Effect of Starch-Coated Urea Fertilizer on Soil Nitrogen Availability and Growth of Maize (Zea mays L.)

Abstract

Abstract

1. A pot experiment was conducted to investigate the effect of starch-coated urea fertilizer on soil available nitrogen and the growth of maize (Zea mays L.). The experiment was arranged as a Completely Randomized Design (CRD) with three replicates using two soil textures (clay loam and sandy loam). Urea fertilizer coated with starch at two coating levels (1% and 2% starch) was evaluated under four nitrogen application rates (0, 150, 250, and 350 kg N ha⁻¹). Seeds of the local maize cultivar were sown during the spring season of 2025 in pots containing 5 kg of air-dried soil. Soil moisture was adjusted to field capacity before planting and maintained throughout the growing period. Sixty days after sowing, plant height was measured. The plants were then harvested, and the shoots were oven-dried to determine shoot dry weight. Plant samples were subsequently digested to determine nitrogen concentration, from which nitrogen uptake was calculated. After harvest, soil samples were air-dried and analyzed to determine the concentration of available nitrogen. The results demonstrated that starch coating of urea fertilizer significantly increased soil available nitrogen after cultivation compared with conventional uncoated urea. Furthermore, starch-coated urea significantly improved plant height, shoot dry matter production, and plant nitrogen concentration, resulting in a marked increase in nitrogen uptake by maize plants.