A vehicle trailerable, or otherwise moveable or advancable, over the ground, the vehicle carrying an intake for water, a water heater for water received from the intake, a urea dissolving apparatus defining a chamber: (i) into which particulate urea can be gravity fed from above (ii) having an inlet for heated water from the gas heater, (iii) to define in use a dissolution zone for urea above solid urea such that, owing to urea content in the water at that zone, the urea is substantially no longer subject to dissolution or is subject to less severe dissolution, (iv) having a takeoff to provide in use a liquid stream of urea dissolved in water, the takeoff being at or below the dissolution zone, and a pumped reticulation apparatus to receive the liquid stream from the takeoff.
