Availability of NH4+ N in the surface soil (0-15 cm) was initially lower from deep-placed USG compared with prilled urea split and neem-coated urea, but increased up to 45 d after transplanting (Patel et al 1989).
Prilled is a term used in mining and manufacturing to refer to product that has been pelletized. The pellets are a neater, simpler form for handling, with reduced dust. Certain agrochemicals such as urea are often supplied in prilled form
the solidification of droplets of molten material falling against an upward stream of air; used especially to agglomerate ammonium nitrate and urea for use as a fertilizer