New high-speed imaging system for fertilizer granule characterization at the ejection

In the context of fertilizer supply reduction and eco-technology concept development, the understanding of the centrifugal spreading process became essential as this technique is widely used because of its low cost, simplicity and robustness. Although mechanically simple, centrifugal spreaders used for mineral fertilization involve complex physics that cannot be fully characterized at this moment. The most important parameter is the spatial distribution on the ground, for which the quality depends on many factors, such as construction and calibration of the machinery, particle types and properties, field conditions, etc. Previous studies based on optical (Grift and Hofstee, 1997) or image acquisition methods (Cointault et al., 2003; Villette et al., 2006) have shown that the spatial distribution on the ground can be accurately estimated by calculating the ballistics of the particles from their initial conditions of flight, their properties and geometrical parameters (topography …). This paper presents improvements of previous high speed imaging systems developed separately by ILVO Institute1 and Enesad2 (Cointault and Vangeyte, 2005), based on the modification of the illumination system and on the use of stereoscopic approach to provide 3D information necessary for the prediction of the global fertilizer behaviour at the ejection. Results obtained with these improvements will be provide during the conference.