Land: real-world examples
Named cases you can use in an answer, each under the syllabus point it illustrates and linked to the lesson it comes from.
5 Land
5.1.2Soil is made up of inorganic and organic components, water and air.
Rhône glacier moraine around Geneva, Switzerland
Rhône glacier moraine around Geneva is an unsorted mix of clay, silt, sand, gravel and boulders that started out about 25% limestone. Weathering and leaching have since dissolved the limestone and left silica-rich rock behind, which explains why local fields are stony.
Demonstrates that the inorganic component of a soil depends on its parent material and how it was deposited, and that weathering changes that component over time.
Geneva, Switzerland Soil as a System
5.1.3Soils develop a stable, layered structure known as a profile made up of several horizons, produced by interactions within the system over long periods of time.
Geneva basin soil age
Soils in the Geneva basin, Switzerland, have formed on Rhône glacier moraine for about 16,000 uninterrupted years since the ice retreated, so they now carry well-developed profiles. At the Swiss average of about 1 cm per 100 years, that allows at most about 1.6 m of soil.
Shows that a horizon-layered profile builds up only through long, undisturbed interactions within the system, and that time limits how much soil can develop.
Geneva, Switzerland Soil as a SystemRhône valley flooding and soil development, Valais
Repeated floods kept burying soils on the Rhône plain in Valais (between Martigny and Sion) under fresh alluvium, so their profiles stayed young and mostly stacked river sediment. Only the river corrections (1863–1894 and 1930–1960) stopped the flooding and let horizons start developing in place.
Counter-example showing that profile development restarts whenever deposition resumes, so a soil is only as old as the last time deposition stopped.
5.1.4Soil system inputs include those from dead organic matter and inorganic minerals.
Irrigated market gardens, Rhône alluvium, Saxon
Irrigated market gardens on the Rhône alluvium near Saxon, Valais, rely on anthropogenic inputs such as irrigation water pumped from the Rhône, NPK fertiliser and compost. Their natural input of flood silt from another ecosystem stopped once the river was embanked.
Shows that a managed soil's input budget can be dominated by human inputs, and that a natural input from another ecosystem can be cut off by human intervention.
Saxon, Valais, Switzerland Soil as a System
5.1.6Transfers occur across soil horizons, into and out of soils.
Earthworm casts, Swiss soils
FiBL (Frick, Switzerland) reports that where earthworm populations are high, casts can reach 10 kg per m² per year, depositing up to 0.5 cm of soil a year in fields and 1.5 cm in meadows. Swiss soils form at only about 1 cm per century.
Puts a number on biological mixing and shows that bioturbation moves material far faster than soil forms.
Switzerland Flows, Functions and the Soil System DiagramNitrate leaching, Swiss groundwater
Nitrate leaching in Swiss groundwater: fertiliser nitrate percolates below the roots into aquifers, and the Swiss limit of 25 mg/L is exceeded at about one monitoring site in six nationally, rising to more than half in arable and vegetable-growing areas. The nappe du Genevois aquifer (about 80 million m³, shared by Geneva and Haute-Savoie) stays at only 2.5–4.5 mg/L because it is recharged mainly by the River Arve.
Links infiltration, percolation, leaching and groundwater flow into a single chain of outputs from the soil, and shows how land use and aquifer recharge source control how much leaches out.
Geneva, Switzerland Flows, Functions and the Soil System Diagram
5.1.10Soils contribute to biodiversity by providing a habitat and a niche for many species.
Urban gardens study, Zurich
A study of 85 urban gardens across Zurich (170 sampling sites) recorded 18 earthworm species and 39 springtail species alongside 600 plant species. Bacteria and fungi were not counted.
Shows how much hidden diversity soil supports even in urban gardens, and suggests that total soil biodiversity is underestimated because microbes and fungi were left out.
Zurich, Switzerland Flows, Functions and the Soil System Diagram
5.1.14Soils can act as carbon sinks, stores or sources, depending on the relative rates of input of dead organic matter and decomposition.
StudySoil organic carbon under forests and tundra
Duarte-Guardia et al. (2019) estimated soil organic carbon in the top metre at roughly 94–143 t/ha under tropical and subtropical forests, compared with about 310 t/ha under tundra.
Counter-intuitive evidence that high input does not create a large store: fast decomposition in warm, moist tropical conditions prevents carbon building up, while cold slows it in tundra.
UNEP Global Peatlands Assessment
UNEP's Global Peatlands Assessment (2022) found that peatlands cover only 3–4% of the world's land but hold up to a third of all soil carbon, twice as much as the world's forests. About 12% have been drained and degraded, and these areas now emit around 4% of annual human-caused greenhouse gas emissions.
Demonstrates a waterlogged soil acting as a long-term sink and then flipping to a carbon source once drainage lets air in and decomposition speeds up.
5.2.1Land is a finite resource, and the human population continues to increase and require feeding.
Swiss cropland protection, Switzerland
Since 1992 Switzerland has legally protected at least 438,460 ha of its best cropland (crop rotation areas), worked out from 2,340 kcal per person per day in a crisis. Geneva must keep 8,400 ha and held only 8,457 ha in 2023. Only 38% of Swiss farmland is arable and 58% is meadow and pasture.
Shows that the real limit is the small share of flat, fertile land that can be cropped, and that once it is built on it cannot be replaced.
5.2.2Marginalized groups are more vulnerable if their needs are not taken into account in land-use decisions.
Girjas case, Sweden
In the Girjas case (Swedish Supreme Court, T 853-18, 23 January 2020), the Girjas sameby in Gällivare won the right to grant hunting and fishing permits on its 5,449 km² of land through immemorial possession. It took 11 years of litigation, and the court did not rule on who owns the land.
Shows that an indigenous group holding only use rights is left out of land decisions and has to fight long, costly legal battles to have its needs recognised.
5.2.5Agricultural systems are varied, with different factors influencing the farmers' choices. These differences and factors have implications for economic, social and environmental sustainability.
Contrasting farming, Geneva plain and Girjas
A contrasting pair: on the Geneva plain, flat fertile soils, a long growing season and a nearby city market support intensive, mechanised commercial arable farming (56% of farmed area in field crops). In Girjas, Norrbotten, thin cold soils and a growing season of only weeks support extensive, nomadic, commercial reindeer herding.
Demonstrates how physical and human factors (including law) shape farmers' choices, and how economic, social and environmental sustainability differ between the two systems.
Geneva, Switzerland Land, Food and Farming Systems
5.2.6Nomadic pastoralism and slash-and-burn agriculture are traditional techniques that have sustained low-density populations in some regions of the world.
Jhum cultivation and soil recovery, Nagaland
Jhum (shifting cultivation) in Nagaland, north-east India: the traditional 15–20 year cycle has shrunk to 5 years or fewer as population grew. A Mokokchung district study (Temjen et al., 2022) found the topsoil quality index rose from 0.68 on cultivated land to 0.82 after a 12-year fallow, and soil organic carbon more than doubled.
Demonstrates that slash-and-burn only stays sustainable at low density: the soil is degraded by the shortened fallow, not by the burn.
Sámi reindeer herding, Sweden
Sámi reindeer herding in Sweden: 51 samebyar with about 4,700 owners and around 230,000 reindeer use close to 40% of Sweden's land, and 33 communities migrate between mountain summer pasture and boreal winter forest. Forestry, mines and wind farms cut into the migration routes, and rain-on-snow icing forces herders to buy feed.
Shows nomadic pastoralism using land that cannot be cropped, and how fixed modern land uses and climate change weaken a system that depends on moving.
Norrbotten, Sweden Land, Food and Farming Systems
5.2.7The Green Revolution (also known as the Third Agricultural Revolution in the 1950s and 1960s) used breeding of high-yielding crop plants—combined with increased and improved irrigation systems, synthetic fertilizer and application of pesticides—to increase food security. It has been criticized for its sociocultural, economic and environmental consequences.
Green Revolution in Punjab
Green Revolution in Punjab, India: high-yielding wheat made Punjab (about 1.5% of India's land) grow roughly 20% of India's wheat. However, tube-well irrigation meant the 2022 Central Ground Water Board assessment classified 114 of Punjab's 150 blocks as over-exploited.
Shows yield gains from the package alongside its economic concentration and environmental cost (groundwater depletion), which supports a balanced evaluation.
5.2.8Synthetic fertilizers are needed in many intensive systems to maintain high commercial productivity at the expense of sustainability. In sustainable agriculture, there are other methods for improving soil fertility.
StudyHaber-Bosch process
The Haber-Bosch process fixes atmospheric nitrogen with hydrogen from natural gas at about 450°C and 200 atmospheres. Ammonia production uses about 5% of world natural gas and releases 1–2% of global CO₂ emissions.
Demonstrates why synthetic fertiliser keeps productivity high at the expense of sustainability, because it is built on fossil fuel.
5.2.9A variety of techniques can be used to conserve soil, with widespread environmental, economic and sociocultural benefits.
Lavaux vineyard terraces, Lake Geneva
The Lavaux vineyard terraces, Switzerland: dry-stone walls built from the 11th century by Benedictine and Cistercian monks cut steep slopes above Lake Geneva into about 830 ha of level terraces along roughly 30 km of shore. They hold soil and water in place, and the landscape was inscribed as a UNESCO World Heritage Site in 2007.
Shows terracing delivering environmental benefits (erosion control), economic benefits (nine centuries of wine production and tourism) and sociocultural benefits (community-backed protection) at once, while also showing the costs of hand maintenance.
Soil loss on Prosecco DOCG vineyards, Italy
A modelling study of the Prosecco DOCG hills in north-east Italy estimated potential soil losses of 43.7 t/ha/yr from conventionally managed vineyards on steep ground, which is 31 times Europe's tolerable rate.
Quantifies how severe erosion is on steep land without conservation, which justifies techniques such as terracing and cover crops.
Prosecco DOCG hills, Veneto, Italy Texture, Productivity, Carbon and Conserving Soil
5.2.10Humans are omnivorous, and diets include fungi, plants, meat and fish. Diets lower in trophic levels are more sustainable.
StudyLand use of beef and tofu protein
Poore and Nemecek (2018, Science) found beef needs 163.6 m² of land per 100 g of protein compared with 2.2 m² for tofu. Animal products use about 83% of global farmland but supply only 18% of calories.
Quantifies the land-use advantage of eating at lower trophic levels, giving hard evidence for the 10% energy transfer argument.
5.2.11Current global strategies to achieve sustainable food supply include reducing demand and food waste, reducing greenhouse gas emissions from food production and increasing productivity without increasing the area of land used for agriculture.
Swiss food waste action plan
Switzerland produces 2.8 million tonnes of food waste a year (about 330 kg per person). Its 2022 action plan aims to halve avoidable losses by 2030, but the 2025 interim review found only about a 5% fall against an interim target of 25%.
Shows a national waste-reduction strategy in practice and the gap between the policy target and actual results.
5.2.12Food security is the physical and economic availability of food, allowing all individuals to get the balanced diet they need for an active and healthy life.
Swiss food initiative vote, Switzerland
The Swiss food initiative vote of 27 September 2026 asks to raise self-sufficiency from 46% to 70% by shifting to plant-based food. Opponents argue that 58% of Swiss farmland is pasture unsuited to crops, and that Switzerland is already highly food-secure through imports.
Demonstrates that food security (physical and economic access) is different from self-sufficiency, and shows the limits of plant-based diets on land that can only grow grass.