Five methods — and the syllabus lists only five
Agricultural machinery — works larger areas of land with less labour per hectare. Chemical fertilisers — replace the mineral ions (nitrate ions) the crop removed from the soil, improving yield. Insecticides — kill insect pests, improving quality and yield. Herbicides — kill weeds, cutting competition for light, water and mineral ions. Selective breeding — cross parents with desirable features over many generations, in crops and livestock.
Monoculture — one species, one shared weakness
A monoculture is a single crop species grown over a large area, often the same variety every season. Advantages: machinery and chemicals are optimised for that one crop, so efficiency is high, yield is maximised, management is simpler and cost per unit yield falls. Disadvantages: a pest or pathogen adapted to the crop sweeps the whole area; genetic variation is low; local biodiversity falls; and the same soil minerals are stripped every season.
Intensive livestock — energy redirected into growth
Intensive livestock production rears animals at high density, usually indoors, with controlled diet and temperature and restricted movement. Restricting movement means less food energy is spent on activity and keeping warm, so more is converted into body mass — raising the yield of meat, milk or eggs per unit of feed. Controlled conditions and shelter from predators and weather make production faster and more reliable, and more animals are reared per unit area.
Drawn from real examiner reports.
Monoculture does have advantages
Asked to describe advantages AND disadvantages, many candidates answer only the disadvantages. Monoculture genuinely raises efficiency: with one crop, machinery, fertiliser, insecticide and herbicide can all be optimised for it, planting and harvesting are standardised, and cost per unit yield falls. Half an answer scores half the marks.
Monoculture risk ≠ pollution
Asked for a disadvantage of large-scale monoculture, candidates write "it pollutes the environment" or "it causes global warming". Neither is credited. The required mechanism is about the crop itself: one species — often one variety — across the whole area, so a pest or pathogen adapted to it spreads rapidly, and reduced genetic variation leaves few resistant plants.
Flagged w22 P42/43 Q4a iii · s23 P33 Q8d ii — generic pollution/global-warming answers given instead; genetic consequences of reduced variation rarely mentioned
Fertiliser, insecticide, herbicide swapped
Each chemical has ONE target, and swapping them loses the mark. Fertilisers replace mineral ions such as nitrate ions the crop removed from the soil — they kill nothing. Insecticides kill insect pests. Herbicides kill competing weeds. "Fertilisers kill weeds" or "insecticides improve the soil's minerals" pairs a chemical with the wrong mechanism and scores zero.
Selective breeding ≠ genetic modification
Selective breeding chooses parent plants or animals showing a desirable feature and crosses them repeatedly, shifting the population over MANY generations. Genetic modification alters an organism's genes directly and can work within one generation — it belongs to a different sub-topic. Examiners also refuse "biotechnology" on its own as too vague to credit.
Flagged s22 P42 Q6d · w22 P43 Q3vi — selective breeding named when genetic modification was asked for
Naming the method is only half the mark
Each method must be linked to the effect the syllabus states: machinery to larger land area and efficiency, fertilisers to improved yield, insecticides to improved quality AND yield, herbicides to reduced competition with weeds, selective breeding to improved production. "Insecticides kill pests" and "fertilisers help plants grow" both stop one step short of that link.
Yield ≠ quality of the harvest
Yield is the amount of useable product per unit area or per animal. Quality is the condition of that product — undamaged leaves, unblemished fruit. Insecticides are credited with improving BOTH, because pests destroy some of the crop (yield) and damage what is left (quality). An answer that mentions only one of the two misses the second mark.
Intensive livestock has real costs
High stocking density and restricted movement cause stress, injury and loss of natural behaviour — a genuine welfare cost that production figures do not show. Close contact lets an infectious disease sweep the whole population, often needing routine antibiotics, which risks antibiotic-resistant bacteria. Concentrated waste in a small area can pollute local land and water.
Scaffold an advantages/disadvantages answer
Name the practice precisely — "large-scale monoculture of wheat", not "modern farming". Then give one advantage with its mechanism and one disadvantage with its mechanism. Keep the two points distinct: restating the same idea in different words earns one mark, not two.
Describe means statement plus mechanism
One-word answers — "efficient", "diseases" — do not satisfy "describe". Attach the reason every time: high stocking density means animals are in constant close contact, SO an infectious disease spreads rapidly through the population. State it, then explain why it follows.
Answer from the five listed methods only
Statement 1 of 20.1 is limited to machinery, fertilisers, insecticides, herbicides and selective breeding. Genetic modification, irrigation and greenhouses are not on that list, so they will not be credited on a "how have humans increased food production" question.
Percentage increase divides by the BEFORE value
Yield data questions almost always want a percentage increase. Divide the change by the ORIGINAL figure, never the new one: a rise from 3.0 to 4.5 tonnes per hectare is 1.5 divided by 3.0, times 100, which is 50 per cent. Dividing by 4.5 is the standard slip.
Humans have increased food production using five named methods:
| Method | Mechanism | Effect |
|---|---|---|
| Agricultural machinery | Uses larger areas of land, improves efficiency | More land farmed with less labour/time |
| Chemical fertilisers | Replace/boost mineral ions (e.g. nitrate ions) removed from soil by the crop | Improved yield |
| Insecticides | Kill insect pests | Improved quality and yield (less crop lost to pests) |
| Herbicides | Kill competing weeds | Reduce competition for light, water, mineral ions |
| Selective breeding | Humans choose and cross parents with desirable features over many generations | Improved production by crop plants and livestock |
Monoculture is the large-scale growing of a single crop species over a wide area.
Intensive livestock production is rearing large numbers of animals at high density in a controlled environment (restricted movement, controlled diet/temperature) to maximise growth/production efficiency.
State the FIVE methods by which humans have increased food production.
(a) State THREE methods, other than selective breeding, by which humans have increased food production. [3]
(b) For ONE of the methods you named in (a), state what it specifically targets or replaces. [1]
