The Tobacco-growing Soil Fertilizer And Its Relationship With The Quality Of Tobacco Leaves In Hengnan

The soil fertilizer and nutrient states, which have a close relationship with thequality of tobacco leaves, are the key to achieve quality cultivation production offlue-cured tobacco. Hengnan is one of most important county which produce tobacco,3 000hm2 tobacco were planted and 600 tobacco leaves were purchased. Most of thetobacco-growing soils were derived from quaternary red earth and purple sandstonesin Hengnan. The nutrient states of tobacco-growing soils were surveyed and analyzed,the major mineral elements and the quality of tobacco leaves were analyzed during2002 to 2005.The fertilization programma and technique were adjusted, the soilenvironments and nutrient environments of tobacco growth were improved by soilsurvey. The results through experiments and production by many years are:1. The pH of most soils which derived from quaternary red earth were less than5.0, and some of them were less than 4.0.2. The organic matter of most soils were rich in Hengnan, but the differences oforganic matter of different soils were large; The soils humus/organic matter ratio waslow when the organic matter was high, the humus of different soils were more or less.3. The alkaline N was rich in Hengnan. The available P was low,48.3％of themwere less than 15 mg/kg. The available K of 95％soils were low in Hengnan.4. The Ca and S of tobacco-growing soils were suitable in Hengnan, The Mgwere scare in most places, 88.8％soils were less than the suite content of the tobaccogrowing(1.0 cmol/kg～1.5 cmol/kg),and 49.0％of them were less than 0.5 cmol/kg.5. The available Cu and Fe were rich in tobacco-growing soils of Hengnan. Theavailable Mn and Mo were suitable for tobacco-growing, B was scare and 49.1％ofthem was less than 0.1 mg/kg. The available Cl of 6％soils were more than 25 mg/kg,and 94％of them are less than 25 mg/kg.6. The contents of N, K and S were the suitable content, but K was near the lowsuitable content. The P was scare, only 2.0 g/kg. The average content of Mg was only2.5 g/kg; The average content of Ca was 26.1 g/kg, which was more than 25 g/kg.The average Cl was low, only 1.6 g/kg. The Zn was in the rage of 43 mg/kg～94mg/kg,and the average content was 60 mg/kg, there was a quiet difference in different places of the Hengnan; The average content of B was 7.59 mg/kg,much lower thanthe suitable content(10～40 mg/kg).7. The quality of tobacco leaves was increasing year by year because the contentsof Chemical components were more balance than before. The contents of total N andnicotine in tobacco leaves was high, but the Cl,reducing sugar and sugar/nicotineratio were low. After 2003, the main chemical components were more balance thanbefore.8. The color of tobacco leaves was dark yellow.The upper leaf and cutter weremature and their oil were rich. The cutter's structure was loose, but the upper leafswas not. The lower leaves were mature too, but it's short of oil. The aroma quality andquantity of the upper leaf and cutter were good in Hengnan. The quality of tobaccoleaves were in medium level, but there was a certain irritation and offensive taste inthem.9. There was a direct effect of soil nutrient state on the quality of tobacco. Thetotal N and nicotine of tobacco leaves were rich, when the soil organic matter and Nwere high but the K was scare. The total sugar of tobacco leaves was rich, butreducing sugar was scare, the sugar/nicotine ratio and N/nicotine ratio were low.