NSSCO Agricultural Science 6115 flashcards

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

Sustainable agriculture

Farming that meets present food needs while conserving soil, water and biodiversity, remaining profitable and socially acceptable, so that future generations can also produce from the same land.

Mixed farming

A system combining crop production with livestock on the same farm, spreading income risk and recycling manure as fertiliser while using crop residues as animal feed.

Carrying capacity

The maximum number of animals a pasture can support indefinitely without degrading the vegetation or soil, usually expressed as livestock units per hectare.

Cation exchange capacity

The total negative charge on soil particles able to hold exchangeable cations such as calcium, magnesium and potassium, measured in cmol per kilogram of soil.

Soil texture versus structure

Texture is the proportion of sand, silt and clay particles; structure is how those particles clump into aggregates, which determines drainage, aeration and root penetration.

Sheet and gully erosion

Sheet erosion removes a thin uniform layer of topsoil by runoff; unchecked, it cuts channels called rills and then deep gullies that cannot be crossed by machinery.

Liming

Applying agricultural lime to raise soil pH when it is too acidic, reducing aluminium toxicity and improving availability of phosphorus and molybdenum to crops.

Composite soil sample

A sample made by mixing subsamples collected in a zigzag pattern across a field from the top twenty centimetres, then sent to a laboratory for analysis.

Plant population per hectare

The number of plants established per hectare, calculated as ten thousand divided by the product of row spacing and within-row spacing in metres.

Transplant shock

Wilting and slow growth after seedlings are moved, caused by root damage and water loss; reduced by watering in and transplanting in the cool of the day.

Pre-harvest interval

The minimum number of days between the last pesticide application and harvest, set so that residues on the marketed produce fall within legal safety limits.

Pruning

Deliberate removal of branches or shoots to improve light penetration, airflow, fruit quality and shape, using clean sharp tools to limit disease entry.

Rumen fermentation

Microbial breakdown of fibrous feed in the rumen of cattle, sheep and goats, producing volatile fatty acids and microbial protein that the animal absorbs.

Colostrum

The first milk produced after birth, rich in antibodies; newborn animals must receive it within the first hours of life before the gut stops absorbing antibodies.

Feed conversion ratio

Feed consumed divided by live weight gained; a lower value means the animal converts feed to meat or eggs more efficiently and the enterprise is more profitable.

Balanced ration

A feed mixture supplying energy, protein, minerals, vitamins and water in proportions that meet the animal's maintenance and production requirements.

Three-point linkage

The tractor mounting system of two lower arms and a top link that attaches implements, allowing them to be raised, lowered and held at a set working depth.

Power take-off

A splined shaft at the rear of a tractor that transmits engine power to driven implements such as mowers, balers and sprayers through a guarded shaft.

Drip irrigation

A system delivering water slowly to the root zone through emitters along pipes, saving water and limiting leaf wetness, but requiring filtration to stop emitter blockage.

Grain store requirements

A structure that is dry, well ventilated, rodent-proof and raised above ground, keeping grain moisture low so moulds and aflatoxin do not develop.

Gross margin

Gross output value minus variable costs for one enterprise; fixed costs are excluded, so margins can be compared across enterprises of different sizes.

Break-even yield

Total production costs divided by the price received per unit; producing above this yield gives a profit, producing below it gives a loss.

Depreciation

The annual loss in value of an asset such as a tractor, calculated as purchase cost minus salvage value, divided by the number of useful years.

Partial budget

A management tool listing added returns and reduced costs against added costs and reduced returns to decide whether a proposed change is financially worthwhile.

Value addition

Processing, grading, packaging or branding a raw farm product so it sells at a higher price, requiring investment in equipment and access to a suitable market.

Marketing margin

The difference between the price a consumer pays and the price the producer receives, covering transport, handling, processing and traders' costs and profits.

Post-harvest losses

Loss of quantity or quality after harvest caused by poor drying, insect pests, rodents, rough handling and lack of storage, which can exceed a third of grain.

Agroforestry

Growing trees together with crops or livestock to obtain fuelwood, fodder and shade while improving soil fertility, reducing wind damage and conserving moisture.

Rainwater harvesting

Collecting and storing runoff from roofs or prepared surfaces for later irrigation or livestock use, reducing dependence on boreholes and rivers.

Randomised complete block design

An experimental layout where each treatment appears once per block and blocks group similar plots, controlling field variation so treatment differences can be tested.

Conservation agriculture

A system based on minimum soil disturbance, permanent soil cover with residues or cover crops, and crop rotation, which reduces erosion and conserves moisture.

Pesticide safety equipment

Protective clothing worn when handling pesticides: gloves, boots, overalls, eye protection and a respirator, plus washing facilities and safe container disposal.