The status of magnesium nutrition and its application effect in Fujian tobacco planting area

The results of the study for 117 samples of soils and leaves in Fujian main tobacco planting area were summarized as follows:the content of exchangeable magnesium in the tobacco soil on an average was 31.78 mg.kg -1 .In over 80% of all the soil samples,the content of exchangeable magnesium was lower than the critical level.In over a half of tobacco leaves,magnesium was deficient in different degree.The content of exchangeable magnesium in most tobacco leaves varied from 0.15% to 0.25%. The content of exchangeable magnesium in varied soils was summarized as follows:Purple PaddyTidal Sandy PaddyYellow PaddyMarl FieldSondy FieldBlack Paddy.The content of exchangeable magnesium in tobacco leaves in the two foreign varieties K326 and G80 was higher than that in the two native varieties Cuibi No. 1 and Yanyan97.The effect of applying 225 mg.kg -1 (Mg SO 4·7H 2O) was obvious on the increase in yield and quality of flue cured tobacco.