Effects of tobacco stem biochar-based fertilizer on growth and quality of flue-cured tobacco

【Objective】 To investigate effects of tobacco stem biochar-based fertilizer on tobacco growth，development and quality improvement，so as to provide scientific guidance for promotion and application of biochar-based fertilizer，yield and quality improvement of flue-cured tobacco.【Method】 Five treatments were set through field micro-plot trials： no fertilizer（CK），tobacco fertilizer（F），low amount（525 kg/ha）of tobacco stem biochar-based fertilizer（LBF），medium amount（1050 kg/ha）of tobacco stem biochar-based fertilizer（MBF）and high amount（1575 kg/ha）of tobacco stem biochar-based fertilizer（HBF）.The growth and quality indexes of flue-cured tobacco leaves were measured and analyzed in the vigorous growth period and mature period.【Result】Applying tobacco stem biochar-based fertilizer could improve the agronomic utilization rate of fertilizer，promote the growth and biomass of flue-cured tobacco.Under the same nitrogen（N），phosphorous（P）and potassium（K）nutrient level，dry matter weight of root，stem and leaf in MBF treatment were higher than those in F treatment.By applying tobacco stem biochar-based fertilizer，contents of chlorophyll，total sugar，reducing sugar，nicotine，potassium and total nitrogen of flue-cured tobacco could be increased，and chlorine content could be decreased.Under the same NPK nutrient level，the contents of total sugar in MBF treatment were significantly increased by 7.70%（P<0.05）compared with F treatment，respectively，while the contents of reducing sugar，nicotine，potassium and chlorine were not significantly different（P>0.05）.Overall yield of flue-cured tobacco under different treatments was HBF>MBF>F>LBF>CK，and the proportions of medium and superior tobacco and superior tobacco were MBF> HBF>F>LBF>CK.Under the same NPK nutrient level，the yield，average price，output value and economic benefit of MBF treatment were significantly higher than those of F treatment.【Conclusion】 Applying tobacco stem biochar-based fertilizer can promote the growth of flue-cured tobacco，coordinate chemical components of tobacco leaves，and improve the economic benefits of flue-cured tobacco，among which medium amount of tobacco stem biochar-based fertilizer（1050 kg/ha）leads to the best comprehensive performance，and is worth popularization.