Comparative study of particle size distribution in Commercial urea fertilizers from India

The particle size distribution (PSD) of granular urea plays a crucial role in determining its flow behaviour, spread uniformity, and compatibility with fertilizer applicators and spreaders. This study aimed to evaluate the PSD variability of urea fertilizers produced by ten leading manufacturers in India. The results indicated that the majority of urea granules were retained between the 1.0 mm and 1.7 mm sieves. The proportion of particles within the 1.0-1.7 mm range varied from 75.46% to 96.82%, with an overall average of 91.71%. A one-way analysis of variance (ANOVA) showed that the differences among manufacturers were statistically significant (p<0.05), and the Tukey post hoc test revealed significant pairwise differences in 37 out of 45 comparisons. The findings highlight considerable variation in urea granule sizes, which can affect flowability and uniform discharge in fertilizer applicators.