Abstract:To determine the appropriate proportion of potassium silicate replacing potassium sulfate in the basal fertilizer for flue-cured tobacco, a gradient replacement of potassium silicate for potassium sulfate was designed based on the special basal fertilizer formula for flue-cured tobacco. The effects of this replacement on the agronomic traits, economic traits, quality traits and potassium fertilizer utilization characteristics of flue-cured tobacco were analyzed. The results showed that compared with the potassium sulfate treatment, when the replacement ratio of potassium silicate was 25%, the total scores of sensory quality evaluation of middle and upper leaves increased by 0.61 and 2.84 points respectively, and the potassium accumulation in leaves and potassium fertilizer utilization rate increased by 5.5% and 6.92% respectively. When the replacement ratio was 50%, only the total score of sensory quality evaluation of upper leaves increased by 1.21 points, and the other indicators showed no significant difference or decreased. When the replacement ratio was ≥75%, the maximum leaf area, the area of the third leaf from the top, output value, yield, chemical quality of middle leaves, sensory quality and potassium fertilizer utilization characteristics of flue-cured tobacco were all inferior to those with a 25% replacement ratio. That is, an excessively high replacement ratio was not conducive to the yield, quality and potassium fertilizer utilization of flue-cured tobacco. Combined with the curve fitting results, the appropriate replacement ratio of potassium silicate for potassium sulfate was 20.5% to 34.2%, which could improve the potassium fertilizer utilization efficiency, yield and sensory quality of flue-cured tobacco leaves.
