A reductant mixing system having injector and mixing plate positioned within mixing canister is disclosed. Injector discharges reductant directly into vehicle exhaust gases. Mixing plate effects turbulence to mix gases for NO reduction. Mixing plate includes plurality of arms each having surface area and extending from center of plate, barrier region defined by collective surface areas of arms and substantially centered for diverting fluid flow outward, and first and second cut-outs, which allow the gases diverted by barrier region to pass mixing plate into adjacent canister of exhaust treatment system. Each of the first cutouts is defined by outer edge between adjacent arms, and second tier of cut-outs defined by inner edge proximate end of each arm.