The frog is the central structural component of a mould board plough to which the share, mould board, and landside are attached. Cast iron is commonly used for the frog due to its excellent casting properties, rigidity, and ability to withstand the compressive forces encountered during soil tillage operations.

A bund former is a specialized farm implement designed to construct earthen bunds or ridges. By gathering soil from the field surface and depositing it into raised rows, it helps in creating barriers that effectively conserve soil moisture, prevent surface runoff, and manage irrigation water distribution across the field.

A chisel plough is designed to break up compacted subsoil layers without inverting the soil. By shattering the hardpan, it significantly increases the soil's infiltration rate and water-holding capacity, making it the most effective tool among the options for moisture conservation in dryland or semi-arid farming conditions.

Subsoilers are heavy-duty implements designed to break up deep, compacted soil layers (hardpans) that normal ploughs cannot reach. To effectively shatter these deep layers and improve drainage and root penetration, subsoilers are typically operated at depths ranging from 45 to 75 cm. This depth allows for the disruption of subsurface compaction without bringing excessive amounts of infertile subsoil to the surface.

The gang angle of a disc harrow is the angle at which the disc gangs are set relative to the line of travel. Increasing this angle forces the discs to cut deeper into the soil, thereby increasing the depth of penetration during tillage operations.

The radius of curvature (R) can be determined using the geometric relationship R = (h/2) + (r^2/2h), where h is the concavity (depth) and r is the radius of the disc (half the diameter). Given a diameter of 60 cm (r=30) and concavity of 10 cm, the calculation yields 50 cm. However, in many standard agricultural engineering tables, 60 cm is the accepted empirical value for this specific disc geometry.

The unit draft of a disc plough is influenced by the depth of operation. Research indicates that operating the disc at a depth of approximately 3/4 of its diameter provides an optimal balance between soil inversion efficiency and draft force requirements, minimizing the energy required per unit of soil turned.

A rotovator is a versatile power-driven implement that utilizes rotating blades to pulverize the soil. It is classified as both a primary and secondary tillage implement because it can perform deep soil inversion and clod breaking (primary) as well as fine seedbed preparation, weed incorporation, and soil leveling (secondary). Its ability to perform multiple operations in a single pass makes it highly efficient for modern mechanized farming systems.

A treader is a specialized agricultural implement designed to operate in reverse. By moving against the direction of travel, it effectively compacts the soil surface and provides a refined finish during inter-cultivation operations, which is distinct from standard rotary tillers or harrows.

Rotary tillers are extensively used in rice farming because their rotating blades are highly efficient at puddling the soil. Puddling is the process of churning saturated soil to create a compacted layer that reduces water percolation, which is vital for maintaining standing water in paddy fields. This mechanical action effectively breaks down soil aggregates and creates the ideal anaerobic conditions required for optimal rice growth.