Abstract: A field experiment was carried out in tobacco,to study the effect of K application on K content and aroma quality of leaves of flue-cured tobacco under the optimization of C/N with organic fertilizer.The results showed that:In the C3 or C1 level,the biomass of central leaf increased along with the increase of K application;The biomass of upper leaf in high K application was higher than that in low potassium;K application had no significant effect on the biomass of central and upper leaf in C3 level,and increased the biomass of leaf in C2 level;In the same C level,the content of K in leaf had the lower trend along with the growth period,and increased with the increase of K application;Under the same K application,C2 and C1 had no significant effect on K content of leaf;At the budding and mature period,compared with C1,in the medium and high K application,C levels increased K content of leaf,and the lower content of K in C3 level.K content of different parts of leaf was C2 > C3 > C1 level;The number of K bacteria showed an increasing trend from the rosette stage to vigorous growing period and a decreasing trend from bud period to mature period;The number of K bacteria in medium and high K application was higher than that in low K application;In the C2 level,the number of K bacteria in medium and high K application showed an increasing trend with the growth process,and those was significantly higher than other treatment;There was no significant difference in C3 and C1 between medium and high K application,but it was significantly higher than that in low K application;The chemical components of leaves treated with C2 level was higher between medium and high K application,which the total sugar content of the leaves was 25.39%-25.27%,reducing sugar was 22.75%-25.73%, total nitrogen was 1.67%-1.72%, nitrogen base ratio was of 0.79, sugar nicotine ratio was of 10.78-11.80, nicotine content was of 2.11%-2.18%,which showed that the application of K increased the content of total nitrogen,nic otine and protein,improved the ratio of sugar to nicotine,nitrogen base ratio,and increased the potassium content of tobacco leaf;The neutral aroma substances of 28 species in tobacco leaves was found in all treatments,and the total amount of low K application was lower than that of medium and high K application,and the difference was significant between the position of leaves;The upper leaf was lower than that in the middle leaves in the total amount;and the application of medium and high K increased the total amount of aroma substances,and the maximum amplitude in the upper leaves was found with C2 level.It can be seen,under the optimization of medium carbon(C/N ratio),the increased of K application was the best on the effect of neutral aroma substances in tobacco leaves,especially for the upper leaves.

Key words: Organic fertilizer, The ratio of C/N, K application, Chemical compounds, Neutral aroma components

CLC Number: 

• S143