Classification and Kinds of Agricultural Implements
Agricultural implements and machinery are broadly classified based on their primary function in crop production, source of power required for operation, and the unit operations they perform in the field. Understanding these classifications is fundamental for agricultural engineering and crop production.
- Primary Tillage Implements: Implements used for initial major soil working, cutting, and inversion, such as mouldboard ploughs, disc ploughs, chisel ploughs, and subsoilers.
- Secondary Tillage Implements: Implements used for pulverizing, leveling, and firming the seedbed after primary tillage, including disc harrows, cultivators, rotavators, plankers, and rollers.
- Sowing and Planting Equipment: Seed drills, seed-cum-fertilizer drills, planters, transplanting machinery, and dibblers designed for precise seed placement and depth control.
- Inter-cultivation and Plant Protection Equipment: Weeders, hoes, knapsack sprayers, power sprayers, and dusters used for post-sowing crop management and pest control.
- Harvesting and Threshing Machinery: Sickles, reapers, combine harvesters, threshers, and shellers designed for crop separation and grain recovery.
Power Sources in Agriculture
Agricultural operations rely on diverse power sources to drive implements of varying draft requirements and capacities.
- Human Power: The fundamental source of energy for small-scale tools, hand hoes, sprayers, and manual weeders. Average human power output is approximately 0.075 kW (0.1 hp) continuously.
- Animal Power: Draft animals such as bullocks, camels, horses, and donkeys are utilized for traditional ploughing, harrowing, and carting. A pair of bullocks typically develops about 0.75 kW (1.0 hp) of draft power.
- Mechanical Power: Internal combustion engines fueled by diesel or gasoline, utilized in tractors, power tillers, and self-propelled harvesters, providing high torque and speed versatility.
- Electrical Power: Stationary electric motors employed in irrigation pumping units, threshers, feed grinders, and grading sheds due to high operational efficiency and low maintenance.
- Renewable Energy Sources: Solar photovoltaic pumps, wind mills, and biomass gasifiers gaining prominence in sustainable farm mechanization.
Tillage Implements: Mechanics and Operation
Tillage is the mechanical manipulation of soil to provide a favorable condition for seed germination and root growth. Implements are engineered to overcome soil resistance, shear strength, and friction.
- Mouldboard Plough (MB Plough): Consists of a share, mouldboard, landside, frog, and tailpiece. It performs cutting, lifting, pulverizing, and complete inversion of the soil furrow slice.
- Disc Plough: Features individually rotating concave steel discs tilted at an angle to the direction of motion. Highly suitable for stony, hard, sticky, and root-infested soils where MB ploughs fail to scour.
- Cultivators and Tines: Equipped with rigid or spring-loaded tines to stir the soil without complete inversion, widely used for seedbed preparation and secondary tillage.
- Rotavator (Rotary Tiller): Powered by the tractor's Power Take-Off (PTO) shaft, utilizing L-shaped blades to intensely chop, mix, and pulverize the soil in a single pass.
Sowing, Planting, and Fertilization Machinery
Precise seed and fertilizer placement ensures optimal plant population and nutrient use efficiency.
- Seed Drill Mechanics: Comprises a seed box, metering mechanism (fluted roller, cup-feed, or internal double-run), delivery tubes, and furrow openers (shoe type, disc type, or hoe type).
- Seed-Cum-Fertilizer Drills: Deliver seeds and granular chemical fertilizers simultaneously into separate bands at targeted depths below and to the side of the seed.
- Planters: Utilize precise plate-type or pneumatic metering mechanisms to drop single seeds at exact intra-row spacings, crucial for wide-row crops like maize, cotton, and soybean.
- Transplanters: Semi-automatic or automatic mechanical devices that plant vegetable seedlings or pre-germinated paddy mat-type seedlings into puddled fields.
Plant Protection and Harvesting Equipment
Safeguarding crops from biotic stresses and gathering produce efficiently requires specialized machinery.
- Sprayers and Dusters: Convert liquid agrochemicals into fine droplets or dust particles. Key types include pneumatic knapsack sprayers, hydraulic power sprayers, and ultra-low volume (ULV) sprayers.
- Reapers and Mowers: Mechanical devices equipped with reciprocating knife cutter bars or rotating discs to harvest cereal crops, forage, and grasses.
- Combine Harvester: A multi-functional machine that performs harvesting, threshing, separating, and cleaning of grains in a single continuous forward pass across the field.
Comparison Between Mouldboard Plough and Disc Plough
| Parameter | Mouldboard (MB) Plough | Disc Plough |
|---|---|---|
| Soil Inversion | Complete soil inversion and burial of trash | Partial soil inversion and mixing |
| Soil Condition | Best suited for friable, stone-free soils | Ideal for hard, dry, stony, and sticky soils |
| Draft Requirement | Lower draft per unit width in light soils | Higher draft due to rolling and sliding friction |
| Scouring Action | Requires proper scouring; sticky soils cause choking | Self-cleaning rolling action prevents sticky soil buildup |
| Maintenance | Requires frequent share sharpening and landside adjustment | Requires bearing lubrication and disc edge maintenance |
Comparison Between Seed Drill and Planter
| Parameter | Seed Drill | Planter |
|---|---|---|
| Seed Placement | Continuous stream of seeds in rows | Precise single-seed placement at set intervals (hill/drill dropping) |
| Metering Device | Fluted roller, cup-feed, or brush-feed | Cell feed plate, finger pickup, or pneumatic vacuum disc |
| Crop Suitability | Cereals and pulses (Wheat, Paddy, Barley) | Wide-row crops (Maize, Cotton, Soybean, Sunflower) |
| Intra-row Spacing | Difficult to regulate precisely | Highly uniform and adjustable intra-row spacing |
Memory Trick / Mnemonic
Mouldboard Plough Main Parts
S-M-L-F-T (Some Men Like Fast Tractors)
S = Share, M = Mouldboard, L = Landside, F = Frog, T = Tailpiece. These are the five fundamental structural components of a standard mouldboard plough.
Memory Trick / Mnemonic
Classification of Tillage Operations
P-S-S (Primary Seeks Subsoil)
P = Primary Tillage (Ploughs, Subsoilers), S = Secondary Tillage (Harrows, Cultivators, Plankers), S = Special Tillage (Mulching, Subsoiling). Helps remember the chronological stages of seedbed preparation.
⚡ High-Yield Exam Points (UP TGT / PGT Focus)
- The power of a standard pair of bullocks is approximately 0.75 kW (1.0 hp).
- Mouldboard plough performs four distinct actions: cutting, lifting, pulverizing, and inversion.
- Disc plough is preferred in sticky, stony, and hard dry soils where mouldboard plough fails to scour.
- Fluted roller is the most common seed metering mechanism used in standard Indian seed drills.
- Rotavator is driven directly by the tractor Power Take-Off (PTO) shaft, running at standard speeds of 540 rpm or 1000 rpm.
- Combine harvester performs four simultaneous operations: harvesting, threshing, separating, and cleaning.
- Subsoiler is a heavy-duty primary tillage implement designed to break hardpans beneath the plough layer at depths exceeding 45-60 cm.
- The angle at which the disc of a disc plough is set relative to the direction of travel is called the disc angle (usually 42° to 45°).
⚠️ Common Mistakes & Exam Pitfalls
- Confusing primary tillage with secondary tillage: Remember that primary tillage involves deep soil cutting and inversion, whereas secondary tillage involves seedbed smoothing, leveling, and pulverization.
- Assuming rotavators are pulled by draft alone: Rotavators are active implements driven by the tractor PTO shaft, not passive implements like disc harrows.
- Mixing up seed drill and planter metering mechanisms: Seed drills use fluted rollers for continuous sowing, whereas planters use cell feed plates or pneumatic discs for hill/precision dropping.