[Objective] To study temporal variability of potassium content in flue-cured tobacco, so as to provide basis for application of geostatistics in tobacco quality chemical constituents temporal distribution. [Method] Temporal and spatial variability characteristics of potassium content of flue-cured tobacco leaf in Henan Province in 1999 and 2007 were evaluated using geostatistics and geographic information system (GIS). [Result] The results indicated that average potassium content in 1999 and 2007 were 1. 30% and 1.48% , respectively. Coefficients of variation of potassium content of two periods were similar and both belonged to moderate variability. The ratio of nugget to sill of potassium content in 1999 and 2007 were 4. 7% and 23. 5% , respectively. Both embodied stronger spatial correlation and were best described by spherical model. Their spatial correlation distances in 1999 and 2007 were 284 m and 234 m, respectively, which showed a descending trend. The spatial distributions of potassium content in both years were similar, increasing from east to west. [ Conclusion] The spatial distributions of potassium content were mainly affected by structural factors and the effects of human activities were increasing.%[目的]探讨烤烟钾含量的时间变异性,以期将地统计方法应用于烟草品质化学成分时间分布研究提供理论依据.[方法]以1999和2007年在河南66个采样点采集的C3F烤烟为研究对象,采用地统计学和GIS相结合的方法,研究了河南烤烟钾含量的时空变异.[结果] 1999和2007年河南烤烟钾含量的平均值为1.30％和1.48％,2个时期的烤烟钾含量的变异系数相近,均为中等程度变异；1999和2007年烤烟钾含量的块金值与基台值之比分别为4.7％和23.5％,空间相关性均体现为强相关,拟合的半方差函数模型均为球状模型,它们的空间相关距离分别为284和234 m,呈递减的趋势.2个时期烤烟钾含量的空间分布特征类似,均呈西高东低的趋势.[结论]河南烤烟钾含量的空间分布主要受结构性因素影响,并且人类活动因素对其的影响程度在加大.
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