EFFECT OF SEEDING RATE AND NITROGEN FERTILIZER ON GRAIN YIELD AND ITS COMPONENTS OF MISR 3 BREAD WHEAT CULTIVAR UNDER TWO TILLAGE SYSTEMS

Climatic changes characterized by unusually heavy rainfall during wheat land preparation in the Nile Delta. Farmers were compelled to adopt zero-tillage (ZT) practices instead of traditional methods due to these conditions. To address this issue, two field experiments were conducted at El-Gemmeiza Agricultural Research Station during the 2023/2024 and 2024/2025 growing seasons to evaluate the effects of seeding rate and nitrogen fertilization under two tillage systems. Two separate experiments were established: one under conventional tillage (CT) and the other under zero tillage (ZT). A split-plot design was applied, assigning three seeding rates (71, 107, and 143 kg ha⁻¹) to main plots and four nitrogen levels (60, 120, 180, and 240 kg N ha⁻¹) to sub-plots. Increasing the seeding rate improved spike density and grain yield, particularly under ZT. The highest rate (143 kg ha⁻¹) was found to be optimal for both tillage systems. Nitrogen fertilization had a noteworthy effect on yield and its components, with 180 kg N ha⁻¹ resulting in the highest grain yield (6.62 and 6.49 t ha⁻¹ for CT and ZT, respectively). No further significant improvements were obtained at 240 kg N ha⁻¹, suggesting diminishing returns. A significant interaction was detected, where the combination SR3 × N3 (143 kg ha⁻¹ × 180 kg N ha⁻¹) achieved maximum productivity (7.14 and 7.19 t ha⁻¹ under CT and ZT, respectively) and the highest harvest index. Soil analyses demonstrated that ZT maintained higher organic matter content (1.26–1.62%), whereas CT improved bulk density and infiltration rate. Overall, integrating a high seeding rate (143 kg ha⁻¹) with moderate nitrogen fertilization (180 kg N ha⁻¹) under ZT provided the most effective balance between productivity and soil sustainability in the Nile Delta