Abstract: A baler for making large sized rectangular bales of agricultural crops, has a bale chamber the size and shape of the bales to be formed. At one end of the chamber the crop is introduced into the chamber by feed means which compresses the crop. A restraining member in the bale chamber is movable from adjacent the inlet towards a position in which the chamber is full so as to define an increasing volume of the chamber accessible to the crop and enable bales of variable, relatively high density to be formed.The restraining member is moved intermittently by the pressure of the crop in the chamber and after completion of each bale is returned to its initial position. Each bale is bound together when completed and a packing plate is optionally provided to assist in forming the bales.