PSLE Agriculture flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Definition of agriculture

Agriculture is the practice of growing crops and raising animals to produce food, fibre and other useful materials for people, using land, water, labour and knowledge.

Arable farming

Arable farming means growing crops on cultivated land, such as wheat, rice, maize or vegetables, rather than keeping animals as the main enterprise.

Pastoral farming

Pastoral farming is the rearing of livestock such as cattle, sheep, goats or poultry, usually on grassland, to produce meat, milk, wool, eggs or hides.

Photosynthesis equation

Carbon dioxide plus water, using light energy captured by chlorophyll, produces glucose and oxygen; the glucose is used for growth or stored as starch.

Chlorophyll

Chlorophyll is the green pigment in leaf chloroplasts that absorbs light energy for photosynthesis, giving healthy leaves their characteristic green colour.

Transpiration

Transpiration is the loss of water vapour from leaves through tiny pores called stomata, which pulls water and dissolved minerals up from the roots.

Stomata

Stomata are small openings, mostly on the underside of leaves, that let carbon dioxide in and water vapour and oxygen out; guard cells open and close them.

Soil composition

Soil is a mixture of mineral particles, decayed organic matter called humus, water, air and living organisms such as worms, bacteria and fungi.

Loam soil

Loam is a soil with a balanced mixture of sand, silt and clay particles; it drains well, holds moisture and nutrients, and is usually best for crops.

Humus

Humus is dark, fully decomposed organic matter in soil that improves structure, helps retain water and nutrients, and supports beneficial soil organisms.

Nitrogen function

Nitrogen is a nutrient that promotes healthy green leaves and stems; too little causes pale, stunted plants, while too much delays flowering and fruiting.

Phosphorus function

Phosphorus supports strong root development, flowering and seed formation; a shortage often shows as poor roots and purplish or dull leaves.

Potassium function

Potassium strengthens overall plant vigour, improves fruit quality and helps plants resist disease and drought stress; shortages cause weak growth and poor fruit.

NPK ratio

The NPK ratio on a fertiliser label shows the percentage of nitrogen, phosphorus (as phosphate) and potassium (as potash) in the product, in that order.

Conditions for germination

Most seeds germinate when they have enough water, oxygen and a suitable warm temperature; light is generally not required for germination itself.

Pollination

Pollination is the transfer of pollen from the anther of a flower to the stigma, allowing fertilisation and the formation of seeds and fruit.

Wind-pollinated flowers

Wind-pollinated plants such as maize and rice have small dull flowers, large feathery stigmas and lightweight pollen produced in huge amounts to reach other plants.

Insect-pollinated flowers

Insect-pollinated flowers are usually brightly coloured and scented, produce nectar to attract bees and other insects, and have sticky pollen that clings to visitors.

Crop rotation

Crop rotation means growing different crops in sequence on the same land, which helps prevent pest and disease build-up and avoids exhausting particular soil nutrients.

Biological pest control

Biological control uses natural enemies, such as ladybirds eating aphids, to reduce pest numbers instead of relying mainly on chemical pesticides.

Irrigation

Irrigation is the artificial supply of water to crops through channels, sprinklers or drip lines when rainfall is insufficient for healthy growth.

Erosion

Erosion is the wearing away and removal of fertile topsoil by wind or flowing water; planting cover crops and contour ploughing help reduce it.

Compost

Compost is decayed organic material made from plant waste and kitchen scraps, used to add humus and nutrients and improve soil structure.

Monoculture

Monoculture is growing a single crop over a large area for several seasons; it increases efficiency but raises the risk of pests, disease and nutrient depletion.

Greenhouse cultivation

A greenhouse is a glass or plastic structure that traps heat and controls light, temperature and moisture, allowing crops to grow out of season or in harsh climates.

Weeds and competition

Weeds are unwanted plants that compete with crops for light, water and nutrients, so removing them by hand, hoeing or mulching protects crop yields.

Mulching

Mulch is a layer of material such as straw, leaves or plastic spread on the soil surface to conserve moisture, suppress weeds and moderate soil temperature.

Seed dispersal

Seed dispersal is the movement of seeds away from the parent plant by wind, water, animals or explosive mechanisms, reducing competition between seedlings.

Farm animal products

Livestock provide products including meat, milk, eggs, wool, leather and manure, the last being a valuable natural fertiliser for crops.

Food chain in farming

In a farm food chain, crops are producers, pests are primary consumers and predators such as birds or ladybirds are secondary consumers, keeping pest numbers in check.

Sustainable farming

Sustainable farming meets current food needs while conserving soil, water and biodiversity, for example through crop rotation, composting and reduced chemical use.

Seedbed preparation

Seedbed preparation involves loosening and levelling soil and removing weeds so seeds can be sown at the right depth to get water, air and warmth.