Abstract: We collected samples of soil and tobacco leaves from 109 field sites in Wumeng tobacco-growing area in Guizhou Province, and identified the agro-geological background characteristics of light-sweet flavor style of flue-cured tobacco in terms of soil parent rock, parent material source, soil type and nutrition, and landform. The results indicate that carbonate and clastic sedimentary rocks are mainly the soil parent rocks for the typical light-sweet flavor style, carbonate sedimentary rocks for the light-sweet flavor style, and carbonate and clay sedimentary rocks for the weak light-sweet flavor style. Although the sources and compositions of parent materials that affect the formation of fluecured tobacco styles are different, they are all characterized as slope sediments. Yellow brown soil and sand land can improve the light-sweet flavor of flue-cured tobacco, and the contents of organic matter, available nitrogen, total potassium, watersoluble chlorine in the soil for the typical light-sweet flavor style are low, while the available potassium content is the highest. Furthermore, the high-middle mountain landform is mainly responsible for the typical light-sweet flavor style, the shares of high-middle and middle mountain landform are equivalent for the light-sweet flavor style, and the middle mountain landform is for the weak light-sweet flavor style.

Key words: error-in-variable model., aboveground biomass, compatibility, tree volume, natural spruce