To provide a soil loosening apparatus to reduce traction resistance by loosening a hard soil layer trod down with a wheel of a traveling body in a rotary tilling work.

The soil loosening apparatus 40 is attached to a rotary implement which is attached to the back of a traveling body 90 and moves while rotating a tilling rotor 15 provided with tilling tines 17 to till a field H. The loosening apparatus is positioned at the back of a rear wheel 92 of the traveling body 90 in traveling direction and in front of or at the back of the tilling rotor 15, and is provided with a supporting member 41 supported by the rotary implement and a blade 45 attached to the lower part of the supporting member and extending in a lateral direction. The blade 45 is positioned at the bottom of a hard soil layer K trod down with the rear wheel 92 of the traveling body 90 and moves according to the forward movement of the traveling body 90 to loosen the hard layer K. The lateral thickness of the supporting member 41 and the vertical thickness of the blade 45 are comparable to the thickness of the tilling tine 17, and the lateral width of the blade 45 is nearly the same as the lateral dimension of the rear wheels 92 of the traveling body 90.