VCE Agricultural and Horticultural Studies flashcards

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

Monoculture

Production system where a single crop species is grown over a large area or successive seasons, simplifying management but increasing pest, disease and market risk.

Gross margin

Enterprise gross income minus variable costs. It excludes fixed costs, so it compares enterprises within a whole-farm budget rather than measuring overall farm profit.

Stocking rate

Number of animals or dry sheep equivalents carried per hectare over a defined period. It sets grazing pressure and must be matched to available pasture.

Crop rotation

Planned sequence of different crop species on the same paddock to interrupt pest and disease cycles, manage weeds and restore soil nitrogen.

Feed conversion ratio

Feed consumed divided by liveweight gain. Lower values mean animals convert feed into body weight more efficiently, reducing feed cost per kilogram produced.

Cation exchange capacity

Soil's capacity to hold exchangeable cations, measured in cmol(+)/kg. Clay and organic matter raise CEC, improving nutrient retention and buffering.

Soil pH

Measure of soil acidity or alkalinity. Most nutrients are most available near pH 6.0-7.0; lime raises pH and sulfur or acidifying fertilisers lower it.

Dryland salinity

Salt accumulation at the soil surface caused by rising water tables. Managed by recharge control, deep-rooted perennials and maintaining ground cover.

Riparian buffer

Vegetated strip beside a waterway that filters sediment and nutrients from runoff, stabilises banks and shades streams. Wider, continuous buffers are more effective.

Nutrient budget

Comparison of nutrient inputs such as fertiliser, fixation and feed against outputs such as harvested product, leaching and runoff, revealing surplus or deficit.

Irrigation efficiency

Beneficial water use divided by water delivered. Losses arise from evaporation, deep drainage and runoff; scheduling by evapotranspiration or soil moisture reduces them.

Water erosion

Detachment and transport of soil by rainfall and runoff. Risk increases with slope, low ground cover and intense storms; maintaining cover above about 70% reduces loss.

Disease triangle

Model stating disease requires a susceptible host, a virulent pathogen and a favourable environment together. Removing any one factor prevents or limits disease.

Integrated pest management

Decision framework combining cultural, biological, physical and chemical controls, using monitoring and economic thresholds so sprays are applied only when justified.

Economic threshold

Pest population density at which the cost of control equals the value of crop loss prevented. Control is justified only above this level.

Herbicide resistance

Inherited ability of weeds to survive a herbicide dose that would normally kill them. It develops under repeated use of one mode-of-action group and is slowed by rotation.

Five Domains

Animal welfare framework assessing nutrition, environment, health, behaviour and mental state. Welfare is a property of the animal, not of the housing alone.

Notifiable disease

Disease of livestock or plants that must be reported to authorities by law, such as foot-and-mouth disease or avian influenza, to enable rapid containment.

Withholding period

Minimum time between treating an animal with a chemical and harvesting meat, milk or eggs, ensuring residues fall below permitted maximum limits.

Biosecurity

Practices preventing introduction and spread of pests and diseases, including quarantine, hygiene, restricted visitor access, pest control and clean equipment.

Break-even yield

Total costs divided by price per unit. It is the minimum yield needed to cover costs at a given price, so falling prices raise the required yield.

Partial budget

Analysis of a proposed change comparing added returns and reduced costs against added costs and reduced returns. A positive net change favours adopting the change.

Cash flow versus profit

Cash flow records timing of money entering and leaving the business; profit matches income and expenses to the production period, so they can differ within a year.

Precision agriculture

Use of GPS guidance, variable-rate application, yield mapping and remote sensing to match inputs to within-paddock variability, improving efficiency and reducing waste.

Variable costs

Costs that change with the level of production, such as seed, fertiliser, chemicals and casual labour. They are deducted from gross income to calculate gross margin.

Fixed costs

Overhead costs that do not vary with output in the short term, such as depreciation, insurance, rates and permanent labour. They are excluded from gross margin calculations.

Sustainability pillars

Economic, environmental and social dimensions of sustainability. A system is sustainable only if it remains viable across all three over the long term.

Life cycle assessment

Method quantifying environmental impacts, such as greenhouse gas emissions per kilogram of product, across all stages from inputs through production to the farm gate.

Carrying capacity

Sustainable stocking rate a paddock supports in an average season without degrading pasture or soil, accounting for pasture growth and ground cover.

Crop water use

Water transpired by a crop plus that evaporated from soil and canopy. Scheduling irrigation to match this demand avoids under- or over-watering.

Vaccination

Administration of antigen to stimulate adaptive immunity and protect animals against specific pathogens. It supports herd health but does not replace biosecurity.

Forward contract

Agreement to sell a specified quantity at a set price on a future date, locking in income and reducing price risk but forgoing potential upside.