恩施烟区土壤氮素和烤烟烟碱含量的分布特点及关系分析

Distribution and relationship of soil nitrogen and flue-cured tobacco nicotine content in Enshi tobacco fields

以恩施烟区有代表性的宣恩县和咸丰县为试验地点,采用野外调查与室内分析相结合的方法,分析了土壤氮素和烤烟烟碱含量的分布状况及其相互关系,结果表明:恩施烟区土壤全氮含量适宜,速效氮含量明显偏高,依据土壤氮素含量,可把129个供试土壤样品聚成高、中、低3类,其中低氮类样本所占比例(60.47%)最大。烤烟烟碱含量变幅为8.18～42.25g·kg-1,平均为22.80g·kg-1,变异系数为36.42%;烟碱含量在15～35g·kg-1的样本占总样本数的66.94%;烟碱含量在不同品种间、等级间和海拔高度间均存在显著变异,品种间烟碱含量表现为"K326">"云烟85">"云烟87",不同等级间表现为B2F>C3F>X2F,不同海拔间表现为低海拔>中海拔>高海拔。建立了土壤速效氮含量对烤烟烟碱含量的回归方程,经F测验未达到显著水平。

Field survey and laboratory analysis were conducted to determine the distribution and relationship of soil nitrogen and flue-cured tobacco nicotine content in representative locations in Xuan＇en and Xianfeng of Enshi tobacco cultivation areas.The results show a suitable total nitrogen content and a markedly higher available soil nitrogen content in Enshi tobacco cultivation areas.Based on soil nitrogen content,129 soil samples are divided into three groups of high,medium and low nitrogen content via cluster analysis.Samples with low nitrogen content account for 60.47% of the 129 soil samples.Flue-cured tobacco nicotine content ranges from 8.18 g·kg^-1 to 42.25 g·kg^-1,with a mean and variation coefficient of 22.80 g·kg^-1 and 36.42% respectively.Samples with nicotine content in the range of 15 g·kg^-1 to 35 g·kg^-1 account for 66.94% of the total.Significant differences exist in nicotine content of flue-cured tobacco from different cultivars,gradings and altitudes.Flue-cured tobacco nicotine content occurs in the following trend of ＂K326＂ ＂Yunyan85＂ ＂Yunyan87＂ for cultivars;B2F C3F X2F for grades;and low altitude medium altitude high altitude for altitudes.A regression relationship exists between flue-cured tobacco nicotine and soil nitrogen content.However,F-test shows that the relationship is insignificant at 5% confidence level.