English for Agriculture - Beginners and Intermediate
Harvesters are one of the most economically important labor, significantly reducing the fraction of the population that must be used for agriculture. A harvester (combine harvester, or just combine), is a machine that harvests many grain crops. The name, combines, is given to harvesters because it combines three separate operations comprising harvesting into a single process; these operations are reaping, threshing, and winnowing. Harvesters can be discrete vehicles or tractor-towed machines with diesel-powered units and with a high driver cab for visibility with tread wheels. Some include hillside leveling systems for harvesting on hills. Many crops can be harvested with a combine such as wheat, oats, rye, barley, corn (maize), sorghum, soybeans, flax (linseed), sunflowers, and canola. In normal combines, the process of how a harvester works can be explain as follow: first, crops move from the head ,by the transporter, to the feed accelerator that in turn moves crops to the rotor for threshing. Threshed grains pass into the grain tank, while trash and debris is moved to a chaffing mechanism so it can divide grains from the plant. The processing speed and threshing tolerances are operator controlled to handle different crops. Plant debris is expelled from the back of the harvester, The waste straw left behind on the field is the remaining dried stems and leaves of the crop with limited nutrients which is either chopped and spread on the field or baled for feed and bedding for livestock. The grain tank is frequently emptied into a grain hopper, usually towed by a tractor or even the combine itself. Rotary-style combines thresh crops via one or two drills that are along in the combine.
Combines use tools that can be change, called heads, which are specific to the type of crop collected. They are responsible for shearing or picking and sending crops to the feedhouse, where crops are later processed by integral combine machinery.
- Grain platform: uses a toothed metal reel to cut and feed into horizontal drills directed at the feedhouse
- Corn head: It has blades that cut stalks and sends corn into the feedhouse
- Forage harvester: collects loosened and cut foliage and plant material from fields
- Pickup head: useful for short-grain windrow harvesting
- Cotton picker: removed grasp bloomed cotton, as well great plant matter, and then separates the materials through gravity; or rotating, spiked spindles remove the seed-cotton from the plant and a worker( in this case doffer)divides the cotton from plant material
- Cane harvester: It is equipped with saws shred sugar canes from top to bottom while being fed through vertical drills that direct cut cane into the feedhouse
Many crops require unique harvesting machines. This is mostly due to unique picking requirements, as with root and orchard crops, crop size (small nuts or fruits), or crop picking techniques. Some of the crops which need unique harvesting machines include: carrot, onion, garlic, radish, spinach, potato, cabbage, tomato, pepper, bean, rice, coffee bean, tobacco, tea, mango, grape, cherry, orchard (apple, pear, plum, lemon, etc…,). Now, I will give some examples of exclusive harvesters:
· A swather: It is used in northern climates to cut hay or small grain crops due to shorter growing seasons. Cut grains will dehydrate faster, a necessity before harvest. Swathers cut these crops and a transporter organizes and layers them into windrows for later collection