The combine harvester, also known as the combine, is a modern, multifunctional machine used to harvest various grain crops efficiently. Its name comes from the fact that it combines four separate operations: reaping, threshing, gathering, and winnowing into a single process.

The combine is capable of harvesting crops such as wheat, rice, oats, rye, barley, corn (maize), sorghum, soybeans, flax (linseed), sunflowers, and rapeseed. After the grain is separated, the remaining straw is left on the field. The straw consists of the stems and any remaining leaves of the crop, with limited nutrients left in it. The straw is either chopped, spread on the field, plowed back in, or baled for bedding and limited feed for livestock.

The combine harvester is one of the most significant inventions in agriculture that has helped reduce the fraction of the population engaged in farming. The primitive version of the combine was the horse-drawn “combination harvester-thresher” that was introduced in Michigan in 1836 and later used in California.

Combines became more widespread in the 1930s, with the availability of tractor-drawn models. Self-propelled machines that could cut swaths 2.5 to 5.5 meters (8 to 18 feet) wide appeared a decade later. While originally designed to harvest wheat, they have come to be used to harvest many other crops.

The design of the combine is essentially a binder-type cutting device that cuts and delivers the grain or seed crop to a threshing machine that is modified to work as it moves across the field. The cutting-gathering component, designed to take the grain with a minimum of straw, is sometimes called the header.

A threshing cylinder rubs the grain out of the heads against a concave surface. Some grain and chaff go with the straw to the straw deck, where grain is shaken out and delivered to the cleaning shoe. Some of the grain and chaff go directly to the cleaning shoe, where sieves and a blast of air are used to separate and clean the grain.

After passing through the air blast, the grain drops into a clean-grain auger that conveys it to an elevator and into a storage tank. Straw drops out of the back of the combine in a windrow for baling or is scattered over the ground by a fan-like spreader. Some combines used on steeply rolling land have a body supported in a frame by hydraulic cylinders that automatically adjust to keep the body level.

Combine harvesters are a very useful addition to a farmer’s machinery set, especially if the farm exceeds a certain size and focuses on certain crops. Different brands of combines have different specifications and weights. Some popular brands and their specifications include:

John Deere S690 is a popular machine from one of the most experienced manufacturers of agricultural machinery. This heavy-duty machine is capable of making short work of dense, heavy crops while exhibiting exemplary performance in terms of speed and maneuverability. The weight of this machine (without headers) is 15,636 kg.

The Claas Lexion 780 is a popular German brand that exhibits exemplary performance and is popular across five continents. This machine is touted as being eco-friendly due to its environmentally advanced engine.

The sieve positions and fan speed adjust automatically as the machine moves over variable terrain, enhancing cleaning performance. This machine weighs (without headers) 18,920 kg.

The Claas Lexion 795 is a more recent iteration of Claas machines. This limited edition machine stands out due to its unusual green and black paint job and its informal moniker “Monster Limited Edition”.

Additionally, some modern combine harvesters are equipped with advanced features such as yield mapping, GPS guidance systems, and automated crop sensors that allow for precise crop management and improved efficiency.

These features enable farmers to monitor crop yields and make informed decisions about fertilization, irrigation, and other agricultural practices to optimize crop production and minimize waste.

Despite their numerous benefits, combine harvesters also pose several challenges to farmers. The high cost of purchasing and maintaining these machines can be prohibitive for small-scale farmers, and the complex technology requires specialized training and expertise to operate and maintain.

Additionally, the use of combines can contribute to soil compaction, which can have negative impacts on soil health and productivity over time.

A modern combine harvester is a remarkable machine that has revolutionized agricultural production and significantly reduced the labor required for crop harvesting. With continued advancements in technology, these machines will undoubtedly play a crucial role in feeding the growing global population.

However, farmers must also be aware of the potential challenges associated with their use and take steps to mitigate any negative impacts on soil health and productivity.