不同供应时期氮素形态对烤烟生长及养分吸收的影响

通过水培方法研究了在烟草不同生育时期供应不同形态氮素对烤烟生长、烟叶氮、钾吸收、分配的影响。结果表明,无论是在六叶一心时还是在十二叶一心时进行氮素形态处理,各氮素形态均表现出随着溶液中硝态氮含量的提高,烟株的生物量、钾吸收量、叶片钾含量均呈现增高的趋势;在六叶一心时处理各指标在各氮素形态之间呈现出显著差异,在十二叶一心时处理,硝酸铵和硝态氮处理间差异不显著,并且十二叶一心时处理烟株各项指标均高于六叶一心处理。因此建议在烟株生长到一定时期可以减少硝态氮肥的用量,追施部分硝酸铵,增加铵态氮肥的用量,以减少农民化肥投入成本。

Effect of Different Nitrogen Forms Supplied at Different Growth Period on the Growth and the Nutrients Distribution of Flue-cured Tobacco

The effect of different nitrogen forms supplied at different growth period on the growth and the nutrients absorption and distribution of flue-cured tobacco was studied.The results showed that the weight,potassium absorption,potassium content of tobacco increased with the increasing of nitrate in solution no matter in six leaves one spear leaf or in twelve leaves one spear leaf period.There were significant differences among the three N forms treatments when treated at six leaves one spear leaf period,but there were no significant differences between NH4NO3 and NO3-treatments when treated at twelve leaves one spear leaf period.Besides,each index of supplying with different N forms at twelve leaves on spear leaf period was higher than that at six leaves one spear leaf period.These results indicated that when tobacco grown up to some stage,decreasing the amount of NO3——N fertilizer and increasing the amount of NH4+-N fertilizer was necessary for reducing the production cost.