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  • This resource provides explanations of the key concepts encountered when looking at applying science to improve farming and the environment – the ‘basics’ that every student should understand.

    Agricultural effluent

    The treated and untreated wastes and wastewater collected during the management of livestock.

    Agricultural intensification

    The production of more milk, meat, wool or food crops on the same amount of land. Intensification often involves increased inputs of chemical fertilisers.


    The process of reducing nitrate (NO3-) in the soil to gaseous nitrogen (N2) released into the atmosphere.

    Environmental pollution

    The contamination of air, water or soil by substances that are harmful to living organisms.


    Chemicals containing essential chemical elements needed for plant growth that are added to soil.

    Fixation (fixing nitrogen)

    The process of converting nitrogen from its atmospheric gaseous form (N2) to forms that can be used by plants and animals.

    Greenhouse gas emissions

    The release of gases that trap heat in the atmosphere. Examples are water vapour, carbon dioxide, methane and nitrous oxide.


    In agriculture, leaching refers to the movement of plant nutrients down through the soil when water is in excess of what the soil can hold.

    Microbial activity or microbial processes

    This refers to the activities of microbes, such as bacteria, as they break down organic material to forms that can be used by plants.


    The process of converting ammonia/ammonium ions (NH3, NH4+) in the soil into nitrate (NO3-) that can be used by plants.

    Nitrogen cycle

    The process of nitrogen being taken from the atmosphere, deposited in soil, made available to plants and animals (through microbial activity) and later returned to the atmosphere.

    Nitrous oxide

    Nitrous oxide (N2O) is a gaseous byproduct emitted during the nitrogen cycle. It is a greenhouse gas and is 310 times more efficient in warming the atmosphere than carbon dioxide.


    Chemicals taken from the environment that organisms need to live and grow

    Phosphorus cycle

    The circulation of phosphorus in various forms through rocks, water, soil and sediments and organisms. Inorganic phosphorus originates from rocks. Organic phosphorus comes from living things.

    Riparian zones

    The interface between land and surface water. Vegetation growing between the land and water may protect the aquatic environment from sediment, nutrient run-off or erosion.


    The flow of water over land from rain, irrigation or other sources. Run-off water can transport sediments, nutrients and other substances from one location to another.

      Published 30 June 2014 Referencing Hub articles
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