APPLIED ENGINEERING IN AGRICULTURE, cilt.24, sa.2, ss.173-179, 2008 (SCI-Expanded)
Rotary fertilizer spreaders, with single- or twin-disc, should be level during field applications for a proper fertilizer distribution pattern. Pattern tests are recommended to be conducted with the spreader level. Even if the spreader is initially level, it can become unlevel due to reasons such as connection errors on three-point hitches, different inflation pressures of the tires on the tractor, surface properties of the field, and other factors. In previous studies, the spreader angle, front to rear, was investigated. The effect of side to side out of level, which has not been previously addressed, was investigated in this study on fertilizer distribution patterns in single- and twin-disc rotary fertilizer spreaders using triple superphosphate and calcium ammonium nitrate. Spreader angles of -10 degrees -5 degrees +5 degrees, and +10 degrees along with a level position (0 degrees), with respect to a line perpendicular (left-right or side to side) to the direction of travel of spreader, were tested with both spreaders and both fertilizers. The experimental results showed that the angle of the spreader had a significant effect (P < 0.001) on the fertilizer distribution pattern. The more the spreader was angled down (-10 degrees), the greater the fertilizer distribution pattern skewed to the right. Similarly, the more the spreader was angled up (+10 degrees), the greater the pattern skewed to the left. Even the distribution patterns obtained from an angular change of only 5 degrees were significantly different from the distribution patterns at the optimum level position.