Effects of zinc application on growth and zinc uptake of maize under soil moisture stress

Effects of applied zinc on early growth and zinc uptake of maize (Zea Mays L) plants under different soil moisture was investigated through the pot experiment under greenhouse condition Maize plants were grown at two Zn levels (Zn 0 and 30 mg /kg) and three levels of soil moisture(soil water capacity 30%～35%, 45%～50%,70%～75%, respectively) in two zinc deficient soils (cumulic cinnamon soil: clay soil with water capacity is 36% (w/w) soil water content; fluvoaquic soil: sand soil with water capacity is 26%(w/w)soil water content ) Zinc treatments were applied at planting, while soil moisture treatments were applied after the stage with 4 fully expanded leaves and continued for one month Zinc application and adequate soil moisture significantly enhanced the dry matter weight of roots, stems , leaves and total plants The root to shoot ratio, root to leaf ratio and root to stem ratio trend to increased by zinc deficiency and soil moisture stress The Zn concentration and Zn content in roots, stems, leaves and whole plants were significantly increased with Zn application Zn translocation from root to shoot was stimulated by zinc application and the adequate soil moisture supply Except that the lowest Zn concentration in leaves was found in plants grown at serious soil moisture stress in cumulic cinnamon soil, Zn concentration in plant parts of maize increased with increasing soil drought However Zn content in plants decreased with soil moisture stress The interactive effect of applied Zn and soil moisture treatments on plant growth was observed in cumulic cinnamon soil The highest biomass of plant was found under zinc application and adequate soil moisture while root to stem ratio and leaf to stem ratio were enhanced by zinc deficiency and soil moisture stress Significant positive interactive effect of zinc application and serious soil moisture on zinc concentration of roots in plants grown at fluvoaquic soil and similar effect of zinc application and moderate soil moisture stress on the zinc concentration of roots and stems was found in plants grown at cumulic cinnamon soil Under soil water stress in fluvoaquic soil, the Zn uptake by leaves with Zn application decreased more than that without Zn application, while Zn content of stems with Zn application increased more than that without Zn application However, the opposite trend was observed in maize plants grown at cumulic cinnamon soil.