Effects of magnesium nutrition on growth and nutrient absorption of flue-cured tobacco

Magnesium is an essential element in biological systems of flue-cured tabacco. A pot culture experiment was conducted to investigate the effects of different magnesium nutrition levels on the growth and nutrient absorption of flue-cured tobacco. The results showed that: compared to control, application of Mg significantly promote the growth status and enhance the dry matter accumulation of flue-cured tobacco as the magnesium application rate was 0.06–1.08g/kg. The uptake of K2O was the highest, followed by N, and the lowest was P2O5 in different tobacco organs for all magnesium treatments. The uptake of N, P2O5 and K2O of different tobacco organs with Mg application rate being 0.18–0.72 g/kg was significantly higher than the other treatments. The highest uptake of N, P2O5 and K2O was observed as the Mg application rate was 0.36g/kg. Both magnesium deficit (MgSO4≤0.06 g/kg) or magnesium surplus (MgSO4≥1.08 g/kg) restrained the growth, accumulation of dry matter and nutrient uptake of tobacco. Magnesium uptake in different organs of tobacco increased with the increasing of magnesium application rate for all treatments. The application of magnesium fertilizer can promote magnesium uptake of flue-cured tobacco.