Plowing is a foundational agricultural practice that involves turning over the top layer of soil, a process known as primary tillage. The purpose of this action is to create an optimal environment for new crop growth by improving the soil’s structure and readiness for planting. Effective plowing achieves several outcomes, including the physical burial of existing weeds and crop residue, which helps suppress competition for resources and aids in decomposition. This mechanical inversion also enhances soil aeration and porosity, allowing for better gas exchange and water infiltration to support healthy root development.
Preparing the Field and Selecting the Plow
Before any soil is turned, proper preparation of the equipment and the field is necessary to ensure efficiency and a quality result. Selecting the correct implement is determined by the type of soil and the amount of crop residue present. A moldboard plow, with its curved surfaces, fully inverts the soil slice, making it suitable for burying heavy residue and achieving a clean seedbed in softer, loamy soils. Conversely, a disc plow uses angled, concave discs to cut and mix the soil, making it a better choice for hard, rocky, or sticky clay soils where moldboards can struggle with penetration or clogging.
Once the plow is selected, it must be properly hitched and aligned to the tractor to manage the width of cut. The front bottom’s width of cut is a particularly important adjustment, often set slightly wider than the subsequent bottoms to accommodate the tractor’s wheel running in the furrow. This width is controlled either by adjusting the plow’s hitch frame horizontally or by modifying the tractor’s rear wheel spacing. The initial plowing depth is typically set to about half the width of the plow bottom, translating to a working range of six to eight inches for most general-purpose plowing.
Prior to entering the field, a safety and maintenance check of the equipment is necessary. This includes verifying adequate fluid levels in the tractor and confirming correct tire pressures to ensure optimum traction and minimize soil compaction. The plow itself should be checked for worn components, particularly dull plowshares, which significantly increase the force, or draft, required to pull the implement. Finally, any heavy, tall surface residue should be managed to prevent the plow from clogging.
Step-by-Step Guide to Executing the Furrow
The plowing process begins by establishing the headland, the area at both ends of the field where the tractor will turn around and the plow will be raised or lowered. This area should be marked off to ensure enough space for smooth turns without having to lift the implement while in motion. The first pass, known as the “opening cut” or “back furrow,” sets the line for all subsequent passes and is often started near the center of the field. To ensure this initial furrow is perfectly straight, the operator should fix their gaze on a distant, stationary marker and steer directly toward it.
Upon reaching the end of the field, the plow is lifted, the tractor is turned, and the operator returns along the opposite side of the initial furrow, throwing the second slice of soil against the first to form a small ridge. For the third pass and all subsequent passes, the tractor’s right-side wheels will run inside the furrow created by the previous pass. This action lowers the right side of the tractor, necessitating an adjustment to the three-point hitch’s leveling links to ensure the plow bottom remains level. Maintaining a consistent overlap is important for the front plow bottom to cut the correct width of unplowed ground.
The tractor’s forward speed must be consistent and appropriate for the soil conditions to achieve the desired soil inversion. Moving too quickly can cause the furrow slice to be thrown rather than rolled gently, leading to an uneven plowing job and excessive soil pulverization. A smooth, steady pace allows the moldboard to cleanly cut the soil slice and invert it by 135 to 180 degrees, effectively burying the trash and weeds underneath. Consistent speed also helps prevent side draft, which can cause the implement to pull crookedly.
Adjusting for Soil Conditions and Troubleshooting
The condition of the soil at the time of plowing requires operator adjustment. Plowing should only be attempted when the soil is at a friable moisture level, meaning it is neither too wet nor too dry. Plowing heavy clay soil when it is too wet, or “plastic,” can result in smearing the furrow wall. Plowing overly dry or hard soil produces large, resistant clods that require excessive secondary tillage to break down. For heavy clay soils, moldboard plows with a long, gently curved “sod bottom” design are more effective at turning the soil slice without extreme shattering.
When encountering different soil types or moisture levels, the depth of cut may need adjustment using the plow’s depth wheel or the tractor’s hydraulic controls. Adjusting the top link of the three-point hitch controls the fore-and-aft pitch of the plow, directly influencing the depth and the amount of “suction,” or the plow’s ability to pull itself into the ground. Lengthening the top link lowers the front of the plow, increasing penetration, while shortening it raises the front. This adjustment ensures that the plow is not running on its heel, which would increase draft and prevent the share from cutting at the correct depth.
Troubleshooting crooked or uneven furrows often involves correcting side draft, which occurs when the plow’s center of resistance does not align with the tractor’s line of pull. This issue can be resolved by making fine adjustments to the horizontal position of the hitch frame or by adjusting the tractor’s wheel width. For fields with unexpected obstacles, such as large rocks or buried debris, plows equipped with spring-trip or shear-bolt mechanisms are necessary. These protective devices allow the plow bottom to momentarily lift or break away from the obstruction, preventing damage to the implement before resetting to continue the pass.