Case Study: Distribution Uniformity of a Blended Fertilizer Applied Using a Variable-Rate Spinner-Disc Spreader

An Investigation into the FertilizerParticle Dynamics Off-the-Disc

“…Segregation is produced because smaller particles percolate through the voids of the material and are released in turns during spreading according to their relative sizes (Lance, 1996). As a result, the spreading width may be initially narrow and it may widen up progressively as larger particles reach the disc, which will produce inconsistent particle distribution patterns along the tramline (Jensen and Pesek, 1962c;Bradley and Farnish, 2005;Virk et al, 2013). Severe granulometric segregation can occur when Granulometric Spread Index (GSI) is above 25% (Miserque and Pirard, 2004), value that is largely exceeded in samples of OMF and biosolids granules (GSI >40%) presented in table 1 (Antille et al, 2013c).…”

Ballistic Modeling and Pattern Testing to Prevent Separation of New Zealand Fertilizer Products

“…Striping is a real economic issue as it is only visible at in-field coefficient of variation (CV) of around 40%, giving a yield reduction of at least 20%, (Miller et al, 2009;Mersmann et al, 2013;Grafton, et al, 2013;Yule and Grafton, 2013). This reduction in yield and economic impact on the fertilizer end user has resulted in farmers' concern in many parts of the world (Miller, 1996;Miserque and Pirard, 2004;Miserque et al, 2008;Virk et al, 2013). The fertilizer blends that are spread have not changed.…”

“…Miserque et al (2008) and Yule and Grafton (2013) identified the elements which lead to separation, they are: particle size, particle density or specific density, and particle shape in order of importance. Virk et al (2013), Yule and Pemberton (2009), and Miserque and Pirard (2004) have undertaken field experiments which have demonstrated that blends separate and nutrient application varies greatly from the targeted application rate. Virk et al (2013) found that the resultant application of blended fertilizers was significantly different from the targeted application using variable rate technology.…”

“…Virk et al (2013), Yule and Pemberton (2009), and Miserque and Pirard (2004) have undertaken field experiments which have demonstrated that blends separate and nutrient application varies greatly from the targeted application rate. Virk et al (2013) found that the resultant application of blended fertilizers was significantly different from the targeted application using variable rate technology. It is intended to shed some light on these experimental findings by predicting the ballistic properties of various fertilizers and measuring their performance when spread in the field.…”