Effects of water and 15N-labelled fertilizer coupling on the growth, N uptake, quality and yield of flue-cured tobaccos: a two-year lysimeter experiment.

摘要

To identify the regularity on growth, N uptake, yield and quality of flue-cured tobaccos under different conditions, the 15N tracing technique was introduced and a two-year lysimeter experiment with four water-nitrogen treatments for flue-cured tobaccos was conducted in Nanjing, south of China, from 2010 to 2011. One year continuous cropping had little effects on agronomic characters, N uptake regularity and yield of flue-cured tobaccos, which had slight influences on the quality of flue-cured tobacco leaves, reflecting in the increasing of the total N and nicotine concentration, and the decreasing of total sugar and reducing sugar concentration. At early growth period, fertilizer N and soil N absorbed by tobacco plants accounted for about 50% of the total N absorption respectively, however, in the middle and later periods at about 56 to 84 days after transplanted, soil N became the main N absorption form of flue-cured tobaccos, which was at least 50% higher than fertilizer N absorbed at 84 days, the overabundance of soil N absorption in later periods could probably be the reason that the nicotine concentration of upper leaves was excessive. Higher N application under the same irrigation level increased the concentration of total N and nicotine in tobacco leaves, meanwhile decreased total sugar and reducing sugar. Treatments with higher N application detected a decline in tobacco quality through the surveying results of 2011, total sugar and reducing sugar concentration of which were too low. From the perspective of yield and quality stability, 800 mm irrigation water combined with 90 kg/hm2 N application was preferable for the cultivation of flue-cured tobaccos in this study.