Effects of Combined Application of Chemical Fertilizer and Microbial Fertilizer on the Chemical Components Contents of Flue-Cured Tobacco Leaves

Abstract

[Objective] To determine the effect of microbial fertilizer combined with compound fertilizer on the chemical composition content of flue-cured tobacco leaves. [Method] Before planting the flue-cured tobacco, the local conventional fertilizer varieties and microbial fertilizer were applied to tobacco pond annular hole according to the conventional dosage. The experiment has four groups with different treatments, namely T1: without any fertilization; T2: 4 kg of pure nitrogen per mu, applying humic acid organic-inorganic compound fertilizer with 50 g/plant when planting tobacco; T3: reducing the total amount of conventional fertilization by 50%, and applying 80 g/plant of microbial fertilizer; T4: applying only 80 g/plant of microbial fertilizer. The trial adopted a randomized block design, with 3 replicates for each treatment. After the tobacco leaves were harvested and cured at the maturity stage, 5 kg of the lower (X2F), middle (C3F) and upper (B2F) first-cured samples were taken for chemical composition determination and analysis. [Results] The results show that T3 treatment can effectively increase the total sugar, reducing sugar, total nitrogen, nicotine, potassium, and chlorine content in X2F, C3F, and B2F grade tobacco leaves, which ratios are between 20.10% ∼ 21.03% and 18.90% ∼ 19.90%, 2.68% ∼ 3.26%, 2.28% ∼ 3.15%, 2.21% ∼ 2.50%, 0.56% ∼ 0.72%, meeting the production standards of high-quality tobacco. Secondly, T4 treatment can significantly improve the sugar-alkali ratio, nitrogen-alkali ratio, and potassium-chloride ratio of X2F grade tobacco leaves, and it can improve the sugar-nitrogen ratio of C3F and B2F grade tobacco leaves, but the effect is not significant; T3 treatment has a significant effect on B2F grade tobacco. The nitrogen-nitrogen ratio of tobacco leaves has a significant effect on improving the sugar-nine ratio, potassium-chloride ratio and the sugar-nitrogen ratio of X2F ∼ B2F grade tobacco leaves, but the effect has not reached a significant level. [Conclusion] Microbial fertilizer combined with compound fertilizer can improve the content of chemical components in flue-cured tobacco. On the whole, the application effect of T3 treatment is better, that is, the application effect of 80 g/plant microbial fertilizer and 50% reduction of conventional chemical fertilizer is more ideal.