Forage harvester - AbsoluteAstronomy.com

A forage harvester is a farm implement that harvests forage

Forage

Forage is plant material eaten by grazing livestock.Historically the term forage has meant only plants eaten by the animals directly as pasture, crop residue, or immature cereal crops, but it is also used more loosely to include similar plants cut for fodder and carried to the animals, especially...

plants to make silage. Silage

Silage

Silage is fermented, high-moisture fodder that can be fed to ruminants or used as a biofuel feedstock for anaerobic digesters. It is fermented and stored in a process called ensiling or silaging, and is usually made from grass crops, including corn , sorghum or other cereals, using the entire...

is grass

Grass

Grasses, or more technically graminoids, are monocotyledonous, usually herbaceous plants with narrow leaves growing from the base. They include the "true grasses", of the Poaceae family, as well as the sedges and the rushes . The true grasses include cereals, bamboo and the grasses of lawns ...

, corn

Maize

Maize known in many English-speaking countries as corn or mielie/mealie, is a grain domesticated by indigenous peoples in Mesoamerica in prehistoric times. The leafy stalk produces ears which contain seeds called kernels. Though technically a grain, maize kernels are used in cooking as a vegetable...

or other plant that has been chopped into small pieces, and compacted together in a storage silo

Storage silo

A silo is a structure for storing bulk materials. Silos are used in agriculture to store grain or fermented feed known as silage. Silos are more commonly used for bulk storage of grain, coal, cement, carbon black, woodchips, food products and sawdust. Three types of silos are in widespread use...

, silage bunker, or in silage bags. The silage is then fermented to provide feed for livestock

Livestock

Livestock refers to one or more domesticated animals raised in an agricultural setting to produce commodities such as food, fiber and labor. The term "livestock" as used in this article does not include poultry or farmed fish; however the inclusion of these, especially poultry, within the meaning...

. Haylage is a similar process to silage but using grass which has dried.

Uses

Forage harvesters can be implements attached to a tractor

Tractor

A tractor is a vehicle specifically designed to deliver a high tractive effort at slow speeds, for the purposes of hauling a trailer or machinery used in agriculture or construction...

, or they can be self-propelled units. In either configuration, they have either a drum (cutterhead) or a flywheel with a number of knives fixed to it that chops and blows the silage out a chute of the harvester into a wagon that is either connected to the harvester or to another vehicle driving alongside. Most larger machines also have paddle accelerators to increase material speed and improve unloading characteristics. Once a wagon is filled up, the wagon can be detached and taken back to a silo for unloading, and another wagon can be attached. Because corn and grass require different types of cutting equipment, there are different heads for each type of silage, and these heads can be connected and disconnected from the harvester. Grass silage is usually cut prior to harvesting to allow it to wilt, before being harvested from swathes with a collection header (windrow pickup). Maize and wholecrop silage are cut directly by the header, using reciprocating knives, disc mowers or large saw-like blades. Kernel processors (KP), modules consisting of two mill rolls with teeth pressed together by powerful springs, are frequently used when harvesting cereal crops like corn and sorghum to crack the kernels of these plant heads. Kernel processors are installed between the cutterhead and accelerator. In most forage harvesters, the KP can be quickly removed and replaced with a grass chute for chopping non-cereal crops.

While towed harvesters continue to be used by small family farms, the large factory-farm way of silage making is with a self-propelled machine with a tractor or truck running along with the forager. Today's largest machines have engines producing in excess of 1000 hp, are fitted with headers able to cut up to a 35 feet (10.7 m) swath of corn in a single pass, and an output exceeding 400 tons of silage per hour. Silage made from grass

Grass

, canola

Canola

Canola refers to a cultivar of either Rapeseed or Field Mustard . Its seeds are used to produce edible oil suitable for consumption by humans and livestock. The oil is also suitable for use as biodiesel.Originally, Canola was bred naturally from rapeseed in Canada by Keith Downey and Baldur R...

, oats

OATS

OATS - Open Source Assistive Technology Software - is a source code repository or "forge" for assistive technology software. It was launched in 2006 with the goal to provide a one-stop “shop” for end users, clinicians and open-source developers to promote and develop open source assistive...

or wheat

Wheat

Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...

are chopped in pieces 6 to 30 millimeters and treated with additives including bacteria, enzymes, mold inhibitors, and preservatives to accelerate the fermentation process. When silage is made of corn

Corn

Corn is the name used in the United States, Canada, and Australia for the grain maize.In much of the English-speaking world, the term "corn" is a generic term for cereal crops, such as* Barley* Oats* Wheat* Rye- Places :...

or sorghum

Sorghum

Sorghum is a genus of numerous species of grasses, one of which is raised for grain and many of which are used as fodder plants either cultivated or as part of pasture. The plants are cultivated in warmer climates worldwide. Species are native to tropical and subtropical regions of all continents...

additives are not necessary because of the high sugar and starch levels in the plants. Additives however are frequently added to corn and sorghum to augment their fermentation.

Small family farms still used towed behind harvesters, these are either single chop, double chop or precision chop. Older machines were operated by cables, then they were operated by hydralics and the newer types are operated by electronics.

Uses

See also