Optimization of tobacco water‐fertilizer coupling scheme under effective microorganisms biochar‐based fertilizer application condition

Abstract

AbstractAn appropriate coupling of water fertilizer can improve the quality and yield of tobacco (Nicotiana tabacum L.). However, the optimal scheme of that is still unknown under the condition of effective microorganisms (EM) biochar‐based fertilizer application. In this study, 12 treatments were set up, which were divided into four fertilization gradients (0, 100, 300, and 600 g pot–1, represented CK1–CK3, T1–T3, T4–T6, and T7–T9, respectively), and each fertilization gradient had three irrigation gradients (40, 80, and 120 L pot–1). Each treatment was set in triplicate. Compared to CK, the nicotine content, reducing sugar, total nitrogen, potassium, chlorine, and yield of flue‐cured tobacco increased by 13.22–48.87%, 1.53–13.46%, 7.68–29.23%, 7.73–21.76%, 6.48–34.55%, and 7.93–65.51% after the application of EM biochar‐based fertilizer. The quality of flue‐cured tobacco was less affected by the amount of irrigation (P > .05), and the yield was positively correlated with the amount of irrigation and EM biochar‐based fertilizer (P < .05). The principal component analysis (PCA) was performed on all indexes of flue‐cured tobacco quality and established the comprehensive evaluation system. Analytic hierarchy process–entropy weight method (AHP–EWM) and projection pursuit classification (PPC) algorithms were utilized to build the model, and the optimal water–fertilizer coupling scheme was selected according to AHP–EWM score and projection values. In conclusion, 120 L pot–1 irrigation combined with 100 g pot–1 of EM biochar‐based fertilizer application treatment was the best water‐fertilizer coupling scheme, and the AHP–EWM score and projection value were .632 and 1.169. The results of this study might provide theoretical and practical guidance for the plantation of flue‐cured tobacco in production areas.