When you playback animation on an object with motion blur enabled, the object appears blurred in the viewport. You can enable Motion Blur on a per-object basis using the Attribute Editor, under the Render Stats section when you select an object shape node.
If some surfaces in the scene don’t move, or move only slightly, do not enable motion blur for them. Being selective about what you motion blur can decrease rendering times.
To set motion blur when rendering using the Maya Software renderer, enable it via the Render Settings window, Motion Blur section. See Render Settings: Maya Software tab. See also Set motion blur for more information.