Effects Of Peat On The Growth,Yield And Quality Of Flue-cured Tobacco And The Planting Soil In Fengdu

In Chongqing Fengdu tobacco-growing areas,most of the flue-cured tobacco plants are cultivated in the mountainous fields.Under the topography conditions,nutrient deficiency and poor water retention are commonly found in tobacco-planting soils,affecting the growth,development,yield and quality of the flue-cured tobacco.Therefore,research is conducted to study on the characteristics of soils,soil enzyme activities,rhizospheric microbial functional diversity of tobacco-planting soil,and the agronomic traits,dry matter accumulation,fresh tobacco leaf enzyme activity,economic characteristics,chemical composition and sensory quality of tobacco leaf after curing,used flue-cured tobacco"Yanyan 97" as the experimental material in Chongqing Fengdu.The purples was to study the effects of applying peat on the soil improvement,tobacco plant growth and development,and the yield and quality of cured tobacco leaves.The main results are as follows:(1)Using of peat can increase the contents of alkali-hydrolyzable nitrogen,available phosphorus,available potassium,organic matter and humus.It can significantly increase the activities of soil invertase,urease,acid phosphatase and utilization of carbon sources,decrease the activity of polyphenol oxidase in soil and increase the microbial community in rhizosphere.T4(18000 kg/hm2)had the best effect on improving soil fertility and soil enzyme activity,followed by T3(13500 kg/hm2);The effect of using of amines,carbohydrates,polymers,amino acids,carboxylic acids,phenolic carbon sources of T2(9000 kg/hm2)and T3 are significant.(2)Using of peat can promote the growth and development of tobacco plants,reduce the pitch,increase the number of effective leaves,maximum leaf length,maximum leaf width,stem circumference,maximum leaf area and other agronomic traits at 30 days after transplanting.T3(13500 kg/hm2)promoted dry matter accumulation of 22.22%compared to CK,T2(9000 kg/hm2)increased 29.16%at 60 days after transplanting,and T3 increased by 22.05%at 75 days after transplanting.Using peat can significantly increase the accumulation of dry matter.(3)Using of peat significantly increase the activity of nitrate reductase,glutamine synthetase,sucrose invertase,superoxide dismutase,catalase and peroxidase of fresh tobacco leaves.Nitrate reductase activity increased by 208.82%to 338.07%at 30 days after transplanting.Glutamine synthetase activities of T1(4500 kg/hm2)increased by 52.68%.Catalase and peroxidaseand Activities of T3(13500 kg/hm2)increased 74.03%,106.92%?169.94%,respectively at 30 days after transplanting.Sucrose invertase of T2(9000 kg/hm2)increased 111.41%.T3 increased sucrase activity and catalase activity 89.43%,117.78%at 60 days after transplanting.T2 increased 132.09%of sucrose invertase.Compared with CK,the activities of glutamine synthetase,sucrose invertase,catalase,and superoxide dismutase increased by 34.99%,76.42%,30.46%,and 217.76%,respectively at 75d after transplanting.In terms of comprehensive leaf enzyme activities,T3 showed better performance in each leaf enzyme activity,followed by T2.(4)Using peat can improve the economical characters of the cured tobacco leaves.Among them,the ratio of upper grade tobacco leaf,middle and upper grade tobacco leaf,output,output value,average price,grade index and production index increased by 17.55%,27.73%,14.41%,35.76%,12.55%,14.37%,and 27.74%respectively,compared with CK.All economic index have increased significantly.T1(4500 kg/hm2)was the best,followed by T3(13500 kg/hm2).(5)Using of peat can increase the aroma quality,aroma,the content of total nitrogen and nicotine,the total sugar,reducing sugar and potassium content.The chlorine content is decreased.Among them,the nicotine content of T3 treatment(2.2%)is closest to that of high-quality flue-cured tobacco.The range,the content and coordination of various chemical components of it are the best,and the quality of sensory evaluation of it is the highest.In summary,using the appropriate amount of peat can effectively improve the nutrient content of tobacco-planting soil and the utilization of carbon sources by rhizosphere microorganisms,optimize the agronomic traits of tobacco plants and enzyme activity of fresh tobacco leaves,improve the economical characteristics of cured tobacco leaves,and improve tobacco leaf quality,coordinate chemical composition.Among them,T3(13500 kg/hm2)has the best comprehensive performance in all treats and it is suggested to promote the application after further verification in the Chongqing Fengdu.