Growth and Accumulation of Nitrogen and Potassium in Flue-Cured Tobacco as Affected by Calcium Nitrate and Ammonium Nitrate.

摘要

The process of biomass, nitrogen (N), and potassium (K) accumulation over time as affected by N forms is poorly understood. The objective of this study was to identify the effects of N form on growth as well as on N and K nutrition of flue-cured tobacco plants (Nicotiana tobaccum L.). The plants were grown in a greenhouse with pots of soil for 117 days after 200 days of preculture. Three treatments (calcium nitrate [Ca(NO3)2], ammonium nitrate (NH4NO3), and ammonium nitrate plus straw (NH4NO3 + straw)) were used. The results showed that there were no significant differences in shoot dry mass of tobacco among the three treatments during the entire growth stage except at 30 and 117 days after transplanting. At these two growth stages, shoot biomass with the Ca(NO3)2 treatment was significantly less than that with NH4NO3 with or without straw. The NH4NO3 + straw plants had more mature leaves and greater leaf dry weight than the other two treatments. At an early stage (before 66 days), N concentration of Ca(NO3)2-fed plants was less than with the other two treatments. The leaf K concentration and shoot K content of NH4NO3 and NH4NO3 + straw plants were more than with the Ca(NO3)2 treatment before maturity. Also, K concentration in mature leaves with these two treatments was greater than with Ca(NO3)2 treatment. All these results indicated that NH4NO3 application had benefits to the maturity and K accumulation in leaves of tobacco.