A farm is a system: A farm is a human-managed ecosystem built to produce as much food as possible. Farmers change its energy flows and nutrient cycles to send more of the productivity into food, and that has environmental costs.
Inputs
- Solar energy
- Seeds or young livestock
- Fertilizers (nitrogen, phosphorus, potassium)
- Pesticides and herbicides
- Water for irrigation
- Fossil fuels for machinery
- Labour
Outputs
- Food: crops, meat, milk
- Animal feed and biofuels
- Wastes: manure, crop residues
- Pollution: fertilizer runoff, greenhouse gases
- Soil lost by erosion
The points to remember
- Every farm has inputs, outputs, storages (soil, crops, animals) and flows.
- Some outputs are unwanted: runoff, greenhouse gases, eroded soil. Always name one.
- Farming uses about 70% of the world's fresh water withdrawals.
- It covers over a third of the land and gives about a quarter of greenhouse gases.
A family farm in Iowa, USA, grows maize on 400 hectares.
Outline the main inputs and outputs of this commercial cereal farm.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.
Free preview
This is the free notes preview
You're reading the free notes. Aimnova Pro unlocks the full study experience — and you can try it with your first topic free to keep:
- FlashcardsLock in vocabulary and key terms with spaced repetition.
- Practice questionsAnswer exam-style questions and get instant AI marking.
- Mock exams & past-paper vaultSit full mocks and see exactly how examiners award marks.
- Personalised study planA daily plan built around your exam date and weak areas.
Farms can be sorted by what they produce and why the farmer produces it.
| Basis | One type | The other type |
|---|---|---|
| Outputs | Arable: wheat, rice | Pastoral: cattle, sheep |
| Outputs | Mixed: crops and livestock on one farm | Agroforestry: trees with crops or animals |
| Variety | Monoculture: e.g. a plantation | Diverse (polyculture): many crops together |
| Reason | Commercial | Subsistence |
| Movement | Sedentary: the farm stays in one place | Nomadic: herders move with their animals |
The points to remember
- Arable, pastoral or mixed: what comes out of the farm.
- Monoculture gives big, cheap harvests but is open to pests and drains the soil.
- Commercial farms sell for profit; subsistence farms feed the family.
- Sedentary farms stay put; nomadic herders move with the seasons.
- Plantations are large commercial monocultures, such as oil palm or sugarcane.
Example (SL): a maize farm in Iowa. It is arable, a monoculture, commercial and sedentary: the same maize is grown on the same fields every year and sold.
Never wonder what to study next
Get a personalized daily plan based on your exam date, progress, and weak areas. We'll tell you exactly what to review each day.
Farms can also be sorted by their inputs. The most important pair is intensive and extensive.
Intensive farming
- Intensive
- High yield per hectare
- Fertilizers, pesticides, irrigation, machinery
- Small area of land
- High energy use (fossil fuels)
- e.g. glasshouses, irrigated rice, indoor poultry
Extensive farming
- Extensive
- Low yield per hectare
- Natural rainfall and soil fertility
- Large area of land
- Low energy use
- e.g. ranching, shifting cultivation, dryland farming
The points to remember
- Irrigated or rain-fed: is water brought to the crop?
- Soil-based or hydroponic.
- Organic (manure, compost, no synthetic chemicals) or inorganic (synthetic fertilizer and pesticides).
- Compare intensive and extensive per hectare and per tonne of food.
Example (SL): Patagonian sheep. In southern Argentina, sheep graze huge dry grasslands with no fertilizer or irrigation, often less than one sheep per hectare: extensive, rain-fed, pastoral.
Why does one farmer choose cattle and another rice? Many factors combine.
The points to remember
- Environmental: climate, soils, relief, water, biome: they set the limits.
- Economic: prices, markets, costs of technology, subsidies, trade, cash crops, land tenure.
- Cultural: beliefs, traditions, food preferences, religion (no pork, no beef).
- Political: laws, subsidies, trade deals, food security plans, bans on GM crops.
- Social: labour, family size, education, population, who owns the land.
- Technological: machinery, seeds, irrigation and know-how available.
Example (SL): New Zealand's sheep. In 1984 the government ended farm subsidies. Lamb and wool prices were low, so many farmers switched to more profitable dairy cattle, crops or forestry. Sheep fell from about 70 million in 1982 to about 25 million.
Factors in a [9]: Name a real place for each kind of factor, then weigh them. Environmental factors often set the limits; economic and political ones decide within them.
Stop wasting time on topics you know
Our AI identifies your weak areas and focuses your study time where it matters. No more overstudying easy topics.
A pair of named contrasting systems: maize farms in Iowa, USA, and the rice-fish farms of Qingtian, Zhejiang, China, where carp have been kept in rice paddies for over 1,000 years.
| Iowa maize (USA) | Qingtian rice-fish (China) | |
|---|---|---|
| Outputs | Arable monoculture: maize | Diverse: rice and fish together |
| Reason | Commercial, large farms | Mostly subsistence, small family plots |
| Inputs | Intensive, inorganic: fertilizer, machines, GM seed | Low input, mostly organic: fish eat pests and weeds and fertilize the rice |
| Yield | Very high per hectare and per worker | Lower per hectare, but two foods |
| Environment | Nitrate runoff to the Gulf of Mexico; fossil fuels | Far less pesticide and fertilizer; methane from flooded paddies |
| Society and economy | Few jobs, high profit, exposed to world prices | Family labour, food security, a protected heritage system |
The points to remember
- Learn one pair in detail: names, inputs, outputs, reasons, impacts.
- Iowa: intensive, commercial, monoculture, inorganic.
- Qingtian: diverse, subsistence, organic, rain-fed and flooded paddies.
- Compare on all three kinds of sustainability.
Every choice has costs and benefits for the three kinds of sustainability: environmental, economic and social.
Intensive: impacts
- Water pollution from fertilizer and pesticide runoff
- Soil degraded: compaction, nutrients used up, salinization
- High greenhouse gases
- Biodiversity lost to monocultures
- But less land needed for the same food
Extensive: impacts
- Large areas of habitat cleared
- Overgrazing and desertification
- Less pollution per hectare
- More wildlife can live alongside
- But more land needed for the same food
The points to remember
- A monoculture like sugarcane drains the same nutrients every year.
- Machinery compacts the soil; over-irrigation can salinize it.
- Pesticides kill soil life; bare fields lose soil to erosion.
- Land sparing: high yields, more wild land kept.
- Land sharing: there is no single right answer.
- Productivity has risen hugely since the Green Revolution, but often at a cost to sustainability.
Remember it as: High input, high output, high impact per hectare.
Example (SL): Queensland sugarcane and the Great Barrier Reef. Fertilizer and sediment washing off sugarcane farms feed algae on the reef. Farmers are now paid to use less fertilizer and keep the soil covered.
Farming and climate work both ways: Climate shapes farming (drought, heat, shifting biomes), and farming changes climate (methane, cleared forest, fossil fuels, transport).
Adapt: drip irrigation, terracing, drought-tolerant crops, greenhouses. Mitigate: eat less meat, buy local, low-energy farming, feed additives that cut methane.
See how examiners mark answers
Answer exam-style questions with model answers. Learn exactly what earns marks and what doesn't.
How this comes up: Paper 2 Section B asks you to compare two named systems [7] or to weigh the factors behind farmers' choices [9]; Paper 1 asks for a reason from a graph [1].
Food production systems range from large commercial farms to small family plots.
Compare and contrast the environmental impacts of two named food production systems.
Model answer plan
See the mark-by-mark plan — for / against / judgement, with marking guidance — in study mode.