Effect Of Soil Amendment On Physical And Chemical Properties Of Acid Soil And The Growth And Quality Of Flue-cured Tobacco

Soil is the supporter of tobacco growth,the excessive application of chemical fertilizer and long-term continuous cropping leading to acidification of tobacco-growing soils,which has become a restraint factor of sustainable development of flue-cured tobacco production.The study explored the using level of soil amendment(lime and tobacco rods ash)with pot experiment,researched the effect of using soil amendment(lime,biochar and tobacco rods ash)on the tobacco planting soil,the growth of flue-cured tobacco and the quality of flue-cured tobacco with field experiments.The main research results are as follows:(1)The results showed that there was a non-linear relationship between the amount of limeapplicationandtheincrementsofsoilpH.Theequation was:y=0.002x~3-0.064x~2+0.703x+0.469.The determination coefficient was 0.975.However,there was a linear relationship between the amount of tobacco rods ash application and the variable quantity of soil pH.The equation was:y=0.042x+0.926.The determination coefficient was 0.973.(2)Results showed:(1)Application of soil amendments can improve the soil pH,ameliorate the soil physical properties,increase the soil moisture content and soil porosity,reduce the soil bulk density.(2)The application of soil amendments could improve the content of soil organic matter and available P,the application of tobacco rods ash treatment cut down the content of soil available N and raised the content of soil available potassium.(3)Results showed:(1)Applying biochar could promote the growth of flue-cured tobacco,boost the growth of tobacco-rods and increase the leaf area.In later growth stage of tobacco,applying lime and tobacco rods ash could promote the growth of tobacco plant height and stem girth.(2)In early growth stage of flue-cured tobacco,application of soil amendment restrained the leaf’s photosynthetic characteristics and leaf’s chlorophyll content of flue-cured tobacco.But application of lime,when arrive to the middle growth stage of tobacco,it can effectively improve the chlorophyll content of flue-cured tobacco,enhance the photosynthetic characteristics,heighten the net photosynthetic rate,stomatal conductance,transpiration rate.(4)Results showed:(1)The lime treatment can effectually improve the availability of middle leaves,leaf opening rate and the leaf weight is moderate.(2)With using three kinds of acidic soil improvement later,in upper leaves of flue-cured tobacco the content of starch,total sugar and potassium was reducing,the content of total nitrogen increased,lime treatment had the highest content of nicotine and nirogen-nicotine ratio,the highest sugar-nicotin ratio was using tobacco-rods ash treatment.(3)Application of three kinds of acid soil amendments improve the proportion of superior tobacco,improve production and output value,the treatment of using tobacco-rods ash 9000kg/hm~2 had the best of economic characters.Followed by the application of lime 2250kg/hm~2 treatment.