Study On Henan Tobacco Growing Regionalization Of Ecological Suitability

Based on the collection and analysis of a large number of data of soil and tobacco leaf samples and meteorology, the soil suitability of tobacco-growing areas, the ecological suitability of tobacco-growing areas and quality of flue-cured tobacco qualitative and quantitative evaluation system were established, using the combination of qualitative and quantitative evaluation methods of Hierarchical Analysis, Correlation Coefficients Analysis in this paper. According to the evaluation index system, the qualitative and quantitative assessment and zoning classification of tobacco region in Henan Province were completed.1. The ecological adaptability evaluation system of Henan tobacco planting areas was constructed. (ⅰ) The indexes of evaluation system of the soil suitability of tobacco-growing areas was established, including 10 factors of available potassium, available nitrogen, water-soluble chlorine, available phosphorus, organic matter, topsoil thickness, pH, soil texture, total nitrogen, salinity; (ⅱ) The indexes of evaluation system of climate suitability of tobacco-growing areas was established, including 5 factors of average temperature at maturity and average temperature, sunshine hours, rainfall and relative humidity in the whole growth stage; (ⅲ) The indexes of evaluation system of topography of tobacco-growing areas was established, including 3 factors of landforms, altitude and slope.The weights of soil, climate and topography suitability evaluation were 0.60, 0.30 and 0.10, respectively, in the ecological adaptability division evaluation system of Henan tobacco planting areas.2. The coincidence of the growth and development regulation of tobacco NC89 and the meteorological conditions was systematically studied, and the area of the temperature in transplanting period stabling up to 12℃and the daily average temperature at mature stage lower than 20℃in Henan tobacco fields were analyzed. The relationships between some of quality factors and soil physical-chemical properties were discussed. (ⅰ)Effective leaf presenting leaf law, leaf length and leaf width, plant height and girth growth law and dry matter accumulation law were systematically analyzed and had established each kind of target fitting equation; (ⅱ)Leaf age between 21d-41d was the primary period of the mesophyll cell fast expansion and the inner content gradually rich. With the maturity degree increasing, the definition of chloroplast laminar structure declined, and the structure gradually loosed and vanished, eventually result in the disintegration of chloroplasts, inner contents ionizing and the appearance of vacuoles; (ⅲ)The year's main meteorological fators and calendar year meteorological fators were well coincided with the growth and development law of tobacco NC89; (ⅳ)The time of the average daily temperature stability reaching 12℃in transplanting period was divided into three times, respectively were early April, mid-April and late April. The time of daily average temperature lowing than 20℃at maturity were late August, early September, mid-September and late September; (ⅴ)Soil pH, organic matter content, the percentage of soil particle which the soil particle size is situated between 0.05mm and 0.001mm, and the content of calcium, magnesium, iron, aluminum and sodium in soil had various degree influenced on the content of the four isomers of Megastigmatrienone; (ⅵ) The indicators of total phosphorus, available potassium, organic matter, total nitrogen, magnesium, pH, and sodium in soil had more close relationships with organic acids content in tobacco leaves.3. The relationship of geological background and tobacco leaf quality was researched, and the division of topography suitability was completed. (ⅰ)The areas of holocene geological layer deposition which the most widely distributed in the county of tobacco-growing areas in Henan province was relative appropriate areas for tobacco-growing, the areas of early in the quaternary strata was the medium appropriate areas for tobacco-growing, the areas of pleistocene was less appropriate areas for tobacco-growing, the areas of late pleistocene deposits was less relative appropriate areas for tobacco-growing, and the areas of early pleistocene deposits was appropriate areas for tobacco-growing; (ⅱ) The tobacco-growing areas in Henan province was divided into four grades, the first appropriate areas was accounted for 70% of Henan province, the second appropriate areas were mainly distributed in Zhoukou, Shangqiu, Luohe, Zhumadian and Xinyang, the third appropriate areas were mainly distributed in the Zhoukou, Shangqiu, Zhumadian, Xinyang, and the fourth appropriate areas were mainly distributed in Sanmenxia, Nanyang, Luoyang, Jiyuan.4. The soil suitability level for tobacco-planting in Henan province was systematically researched and evaluated. (ⅰ)The content of soil organic matter in Henan province was in appropriate level in general, most soil samples were neutral or alkaline, the content of available nitrogen was in appropriate level, the content of available phosphorus of most soil samples was low, the average content of available potassium was relatively appropriate but the variation in different areas was great, the content of water-soluble chlorine was high in whole, the CEC of soil was in middle level, and the content of total nitrogen was appropriate. The salinity content of 49 samples was greater than 1.0%, the soil for tobacco-planting of Zhoukou and Shangqiu belonged to light salinization soil, but the soil for tobacco-planting of other areas was non-salinization soil. The soil of Zhengzhou was sandy, and Sanmenxia, Luoyang and Jiyuan were comparatively sticky; (ⅱ)In terms of fertility level, the region of level 1 included 29 counties, the region of level 2 included 19 counties, the region of level 3 included 15 counties, and the region of level 4 region included 1 counties.5. Based on meteorological data of Henan province between April and September in 1971-2005, the mainly climate factor change trend of 35 years in tobacco-planting areas in Henan province was systematically evaluated, and climate suitability of Henan province was divided. (ⅰ) As a whole, the average temperature had a ascend trend, the temperature change trend rate was 0.0061℃/a, and the average temperature of the south of Henan province was higher than the middle which was bigger than the west; The annual sunshine hours had a significant decrease trend, and the trend rate was -4.1575 h/a, and the annual sunshine hours of the west of Henan province were higher than the middle which was bigger than the south; The change trends of rainfall were close to perennial average and had a slight increase trend. The change trend rate was 0.31 mm/a, and rainfall of the south was higher than the middle which was bigger than the west; The relative humidity had a rising trend with fluctuation. The trend rate was 0.047%/a and the west was higher than the middle which was bigger than the west.The rise in average temperature can be made in advance of transplanting of tobacco, and the decline in sunshine hours has a direct impact on leaf photosynthesis which affect the quality formation. (ⅱ) In terms of climate suitability, 7 regions belonged to level 1 , during which the appropriate area of Nanyang was the largest; 11 regions belonged to level 2, during which the appropriate area of Xinyang and Zhumadian was the largest; The area of level 3 in Xinyang (20.97%) was relatively bigger; The area of level in Shangqiu(16.71%)was relatively bigger.6. The indexes in evaluation system of tobacco leaf quality was established and the flue-cured tobacco quality of Henan province was systematically studied and evaluated. (ⅰ) The appearance of most samples was good quality, including more orange color leaves, good maturity, relatively loose structure, good bodied, oilly, medium color saturation, small color difference between blade on the face and blade on the back and leaf color more uniform; (ⅱ) Stem ratio and equilibrium moisture content of tobacco leaves in the appropriate range was in lower proportion.; (ⅲ)Total sugar content was overall high levels, and K+ content was overall low levels; (ⅳ) Sensory evaluation scores of Henan province samples was in the mid to upper level and the samples of Jiyuan got the highest scores, the samples of Nanyang got second scores, and the samples of Shangqiu got the lowest scores; (ⅴ) Comprehensive quality index scores of tobacco in different district of Henan province were all over 70 and the samples of Zhoukou, Xinyang, Shangqiu was lower.7. Growing regionalization of ecological suitability zone of flue-cured tobacco was divided in Henan province. And the zone include 5 first-grade growing areas, respectively was mountainous and hilly-growing areas in western of Henan, plain-growing areas in middle-Henan, Nanyang basin-growing area in southwest of Henan, Dabie mountain and Tongbai mountain-growing areas in southern-Henan, plain-growing areas in east-Henan. And 64 tobacco-growing counties were divided based on appropriate levels.