression relationship with soil CEC and p H,had positively correlated relationship with CEC,had negatively correlated with the p H;soil HA/FA ratio had significant positive correlation with soil p H;the relationship between physiochemical characteristics of soil and soil humus had the same rule with the Yunnan Golden Corridor tobacco-growing areas.3.Soil humus carbon and its components had a significant positive relationship with soil total nitrogen,had no significant correlation with total potassium,soil humus and humin has significant positive correlation with total phosphorus;soil humus and its components had significant or extremely significant positive correlation with effective iron,effective boron and water-soluble chloride ions,there was no significant correlation with effective fierce and effective molybdenum;only the soil total nitrogen had a significant positive correlation with HA/FA ratio.4.Compared to hifh-quality flue-cured tobacco chemical composition index suitable scope,Yunnan Golden Corridor tobacco-growing areas tobacco leaf total sugar and reducing sugar content is higher,the content of total nitrogen,nicotine,chloride,potassium chloride ratio,alkali nitrogen ratio and petroleum ether extract was appropriate,the ratio of sugar to alkali was higher,potassium content was low;soil humus and its components carbon concents had a significant difference between different types of tobacco leaf quality,with subtypes Ⅲsignificantly higher,HA/FA ratio was significantly higher in subtypes area,and it was as follows(frow high to Ⅰlow): subtypes Ⅰ> subtype Ⅲ> subtypes Ⅱ;soil humus and its components had a relatively close relationship with the chemical composition of tobacco leaves,soil humus and tobacco polyphenols content had a significant positive correlation,soil fulvic acid carbon concents had a significant positive correlation with the ratio of potassium to chlorine,soil humic acid carbon concents had a significantly negative correlation with total sugar,reducing sugar,the ratio of sugar to alkali,and had a significant positive correlation with nicotine,there were extremely significant positive correlation between soil humus acid carbon concents,HA/FA ratio and the content of potassium,soil humin carbon concent had a significant negative relationship with petroleum ether extract.