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Planter (farm implement)

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A planter is a specialized farm implement used to sow seeds in precise rows across a field.

Kinze 2200 planter
Kinze 2200 planter

These machines are typically towed behind a tractor using a drawbar or a three-point hitch. While they share concepts with seed drills or grain drills, the term "planter" is specifically used for machines handling larger seeds. This includes crops like maize, also known as corn, as well as beans and peas. The main goal of a planter is to ensure seeds are placed in a very accurate manner. This precision helps manage the density and placement of crops for better growth.

Planters vary significantly in their physical scale and configuration. They can range from a single row to massive machines with 54 rows. Currently, the largest planter in the world is the 48-row John Deere DB120.

JD 71 Flexi Planter, 2 Row
JD 71 Flexi Planter, 2 Row

Large, modern planters are built using multiple modules called row units. These units are spaced evenly along the machine at specific intervals. In the United States, the most common row spacing is 30 inches. This spacing ensures each plant has enough room to develop without competing too heavily with its neighbors.

To understand how a planter works, one must look at how seeds are metered out. Older planter designs featured an individual seed bin for every single row. They also often included a fertilizer bin that served two or more rows. Inside these seed bins, operators installed plates with specific tooth spacing. The size of the space between these teeth was carefully chosen. It was large enough to allow exactly one seed to pass through at a time, but too small to allow two seeds to fall together.

John Deere Planter with Case IH Tractor
John Deere Planter with Case IH Tractor

Modern machines have moved toward central commodity systems. These use one large bin to distribute seeds to every row simultaneously.

Planters use different drive systems to manage the speed of seed delivery. In a mechanical drive system, a small suspended tire is driven by another tire in contact with the ground. When the operator lowers the planter, these two tires make contact. As the driven wheel turns, it rotates a series of gears. These gears determine the planting population, which is the number of seeds planted in a given area. An operator can manually change these gears to adjust the population. However, mechanical systems are limited by the specific number of gear settings provided by the manufacturer.

To overcome the limits of mechanical gears, hydraulic and electrical systems were developed. Hydraulic driven systems allow an operator to change the planting population while the tractor is still moving. These systems can also follow a computer-generated prescription for an individual field. This allows for an "infinite" range of population settings compared to fixed gears. More recently, electrical systems have revolutionized speed. In 2014, John Deere introduced the ExactEmerge row unit for high-speed planting.

John Deere Planter with Case IH Tractor
John Deere Planter with Case IH Tractor

Precision Planting followed this with their vDrive system. These electrical motors allow the operator to double their planting speed.

High-speed planting requires a special technique called the "dead-drop" method. Traditionally, operators planted at speeds between 4.5 and 5.5 mph for optimal performance. In older systems, seeds were simply dropped through a tube after being metered. To plant faster, modern electrical systems use a belt or a brush-belt. This mechanism offsets the forward momentum of the planter with the rearward momentum of the seed. This ensures the seed is placed accurately in the trench even when the tractor is moving quickly.

Modern technology also uses GPS and computer-controlled systems to manage field navigation. Older planters used a marker, which was a single disc harrow disc on a rod, to create a line for the tractor to follow. Today, GPS navigation and auto-steer systems have largely replaced the need for physical markers. Systems like Case IH AFS use GPS/RKS and computers to sow seeds within 2 cm of their intended position.

John Deere Planter with Case IH Tractor
John Deere Planter with Case IH Tractor

In irregularly shaped fields, this equipment can detect when a tractor is overlapping an area already sown. The system will then automatically hold the seed release to avoid wasting seeds near obstacles like trees.

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🖼️ Images & Media (3)
File:JD 71 Flexi Planter, 2 Row.jpg
JD 71 Flexi Planter, 2 Row.jpg
File:John Deere Planter with Case IH Tractor.JPG
John Deere Planter with Case IH Tractor.JPG
File:Kinze 2200 planter.jpg
Kinze 2200 planter.jpg
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