Soil, especially in reclaimed areas, need fertilizing application to rich it with all plants requirement of nutrient elements, but due to the consequent increase of commercial fertilizer prices and the desire to prevent the environmental contamination by the excessive application rates, the best management practices of fertilizer broadcasting machines become more important nowadays. Hence, the aim of this investigation was to evaluate and predict the performance of a twin-disc spreader using granular Ammonium Nitrate during fertilizing sugar beet through two main groups of experiments, the first was the preliminary experiment, to select the proper operating parameters. Without overlapping, The obtained results showed that the lower value of coefficient of variation (C.V) and highest values of correlation (R2) were achieved at spinner speed 52.3 rad/s( 500 rpm), backward blade angle of -15, spinner angle of zero degree and gate opening area of 18 cm2 using four C-shaped blade and spinner height of 50cm. While the second one was the field experiment which carried out according to the results of preliminary experiment by using the computer programmer of Curve Fit 1.37 (2001) which expressed the relationship between forward speed and the parameters affecting the performance of spreader such as; application rate, pattern uniformity, energy requirement, total yield and spreading cost to predict the performance of spreader. Also, the obtained data showed that the high degree of uniformity and correlation between operating factors were achieved at overlap percentage of 42.8% equals to effective swath width of 11m which gave an acceptable pyramidal pattern.