Effects Of Microorganism's Population, Enzyme Activity On Tobacco Quality Of Differently Textured Soil

In order to explore the soil nutrient, microorganism, enzyme activity and tobacco quality's characterization of different texture tobacco-growing soil, the present research studies the contents of available N, total N, available P, total P, available K, total K, organic and pH, the amount of bacteria, fungi and actinomycete, the enzymatic activity of dehydrogenase, catalase, peroxidase, urease, invertase, polyphenoloxidase and acid phosphatase, the tobacco leaf's physico-chemical characteristics, main pigment, polyphenol, organic acid and higher fatty acid's content, the smoking quality of differently textured tobacco-growing soil in Wuping, and the relationships between the soil texture, microbial populations, soil enzyme's activity and tobacco quality also be studied. The results as follows:1. Sand soil, loam soil and clay respectively account for 37.07%,58.05%,4.88% in Wuping's tobacco-growing soil; The differences of main nutrient in different soil texture were significant; There were some relationship between sand, clay and most main nutrient, the relationship between silt and main nutrient wasn't significant.2. The difference of microbe's amount was significant in different texture soil. The amount of bacteria, actinomycete and total microbe in loam were the largest, while the least in clay. The amount of fungi in the clay was the largest, while the least in sand; the negative correlationship between the content of sand and the amount of fungi was in a significant level; there was a significant positive correlation between the content of silt and the amount of actinomycete, a significant positive correlationship between the content of clay and the amount of bacteria and total microbe, and a very significant positive correlationship between the content of clay and the amount of actinomycete.3. The differences of enzyme activity of urease, catalase, peroxidase and dehydrogenase in different texture soil were above the significant level. The activity of catalase in loam was the highest, while in sand was the lowest. The activity of dehydrogenase, peroxidase and urease in clay were the highest, while in sand was the lowest. There was a significant negative correlation between the content of sand and the enzyme's activity of dehydrogenase, urease, a significant positive correlationship between the content of silt and the enzyme's activity of dehydrogenase, urease, a significant positive correlationship between the content of clay and the enzyme's activity of catalase, and a very significant positive correlationship between the content of clay and the enzyme's activity of dehydrogenase, peroxidase and urease.4. There is some difference of tobacco's quality in different texture tobacco-growing soil. The tobacco leaf's weight per leaf, stem percentage, moisture content, content of total nitrogen, nitrogen, potassium, calcium, magnesium, cuprum and nitrogen-nicotine ratio in clay were the highest, while lowest in sand, phosphor's content in loam soil were higher than clay and sand; The tobacco leaf's score of aroma's quality, aroma's volume, aftertaste and total smoking in sand were the highest, while lowest in clay.5. There were some relationships between the mechanical constituent of soil and tobacco leaf's quality, this relationship mainly showed on tobacco leaf's single leaf weight, stem percentage, leaf thickness, the content of total nitrogen, nitrogen, potassium, calcium, magnesium, cuprum, phosphor, quality of aroma, volume of aroma, irritation and the total score of smoking, and this phenomenon showed on sand and clay more significant than silt; There were some relationships between the microorganism, enzyme and tobacco leaf's quality, this relationship mainly shows on tobacco leaf's content of reducing sugar, total nitrogen, nitrogen, potassium, calcium, magnesium, cuprum and phosphor, and this phenomenon showed on bacterial number, activity of dehydrogenase, polyphenoloxidase, urease, invertase were more significant than the other microorganism and enzyme.