EFFECT OF NPK FERTILIZER ON THE AVAILABILITY OF ZINC, IRON, AND MAIZE YIELD IN CALCAREOUS SOIL

A field experiment was carried out in the fields of the Department of Soil Sciences and Water Resources / College of Agriculture and Forestry/ University of Mosul to study the impact of mineral fertilization with N, P, and K on the concentration of iron and zinc in both soil and corn plant (Zea mays L.) grown in calcareous soil suffers from iron and zinc deficiency. The experiment was carried out in three replicates and included two factors: the first was fertilized with three levels, control treatment, the fertilization treatment with half the recommended amount, and finally, the fertilization treatment with the full recommended amount of N, P, and K, which is 320 kg N ha-1, 200 kg P2O5 ha-1, and 80 kg K2O ha.-1, the second factor is the measuring periods for the concentration of iron and zinc in the leaves, which are 15, 30, and 60 days after germination, in addition to measuring the concentration of the two elements in the seeds after harvest. The results showed a decrease in the available concentration of iron and zinc in the study soil, and the added NPK elements did not have a significant effect on the available concentration of these two elements in the soil, while it increased the concentration of iron and zinc in the leaves. It also increased the concentration and content of grains of the two elements. The highest concentration of the two elements and the highest grain yield were used as the full fertilizer recommendation for N, P, and K elements.