Nhill spreader calibration with Accu-Spread Russell Nichol
Five spreaders were put through their paces at the BCG Nhill spreader calibration day on the 28th June. Feature spreaders ranged from Amazone, Bredal, Bogballe, Marshall and Landico.
We had an extremely successful turn out with over 15 growers present and numerous spreader sales men coming to watch the spreaders perform. Russell Nichol from Accu-spread ran spreaders over the paddock and used software to analyse each spreaders performance by producing graphs with show the spread width and evenness of spread, once the graphs have been evaluated the spreader configurations can altered to obtain an evener spread of urea.
To evaluate a spreaders performance a 60 meter line of urea catchers (boxes designed to capture the urea so it doesn’t bounce out) are laid out. The spreader will pass through the line going at normal speed spreading urea at 80kg/ha. Once the spreader has passed through each individual box has the urea weighed so a spread with can be calculated, these weights are then put into the software so a bout width and distribution can be calculated.
The quality of urea should be ideally 2-3.5mm with 70% of the product being within this range. A good machine will spread the urea well, the spreading pattern behind the machine will be the final pattern as there wont be any overlap from the following pass.
The Bredal spreader was an outstanding performer on the day with one of the most even spread width’s. The distribution graph shows how wide the spread is and how much urea is leaving the spreader. The Bredal machine can be operated at any width where the graph line is below 15% coefficient of variation (CoV) and still achieve an acceptable level of variation across the spreader pattern. The Bredal has a 33 meter spread pattern which is well above the 30 meter spread width aim.
Figure 1: Bredal K85 spreader at 1000 spinner RPM at drop point 4.5
The Sulky PDX 85 spreader was a contender for second best performing but only because the distance of spread was less even though the coefficient of variation remained less than 15%. It was spreading heavily 15 meters out each side which can be seen on the distribution graph in figure 2.
Figure 2: Sulky DPX 85 urea apreader at PTO 620 spinner RPM at drop point 145
The Amazone spreader was a standout among the other spreaders as it had the widest spreading distribution. The spreader was 750mm off the ground with short veins filling the center of the Amazone. Although a higher coefficient of variation is seen the racetrack path will produce a better bout width.
The spreaders all made one pass through the line of urea catchers before adjustments were made based on the output graphs. Some spreaders required more than one adjustment to alter the urea distribution. It should be noted that the height of the spreader will not make a difference in spreader width.
The Amazone and Bredal spreaders were the only two standout spreaders which required the least amount of modifications to reach optimum spreading distribution.
The day was a clear success which was supported by the GRDC BWD00024 Maintaining profitable farming systems with retained stubble project.