Abstract: An agricultural machine for picking up and chopping crop, particularly green crop such as grass to be made into silage, and comprising a picking up device for collecting crop from ground over which the machine is travelling and at least one chamber to which the crop is delivered from said picking up device through a lateral opening and the chamber containing a reciprocable ram movable towards and away from stationary knives in an open end of the chamber, the ram preferably having knives on its face presented towards the stationary knives, the movement of the ram towards the stationary knives causing the knives to co-operate to chop up the crop, the cut crop being discharged from the open end of the chamber into a collector cage.