Hui Mao, Zhaohui Wang, Menghua Li
College of Natural Resources and Environment;
and State Key Laboratory of Crop Stress Biology in Arid Areas
Northwest A& F University

Zn and Fe are essential micronutrients for organisms. Field experiments were conducted in three sites to study the effect of Zn application on the Zn and Fe concentrations in maize grains grown in Loess Plateau, China. The maize yields were unaffected by the Zn applications. The Zn concentrations in the grains increased significantly by 27% and 38% in the foliar and soil-foliar combined treatments at a low nitrogen level, while also increased by 18% and 16% in the same treatments at a high nitrogen level respectively, in the rain-fed dry land. The Zn concentrations in the grains significantly increased from 12% to 15% in the irrigated area. Zn accumulation in grains increased significantly in the rain-fed area with foliar Zn application, whereas it increased with Zn application in soil in the irrigated area. The highest Zn recoveries in grains were in experimental sites with foliar-applied Zn. Grain Fe concentrations increased by 61% with foliar Zn application in the rain-fed area and increased from 22% to 45% with Zn application in the irrigated area. Investigation of the rates of Zn intake in different parts of the maize showed that a rate decrease was observed in the grain, whereas rate increases observed found in the stem and leaf with Zn applications in the experimental sites. An increase in the rate of Fe intake was observed in the grain with Zn applications in the experimental sites.