⛏️ Primary Tillage Implements

This lesson explains the main implements used in primary tillage and how they differ in soil cutting, inversion, penetration, and residue handling.

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What Primary Tillage Means

Primary tillage is the first major operation that opens and loosens the soil more deeply than later seedbed operations.

It is mainly used to:

• reduce soil strength
• bury weeds and residues
• break up the upper soil mass
• improve initial root-zone condition

Because it is deeper and heavier than later operations, it requires stronger implements and greater draft.

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Why Primary Tillage Implements Matter

Different soils and field situations do not respond equally to the same plough.

An implement may be chosen because the field needs:

• full inversion
• residue burial
• deep loosening
• operation in sticky or hard soils
• breaking of compact subsurface layers

So primary tillage implements are selected according to the soil problem, not only by tradition.

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Plough as the Main Primary Tillage Tool

The plough is the classic primary tillage implement.

Its general roles are:

• cut the soil slice
• lift it
• break it
• sometimes invert it

The degree of inversion and pulverization depends on the plough design.

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Indigenous Plough

The indigenous plough is a traditional animal-drawn tool.

Its main features are:

• simple construction
• shallow operation
• V-shaped furrow formation
• low cost

Typical parts include:

• share
• body
• shoe
• beam
• handle

It is still relevant in small holdings where mechanization level is low, but it does not perform deep and efficient inversion like improved ploughs.

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Mould Board Plough

The mould board plough is one of the most important primary tillage implements.

It performs four main actions:

• cuts the furrow slice
• lifts the slice
• turns or inverts it
• partly pulverizes it

This makes it highly suitable where complete burial of weeds and residues is desired.

The mould board plough is the standard implement for strong soil inversion.

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Main Parts of a Mould Board Plough

The essential bottom parts are:

• share
• mould board
• landside
• frog
• tailpiece

Share

• makes the horizontal cut
• penetrates the soil first

Mould board

• lifts and turns the furrow slice
• contributes strongly to inversion and pulverization

Landside

• presses against the furrow wall
• stabilizes the plough against side thrust

Frog

• supports and joins the main bottom parts

Tailpiece

• helps in completing furrow turning

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Types of Shares and Mould Boards

Different shares are used for service and replacement convenience, such as:

• slip share
• slip-nose share
• shin share
• bar-point share

Different mould board shapes are used for different soil and residue conditions, such as:

• general-purpose type
• stubble type
• sod or breaker type
• slat type

The main idea is that plough geometry affects the degree of cutting, turning, and scouring.

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Plough Accessories

Primary ploughs may be fitted with accessories to improve work quality.

Important accessories include:

• jointer
• coulter
• gauge wheel
• land wheel
• furrow wheel

Coulter

The coulter makes the vertical cut ahead of the plough bottom and helps create a clean furrow wall.

Jointer

The jointer cuts and turns a small upper strip so that surface trash is buried more effectively.

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Disc Plough

A disc plough uses large concave discs instead of a mould board bottom.

It is especially useful where:

• soil is hard
• soil is sticky
• roots and stubbles are abundant
• mould board plough scouring is poor

Because the discs rotate, they handle tough residue and sticky soil better than a mould board plough in some conditions.

Main advantages

• works well in hard and trashy soils
• better suited to sticky conditions
• less clogging in residue-heavy fields

Main limitations

• inversion may be less complete
• furrow finish may be rougher
• adjustment and penetration behavior differ from MB plough

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Chisel Plough

A chisel plough loosens soil deeply with narrow shanks and points, but it does not invert the soil like a mould board plough.

It is used when the goal is:

• deep loosening
• breaking dense layers
• improving infiltration
• reducing compaction effects

It disturbs the soil strongly but leaves more residue near the surface compared with a full inversion plough.

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Subsoiler

A subsoiler is used to break hard layers below normal plough depth.

Its purpose is to:

• shatter hardpan
• improve deep root penetration
• improve internal drainage
• help water percolation

Unlike ordinary ploughing, subsoiling targets compaction below the cultivated layer.

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Choosing the Right Primary Tillage Implement

Implement selection depends on field need.

• Mould board plough
  • best when inversion and burial are important
• Disc plough
  • better in hard, sticky, or root-filled soils
• Chisel plough
  • best for deep loosening without full inversion
• Subsoiler
  • best for breaking subsurface hardpan

So the right question is not “which plough is best,” but “which soil problem must be solved.”

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Why Correct Adjustment Matters

Even a good primary tillage implement performs poorly if adjustment is wrong.

Important aspects include:

• penetration depth
• width of cut
• suction and clearance
• hitch alignment

Poor adjustment:

• increases draft
• wastes fuel
• reduces work quality

Good adjustment improves field finish and power economy.

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Summary Cheat Sheet

• Primary tillage is the first major soil-working operation used for deep loosening and initial field preparation.
• Main primary tillage implements include indigenous plough, mould board plough, disc plough, chisel plough, and subsoiler.
• The mould board plough is best known for cutting, lifting, turning, and inverting the furrow slice.
• Disc plough suits sticky, hard, and trashy soils; chisel plough and subsoiler are used more for loosening than inversion.
• Correct implement choice and proper adjustment are essential for efficient primary tillage.

References

1 source • [1]

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