Differential Analysis of Nitrogen Nutrition Characteristics Between Tobacco Cultivars of Different Nitrogen Utilization

In order to investigate the difference of nitrogen nutrition characteristics between different tobacco cultivars, a sand-culture pot experiment was carried out at two nitrogen levels on 12 major tobacco cultivars, and their nitrogen nutrition characteristics were evaluated and classified. The results showed that the trend of nitrogen absorption efficiency was consistent with that of nitrogen utilization efficiency for the same cultivar. Nitrogen content, nitrogen accumulation amount, and response to nitrogen level were obviously different between cultivars, and the cultivars could be divided into four types. The variation of nitrogen content in stalk and leaf was obviously higher than that in root, while the variation of nitrogen accumulation amount in stalk and leaf was significantly lower than that in root. Nitrogen application could obviously increase the nitrogen content in all organs of tobacco plant, raise nitrogen accumulation amount and the proportions of nitrogen distribution in stalk and leaf. Tobacco root vigor significantly positively correlated to the nitrogen accumulation amount and nitrogen absorption efficiency of tobacco plant at the two nitrogen levels. The difference of tobacco root vigor between cultivars was an important reason causing the differences of nitrogen accumulation and absorption efficiency between cultivars.