Effect of Granule Size on Application
Balay, Hubert L.
Broder, Michael F.
This study investigates the effect of granule size on the application of dry fertilizer using spinner spreaders, which are commonly used in the United States for broadcasting fertilizer. Previous research has emphasized the importance of particle size in maintaining uniform distribution within blends. However, the focus has been on smaller particles, discouraging using larger materials. This paper explores the advantages of broadcasting materials larger than typical granular products and examines the impact on spread patterns. The literature review reveals that particle size significantly influences the segregation of raw materials in blends. Small particles travel a shorter distance from the spinning discs than large particles, affecting the distribution pattern. Studies have also shown that irregularly shaped particles travel less distance than spherical particles due to their larger drag coefficients. However, recent research suggests that while median particle size is crucial, size variability has little effect on the spread pattern. The study conducts field spreading tests using a double-spinner spreader and a high-flotation applicator with a single spinner. Three different sizes of urea granules are used, with similar density, shape, and surface roughness. The spread patterns are analyzed using a computer program, and various spinner and chute adjustments are tested to determine the optimal settings. Results demonstrate that larger granules can be broadcasted more effectively when placed nearer to the centers of double spinners. Swath widths increase significantly, with improvements of up to 30 feet observed. The study also reveals that larger granules produce less dust and are less prone to drifting, making them advantageous in reducing environmental concerns.
Granule, Fertilizer application, Blended fertilizers