WBCHSE HS Vocational Agriculture key terms

The relative proportion of sand, silt and clay particles in a soil. It controls water holding, drainage, aeration and workability, and is judged in the field by the feel or ribbon test.

The way soil particles are grouped into aggregates or crumbs, giving pore space for air and water. Good structure improves root penetration, infiltration and resistance to erosion; it is damaged by continuous tillage and puddling.

The water content a soil retains after excess water has drained away by gravity, usually one to three days after rain or irrigation. It is the upper limit of water readily available to crops.

The soil moisture level below which plants can no longer extract water and wilt irreversibly. The gap between field capacity and this point is the available water range for crops.

The portion of soil moisture held between field capacity and permanent wilting point that plant roots can absorb. Sandy soils hold little; clay and loam soils hold more, so irrigation scheduling depends on it.

The ability of soil colloids, mainly clay and humus, to hold positively charged nutrients such as calcium, magnesium and potassium and release them to roots. High capacity means better nutrient retention and less leaching.

The acidity or alkalinity of soil expressed as pH. It governs nutrient availability, microbial activity and choice of crop; most field crops grow best between pH 6.0 and 7.5, and lime or gypsum corrects extremes.

The dark, stable, decomposed organic matter remaining after microbes break down plant and animal residues. It improves structure, water retention and cation exchange capacity and slowly releases nitrogen and other nutrients.

A quick-growing legume or other crop grown and ploughed into the soil while still green to add organic matter and nitrogen. Examples include sunhemp and dhaincha, often used before transplanting rice.

A preparation containing live beneficial microorganisms, such as Rhizobium, Azotobacter, Azospirillum or phosphate-solubilising bacteria, applied to seed or soil to fix nitrogen or release bound phosphorus and improve nutrient supply.

Supplying crop nutrients through a planned combination of chemical fertilizers, organic manures, biofertilizers and crop residues, matched to soil test values and crop demand, to sustain yields while protecting soil health.

The growth stage at which a crop is most sensitive to shortage of water or nutrients and yield loss is greatest. For cereals this is usually flowering to grain filling, and irrigation must not be missed then.

The process by which green leaves use sunlight, carbon dioxide and water to make carbohydrates and release oxygen. It supplies the dry matter that becomes grain, tuber, fruit or fodder yield.

Loss of water vapour from plant leaves through stomata, which pulls water and dissolved nutrients upward from the roots. Together with evaporation from soil it forms evapotranspiration, the basis of irrigation planning.

The proportion of total biological yield that is economic produce, expressed as economic yield divided by biological yield. Modern dwarf cereals have a higher harvest index than tall traditional types.

The quantity of seed sown per unit area, chosen to give the recommended plant population for the crop, variety, sowing method and germination percentage. Too low a rate reduces yield; too high causes lodging and disease.

The proportion of seeds in a sample that produce normal seedlings under standard test conditions. It is used to adjust seed rate and to judge whether seed is worth sowing.

Coating seed before sowing with fungicides, insecticides or bioagents, sometimes with Rhizobium culture, to control seed-borne and soil-borne pests and diseases and to improve establishment.

The number of crops raised on the same field in a year, expressed as a percentage of the net sown area. Growing three crops where one was grown before raises it from 100 to 300 per cent.

Growing two or more crops together in the same field in a definite row arrangement, such as cereal with pulse, so that land, light and nutrients are used more fully and risk is spread.

Growing different crops in a planned sequence on the same land over seasons. It helps break pest and disease cycles, balances nutrient use and maintains soil fertility compared with continuous monocropping.

A prepared, raised or sunken plot where vegetable and paddy seedlings are raised under close care before transplanting. Good bed preparation, seed spacing and protection give healthy, uniform transplants.

Lifting young seedlings from a nursery and setting them in the main field at the recommended spacing and depth. It allows a better start, uniform stand and easier weed control than direct sowing in many crops.

Removal of unwanted branches, shoots or roots from a fruit tree or shrub to shape the plant, admit light and air, and balance vegetative growth with fruiting. It is done in the dormant or post-harvest season.

Joining a scion shoot of a desired variety onto a rootstock so they unite and grow as one plant. It is used to propagate fruit trees, to change varieties and to secure hardy roots.

Construction of small earthen embankments along the contour of sloping land to slow runoff, trap sediment and increase water infiltration. It is a common measure for conserving soil and water on cultivated slopes.

Ploughing across a slope along contour lines so that each furrow checks the downward flow of water. It reduces runoff and soil loss on gently sloping fields and supports crop growth.

Detachment and removal of soil by flowing water, seen as sheet, rill, gully or stream-bank erosion. It removes fertile topsoil, lowers yields and silts up tanks and channels.

Collection and storage of rainwater from a catchment surface for later use in irrigation or livestock. Farm ponds, check dams and rooftop collection are common methods in rainfed areas.

Deciding when and how much to irrigate a crop, based on soil moisture, evapotranspiration, crop stage or critical growth periods, so that water is used efficiently and yield is not reduced.

Applying water slowly and frequently through emitters placed near the plant root zone. It saves water, limits weed growth and allows fertigation, and suits horticultural crops and water-scarce areas.

Spraying water over the crop like rain through nozzles under pressure. It suits closely sown crops and undulating land, but is less efficient in high wind and hot dry weather than drip.

The energy available on a farm from human, animal, mechanical or electrical sources for tillage, sowing, threshing, pumping and transport. Adequate farm power reduces drudgery and timeliness losses.

A self-propelled power unit that pulls or drives implements such as ploughs, harrows, seed drills and pumps. Its power is rated in horsepower, and matching implements to it avoids overload and waste.

An implement that opens furrows, drops seed at a controlled rate and depth, and covers it, often placing fertilizer simultaneously. It gives a more uniform stand and uses less seed than broadcasting.

A feed mixture that supplies all required nutrients in the right proportion for a given animal and production level. It includes energy, protein, minerals, vitamins and clean water in adequate amounts.

Feed low in fibre and rich in digestible nutrients, such as oilcake, cereal grain and bran, given to supplement roughage. It is used to meet the higher nutrient needs of growing, pregnant or milking animals.

Green fodder preserved by controlled anaerobic fermentation in a silo or pit. It retains moisture and nutrients for lean periods, and good silage is firm, acidic and free from mould.

The first milk secreted by a dam after calving, rich in antibodies, protein and vitamins. It must be fed to the newborn within the first hours of life to build immunity and prevent infection.

Depositing semen collected from a selected male into the reproductive tract of a female by instruments, instead of natural mating. It widens the use of superior sires and reduces disease spread.

Rearing several fish species with different feeding habits together in one pond, such as surface feeder, column feeder and bottom feeder, so that food in all zones is used and yield per pond rises.

Adding organic manure or inorganic nutrients to a fish pond to encourage growth of plankton, the natural food of fish. Over-fertilization causes oxygen depletion and must be avoided.

The suitability of pond water for fish, judged by temperature, dissolved oxygen, pH, ammonia and turbidity. Poor quality stresses fish and causes disease and mortality, so it is tested and managed regularly.

A planned combination of cultural, mechanical, biological and chemical methods to keep pest populations below economic injury level, with pesticides used only as a last resort and in recommended doses.

The pest population density at which control measures must be started to prevent the pest from reaching the level that causes economic loss. It guides spraying decisions in integrated pest management.

Suppression of pests using their natural enemies, such as predators, parasitoids and pathogens. Examples include Trichogramma against stem borer and Bacillus thuringiensis against caterpillars.

Planning and organising the use of land, labour, capital and other resources on a farm to achieve the highest sustained profit consistent with good husbandry and conservation of resources.

The total expenditure incurred in raising a crop, including seed, fertilizer, irrigation, labour, machinery and other charges. It is compared with gross income to work out net return and profitability.

The difference between the price paid by the final consumer and the price received by the producer, covering the costs and profits of middlemen, transport, storage and processing.

A voluntary organisation of farmers or other members who pool resources for shared services such as input purchase, credit, processing or marketing, with benefits distributed according to agreed rules rather than outside ownership.

Processing or presenting a farm product, such as paddy into rice, milk into paneer or curd, or fruit into jam, to raise its market worth and shelf life and to create employment in rural areas.