Study On The Effect Of Topdressing Organic Fertilizer, Biological Fertilizer On Reduction Of Flue-cured Tobacco Continuous Cropping Obstacle

In order to eliminate the obstacles of continuous cropping of flue-cured tobacco,the experiment was conducted in Da Guo Xiang technology experimental field of Linying County of Luohe City,Henan Province,select tobacco continuous of cropping three years,take the one of local main planting varieties—Yuyan No.10 as material,and then study the effects of different fertilizer mixed topdressing and different period topdressing bio fertilizer on soil and quality of continuous cropping of flue-cured tobacco through long-term field experiment,and provide a scientific basis for Studying on continuous cropping obstacle reduction technology of continuous cropping,the main results were as follows:1 Through the analysis and study of the effects of different mixed fertilizer topdressing on the continuous cropping of flue-cured Tobacco soil,The results revealed that different mixed fertilizer topdressing could increase the content of available potassium,organic matter,available phosphorus and alkali hydrolyzable nitrogen in flue-cured tobacco,there were significant differences among treatments,The soil nutrient content showed a peak value when tobacco seedlings were transplanted for forty-five days.The soil enzyme activities of each treatment were higher than that of the conventional chemical fertilizer,and the soil enzyme activity of conventional chemical fertilizer combined with seaweed organic fertilizer and amino acid fertilizer was higher.Along with the change of tobacco seedling days,the numbers of soil fungi,bacteria and actinomycetes all showed a trend of increasing first and then decreasing,all microbial quantities in each treatment were higher than that of conventional chemical fertilizer,the conventional chemical fertilizer combined with seaweed organic fertilizer and amino acid fertilizer topdressing overall was the highest,followed by conventional chemical fertilizer combined with amino acid fertilizer.On the whole,the effect of the conventional chemical fertilizer + seaweed organic fertilize + amino acid fertilizer was better.2 Through studying the growth status of flue-cured tobacco in field and the change of physical properties,chemical composition and the content of neutral aroma components in flue-cured tobacco leaves.The results revealed that different treatments on tobacco plant height,stem girth and leaf area were the most obvious,and the numerical values were all significantly higher than that of conventional chemical fertilizer.The effect on the effective leaf number is small.The conventional chemical fertilizer combined with amino acid fertilizer topdressing benefited growth and width of flue-cured tobacco leaves,the single leaf weight,tensile strength and filling value of flue-cured tobacco were significantly increased.The reducing range of the conventional chemical fertilizer combined with seaweed organic fertilizer on stem ratio of flue-cured tobacco was significantly.The conventional chemical fertilizer combined with amino acid fertilizer and the conventional fertilizer combined with seaweed organic fertilize all could reduce the contents of nicotine and chlorine,could significantly increase the ratio of sugar to nicotine,the ratio of nitrogen to nicotine and the ratio of potassium to chlorine,reducing sugar,total sugar and potassium content increased significantly.And they also had a certain effect to improve the content of phenylalanine degradation products.3 Through the study of the effects of different periods topdressing biological fertilizer on the continuous cropping of flue-cured tobacco soil,The results revealed that the soil nutrient content and soil enzyme activity of the rosette stage topdressing the conventional chemical fertilizer + biological fertilizer was higher in the early growth stage of flue-cured tobacco.When tobacco seedlings were transplanted for Seventy-five days,the soil nutrient content and soil enzyme activity of three periods of rosette stage,flourishing stage,topping stage topdressing partly conventional chemical fertilizer + biological fertilizer showed a higher trend.The content of available potassium reached peak value of four hundred and forty-four mg/Kg when tobacco seedlings were transplanted for forty-five days.The content of available phosphorus showed the trend of increasing first and then decreasing.The change trend of organic matter and alkali hydrolyzable nitrogen was the same,both reduced at the mature stage.The numbers of microorganism were higher when the rosette stage and three periods of rosette stage,flourishing stage,topping stage topdressing partly the conventional chemical fertilizer + biological fertilizer.The number of fungi reached the peak value when tobacco seedlings were transplanted for forty-five days,and the number of actinomycetes reached the peak value when tobacco seedlings were transplanted for Sixty days,and the number of bacteria reached the peak value when tobacco seedlings were transplanted for Seventy-five days.4 Through the study of the effects of different periods topdressing biological fertilizer on the growth and quality of continuous cropping of flue-cured tobacco.The results revealed that the effects of different treatments on the plant height,stem girth and leaf area of flue-cured tobacco were obvious,and the effects of leaf width and effective leaf number were smaller.the rosette stage topdressing the conventional chemical fertilizer + biological fertilizer on early opening of tobacco had a significant role in promoting development.Overall physical characteristics and aroma components of the rosette stage and three periods of rosette stage,flourishing stage,topping stage topdressing partly conventional chemical fertilizer+biological fertilizer were higher.Compared with topdressing the conventional chemical fertilizer,the single leaf weight,leaf weight,tensile stress and filling value of each treatment were markedly increased,but the stem ratio was decreased significantly.Different periods topdressing conventional chemical fertilizer + biological fertilizer all could reduce the contents of nicotine and chlorine in tobacco leaves,reducing sugar,total sugar,total nitrogen and potassium content increased obviously.The chemical composition of the rosette stage topdressing conventional chemical fertilizer + biological fertilizer were more coordinated.