Effects of Combined Application of Biochar and Nitrogen Fertilizer on Growth and Chemical Quality of Flue-Cured Tobacco

PurposeTo study the effects of combined application of biochar and nitrogen fertilizer on growth and chemical quality of flue-cured tobacco.

MethodsA two-factor randomized block experiment was carried out with Yunyan87 as experimental material, two biochar application levels (B₀: no biochar; B₁: 3 kg biochar per 100 kg soil) and three nitrogen fertilizer application levels (N₀: 0 kg/hm²; N₁: 52.5 kg/hm²; N₂: 105.0 kg/hm²) were set, a total of six treatments. The growth indexes of flue-cured tobacco in different growth stages, the chemical components of flue-cured tobacco and the contents of aroma precursors were determined.

ResultsNitrogen fertilizer combined with biochar extremely significantly affected the plant height, stem girth and maximum leaf length of flue-cured tobacco at the resettling growth stage and vigorous growth stage (P<0.01), and significantly affected the maximum leaf length at the root extending stage and the maximum leaf width at the vigorous growth stage and maturity stage (P<0.05); the combined application extremely significantly affected the contents of total nitrogen, nicotine and potassium in the lower leaves, the contents of nicotine, chlorine, nitrogen-nicotine ratio and sugar-nicotine ratio in the middle leaves, and the total sugar content and sugar-nicotine ratio in the upper leaves (P<0.01), and significantly affected the reducing sugar content in the upper leaves (P<0.05). From the perspective of aroma precursors, the combined application could extremely significantly increase the content of β-carotene and lutein in middle leaves (P<0.01).

ConclusionThe combined application of biochar and nitrogen fertilizer can promote the growth of tobacco plants and increase the contents of chemical components and aroma precursors.