This study evaluates the performance and calibration efficiency of a mechanical disc seed drill through integrated laboratory and field trials, supported by mathematical modeling and statistical validation. Conducted in Nineveh Province, Iraq, the study examined a seven-row seed drill at three forward speeds (3.5, 5.5, and 7.5 km/h) during spring wheat sowing. Key parameters included seed spacing, actual seeding depth, standard deviation (SD), and coefficient of uniformity (CU). Results revealed a negative correlation between speed and seed placement accuracy; CU decreased from 85.4% at 3.5 km/h to 68.2% at 7.5 km/h.

ANOVA analysis confirmed the statistical significance of the observed differences, particularly for CU (F = 18.63, P = 0.001), SD (P = 0.003), and spacing (P = 0.008), validating the robustness of the experimental findings.

A linear regression model (R² = 0.97) was developed to predict field performance based on operational speed.