Impact of Bottoms Number on Draft Force Requirements and Stability of Moldboard Plow at Various Tillage Depths and Forward Speeds

The study aimed to evaluate the bottom effect of the numbers of different moldboard plows, namely single bottom (MB1), two bottoms (MB2), three bottoms (MB3), and four bottoms (MB4), three levels of forward speeds (3.17, 4.78, and 6.43 km h-1), and three levels of plowing depths (15, 20, and 25 cm) for the moldboard plow, and the interaction between these factors on draft force, fuel consumption, and longitudinal and lateral deflection of the moldboard plow. The experiments were carried out in the Basrah governorate (29° 31′N, 46° 48′ E). The experiment used a randomized complete block design with a split plot method for a factorial experiment (4 × 3 × 3) with three replicates. The results showed that increasing the number of bottoms from MB1 to MB4 reduced the draft force per bottom from 5.55 to 3.22 kN, fuel consumption from 18.83 to 14.72 L ha-1, lateral deflection from 4.58% to 2.22% and longitudinal deflection from 8.04% to 2.76%. Although increasing the speed from 3.17 to 6.43 km h-1 increased the draft force by 64.3%. Increasing the plowing depth from 15 to 30 cm increased the draft force from 3.50 to 7.84 kN, fuel consumption from 14.00 to 23.69 L ha-1, longitudinal deflection from 2.31% to 6.27%, and lateral deflection from 2.43% to 3.22%. The best performance was recorded when using the MB4 at a speed of 6.43 km h-1 and a depth of 15 cm, achieving the lowest draft force (3.22 kN), the lowest fuel consumption (10.00 L ha-1), and lateral and longitudinal deflection of 0.78% and 2.76%, respectively.