摘 要 ：铁是作物必需的营养元素之一，是血红蛋白和细胞色素的组成成分，也是细胞色素氧化酶、过氧化氢酶、过氧化物酶等的组成成分，与烟叶香气前体物的形成密切相关。精准农业通常研究的是微尺度下（米级或亚米级）土壤养分的空间变异性。为此，在米级尺度下（11 m×10 m）对烟田全铁在种烟前后的空间变异性进行比较，并分析相应网格上烤后烟叶样品的铁含量，探讨土壤在种烟前后全铁含量与烟叶铁含量间的相互关系。结果表明：收完烟后试验地全铁含量平均值与种烟前相比有所下降，由30.3 g kg-1降到了24.79 g kg-1。种烟前土壤全铁具有中等的空间相关性（块金效应为48.8%），变异函数的最佳理论模型为线性模型，决定系数达到0.999，Block-Kriging内插图显示试验地全铁具有较强的空间异质性，方差分析的结果也表明取样点间的差异达极显著水平（p=0.00008）。种烟后土壤全铁含量以球状模型为变异函数的最佳理论模型，决定系数达到0.956，Block-Kriging内插图显示种烟后土壤全铁含量的最高值比种烟前往南移动了一些，最低值也往北移了一些，整个试验地土壤全铁在种烟后的空间变异性比种烟前有所升高。相关分析表明，烟叶铁含量只与种烟前土壤全铁含量呈极显著相关，与种烟后土壤全铁含量、种烟前后土壤全铁的相对变化量都没有显著相关。根据相关分析的结果，建立了以种烟前土壤全铁含量为自变量，以烟叶全铁含量为因变量的回归方程，并对方程进行验证，结果表明在自变量X的分布区间内预测效果比较好。
Abstract:Iron is one of the indispensable nutrition elements to crop, which is a component of haemoglobin, cytochrome, oxidase of cytochrome, catalase, peroxide etc, and it is strongly relative to the formation of aroma precursor. The spatial variability in micro sampling scale (at the meter or submeter level) was more useful for precision farming than that in small or large sampling scale. So a micro sampling scale of 11m×10m was fixed in this paper to study the spatial variability of soil total iron before tobacco planting and after tobacco harvest. Later, the iron content in tobacco leaves sampled from the same scale was mensurated to study the relationship of iron content between soil and flue-cured tobacco leaves. Results showed that the mean of soil iron content reduced to 24.79 g kg-1 after tobacco harvest from 30.3 g kg-1 before tobacco planting. There was a medium spatial correlation (the nugget effect was 48.8%) and highly spatial heterogeneity of the soil total iron before tobacco planting, the optimum theoretical model of soil total iron variation function was a linear one (R2=0.999). And the ANOVA analysis also showed the difference of total iron content among soil samples was significant (p=0.00008). While the optimum theoretical model of soil total iron was a spherical one（R2= 0.956）after tobacco harvest. The maximum total iron content shift a little from north to south, the minimum content shift a little from south to north, and the spatial heterogeneity of soil total iron after tobacco harvest was higher than that before tobacco planting. The iron content of flue-cured tobacco leaves was significantly correlated to the total iron in soil before tobacco planting (X1) not to that after tobacco harvest (X2) and to the difference content between X1 and X2. Finally, a regression equation of soil total iron before tobacco planting（the independent variable）and the iron content of flue-cured tobacco leaves (the dependent variable）was constructed, and test result showed that it had a good expectant effect in the distributing interval of the independent variable.