English for Agriculture - Beginners and Intermediate

Harvesters (Combines)

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.

Harvester’s head

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. 

Head types:


Exclusive Harvesters

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

·         Nut harvester:  grab the trunks of trees and shake them to force loose nuts (almonds, pecans, etc.) to fall.

·         Chicken harvesters: collect chickens and place them in a holding area, typically before being sent for slaughter.

Dictionary meaning

A doffer is someone who removes ("doffs") bobbins, pirns or spindles holding spun fiber such as cotton or wool from a spinning frame and replaces them with empty ones.

Last modified: Sunday, 5 June 2016, 5:08 PM
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