Glossary: I

Here you will find definitions of terms used in resources on the Foodsource website. You will also find these definitions on the right-hand side within chapters. If you have any suggestions for new glossary items, let us know here.

A (12) | B (4) | C (13) | D (3) | E (8) | F (7) | G (4) | H (2) | I (6) | L (5) | M (11) | N (3) | O (4) | P (5) | R (6) | S (9) | T (1) | U (1) | W (4) | Y (1) | Z (1)


Intensification refers to a process by which farming systems (for crops or livestock) are reorganised – often through the application of new technologies, economies of scale, and the use of additional inputs, such as nutrients, chemicals, energy and water – in order to produce more of a desired output (e.g. meat) while using less land, human labour, or capital. The result is that the costs of production for a given amount of food are reduced, thereby increasing profits through larger profits per unit of food, or by expanding total consumption through lower prices, enabling more people to buy more. Often, environmental impacts per unit of product are also reduced, but may be counterbalanced by increases in total production. The impacts of intensification processes on animal welfare, biodiversity, and other issues is also a widely held concern.

Intensive agriculture

Often used synonymously with the terms industrial agriculture and conventional farming, IA is generally used to denote farming systems that use modern technologies and economies of scale to maximise yields relative to land use and production costs (e.g. costs of labour, technology, seeds, fertilisers, and pesticides). IA is associated with high use of chemical fertilisers, agrochemicals, and irrigation. This combination of agricultural technologies became common during the Green Revolution in the mid-20th century, and has long been criticized for its high social and environmental impacts.

Interstitial waters

Interstitial waters refers to water trapped in sediments or in pores (voids or spaces) in sedimentary rocks – rocks formed by the deposition and cementation of material, as opposed to rocks formed by volcanic processes.


The Intergovernmental Panel on Climate Change (IPCC) is the international body for assessing the science related to climate change. It is administered by the United Nations with participation and decision making from 195 member states. The assessments that it produces provide the basis for government at all levels to create climate related policies.

Iso calorific

Iso-calorific is a term that means to hold the amount of calories in a diet constant, while changing other variables. It is used in research as a way to make meals with different compositions in terms of foods and nutrients, equivalent and comparable in terms of the energy that they provide.

Isotopic signature

The ratio of different isotopes. Isotopes are atoms which have a different number of protons and neutrons. For example, most carbon (C) has 6 protons and 6 neutrons, giving it an atomic weight of 12. This form of carbon is known as carbon-12 (or 12C). Another stable form of carbon exists with 6 protons and 7 neutrons, giving it a molecular weight of 13, hence it is known as carbon-13 (or 13C). Different sources of methane emissions can be composed of different proportions of 12C and 13C, with fossil fuel sources often containing relatively more 13C than biological sources.