Effect of Sulfur Levels and Application Timing on Microelement Concentration and Soil Interaction during the Growth Stages of Zea mays L.

Background and Objective: Soil pH and micronutrient availability play a crucial role in the productivity of maize (Zea mays L.). However, limited information exists on how different levels and application times of agricultural sulfur influence the soil interaction degree and micronutrient concentrations during maize growth. This study aimed to evaluate the effect of sulfur application levels and timings on soil interaction (pH) and the concentration of iron, manganese, zinc, and copper at various growth stages of maize. Materials and Methods: A field experiment was conducted during the summer seasons of 2021-2022 at the College of Agriculture, University of Wasit. The experiment involved two sulfur application times 30 days before planting and 15 days after the first application with four sulfur levels (500, 1000, 1500, and 2000 kg/ha) in addition to a control. Soil pH and micronutrient concentrations in maize tissues were measured at germination, flowering, and harvesting stages. Data were statistically analyzed using Genstat and an electronic calculator based on ANOVA, with treatment means compared using the modified LSD test at a 0.05 significance level. Results: Sulfur application at 2000 kg/ha, added 30 days before planting, resulted in the lowest soil interaction (pH) values 6.43, 6.83, and 6.93 during germination, flowering, and harvesting, respectively, compared with the control (7.65, 7.68, and 7.77). The same treatment recorded the highest concentrations of iron (56.77 mg/kg/plant), manganese (46.80 mg/kg/plant), zinc (21.33 mg/kg/plant), and copper during the flowering stage, significantly exceeding the control values (33.47, 22.33, and 11.77 mg/kg/plant, respectively). Conclusion: The study demonstrated that applying 2000 kg/ha of agricultural sulfur 30 days before planting effectively reduced soil pH and enhanced the availability of essential micronutrients, thereby improving maize growth. These findings highlight the importance of optimizing sulfur management for better nutrient uptake and soil health in maize cultivation.