Investigation on the Quality of Irrigation Water in Southern Anhui and the Effects of Metal Elements in Irrigation Water on the Coke Sweet Aroma Style of Tobacco Leaves

[Objectives]The effects of metal elements in irrigation water in the tobacco areas of southern Anhui on the coke sweet aroma of tobacco leaves was determined.[Methods]53 representative areas for tobacco planting in southern Anhui were selected,and the quality of irrigation water,especially the content of metal elements,was investigated.[Results]The contents of micro(medium)elements in the irrigation water were too low to have a significant effect on the formation of the coke sweet aroma style of tobacco leaves.The contents of Mg,Ca and Zn were 0.7-8.0,<40 and 0.002-0.029 mg/L,respectively.The heavy metal contents of the irrigation water and other basic control items all met corresponding national standards.Furthermore,the tobacco planting experiment under controlled irrigation using paddy soil in the greenhouse proved that Zn was a negative correlation factor for forming the coke sweet aroma style of tobacco and the threshold value was≥10 mg/L in the irrigation water.Meanwhile,Mg was a positive correlation factor and the content of Mg to promote the coke sweet aroma style should be maintained at 40-90 mg/L.Ca and Mg had a synergistic effect,which was mainly appropriate for acid paddy soils.[Conclusions]This study improves the quality and yield of the coke sweet aroma of tobacco leaves,and has important theoretical and practical value for the formation of a popular agronomic control method.