Abstract: 53 representative areas for tobacco planting in southern Anhui province were selected and the quality of irrigation water, especially the content of metal elements, was investigated. It was found that the content of micro （medium） elements in irrigation water was too low to have a significant effect on the formation of burned sugar aroma style of tobacco leaves. The contents of Mg, Ca and Zn were 0.7~8.0 mg/L, <40 mg/L and 0.002~0.029 mg/L, respectively. The heavy metal content of irrigation water and other basic control items all met corresponding national standards. Furthermore, the experiments on tobacco planting under controlled irrigation using paddy soil in a greenhouse proved that Zn was a negative correlation factor for forming the burned sugar aroma style of tobacco and the threshold value was ≥10 mg/L in irrigation water. Meanwhile, Mg was a positive correlation factor and the content of Mg to promote the burned sugar aroma style should be maintained at 40~90 mg/L. Ca and Mg had synergistic effects, but which was mainly appropriate for acid paddy soils.

Key words: irrigation water, metal elements, tobacco leaves, burned sugar aroma style