Short-term effects of drought and salinity on mineral nutrient distribution along growing leaves of maize seedlings

The objectives were to study the effect of drought and salinity on the spatial distribution of mineral nutrients along the growing leaves of maize. Maize plants were grown in a greenhouse in soil under drought and saline conditions for 23 days after sowing. At harvest, the spatial distribution of fresh weight and dry weight contents and mineral nutrient concentrations along growing leaves 4 and 5 of maize was determined. Drought and salinity reduced the fresh weight content regardless of leaf number and caused a similar reduction. However, they affected the dry weight content differently, resulting from the reduction in the relative water content by drought. The results showed that the change in ion concentration along the growing leaf axis for most ions is independent of treatments. Although both drought and salinity cause a low nutrient availability in soil and low nutrient transport in plants, this study showed that except for Na+, there was no difference in the concentrations of most ions at any given location between plants in the control and either of the drought or saline treatments. Thus, reduction in leaf growth under drought and saline conditions may be due to other causes rather than the limitation of nutrients in a short-term period of drought and salt stresses.