Most self-propelled and trailed forage harvesters have a pick-up cylinder used to lift a previously cut and wilted crops. Attachments for harvesting maize and whole-crop cereals for silage can also be used on many forage harvesters.
Maize headersOne type (Plate 15.7) consists of a series of dividers which guide individual rows of the crop to rotary cutters where the stems are sheared off and passed by an auger to the feed rolls. Another design (Plate 15.6) can be used to cut along or across the rows. It has smaller crop guides which direct the crop to large rotary cutters where the stems are severed and carried by the cutters to the feed rolls. A kernel processor or corn cracker (Figure 15.3) is used to break up the ears and improve the qualitv when harvesting maize for silage. Maize headers are made for harvesting 4, 6, 8, 10 or 12 rows at a time. A 10-row maize header can clear up to five hectares in an hour. Some self-propelled harvesters have an automatic steering system with sensors on the header linked to a computer in the cab.
Plate 15.7 This self-propelled forage harvester with a 10-row maize header has rotary dividers to separate the rows being cut from those left standing. It can be automatically steered to follow the rows. (John Deere)
Whole-crop headersused to cut, chop and load green cereal crops for silage are very similar to a combine harvester cutter bar and on some machines it is possible to use a rigid combine harvester header up to 6 m wide on a self-propelled forage harvester made by the same manufacturer. Some purpose-made whole-crop headers have a hydraulic motor-driven pick-up reel, self-cleaning knife sections and a hydrostatic auger reverser used to clear heavy blockages on the cutter-bar table.
Rotary MowerSome self-propelled forage harvesters can also be used with a wide rotary mower conditioner in place of the normal pickup unit used to collect previously cut and conditioned swaths. A typical three-section 8.5 m cut rotary mower header is hydraulically folded for transport.