A forage harvester is a piece of farm machinery that is used to harvest forage crops such as grass to process them into silage.
Read More (Forage Harvesters)In the case of maize and some other types of whole-crop silage, the crop is cut directly by the forage harvester\'s header. This unit uses reciprocating knives, disc mowers or sawtooth blades to do the job. Where the machine is being used to harvest cereal crops, it is often fitted with kernel-processing units. These modules have a pair of mill rolls, with teeth that are forced together by springs. Theses teeth crack the kernels of the crop being harvested. The kernel-processing unit is positioned between the accelerator and cutterhead, and it can be swapped out and replaced with a standard grass chute when not in use. Towed harvesters can have single, double or precision chops and may be electronically or hydraulically operated or via a cable.
The towed type of forage harvester is most common on small to medium-size farms, but the larger operations are now moving towards self-propelled forage harvesters. These usually will have a tractor or truck moving beside the forage harvester and trailing a wagon to take the harvested crop. These machines can get extremely powerful, with some boasting engines of more than 1,000hp and capable of cutting swathes 11 metres wide. They can process up to 400 tonnes of silage in a single hour. The harvested crop can be cut precisely to size according to requirements and then treated with enzymes, mould inhibitors or bacteria to aid fermentation.
Checking out a used forage harvester depends entirely on the type of unit being considered. Simple trailed mechanisms are relatively straightforward, but self-propelled harvesters would require a similar degree of inspection as a tractor or combine.