For most of human history, farming worked with whatever the land could give. Then, in the middle of the twentieth century, we learned to force much more out of the same fields using new seeds, water and chemicals. Both approaches feed people. Both have a price. This page shows you what each one is, and how to argue about them without sounding one-sided.
📘 What you need to know
Nomadic pastoralism moves livestock between pastures on a seasonal cycle.
Slash-and-burn (shifting cultivation) clears and burns forest, crops the land for a few years, then moves on so the forest can regrow.
Traditional methods are sustainable at low population density and break down when populations rise and land runs short.
The green revolution (1950s–1960s) raised yields using high-yielding varieties, irrigation, synthetic fertilisers and pesticides.
It increased food supply but caused soil degradation, water pollution, biodiversity loss and greater inequality.
Synthetic fertiliser production depends on nitrogen fixation, which relies on fossil fuels.
Sustainable alternatives for fertility include fallowing, organic fertiliser, herbal leys, mycorrhizae, continuous cover forestry and agroforestry.
Traditional agricultural practices
Nomadic pastoralism
Nomadic pastoralism means herding livestock from pasture to pasture through the year rather than keeping them in one place. Bedouin communities in the Middle East have long moved camels, goats and sheep across desert regions to reach whatever grazing is available.
The logic is simple. In arid and semi-arid land, no single patch of grass can support animals all year. Moving on lets each patch recover while the herd feeds somewhere else. That gives you the main features: it depends on natural pasture and water, it suits dry environments, there are few permanent settlements, and the seasons decide the timetable.
Slash-and-burn (shifting cultivation)
Here, farmers cut down a patch of forest and burn it. The ash releases nutrients into the soil, which lets crops such as cassava and maize grow well for a few years. Once the nutrients are used up, the family moves to a new patch and the old one is left to regrow. Some indigenous communities in the Amazon have farmed this way for generations.
Notice that the criticism of slash-and-burn is really a criticism of pressure on land. The same technique is either a rotation or deforestation depending on how long the rest phase lasts.
Where traditional practices run into trouble
Environmental. Slash-and-burn causes deforestation and biodiversity loss when plots are reused too quickly. Nomadic herding can cause overgrazing and soil erosion if herds get too large for the pasture.
Population pressure. As populations grow, land becomes scarce, rest periods get cut short, and the same method that used to be sustainable turns into overuse of land and resources.
Modernisation. Some indigenous communities have shifted towards more settled ways of living, which changes how the land is used again.
A trap in essays: do not write “traditional farming is sustainable” as a flat statement. Write “traditional farming can be sustainable where population density is low, because the land is given time to recover”. The condition is where the marks are.
The green revolution
The green revolution was a set of research, development and technology programmes running through the 1950s and 1960s, aimed at raising food production worldwide. It is sometimes called the third agricultural revolution.
🧩 The four key inputs
High-yielding varieties (HYVs) — wheat, rice and maize bred to produce far more grain. IR8 rice, nicknamed “miracle rice”, was developed in the Philippines.
Improved irrigation — new infrastructure turned dry and semi-dry land into productive farmland. The Indus Basin Irrigation System in Pakistan is the classic example.
Synthetic fertilisers — chemical nutrients added straight to the soil. Making them needs nitrogen fixation, which runs on fossil fuels.
Pesticides — chemicals to protect crops from pests and disease so less of the harvest is lost.
Wealthier farmers could afford the seeds, water and chemicals; poorer farmers often took on debt to try. That is why the gains landed unevenly.
Reading the consequences properly
The positives are straightforward: crop yields and food availability rose sharply, hunger fell in many regions, farm incomes went up, and the research programmes led to further innovation.
The negatives need the same care as the positives. Heavy use of fertilisers and pesticides degraded soils and polluted water. Intense monoculture cut biodiversity. Economically, larger and wealthier farmers gained most, while smaller farmers who could not afford the new technology took on debt. Socially, traditional practices were displaced and changes in labour demand pushed people from the countryside into cities. And the whole thing was selective — regions without the infrastructure or money to take part saw little benefit at all.
Synthetic fertilisers
Synthetic fertilisers are chemical compounds spread on soil to supply the nutrients plants need, keeping commercial output high in intensive systems.
Advantages
Disadvantages
Nutrients reach the crop immediately
Soil quality declines over time
Higher yields and faster growth
Runoff pollutes rivers and lakes
Reliable and easy to apply at scale
Production depends on fossil fuels, so cost and carbon footprint are tied to energy prices
Why the fossil fuel link matters. Turning nitrogen gas into fertiliser takes a lot of energy, and that energy usually comes from fossil fuels. So a “food” question can become a “climate” question — a link that scores well in HL essays.
Sustainable ways to keep soil fertile
If synthetic fertiliser is the industrial answer, these are the alternatives. Most of them work by feeding the soil rather than feeding the plant directly.
Method
What it is
Why it helps
Fallowing
Leaving land uncultivated for a period
Soil recovers and rebuilds its nutrient store, so less synthetic fertiliser is needed
Organic fertiliser
Manure from farm animals, or treated human waste
Improves soil structure as well as fertility, and recycles nutrients on the farm
Herbal mixed leys
Sowing a mixture of herbs and grasses
Different roots draw up different nutrients, improving soil health and biodiversity
Mycorrhizae
Fungi living in partnership with plant roots
Extends the root network so plants reach nutrients they could not otherwise get
Continuous cover forestry
Keeping a permanent tree canopy over the ground
Roots bind the soil and the canopy intercepts rain, so erosion drops and organic matter builds up
Agroforestry
Growing trees and shrubs among crops or pasture
Improves soil health, cuts erosion, and adds income from fruit or timber
WORKED EXAMPLE
Explain why shifting cultivation can be sustainable in some situations but not in others. [3]
The answer hangs on one variable: population densityAt low density, plots are left for many years, so forest regrows and soil nutrients rebuild.The natural capital is used no faster than it is replaced, so the system is sustainable.At high density, land is scarce, so plots are reused before recovery is complete.Soil is degraded and forest is permanently lost, so the same practice becomes unsustainableSame technique, opposite verdict. Making the condition explicit is what earns the third mark.
WORKED EXAMPLE
Discuss one environmental and one social consequence of the green revolution. [4]
EnvironmentalHeavy fertiliser and pesticide use degraded soils and polluted watercourses through runoff, and monoculture reduced biodiversity across large areas.SocialWealthier farmers could afford the new seeds and chemicals while poorer farmers took on debt, so inequality widened and many moved to cities as labour needs changed.Higher output came with environmental damage and widening inequality“Discuss” wants both sides. One sentence acknowledging the yield gains keeps the answer balanced.
💡 Exam tip
Learn two named examples: IR8 rice in the Philippines and the Indus Basin Irrigation System. Named detail lifts a generic answer.
Always link fertiliser back to fossil fuels. It is a free connection to climate and energy topics.
For traditional practices, state the condition under which they are sustainable rather than judging them outright.
Pair every green revolution positive with a negative. Examiners reward balance in “discuss” and “evaluate” questions.
Remember the green revolution was selective — it did not reach every developing country. This is a strong evaluation point.
Know at least three sustainable fertility methods well enough to explain the mechanism, not just name them.
⚠️ Common mix-up
Calling the green revolution simply “good” or “bad”. It raised food supply and caused damage, and both belong in the answer.
Thinking slash-and-burn is always destructive. The rest period is what decides it.
Mixing up nomadic pastoralism (moving animals) with shifting cultivation (moving crop plots).
Saying fertilisers “damage the soil instantly”. The problem is cumulative degradation over years.
Forgetting the economic consequences. Debt and inequality are as examinable as pollution.
Describing agroforestry and continuous cover forestry as the same thing. Agroforestry mixes trees into farmland; continuous cover forestry keeps a permanent canopy.
Up next: Protecting and Restoring Soil — how erosion, salinisation and desertification happen, and the techniques that stop them.
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