| ABSTRACT:Soil as the most important ecological factors affecting the formation ofthe quality of flue-cured tobacco, is the foundation and premise for the highest yieldand quality of tobacco.Too much use of fertilizers and modern farming methods ofunreasonable, excessive use of land resources to make plant smoke a series ofpollution and damage to the soil, it cannot satisfy the needs of high quality tobaccoproduction. So, The discussion of conservation tillage and soil improvement researchmore and more cause the attention of relevant scholars. Straw returned is attachedgreat importance to the improvement in soil improvement research way,at presentabout returning wheat straw to plant tobacco soil improvement effect, the suitabledosage of wheat straw counters-field set, the specific way of returning is not the exactconclusion. Henan as a big province of wheat production and the characteristics ofluzhou-flavor smoke zone, to carry out the research of wheat straw improvedhas anatural advantage.Based on the previous studies on this subject, pot experiment inHenan agricultural university science park, research is mainly focused on the differentamount of rotten straw returned on flue-cured tobacco growth and the effect of soilimprovement. The main research results are as follows:1.The influence of rotten straw on flue-cured tobacco growth and development.The results show that: After adding the rotten straw, the plant height, stemcircumference, maximum leaf area, leaf number effectively also have differentdegrees of improvement. At the early stage of the transplanting, plant height decreaseafter adding straw, on the effective leaf number of tobacco plant formation has apositive role, T3,T4have obvious advantages. In the last quarter of the growth anddevelopment of tobacco plant, T4,T5treatments which added more straw growingbetter than others, it means the large number of adding straw extended the tobaccogrowth period.In the tobacco growth period, Each treatment’s root dry weight, rootfresh weight, root volume rendering linear rise slightly downward trend in late stage,After added the rotten straw, have positive influence on the development of flue-cured tobacco root, significantly increased the root dry weight, root fresh weight, rootvolume, root dry matter accumulation, but when you start adding excessive loweringeffect of this increase.The overall comparison,growth and development of theindicators of tobacco growth period in good performance, it descript that adding somestraw, has a positive effect on the quality of tobacco.2.The influence of rotten straw carbon and nitrogen metabolism of flue-curedtobacco. Amylase, invertase, nitrate reductase is the key to the process of carbon andnitrogen metabolism, the activity of enzyme activity determines the strength of carbonand nitrogen metabolism of tobacco plant. Amylase and invertase is the key enzymein the process of carbon metabolism, after adding the rotten straw, these two kinds ofenzyme activity was reduced after the first rise trend, up to a maximum of60d aftertransplanting, the accumulation of starch and soluble sugar changes along with thechange of enzyme activity.After transplanting45d, amylase content increased in theleaf, soluble sugar content decreased,Photosynthetic product by providing theskeleton of tobacco plant start to accumulate storage nutrients conversion.In thegrowth period of tobacco，Nicotine content change trend after the first rise in decline,law of the rise again, total nitrogen content is on the decline.90d aftertransplanting,nicotine content is up to the maximum, T4treatment significantly higherthan the other,total nitrogen content is lower.3. The influence of rotten straw to soilimprovement in planting tobacco.In the reproductive period of tobaccoplant,eachtreatment increases in soil pH lower than the control,soil pH performance isbetter on T3,T4treatment.Large effect on soil alkaline hydrolysis n at the earlygrowthstage,help to improve the ability of the soil nitrogen supply, soil fertility is maintainedhigher at late.But the ability to add too much protecting fertilizer and begin to decline.After added the rotten straw45d,90d after transplanting large influence on soilavailablephosphorus, the difference is obviously,with the growth of tobaccoplants,each treatment available phosphorus content decreased.Available k content inthe reproductive period is "concave" shape distribution,30d aftertransplanting,Rapidly-available potassium content is the highest,then fall,90d hadrebounded after transplanting,add straw processing by amplitude is greater than thecontrol, it means that add the rotten straw is advantageous to the maturity of tobaccoplant vega soil rapidly-available potassium supply,improve the potassium content inupper leaves,so as to produce positive effects on improving quality upper leaves.Soil organic matter content distribution is bimodal curve,two peak distribution appeared in45d,75d after transplanting, add the rotten straw increased soil organic mattercontent,T3, T4treatment effect is obvious.Different amounts of decomposition of straw in the whole growth improved tovarying degrees tobacco soil enzyme activity.Soil urease activity at the early stage ofthe transplanting is higher,is advantageous to the soil nitrogentransformation.Invertase activity increased with the flue-cured tobaccogrowth,maximum60d after transplanting,T4treatment highest activity.Catalaseamong treatments were not significant，but after adding straw peroxidase activityincreased compared with control, the whole growth period at a higher level,to ensuretimely hydrogen peroxide decomposition in the soil,create a good environment fortobacco growth and soil microbial activity,T3treatment performed better.Cellulaseactivity increases with the amount of straw,in the group phase of activity,then beganto decline,the lowest maturity,T4treatment highest activity.Add the rotten straw to soil microbial biomass carbon and nitrogen have apositive impact,with the increase of the amount of straw,soil microbial biomasscarbon and microbial biomass carbon increased after the first downwardtrend,microbial biomass nitrogen has been increased,significant difference was foundin each treatment. After transplanting30d,75d,the most significant difference eachdeal with microbial biomass carbon,microbial biomass carbon to peak when30d.30dafter transplanting,microbial biomass nitrogen content in the highest,90d aftertransplanting,each active microbial biomass nitrogen increases with increasingamount of straw.Overall,add the rotten straw can guarantee soil microbial activity hasbeen in a higher level.4.Add the rotten straw effects on tobacco leaf quality.Add the rotten straw,isadvantageous to the tobacco leaf quality formation,each processing inner chemicalcomponents are in high quality levels of tobacco leaf,But different straw add quantityaffect different chemical components in flue-cured tobacco.T3, T4treatment of upperleaves of two sugar ratio increased significantly,that add the rotten straw plays apositive role on the coordination of the ratio between reducing sugar and totalsugar.Flue-cured tobacco in central and upper leaves chlorine content is lower, upperleaf potassium content increase obviously,total nitrogen and nicotine content alsoincreased,Add the rotten straw is advantageous to the upper leavesthe ratio between reducing sugar and total sugar.Starch content reduced,the ratio of nitrogen tonicotineis coordinated,T3treatment performance is best.After add the rotten straw,a larger effect on the petroleum ether extract,but it hasdifferent effects on different parts.After adding the rotten straw,upper leavespetroleum ether extract content of T4treatment is the largest.On the lower leaves andmiddle leaves,petroleum ether extract the highest levels in control treatments.Overall,increase the petroleum ether extract content of upper leaves,reduces the content of thelower leaves, it’s beneficial to increase the availability of upper leaves,T4treatmentsignificantly improved on the upper leaf,it could inhibit the lower leaves decreasepetroleum ether extract content. |
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