An adjustable nozzle assembly for a sieve box and a sieve box including same, including a support assembly and nozzles. A pair of elongated support members may be received through openings in support collars. Nozzles may be operatively connected to the collars. The support assembly, which may include collars and rods, are configured to provide at least one of lateral movement and rotational movement of the nozzles. At least one of the first elongated support member and the second elongated support member may be configured to move when coupled to the sieve box to adjust a spray angle of the nozzles. Pivoting of the one rod about the other rod adjusts the angle at which the nozzles are disposed. The rods may be externally threaded, and the collars may be internally threaded, such that when the rods are rotated, the collars translate laterally along the rods to move the nozzles.