| The experment of chlorinein tobacco-plantings oils and tobacco leaves, as well as the effect of different Cl application on the growth, nutrient absorbed and quality of tobacco were studied by investigation, field experiments and laboratory analysis in Yinbin. The purposes of this study were to understand the status of chlorine content in tobacco-planting soil and tobacco leaves, in order to provide detailed information for improving the quality of flue-cured tobacco leaves in Yibin.The main results were as follows:1. The assay of tobacco-plantings oils and Cl content quantity in Yibin city Based on the chinese tobacco chief company database about the content of tobacco-plantings oils:the tobacco-plantings oils that more than 45 mg/kg are unsuitable to plant tobacco, and that the content of chlorinein less than 30mg/kg are the most suitable to plant tobacco. Through the assay of tobacco-plantings oils and Cl content quantity in Yibin city,the result show: The content of chlorine in various to bacco-plantings oils was low,which average contentw as 13.4mg/kg with the range of trace to 99.7mg/kg in Yibin, so the suitable tobacco-plantings oils account for 90% of all of the oils and the unsuitable oils only 90% in Yibin. The different types of oils showed the order of yellow soil (15.2mg/kg) >lime soil (12.8mg/lkg) >pale brown soil(5.6mg/kg)>purple soil (5.3mg/kg)>rice soil (1.8mg/kg ). In the tobacco-plantings oils, the yellow soil was the most quality that account for 75.6%. The average amount in tobacco leaves was0.70g/kg; which the change range was 0.11~9.19g/kg, and the account of 99% tobacco leaves were lower than the lowest limit of top quality tobacco(3g/kg). Only account of 0.5% tobacco leaf accord with the standard of national top quality tobacco (3.00~6.00g/kg)。2.The effect of flue cured tobacco increasing application of CL fertilizerThe result show that increasing application of CL fertilizer was in the rang of 0~45 kg/hm2,the yield and the upper grade and output value of flue cured tobacco wera improved with the fertilizer adding. When increasing application of CL fertilizer were more than 60 kg/hm2, various indexes were a downward trend. At the same time, the relationship of the increasing application of CL fertilizer and the content of CL in the flue cured tobacco was expermential or linear. correlation. Under the condition of film-covering, leaves chlorine content of each part ,which were 3.00-4.50g/kg ,was the best. But uncovered, leaves chlorine content of each part,which were 2.10-5.00g/kg, was moderate.when the chlorine applied form 45.0-60.Omg/km2 in soil, when the chlorine applied less than 30.0mg/km2 in soil. The different tobacco position content of chlorine showed the order of the upper > the middle >the lower. The leaves chlorine had some effect with the content of sulfur calclum magnesium iron manganese copper and zinc.The contents of totals ugars and reduced sugars in the tobacco leaves were increased by application of proper chlorine, and decrease the content of nicotine and total nitrogen of upper as well as lower leaf, but has a litle effect on middle leaf. M oerover, it can make the indexes, such as K2O/Cl, total sugars/nicotine and nicotine/total nitrogen ,more well-balanced and improve the leaf quality.The results were significant differences about th chlorine residual quantity and chlorineremove in soil environment between two years in field experimen. experiment. The chlorine content of field soils after tobacco harvest were higher than before planting tobacco, but it still fit to plant tobacco but the field soil chlorine content was lower than 30.0mg/kg in 2006. Chlorine content in soils of film-covering and uncovered tobacco finally retuned to the original level after tobacco harvested in 2007. But after harvest the chlorine content was less abvious before the experments. |
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