Assam ASSEB Higher Secondary Skill Subject Agri Engineering Technology key terms

Useful work performed by bullocks, buffaloes or horses through yokes and implements. Measured in animal-hours or watts; about 300-500 W per pair of bullocks during sustained field operations.

Splined shaft at the rear of a tractor that transmits engine power to trailed or mounted implements. Standard speeds are 540 and 1000 rpm, rated at defined engine speeds.

Linkage with two lower lift arms and one upper compression link that mounts implements and controls their working depth through the hydraulic system. Categories I to IV match tractor power classes.

Horizontal pulling force required to move a tillage tool through soil, expressed in newtons or kgf. Draft per unit width rises with speed, depth and soil moisture and determines tractor power needs.

Draft per unit area of soil cross-section cut, usually given as N per square centimetre or kgf per square centimetre. It lets a designer estimate total draft from depth and width of cut.

Tool such as a mouldboard plough, disc harrow or cultivator that cuts, inverts or loosens soil for seedbed preparation. Primary tillage breaks the soil; secondary tillage refines the seedbed.

Field or stationary test that adjusts the metering mechanism so that a set seed rate per hectare is actually delivered. Involves counting seeds or weighing output over a measured travel distance.

Area a machine can cover per unit time, usually hectares per hour, calculated from working width and forward speed with an allowance for turns and refilling. Theoretical capacity ignores such losses.

Ratio of actual to theoretical field capacity, expressed as a percentage. It accounts for turning time, loading, clogging and repairs, and typically ranges from 65 to 90 percent.

Mass of water in a produce sample divided by total mass of the wet sample, expressed as a percentage. Grain trade and storage standards are usually quoted on this basis.

Mass of water divided by mass of dry matter only, expressed as a percentage. Used in drying calculations because dry matter stays constant while water is removed.

Moisture level at which a produce neither gains nor loses water to the surrounding air at a given temperature and relative humidity. It sets the safe storage target for a commodity.

Highest grain moisture at which mould growth and insect damage stay acceptably low for a stated storage period. For paddy it is roughly 12 to 14 percent wet basis.

Mass of water removed per unit mass of dry matter per unit time during drying. It falls in the falling-rate period when internal moisture movement controls the process.

Forcing ambient or cooled air through a grain bulk at low airflow to equalise temperature and prevent moisture migration and hot spots, without deliberately drying the grain.

Sealed bag or silo system in which insects and moulds are controlled by oxygen depletion and carbon dioxide build-up from respiration. Effective for smallholder grain and pulse storage.

Mass of whole milled grains recovered as a percentage of paddy mass. Head rice recovery depends on paddy variety, moisture at milling, and the dehusking and polishing settings.

Speed at which water enters the soil surface, usually in millimetres per hour. It declines during a storm as the surface seals and the profile wets, and it governs runoff generation.

Fraction of rainfall that becomes surface flow for a given catchment and condition. Values near 0.1 indicate permeable, vegetated land; values above 0.6 indicate crusted or built-up surfaces.

Detachment and transport of soil particles by water or wind. Accelerated erosion follows vegetation removal and is controlled by contour tillage, bunds, terracing and cover crops.

Earth embankment built along a contour across a slope to intercept runoff, slow it and store water for infiltration. Spacing depends on slope steepness and expected rainfall.

Surface method where land is divided by low bunds into level basins flooded from a channel. Suited to close-growing crops on medium to fine soils with moderate infiltration.

Deciding when and how much to irrigate, using soil moisture depletion, crop water requirement or pan evaporation data. Good scheduling avoids both yield-losing stress and waterlogging.

Evaporative demand of a standard grass crop over a well-watered surface, computed from weather data and denoted ET0. Crop water need equals ET0 multiplied by a crop coefficient.

Study of moist air properties such as dry-bulb and wet-bulb temperature, humidity ratio and enthalpy. Psychrometric charts are used to design grain dryers and livestock housing ventilation.

Volume of air exchanged per unit time in an animal house or storage building, often quoted per animal or per cubic metre of produce. It removes heat, moisture, gases and dust.

Forces a farm building must safely resist, including dead load, live load, wind load and stored produce pressure. Design follows a recognised code with appropriate safety factors.

Anaerobic chamber that converts cattle dung or other slurries into methane-rich gas and digested slurry. Key parameters are retention time, loading rate, pH and temperature.

Microbial breakdown of organic matter in the absence of oxygen, producing biogas and a nutrient-rich digestate. It proceeds through hydrolysis, acidogenesis, acetogenesis and methanogenesis.

System of collectors and an insulated tank that uses absorbed solar radiation to heat water for dairy or household use. Efficiency depends on glazing, insulation and tilt angle.

Water pumping system in which a PV array powers an electric motor-driven pump, often without batteries. Sizing matches array wattage to head, discharge and daily sunshine hours.

Compacting crop residues or sawdust under pressure, with or without a binder, into dense fuel pieces. It raises bulk density and improves burning compared with loose residues.

Applying seed, fertiliser or pesticide at rates that change across a field according to a prescription map or live sensor data. It requires position guidance and a rate controller.

Use of satellite positioning, often with correction signals, to steer tractors along planned passes. It reduces overlap and skips, saving fuel, seed and fertiliser.

Recording crop yield against position during harvest using a mass-flow sensor and GPS, then producing a field map. The map reveals variability and guides later variable rate inputs.

Maximum weight or force a worker can handle repeatedly with acceptable injury risk, commonly about 25 kg for occasional manual lifting by an adult. It falls for awkward postures and repetition.

Method that multiplies a recommended weight limit by factors for horizontal distance, height, asymmetry, frequency and grip to give a safe load for a two-handed lift.

Vibration transmitted to hands and arms by tools such as brush cutters and chainsaws. Prolonged exposure causes numbness and white-finger symptoms, so exposure time must be limited.

Worn or held gear such as gloves, goggles, respirators, ear muffs and boots that reduces exposure to hazards. It is the last line of defence after elimination and engineering controls.

Practices that prevent operator and environmental harm from agrochemicals, including correct dilution, protective clothing, wind-aware spraying, safe container disposal and a re-entry interval.

Processing or packaging a raw farm product into a form with higher market worth, such as paddy into rice or milk into paneer. It raises income but needs capital and quality control.

Output level at which total revenue equals total cost, so profit is zero. It is found by dividing fixed costs by contribution per unit, where contribution is price minus variable cost.

Funds needed for day-to-day running of an enterprise, covering seed, feed, labour, fuel and repairs until sales are realised. Shortage is a common cause of small enterprise failure.