Future of food: Environmental Sustainability
The value of systems thinking

Glossary

Absorptive capacity: The capacity for water bodies, air and soils to absorb released emissions, such as greenhouse gases or eutrophying compounds.

Acidification: The problem of too much acid in the environment.

Actual production level: A term commonly used in crop production, where it refers to the actual yield achieved on farmers’ fields.

Adsorption (in P cycle): The chemical binding of P available for plants to soil particles.

Agro-ecological context: Specific conditions of the production context determined by e.g. the soil type, steepness of the fields, and the local climate.

Animal source food: Food that comes from an animal source. For example meat, milk, and eggs.

Annual Nutrient Cycling Assessment (ANCA): A tool to calculate nutrient efficiencies of a farm.

Annual crops: Crops that complete their life cycle within one year. In agriculture it also applies to crops that are harvested within a year after sowing.

Anthropogenic: Produced by human activity.

Assimilation (in N cycle): The process where plants can grow by taking up ammonia or nitrate from the soil via their roots.

Auxiliary variables (in modelling): External or intermediate variables in simulation models that help in giving a functional overview of a model structure.

Biodiversity: Biological diversity – or biodiversity – refers to variety within the living world or among and between living organisms.

Characterisation factor: A factor that reflects the relative contribution of that element to the environmental impact.

Complex system: A system with many factors and components that have an impact on a system and may affect each other in different ways (interrelated).

Components of a system: A system consists of components (or sub-systems), which are interrelated.

Crop production system: All processes that are involved in the cultivation of field crops, including for instance the crops selected, the sequence of crops over years and the crop management. In this course we use the term ‘crops’ in it widest meaning: grassland areas used for grazing, are also considered croplands. In  that case, we use the term ‘mixed crop-livestock system’.

Data availability (of an indicator): To what extent data is available to quantify a specific indicator.

Denitrification (in N cycle): This is the reduction of nitrate back into N2. It generally occurs where oxygen is depleted.

Desorption (in P cycle): This is the release of adsorbed P from its bound state into the soil solution.

DPSIR framework: A tool for describing and analysing environmental problems in a consistent and transparent way, looking at Drivers, Pressures, State, Impact and Responses.

Drivers: Variables that contribute to indicator results. It tells us something about the underlying causes of environmental problems.

Dry matter: The fresh weight minus the water content, mostly abbreviated as DM.

Dynamic simulation: The process of using a model to mimic the behaviour of a system in time. For example, crop growth.

Dynamic systems analysis: Systems analysis that includes a time component and looks at the change of a system over time.

Economic sustainability: This implies balancing costs and revenues so that a system can be sustainable, and includes issues of profitability, volatility and employability.

Emergent properties: System characteristics that arise through mutual interaction and that cannot be found as characteristic of any of the individual parts.

Environmental impact: Effects caused by, in this course, food production on the environment.

Environmental indicator: A variable derived from parameters that measures the state of an issue, in this case an environmental issue.

Environmental issue: An environmental problem when the absorptive or regenerative capacity of the system is exceeded.

Environmental sustainability: Natural resources are used in economies or societies at a rate not exceeding their regenerative and absorptive capacity.

Eutrophication: The problem of too many nutrients in water bodies.

Feed conversion ratio: A term commonly used in livestock production, the ratio that expresses the amount of feed needed to produce 1 kg of animal product.

Feed-food competition: Competition for resources, such as land, between humans and animals.

Feedback loop: A feedback loop consists of a series of interrelated components. It is the mechanism (rule or information flow or signal) that allows a change in a stock to affect a flow into or out of that same stock. In modelling: the influence of a state on its own rate of change.

Food production system: The characteristic configuration of a specific system with a combination of animals and/or plants in a given agro-ecological and socio- economic context.

Forrester diagram: A specific type of a relational diagram, using Forrester symbols.

Harvest index: The part of the dry matter that is allocated to the economic product. This is a crop genetic characteristic.

Holistic thinking: Considering the relation between the elements of the whole system, and the placing of the whole system in its (ecological, economic and social) context (opposite of reductionism).

Human-edible-protein conversion ratio: A term commonly used in livestock production, this ratio represents the amount of protein in animal feed that is edible for humans over the amount of protein in the animal product.

Immobilisation (in N cycle): The process where microorganisms in the soil transform ammonium into organic N, which is incorporated in their living cells.

Immobilisation (in P cycle): The process where microorganisms in the soil convert available P into organic P, which is incorporated in their living cells.

Impact indicators: Indicators that directly assess the environmental impact of a food production system.

Inputs of a system: Flows of material or information that enter a system over a period of time.

 Interaction (between system components): A key characteristic of a system - a change in any part of the system may affect any other part of the system.

Intercropping: A multiple cropping practice in which two or more crops are grown together in the same field (e.g. combining a deep-rooted crop with a shallow- rooted crop, to use available soil moisture more efficiently).

Irrigated farming: Farming that makes use of supplementary water, amongst others from rivers and (sub)surface reservoirs.

Leaching (in N and P cycle): The removal of available N and P by vertical water movement.

Liebig’s law: The resource, water or nutrient that is in minimum supply determines the crop yield.

Life Cycle Assessment (LCA): A holistic method, that intends to quantify all environmental impacts along the entire life cycle of a product, varying from resource use (use of water, energy, land), to environmental consequences, such as global warming, ozone depletion, acidification and eco-toxicity.

Limited production level: A term commonly used in crop production, where it refers to the production achieved when limited by water and/or nutrient availability.

Livestock production system: A system in which livestock, such as pigs, cattle, poultry, sheep or goats are kept for food production. It refers to all processes involved in animal production, including type of animals and their management. Many livestock production systems also consist of pasture areas, such as grasslands and shrub lands. In that case, we use the term ‘mixed crop-livestock system’.

Market-oriented production: This type of production is oriented at generating a financial income. So products are sold and leave the farm.

Mathematical models: Description of a system using mathematical symbols and equations.

Mineralisation (in N cycle): The process where microbes, such as bacteria and fungi, convert dead organic material into inorganic ammonium.

Mixed crop-livestock system: A system that consists of both a crop and a livestock component, exchanging feed and manure. It can be organized at different levels for example, within one farm (crops and pigs on the same farm) but also as two (or even more) cooperating specialized farms (e.g. an arable farm and a pig farm exchanging feed and manure).

Model: A simplified or abstracted representation of a system, and thus a simplification of a limited part of reality.

Mono-cropping: A cropping practice in which a single crop per field is grown.

Monogastric animals: Animals with a simple single-chambered stomach, like pigs, poultry and rabbits.

Multi-Criteria Analysis (MCA): A systematic tool that helps to decide on the basis of multiple criteria. It evaluates options in a systematic and explicit way.

Negative feedback: A deviation-counteracting control process, or self-inhibiting control.

Nitrification (in N cycle): The process where soil-living bacteria convert ammonium to nitrate, with nitrite as an intermediate product.

Nomadic pastoralism: Livestock are herded and move over a large area in order to find fresh pastures on which to graze.

Nutrient use efficiency (NUE): The amount of a nutrient in valuable outputs of a systems divided by the amount of that nutrient in all inputs to the system.

Optimisation model: A mathematical technique that optimises a decision-making process in a situation requiring scare or expensive resources (land, capital, labour, feed, etc.).

Outputs of a system: Flows of material or information that leave a system over a fixed period of time.

Perennial crops: These crops are alive year-round and are harvested multiple times before dying (e.g. alfalfa, fruit trees).

Photosynthesis: The process where plants use carbon dioxide and sunlight to form sugar and oxygen.

Positive feedback: A deviation-amplifying control process, or self-accelerating control.

Potential production level: A term commonly used in crop production, where it refers to the production level achieved when a crop is perfectly managed, without water and nutrient stress and pests and diseases. It indicates the maximum possible yield.

Precipitation (in P cycle): The binding of P available for plants with soil minerals, for example with calcium.

Precipitation (in water): rainfall

Pressure indicators: Indicators that assess the potential impact, or pressure, on the environment.

Production Ecological concept: A concept commonly used in crop production, which consists of three levels of productivity and corresponding productivity factors: the potential production level, the water-limited and nutrient-limited production level, and the actual production level.

Productivity: The efficiency of a food production system in relation to a specific input. This can be defined as kg milk/meat/eggs, crop yield or number of people to be nourished per unit of input, which can be land or labour, but also water or nitrogen.

Rainfed farming: Farming that solely relies on rainfall for water.

Rate variable (in modelling): A variable that indicates the rate at which a state variable changes.

Regenerative capacity: Compensating the reduction of a resource, such as crude oil or fossil phosphorus, by a substitute that can provide equivalent functions, e.g. provider of energy or nutrients.

Relational diagram: A visual representation of the most important system components and their relationships, using symbols that indicate the specific nature of the relationships.

Relevance (of an indicator): To what extent the indicator can be associated with one or several issues of concern.

Respiration: The process where plants break down part of the sugars formed by assimilation to get the energy they need to grow. Oxygen reacts with sugar to release energy, water and carbon dioxide.

Responses (in DPSIR): Actions undertaken by groups or individuals in our society or by the government to prevent, compensate, ameliorate, or adapt to changes in the state of the environment.

Rich picture: A relational diagram that expresses the concerns or ideas of a group of stakeholders by showing the relations between different aspects of a problem.

Ruminant animals: Animals with a four-chambered complex stomach, like cows, goats, and sheep. This allows the fermented ingesta (known as cud) to be regurgitated and chewed again.

 Sedentary agriculture: Agriculture by farmers who settled at a location for a long period of time.

Simulation: The process of using a model to mimic the behaviour of a system.

Simulation model: A model that is composed of a series of arithmetic and logical operations that together represent the structure and behaviour of the system-of- interest.

Social sustainability: A production system is socially sustainable if it ensures that production systems, such as a farm, are socially accepted. In other words, a production system should be embedded in its social cultural context, should be respectful towards humans and animals, and should contribute to equitable management of resources.

Socio-economic context: Specific conditions of the production context determined by e.g. the market and political situation.

Spatial scale: Levels of food production, such as crop and livestock level, farm level, regional level, continental level, and global level.

Stakeholder: A group of people or organisations that affect or are affected by the problem.

State (in DPSIR): State in DPSIR refers to the state of the environment.

State variable (in modelling): An element of a system that represents a quantity, such as the amount of biomass or the number of animals. This quantity should be additive.

Static models: Models that assess the performance of a system, or compare different systems, at one moment in time.

Static systems analysis: Systems analysis that focuses on the characteristics of a system at one moment in time.

Stock of a system: An accumulation of material or information that has built up in a system over time.

Subsistence farming: Farming focused on food production for home consumption.

Subsystem: A system at lower hierarchy level, also referred to as a component.

Supra system: A system at higher hierarchy level (the larger system).

Sustainability concept: A concept including three pillars: the pillars of people, planet, and profit. These pillars are also known as social sustainability, environmental sustainability and economic sustainability.

Sustainable development: Development that meets the needs of the present without compromising the ability of future generations to meet their own needs.

Sustainable food production system: A food production system that is economically feasible, environmentally sound and socially acceptable.

Sustainable intensification: Increasing the number of people to be nourished per ha of land, while reducing negative environmental effects. In other words, reducing the environmental impact per kg of food, including animal-source food. For example, increasing crop yields per hectare of land, while minimising input use, such as fossil energy, fertilisers, crop protection agents and so on.

Synergy: Interaction of components where the whole is greater than the sum of its parts.

System: An entity that maintains its existence through the mutual interactions of its parts.

System boundaries: Boundaries that separate the system under study from its context. They define what is included in the system and what is excluded from the system. Where to draw a boundary around a system depends on the purpose of the study.

 System dynamics: The behaviour of a system or any of its components over time.

System language: A fixed set of symbols to visualise a system.

System levels (hierarchy): A system is always part of a higher system (supra system) and always contains lower systems (subsystems or components).

Systems analysis: A way of analysing complex systems that consist of many related components, while maintaining the essential characteristics of the system and the specific interaction with its context. It emphasises a holistic approach to problem solving. Through systems analysis we can study the behaviour of an entire system, rather than focusing on every detail of a single process in a system.

Time scale: Analysis of food production ranging from short-term to long-term effects, for example from hours or days, to months, years or even decades.

Trade-off analysis: A quantitative analysis in which multiple (sustainability) indicators are compared simultaneously. It indicates at what expense of one indicator a better achievement of other indicators can be realized.

Yield Gap: A concept commonly used in crop production. It is the difference between the actual yield and the potential yield. It indicates how much the yield could increase if management under the same climate and soil conditions were optimal and the crop experienced no water or nutrient stress nor problems with weeds, pests and diseases.

Yield Gap Analysis: A quantitative analysis that reveals how much crop production could increase on existing land, if management practices were improved.

Yield Gap Atlas: A tool to identify crop production potentials around the world.