Urea nutrition of young maize and sugar-beet plants with emphasis on ionic balance and vascular transport of nitrogenous compounds.

In a pot trial, maize cv. Prior and sugarbeet cv. Polyrave were given N as urea or ammonium. There was no significant difference between DM producton in either spp. with the different N sources, although plant N content was increased with N supplied as ammonium. Root cumulative net proton extrusion closely agreed with calculated values for net absorption of cations, indicating that urea was absorbed intact, at a rate sufficient for growth. Xylem exudate was free from urea and NH3-N suggesting metabolism in the roots. Urea appeared to be assimilated other than by enzymic breakdown. (Abstract retrieved from CAB Abstracts by CABI’s permission