Responses Of Flue-cured Tobacco Development, Yield, Quality And Tobacco-planting Soil Properties To Biochar Rates

The flue-cured tobacco had an obvious phenomenon of declined quality,unclear features and unobvious style because the soil properties declined on accountof unreasonable cropping system, cultivation methods and fertilization patterns inrecent years. So it is very important to improve tobacco-planting soil physical andchemical properties, produce high quality tobacco and highlight the strong-flavor typecharacteristics. The field trials were conducted at the Xuchang campus of the HenanAgricultural University in2012, and the pot experiment were conducted at Jinyeyuanin Fangcheng County of Henan Province in2013. The test researched the effects ofbiocharon on the improvement of tobacco-planting soil properties, growth and dedevelopment law of tobacco plant, tobacco economy character and physical properties,chemical components and neutral aroma substances and sensory quality in flue-curedtobacco. The results were as follows:1. Effect of biochar application on tobacco-planting soil physical and chemicalpropertiesApplication of biochar can significantly reduce soil bulk density, reduce soilmoisture at30and45days after transplanting, and improve soil moisture beforetransplanting and the middle and later growth period. It can significantly improve soilpH and soil organic matter. Application of biochar can reduce the nitrogen content ofthe soil. There is no obvious law about effects on soil available phosphorus content.The content of soil available potassium increased sharply. It had a greater effect on pHand nutrient content of the soil under the condition of more amount of biocharapplication.2. Effect of biochar application on growth in tobacco plantThe growth period of each treatment will extend as biochar applicationrate increased. T3treatment (biochar application ratio of6.7%) extended9days thanCK treatment. Biochar application had inhibition effect on tobacco plant height, stemgirth, leaf area, dry matter weight and the root activity before60days aftertransplanting, and it had a positive effect after60days. Biochar application hadinhibition effect on root dry weight and root volume before45days after transplanting, and it had a positive effect on the development of tobacco roots in45days aftertransplanting.Application of biochar can increase the content of total nitrogen in tobaccoleaves at early growth stage in flue-cured tobacco. The difference will reducegradually as the delay of growth period, especially at later growth stage. The totalnitrogen content will reduce when the biochar application reached5%. Application ofbiochar had a certain extent of inhibition effect on the starch formation and storage atthe early growth development of tobacco plant, but it had no big influence on starchaccumulation at later growth stage of tobacco plant. The content of total sugar andreducing sugar increased as the increase of the amout of biochar application.3. Effect of biochar application on chemical components in flue-cured tobacco leavesApplication of biochar had great influence on total nitrogen content in the upperleaves and middle leaves, and it had less impact on total nitrogen content inlower leaves. Biochar application can reduce the total nitrogen content of flue-curedtobacco. Biochar application had a different effect on the starch content in differentposition of flue-cured tobacco. Biochar application can reduce the starch content inupper and lower leaves and improve the starch content in middle leaves. Applicationof biochar can reduce the nicotine content in middle leaves. Moderate biocharapplication can increase the nicotine content in upper and lower leaves, and excessiveapplication will reduce the nicotine content. Application of biochar can increase thecontent of total sugar and reducing sugar of flue-cured tobacco. Application ofbiochar can reduce the potassium content in upper leaves. Application of biochar in5%range can effectively improve the potassium content in upper leaves and lowerleaves, but the potassium content will reduce if the amount of biochar applicationcontinued to increase.4.Effect of biochar application on petroleum ether extract and neutralaroma substancesThe content of petroleum ether extract increased first and then decreased as theincrease of biochar application rate in upper leaves. The content of petroleum etherextract increased as the increase of biochar application rate in middle leaves. There isno significant influence of biochar application on petroleum ether extract content inlower leaves.Application of biochar can increase the total amount of neutral fragrantsubstances in flue-cured tobacco, particularly in upper leaves. The neutral aroma components of T3treatment was the highest in middle leaves. Application of biocharcan improve the content of carotene degradation products, phenylalanine products,browing reaction substances, cembratriendiol and neophytadiene in flue-curedtobacco.5. Effect of biochar application on economic characters and physical properties influe-cured tobaccoThe first-class tobacco proportion and average value is higher than theCK treatment under biochar application in the condition of field trials. Theyield, output value and average price of T2treatment (biochar6000kg hm-2) andT3(biochar9000kg hm-2) were better. Biochar application had an obvious effect ontobacco filling value, and it can improve the filling value of tobacco leaves effectively.Biochar application had a different influence on leaf weight, percentage of stem, leafthickness and tension in each treatment.6. Effect of biochar application on the sensory quality in tobacco leavesApplication of biochar can improve tobacco smoking quality, and has a higherimprovement range as the increase of biochar application rate. Application of biocharhad varying degrees of improvement on aroma quality, aroma volume, offensive taste,irritancy, strength and combustion in upper leaves, and it had less impact on theconcentration, tender and gray. Application of biochar had different effects ondifferent indicators of different treatmen in middle leaves. The T3treatment (biochar9000kg hm-2) had a better comprehensive evaluation and sensory quality.