Influence Of Different Succession And Rotational Cropping On Soil Ecological Environment And Flue-cured Tobacco Yield And Quality In Yanbian

Field experiment had been carried out with Jiyan 9 cultivar in Yanbian area of Jilin Province, the effect of different succession and rotational cropping on quality characteristics of flue-cured tobacco and physical and chemical characteristics of rhzisphere soil were studied, and main chemical components of flue-cured tobacco and the corresponding changes of physical, chemical, enzyme and microbe of rhzisphere soil were discussed, The main results were as follows:1 Physical of different succession and rotational cropping rhzisphere were existing soil obvious differences, PH is increasing gradually during its growing period, and it showed that T4>T1>T2>T3>T5 in 60 days after transplanting. Soil organic matter and rapidly-available N, P, K accumulated with the more years succession cropping. Root features were better for T1 and T5.2 Fungi and actinomyces were increased, and potassium bacteria and Phosphorus bacteria reduced, along with succession cropping is extending. Abiogenous azotobacter and bacteria were more suitable in the soil of T4.3 Catalase activity were "the single-peak" change trend, while T1 was the highest and T3 was the lowest. Polyphenol oxidase and urease activity were the highest for T2, and showed that T4>T5 for urease activity.4 Soluble sugar and reducing sugar content, ratio of soluble sugar to total nitrogen, and ratio of total nitrogen to nicotine were significantly higher than appropriate range, nicotine and total nitrogen content, special leaf weight and leaf thickness were lower, and sensory quality was that with poor flavor quality, odor quantity, insufficient strength, heavy irritation and inadequate after-taste, but with good combustion.5 Tobacco physics properties were better for T1 and bad for T3 and T4. The total content of neutral aroma constituents was high for T1, but low for T3 and T4. While the contents of neophytadiene and cembranenoids and carotenoids were increased obviously with T1, and chemical components and aroma constituents were more harmonious.6 Flue-cured quality was obviously different in succession and rotational cropping, T1 took the first place, T3 and T4 were the poorest.