IGCSE Environmental Management Topic 2: Land — Challenge Prep

1 · What the two papers actually pay for▶

Everything on the Topic 2 syllabus is already taught in the study guide. This page is not more content. It is about the gap between an answer that knows the material and an answer that scores — which, in Environmental Management, is almost always a gap in technique rather than in knowledge.

Where the marks actually are

0680 has two papers. Each is 1 hour 45 minutes, each is 80 marks, and each is worth 50% of the grade. They are not the same paper twice.

Paper	AO1 knowledge	AO2 application	AO3 analysis & evaluation	What it feels like
Paper 1 Principles of Environmental Management	55	30	15	Mostly recall and short explanation, building to one longer discuss question.
Paper 2 Environmental Management in Context	30	30	40	Source-led. Nearly every question hangs off a figure, table, map or graph printed on the paper.

The number that should change how you revise

On Paper 2, 40 marks in every 100 are AO3. AO3 is not something you can learn by heart the night before. It is a set of habits: read the axes, quote the figures, say what the data cannot tell you, weigh both sides, land a judgement. Those five habits are the whole of section 4 of this page, and they are worth more than any single sub-topic you could revise.

What each AO is asking for

AO	The question is really asking	Topic 2 example
AO1 Knowledge and understanding	Give back what you were taught, accurately and in the right words.	State two causes of soil erosion.
AO2 Application	Take what you know and use it on a farm, a country or a situation you have never seen before.	Suggest why terracing would be difficult for this farmer to build.
AO3 Analysis, interpretation and evaluation	Work from the source in front of you. Describe what it shows with numbers, work something out from it, say what it does not show, weigh two options and decide.	Using Fig. 2, evaluate whether the farmer should change irrigation method.

Command words, and what they pay

Read the command word before you read anything else. Half of all lost marks in this topic are answers that describe when they were asked to explain.

Command word	What earns the mark	What earns nothing
State / Name / Identify	The correct term. Nothing more is needed and nothing more is credited.	A paragraph. You are not paid for it and you have spent the time.
Describe	What it is, or what the pattern is. For data: the direction, the figures and the units.	Reasons. A reason in a describe question is not credited.
Explain	Why or how — the mechanism, in linked steps.	Restating the question. "It increases yield because it makes the yield higher."
Describe and explain	Both. One mark names it; the rest are the chain.	Naming three strategies and explaining none. Very common, and it caps you at 3.
Suggest	An idea that fits the new situation. There is no single right answer; there is a right kind of answer.	Something true in general but not connected to the case on the page.
Discuss / Evaluate / To what extent	Two sides, then a judgement with a reason attached.	A list of advantages with no disadvantages and no conclusion.
Calculate	Working shown, then the answer with its unit.	A bare number that happens to be wrong. With working, a slip still scores the method mark.

Count the marks, then plan that many points

A [4] is four separate creditable points, not one point said four ways. Before you write, put four dots in the margin. If you can only fill three, you know to think again before you have used the space, not afterwards.

And a [1] is one point. If a one-mark question takes you three lines you have misread it.

Checkpoint — how the papers pay

Three questions on what the examiner is buying.

Score: 0 / 3

Question 1

Which paper carries the larger proportion of AO3 marks, and roughly how large is it?

A Paper 1, about a fifth of the paper

B Paper 2, about two fifths of the paper

C They are the same on both papers

D Paper 1, about half of the paper

Paper 2 is AO1 30 / AO2 30 / AO3 40, so AO3 is 40 marks in every 100 — about two fifths. Paper 1 is AO1 55 / AO2 30 / AO3 15, so its AO3 share is only about a seventh. Both papers are 80 marks and each is worth half the grade, so the AO3 habits are not optional.

Question 2

A question reads: Describe and explain how contour ploughing reduces soil erosion. [3] A student writes one sentence saying what contour ploughing is. What is the most she can score?

A 3, because she has answered the question

B 0, because she has not explained anything

C 1, for describing it — the other two marks are for the mechanism

D 2, because describing counts double

"Describe and explain" means both. Saying that contour ploughing means ploughing across the slope rather than up and down it is the description, and it is worth one mark. The remaining two marks are for the chain: the furrows lie along the contour, so they trap water running downhill, so surface run-off is slowed and less soil is carried away. This one habit — naming and then chaining — is worth more marks in Topic 2 than any other single thing.

Question 3

Which of these is an AO3 task rather than an AO1 task?

A Defining sustainable food production

B Stating three causes of soil erosion

C Naming the three mineral particles found in soil

D Using a graph of yield against fertiliser rate to recommend an application rate, and saying what the graph cannot tell you

AO3 is analysis, interpretation and evaluation, and it always has a source attached. The other three are recall from the syllabus — AO1. Notice that the AO3 task has two halves that students routinely drop: the recommendation must be justified from the figures, and saying what the data does not show is itself creditable.

2 · The describe-and-explain chain▶

Three of the Topic 2 objectives use the words describe and explain: 2.2.3 (strategies to increase food production), 2.2.4 (impacts of unsustainable practices) and 2.3.3 (strategies to reduce soil erosion). Between them they are the bulk of the topic. So the single most valuable technique in Topic 2 is knowing what the second half of that command word buys.

The rule: one mark names it, the rest are the chain

Naming a strategy is worth exactly one mark, once. Everything after that comes from linking the steps between the strategy and the outcome. The links are made with four words and phrases:

so that — "the furrows run along the contour so that water is held on the slope"
because — "the run-off slows because it no longer flows straight downhill"
which means — "the water soaks in, which means less of it flows over the surface"
this causes — "this causes less topsoil to be carried away"

If your answer has no such word in it, you have almost certainly written a list, and a list is capped at one mark per item however many items it has.

Strategy	The 1 naming mark	The chain marks (2.3.3 wording)
Terracing	Cutting the slope into a series of level steps	each step is flat, so water is held rather than flowing downhill → surface run-off is reduced so it carries less energy → less soil is moved down the slope
Contour ploughing	Ploughing across the slope, along the contour	the furrows lie at right angles to the flow so water is trapped in them → run-off is reduced → water soaks in instead of washing soil away
Bunds	Low banks of earth or stone built across a slope or around a field	they block water flowing downhill so surface run-off is reduced and they act as a barrier to the wind so wind speed at ground level falls → less soil is lifted and blown away
Wind breaks	Rows of trees or shrubs planted along field edges	they slow the wind so wind speed at the soil surface falls → less dry soil is picked up → the crop itself is also physically protected from wind damage
Maintaining vegetation cover	Keeping plants growing on the soil rather than leaving it bare	roots bind the soil particles together → leaves intercept rain so drops do not hit bare soil → the plants absorb water and reduce surface run-off
Adding organic matter	Working manure, compost or crop residue into the soil	it improves soil structure so particles stick together in crumbs → the soil holds more water and drains better so less water runs off the surface

The commonest way to throw away a [4]

Writing four strategies instead of one strategy in four steps. Describe and explain a strategy, singular, means go deep, not wide. Four names scores 1 (or at best a couple, if the mark scheme allows a mark per named point), because the mechanism — which is where the marks live — is missing every time.

Worked in fullDescribe and explain how terracing reduces soil erosion on a steep hillside. [4]

Read the model, then read the note underneath it about which words did the earning.

The answer

Terracing means cutting the steep hillside into a series of flat, level steps held up by walls or banks (1 — describe). Because each step is level, rainwater collects and stands on it instead of running straight down the slope (1). This reduces the speed and the volume of surface run-off, so the water carries much less energy (1). The water then has time to soak into the soil rather than washing the topsoil off the surface, so far less soil is moved downhill (1).

Why it scores 4 and not 1

Only the first sentence is description. The other three marks are one continuous chain: level step → water held → run-off reduced → soil stays. Each arrow is a mark. Notice that the word soil only appears at the end — the middle of the chain is about water, because water is the mechanism.

What a weak version looks like

"Terracing makes steps in the hill. This stops soil erosion because the soil cannot move." That is 1 mark. The second sentence is the question repeated back.

The chain is the answer. Level step → water held → run-off reduced → soil not carried away.

Fading step 1 — the chain is blankDescribe and explain how contour ploughing reduces soil erosion. [3]

The description is written for you. You write the chain — two linked steps, ending with what happens to the soil.

Given: Contour ploughing means ploughing across the slope, so that the furrows run along the contour rather than up and down the hill. (1 mark)

You write: This works because , which means .

Model chain

This works because the furrows lie at right angles to the direction water would flow, so each furrow traps water that is running downhill and holds it (1), which means surface run-off is reduced and the water soaks into the soil instead of carrying the topsoil away with it (1).

Marking your own

Did you name what the furrows do to the water? An answer that jumps straight from "ploughing across the slope" to "less erosion" has skipped the mechanism and scores 1 of the 2.

Furrows across the flow → water trapped and held → run-off reduced → soil not washed away.

Fading step 2 — you write all of itDescribe and explain how bunds reduce soil erosion. [4]

Nothing is given. Four marks means four points: one describing what a bund is, then a chain. Bunds are the one strategy on the syllabus that is credited for two different mechanisms — make sure both are in your answer.

Model answer

A bund is a low bank or wall of earth or stones built across a slope or around the edge of a field (1). It acts as a physical barrier to water flowing down the slope, so surface run-off is slowed and water is held behind the bund and soaks in (1). Because the bund stands above the soil surface it also breaks the flow of wind across the field, so wind speed at ground level is reduced (1). Slower wind cannot lift as many dry soil particles, so less soil is blown away (1).

The trap here

2.3.3(c) credits bunds for reducing surface run-off and for reducing wind speed and wind erosion. 2.3.3(d) credits wind breaks for wind only. If you wrote a water-only answer for bunds you have left the wind marks on the table.

Bund = barrier. Barrier to water → run-off reduced. Barrier to wind → wind speed reduced → less soil lifted.

Checkpoint — the chain

Four questions on turning a name into marks.

Score: 0 / 4

Question 1

Which sentence is doing the work that earns a mark in an explain question?

A Mulch is spread on the surface of the soil.

B Mulch is made from crop residue such as straw.

C Mulch covers the soil surface, so raindrops hit the mulch instead of bare soil and cannot dislodge soil particles.

D Mulch is a good way of reducing erosion.

Only C contains a mechanism, and it contains a linking word to signal it. A is a description of what mulch is, which would earn the single describe mark. B is a detail with no consequence attached. D is the question said back to the examiner — the commonest zero-mark sentence in the whole paper.

Question 2

A [4] asks you to describe and explain one strategy to increase crop yield. Which plan is likeliest to reach 4?

A Name four strategies, one line each

B Name one strategy, then give three linked steps from the strategy to the higher yield

C Write everything you know about fertilisers

D Name two strategies and explain both briefly

The question says one strategy, so going wide cannot be credited beyond the first item. B is the shape the mark scheme is built for: 1 for the name, 3 for the chain. D looks like a hedge but it usually produces two shallow answers rather than one complete one, and it takes longer to write.

Question 3

Which of these is the correct chain for organic fertiliser increasing yield?

A Manure is added, so the plants grow better, so yield rises

B Manure is added, so the soil is healthier, so the farm makes more money

C Manure is added, so it decomposes and releases nitrate, phosphate and potassium ions into the soil, so roots take up more of these ions, so more protein and chlorophyll can be made and the crop grows more, so yield rises

D Manure is added because it is cheaper than inorganic fertiliser and easier to obtain

C is a chain with named ions in it — nitrate, phosphate and potassium are on the syllabus at 2.1.2(b) and naming them is worth having. A contains no mechanism at all: "grow better" and "yield rises" are the same statement twice. B drifts into economics, which is not what the question asked. D is a reason for choosing manure, not an explanation of how it raises yield.

Question 4

Why does the phrase "this improves the soil" rarely score?

A It is not true

B It is too long

C It is not on the syllabus

D It names no property of the soil and no consequence — improved how, and with what effect?

It is perfectly true, which is why it feels like it should score. But a mark point has to be specific: improves structure, so particles form crumbs, so the soil holds more water and drains better, so less water runs off the surface. Vague virtue words — improves, helps, is better for — are the ones to hunt out of your own writing.

3 · Three answers, one question▶

The most useful thing anyone can show you is the same question answered three ways. Below is one six-mark question with a weak answer, a middling answer and a strong answer — and, more importantly, exactly which words moved the mark.

The question

Describe and explain two strategies a farmer with a small area of poor soil could use to increase crop yield. [6]

Six marks, two strategies. So the mark scheme is almost certainly 1 for naming each strategy and 2 for the chain behind each. That structure — work it out from the number in the brackets — tells you to write two paragraphs of three points, not one long paragraph about fertiliser.

Weak answer2 of 6

He could use fertiliser and irrigation. Fertiliser makes the plants grow better and irrigation gives them water. This will increase the yield.

What it earned: 1 for naming fertiliser, 1 for naming irrigation. That is all.
Why the other four were lost: "makes the plants grow better" and "will increase the yield" are the question repeated back — the whole point of the question is that yield rises, so saying so cannot be a reason. "Gives them water" is what irrigation is, not how it raises yield. There is not one linking word in the whole answer.

Middling answer4 of 6

He could add organic fertiliser such as manure. Manure adds nutrients to the soil, so the crop has more of what it needs to grow. He could also use trickle irrigation, where water drips slowly onto the soil near the roots, so less water is wasted than with flood irrigation.

What it earned: 1 for naming organic fertiliser (manure), 1 for the nutrient mechanism, 1 for naming trickle irrigation, 1 for the reduced waste.
Why the last two were lost: "nutrients" is a general word where the syllabus gives specific ones — nitrate, phosphate and potassium ions — and specific always outscores general. And the trickle chain stops one link too early: less water wasted is not yet a yield mechanism. It needs to reach the crop: water delivered steadily to the root zone keeps the plant supplied, so it can photosynthesise at close to its optimum rate.

Strong answer6 of 6

He could add organic fertiliser such as manure or compost (1). As it decomposes it releases inorganic ions — nitrate, phosphate and potassium — into the soil water, which the roots absorb (1); nitrate in particular is needed to make proteins and chlorophyll, so the crop makes more leaf and photosynthesises faster, and yield rises. The organic matter also improves soil structure so the soil holds more water (1). Secondly he could install trickle irrigation (1), in which water is delivered drop by drop through pipes directly to the root zone. Because the water goes to the roots and not to the whole field surface, very little is lost to evaporation or to weeds (1), so the crop has a steady water supply through the dry season, its stomata stay open and photosynthesis continues at close to the optimum rate rather than stopping when the soil dries out (1).

Why it is full marks: two strategies, each named and each followed by a chain that ends at the crop rather than at the soil or at the water. The named ions and the words evaporation, root zone and photosynthesis are the specifics that lift it. Length is not what did it — the middling answer is only about a third shorter.

The one-sentence diagnosis

Weak answers stop at the strategy. Middling answers stop at the soil or the water. Strong answers reach the crop. Before you put your pen down, ask: does my last sentence mention the plant?

The same treatment on an evaluate question

The question

"Monoculture is always bad for the environment." To what extent do you agree? [4]

"To what extent" is a discuss command. Four marks means roughly: points against, points for, and a judgement that is not a shrug.

Weak answer1 of 4

I agree because monoculture is bad. It destroys the soil and kills wildlife and farmers should not do it.

One mark, for loss of biodiversity if the examiner is generous. There is no second side at all, and "destroys the soil" is not a mechanism. "Farmers should not do it" is an opinion, and opinions without evidence are not credited.

Middling answer3 of 4

Monoculture means growing one crop over a large area year after year. It takes the same inorganic ions out of the soil every season, so those ions become exhausted, and it supports very few species so biodiversity falls. However, monoculture allows machinery to be used across the whole field and produces large amounts of one crop cheaply, which helps feed a growing population. So it has both advantages and disadvantages.

Three solid marks: nutrient exhaustion, biodiversity, and a genuine other side. The fourth is lost on the last sentence — "it has both advantages and disadvantages" is not a judgement, it is a refusal to make one. An evaluate question pays for the decision and the grounds.

Strong answer4 of 4

Monoculture means growing a single crop over a large area, season after season. It draws the same inorganic ions from the soil each year, so nitrate, phosphate and potassium become exhausted and yields fall unless fertiliser is added; a single crop also supports very few species, so biodiversity is lost, and a pest of that crop can spread through the whole field, which encourages heavier pesticide use. However, it is not always harmful: monoculture allows mechanisation and produces a large amount of food per worker, and where it is combined with crop rotation between seasons, organic fertiliser and careful pest management, the nutrient and pest problems can largely be managed. The word that makes the statement too strong is always — the harm comes from monoculture practised without those measures, so I agree only in part.

The fourth mark is in the last sentence. It takes a position, it says on what grounds, and it does it by attacking the word always — which is nearly always the right move when a quotation in an exam contains an absolute. Learn to look for always, never, only and the best in a quoted statement; they are put there on purpose.

Checkpoint — reading your own answer

Three questions on self-marking.

Score: 0 / 3

Question 1

A student ends a six-mark yield question with "and so the yield will be higher". Why does that sentence earn nothing?

A It is not written in the third person

B It is the outcome the question already stated, not a reason for it

C Yield is not on the syllabus

D It should have said crop instead of yield

The question is how do you increase yield, so "yield is higher" is the given, not the answer. Every mark has to sit on the path between the strategy and that outcome. This is the single commonest wasted sentence in Topic 2 answers, and cutting it costs nothing.

Question 2

In a [4] "to what extent" question, which is the most valuable single sentence?

A A definition of the key term

B A list of three disadvantages

C A judgement that states a position and the grounds for it

D A statement that there are arguments on both sides

Definitions and disadvantages are useful but they are the easy marks; almost everyone gets them. The judgement is the mark most candidates leave behind, because "there are arguments on both sides" feels like a conclusion and is not one. State what you think and why.

Question 3

The middling fertiliser answer said "manure adds nutrients". What was the cheapest available upgrade?

A Writing more sentences about manure

B Naming the ions: nitrate, phosphate and potassium

C Explaining how manure is produced

D Comparing manure with inorganic fertiliser

Six extra words, one extra mark. The syllabus names those three ions at 2.1.2(b), which is a strong signal that the mark scheme will credit them. Wherever the syllabus gives you a specific list — the mineral particles, the ions, the three types of pesticide — use the specific words rather than the general one.

4 · The AO3 toolkit — working from a source▶

AO3 is 40 marks in every 100 on Paper 2. It is also the most trainable thing in the whole syllabus, because it is five repeatable moves rather than a body of knowledge.

Demonstration source

Table 1 — maize yield on two neighbouring farms

Farm P grows maize as a monoculture every year. Farm Q grows maize in rotation with beans. The two farms are next to each other on the same soil type.

Farm	Year 1	Year 2	Year 3	Year 4
P — maize yield / tonnes per hectare	5.2	4.8	4.3	3.9
Q — maize yield / tonnes per hectare	4.9	5.0	5.1	5.2

Table 1. Constructed for practice, not measurements from a named farm, but the size and direction of the change are typical of what continuous cereal cropping does to a soil.

Move 1 — read the axes and the units before you read the question

Ten seconds. What is being measured, in what units, over what range? Here: yield, in tonnes per hectare, over four years, on two farms. Everything you write must be in those units. An answer that says "Farm P went down by 1.3" is worth less than one that says "Farm P fell by 1.3 tonnes per hectare", and on a calculate question the missing unit can be the mark.

Move 2 — quote figures, and quote both ends

A describe-the-trend mark is nearly always split into direction plus data. So give both:

The trend sentence that always scores

"Farm P's yield fell steadily, from 5.2 tonnes per hectare in Year 1 to 3.9 tonnes per hectare in Year 4, a fall of 1.3 tonnes per hectare. Farm Q's yield rose slightly over the same period, from 4.9 to 5.2 tonnes per hectare."

Direction, start value, end value, units, and the change. Four things, one sentence, and it fits almost any dataset you will be given.

Notice the crossover too, because examiners like it: in Year 1 Farm P was 0.3 tonnes per hectare above Farm Q; by Year 4 it was 1.3 tonnes per hectare below.

Move 3 — say what the data does not show

This is the AO3 move most students never make, and it is often worth a mark on its own. There are only about six limitations and they recur:

Limitation	How it sounds in Table 1
Short time period	Only four years; a longer record might show Farm Q falling too.
Small sample	Only two farms, so this may not be true of farms in general.
No control over other variables	Nothing is given about rainfall, fertiliser use or pest attack in those years, any of which could explain the fall.
Correlation is not cause	The table shows that the monoculture farm declined; it does not prove the monoculture caused the decline.
Limited range	Nothing is shown for a farm using rotation and fertiliser, so we cannot compare.
Missing dimensions	No cost, labour or profit data, so we cannot say which farm is better off.

Use it, but do not use it instead of the data

"The data does not show…" is a mark. It is not four marks. Answer the question from the figures first, then add the limitation. A whole answer made of caveats scores about as badly as a whole answer with no figures in it.

Move 4 — weigh both sides

Every evaluate question has a losing side that is still worth writing. Rotation on Farm Q holds yield up, however it means only part of the land grows the cash crop each season, and beans may sell for less than maize. Write the "however". It is often the difference between a level 2 and a level 3 on a longer answer.

Move 5 — land a judgement, and say on what grounds

Not "both have advantages". Something like: "On this evidence rotation is the better strategy for a farmer who intends to keep the land productive for many years, because Farm Q's yield was still rising in Year 4 while Farm P's had fallen by 1.3 tonnes per hectare — though four years is a short record on which to decide." Position, grounds, figure, and an honest limit. That is a full-mark evaluation in three lines.

Checkpoint — the AO3 moves

Four questions on working from a source.

Score: 0 / 4

Question 1

Which sentence would score best as a "describe the trend" answer for Farm P in Table 1?

A The yield goes down.

B The yield falls steadily, from 5.2 tonnes per hectare in Year 1 to 3.9 tonnes per hectare in Year 4, a fall of 1.3 tonnes per hectare.

C The yield falls because the soil is exhausted of nutrients.

D Farm P is doing worse than Farm Q.

B gives direction, both end values, the units and the change. A has the direction and nothing else. C is an explanation, and a reason offered in a describe question is not credited — it also wastes the time you needed for the figures. D is a comparison rather than a trend, and it has no numbers in it.

Question 2

Table 1 shows Farm P declining and Farm Q holding steady. Which statement is the most honest reading?

A It proves that monoculture reduces yield

B It shows that the monoculture farm's yield fell over these four years, but with only two farms and no data on rainfall or fertiliser it does not prove monoculture was the cause

C It shows nothing useful because there are only two farms

D It proves that crop rotation is always better than monoculture

B is the AO3 answer: use the data, then bound it. A and D overclaim from two farms and four years, and overclaiming is penalised in evaluation. C throws the data away, which is the opposite error — the pattern is real and describing it is worth marks, it just cannot carry the weight of the word proves.

Question 3

A question says Calculate the fall in Farm P's yield between Year 1 and Year 4. [2] What earns the two marks?

A The number 1.3 on its own

B Any number as long as it is written neatly

C 5.2 − 3.9 shown as working, then 1.3 tonnes per hectare with its unit

D An explanation of why the yield fell

A two-mark calculation is nearly always one mark for the method and one for the answer with its unit. Showing 5.2 − 3.9 means that if you slip in the arithmetic you still keep the method mark. A bare correct number normally gets both, but a bare wrong number gets nothing at all — so the working costs three seconds and insures the mark.

Question 4

Which of these is a real judgement, of the kind an evaluate question pays for?

A There are advantages and disadvantages to both farms.

B Farm Q is better.

C It depends on many different factors.

D On this evidence rotation is the better strategy for a farmer who wants to keep the land productive long term, because Farm Q's yield was still rising in Year 4 while Farm P's had fallen by 1.3 tonnes per hectare, though four years is a short record.

D takes a position, attaches grounds, quotes a figure and admits a limit. A and C are ways of not deciding. B decides but gives no reason, so it is an assertion rather than an evaluation — it would pick up little more than the position itself.

5 · The seven Topic 2 traps▶

These are the six confusions that cost Topic 2 marks most reliably. Each one is a pair of words that sound similar and are not.

Trap 1 — "intensive" and "monoculture" are descriptions, not verdicts

2.2.1 lists arable, pastoral, mixed, subsistence, commercial, intensive and monoculture as types of agriculture. They describe how a farm operates — intensive means high inputs of labour, machinery, fertiliser or pesticide per unit of land, and monoculture means one crop over a large area — and nothing more.

If a question says Describe what is meant by intensive agriculture, an answer that says "it is bad for the environment because it uses too many chemicals" has answered a different question and may score nothing. The environmental harm belongs to 2.2.4, and even there it comes from overuse and mismanagement, not from intensity as such. Intensive farming feeds a great many people from a small area, which is the reason it exists.

Trap 2 — intercropping, mixed cropping and crop rotation are three different things

Term	What it means	The distinguishing feature
Mixed cropping	Two or more crops grown in the same field at the same time.	Same field, same time, no particular arrangement.
Intercropping	Two or more crops grown in the same field at the same time, in a deliberate pattern — typically alternating rows.	Same field, same time, but arranged: rows of one crop between rows of another.
Crop rotation	Different crops grown in the same field in successive seasons, in a planned order.	Different times, one crop at a time.

The give-away word is when. Mixed cropping and intercropping happen together; rotation happens one after another. A very common lost mark is describing rotation and calling it intercropping.

Trap 3 — bunds do two jobs, wind breaks do one

Straight from 2.3.3: bunds reduce surface run-off and reduce wind speed and wind erosion. Wind breaks protect crops and reduce wind speed and wind erosion — wind only. So on a "describe and explain how bunds reduce soil erosion [4]", a water-only answer is capped. On a wind-break question, do not invent a run-off mechanism: a line of trees along the field edge does not stop water crossing the field.

Trap 4 — salinisation is not water logging

	Salinisation	Water logging
What builds up	Salts at or near the soil surface	Water filling the pore spaces
How it happens	Irrigation water contains dissolved salts. In a hot climate the water evaporates from the surface and the salts are left behind, so they accumulate season after season.	Too much water is applied, or drainage is poor, so water fills the pore spaces and does not drain away.
Why the crop suffers	The soil water becomes salty, so roots cannot absorb water properly and many crops will not grow.	The pore spaces hold water instead of air, so roots cannot get the oxygen they need for respiration.

Both sit under 2.2.4(c), mismanagement of irrigation, and both can happen on the same field — but the mechanisms are different and the mark schemes keep them apart. The one-word test: salt or air?

Trap 5 — pest resurgence is not pesticide resistance

	Pesticide resistance	Pest resurgence
What changes	The pest population changes: individuals that happen to survive the pesticide breed, so over generations a larger share of the population is unaffected by it.	The pest comes back in greater numbers after spraying, because the pesticide also killed the predators and parasites that were controlling it.
The give-away	The same dose stops working.	Numbers crash, then rebound higher than before.

Both are on 2.2.4(d) and both follow from overuse of pesticides, so a question can ask for either. If your answer mentions natural predators, you are describing resurgence; if it mentions survival and breeding of the unaffected individuals, you are describing resistance.

Trap 6 — leaching, nutrient enrichment and eutrophication are a chain, not three names for one thing

2.2.4(e) lists them in order, and that order is the mark scheme: fertiliser is applied in excess → rain dissolves the surplus ions and they are leached through the soil into a river or lake → the water is now nutrient enriched → algae grow rapidly and cover the surface → light is blocked so plants below die → bacteria decompose the dead material and use up the dissolved oxygen → fish and other organisms die. That whole sequence is eutrophication. Writing the three words as a list scores once; writing the chain scores several times.

Trap 7 — soil erosion is a process, desertification is one of its impacts

2.3.1 is the causes of erosion, 2.3.2 is the impacts. Desertification, silting of rivers, mass movement, loss of habitat, reduced yield, malnutrition and famine, and displacement of people all sit in 2.3.2 — they are what erosion leads to. Overcultivation, overgrazing and deforestation sit in 2.3.1, under removal of natural vegetation: they are what leads to erosion. Putting an impact in a causes question is a straightforward zero for that point, however well written it is.

Checkpoint — the traps

Seven questions, one per trap.

Score: 0 / 7

Question 1

A question asks: Describe what is meant by intensive agriculture. [2] Which answer scores both marks?

A It is farming that damages the environment by using too many chemicals

B It is farming with high inputs of labour, machinery, fertiliser or pesticide per unit area of land, giving a high output from a small area

C It is farming where one crop is grown over a large area

D It is farming that is not sustainable in the long term

Intensive describes the level of inputs and outputs per unit of land. A and D are judgements about it, and the question asked what it means. C describes monoculture, which is a different item on the same list — a farm can be intensive without being a monoculture, and vice versa.

Question 2

A farmer plants alternating rows of maize and beans in the same field in the same season. What is this?

A Crop rotation

B Intercropping

C Monoculture

D Agroforestry

Same field, same time, arranged in a pattern — that is intercropping. Crop rotation would be maize this season and beans next season in the same field. Monoculture is one crop only. Agroforestry means growing trees among the crops or livestock, which is a different strategy again.

Question 3

Which strategy is credited on the syllabus for reducing both surface run-off and wind erosion?

A Wind breaks

B Contour ploughing

C Bunds

D Terracing

2.3.3(c) gives bunds all three effects: reduces surface run-off, reduces wind speed, reduces wind erosion. Wind breaks (d) are credited for protecting crops and for wind only. Contour ploughing (b) is run-off only. Terracing (a) is run-off and movement of soil down the slope.

Question 4

Irrigation water evaporates from a hot field and salts are left behind at the surface, season after season. What is this called, and why does the crop suffer?

A Water logging — the roots cannot get oxygen

B Leaching — the nutrients are washed away

C Salinisation — the soil water becomes salty so roots cannot absorb water properly

D Desertification — the soil turns to sand

Salt building up at the surface is salinisation. Water logging is the other irrigation fault: too much water fills the pore spaces so there is no air and roots cannot respire. The one-word test is salt or air. Leaching is nutrients being washed downwards, which is a fertiliser problem rather than an irrigation-salt problem.

Question 5

After repeated spraying, the same dose of insecticide no longer kills the insect. What is this?

A Pest resurgence

B Pesticide resistance

C Eutrophication

D Biological control

The pest population has changed — the individuals that survived have bred and now make up most of the population, so the same dose is ineffective. That is resistance. Resurgence is different: the numbers rebound to above their original level after spraying, because the pesticide also killed the natural predators that were keeping the pest in check.

Question 6

Put these in the order the mark scheme wants them: (1) algae grow rapidly over the surface; (2) surplus ions are leached into the river; (3) bacteria decompose dead material and use up dissolved oxygen; (4) light is blocked so plants below die.

A 1, 2, 4, 3

B 2, 1, 4, 3

C 2, 4, 1, 3

D 3, 2, 1, 4

Leaching first, then nutrient enrichment causes the algal growth, then the algae block the light so the plants below die, then decomposition of all that dead material removes the dissolved oxygen and fish die. Each arrow is a mark, which is why writing the chain is worth so much more than naming eutrophication.

Question 7

Which of these belongs in a question about the impacts of soil erosion rather than its causes?

A Farming on steep slopes

B Deforestation

C Leaving soil bare between crops

D Silting of rivers

Silting of rivers is 2.3.2(a), an impact: the eroded soil ends up in the watercourse. The other three are all 2.3.1 causes. Sorting the syllabus list into causes and impacts before the exam is ten minutes that reliably pays — an impact written in a causes question earns nothing however good the sentence is.

6 · Two source-led practice sets▶

Two complete source-led sets, of the kind Paper 2 is made of. Work each one on paper before you open the model answers — reading a model you have not attempted teaches almost nothing.

Practice set 1 · 12 marks · AO3

Figure 1 — slope angle, ground cover and soil loss

Plots of the same soil type were laid out on four slope angles. On half of them the soil was left bare between crops; on the other half a cover of vegetation was maintained. Soil washed off each plot was collected and weighed over one wet season.

Figure 1. Constructed for practice, not measurements from a named field station. Read the key: the two bars at each slope angle are the two treatments, and the vertical axis is soil loss in tonnes per hectare over one wet season.

(a)[1]

State the soil loss from bare soil on the 20° slope.

(b)[3]

Describe how slope angle affects soil loss from bare soil. Use figures from Figure 1.

(c)[2]

Calculate the soil loss from the vegetated plot on the 20° slope as a percentage of the soil loss from the bare plot on the same slope. Show your working.

(d)[3]

Explain how maintaining vegetation cover reduces soil loss.

(e)[3]

A farmer says Figure 1 proves that vegetation cover will solve soil erosion on his land. Using Figure 1, evaluate that claim.

Model answers — set 1Figure 1 — the full mark scheme

(a) [1]

55 tonnes per hectare. The unit is part of the answer.

(b) [3]

Soil loss increases as slope angle increases (1). It rises from 6 tonnes per hectare at 5° to 55 tonnes per hectare at 20°, an increase of 49 tonnes per hectare (1). The increase is not steady — the steps are 12, 16 and 21 tonnes per hectare, so soil loss rises more and more steeply as the slope gets steeper (1).

Working: 10 ÷ 55 × 100 (1 — method). Answer: 18.2% (accept 18%) (1). In words, the vegetated plot lost under a fifth of what the bare plot lost.

(d) [3]

The roots of the plants bind the soil particles together, so the soil is held in place and is harder for water to carry away (1). The leaves intercept the rain, so drops do not strike bare soil directly and fewer particles are dislodged (1). The plants also absorb water and slow its movement across the surface, so surface run-off is reduced and less soil is washed downhill (1).

(e) [3]

Supporting the claim: at every slope angle the vegetated plot lost far less soil — at 20° the loss fell from 55 to 10 tonnes per hectare, a reduction of 45 (1). Against it: the vegetated plots still lost soil, and the loss still rose with slope angle — 10 tonnes per hectare at 20° against 1 at 5° — so cover reduces erosion rather than solving it (1). Limits of the data: one wet season on one soil type, nothing above 20°, and no information on rainfall intensity, on the yield the farmer would get or on what the cover costs him (1). A judgement such as "cover is clearly worth maintaining, but on the steepest land he would need terracing or bunds as well" is credited.

The three habits on show: figures with units, the chain in (d), and in (e) both sides plus what the data cannot tell you.

Practice set 2 · 10 marks · AO3

Table 2 — nitrogen fertiliser, yield and the stream below the field

A farmer applied different rates of inorganic nitrogen fertiliser to strips of the same field. He recorded the wheat yield from each strip, and the concentration of nitrate in the stream draining that strip.

Nitrogen applied / kg per hectare	Wheat yield / tonnes per hectare	Nitrate in the stream / mg per dm³
0	2.1	2
60	4.0	4
120	5.4	7
180	5.9	14
240	5.8	26

Table 2. Constructed for practice. The shape of the yield response — large gains at first, then smaller ones, then none — is the shape real fertiliser trials produce.

(a)[1]

State the wheat yield when 120 kg per hectare of nitrogen was applied.

(b)[3]

Describe the relationship between the nitrogen applied and the wheat yield. Use figures.

(c)[2]

Calculate the increase in stream nitrate between the 120 and the 240 kg per hectare strips, and state the unit.

(d)[4]

Using Table 2, recommend a rate of nitrogen for this farmer and justify your choice. Refer to both columns of data and to the effect of the nitrate on the stream.

Model answers — set 2Table 2 — the full mark scheme

(a) [1]

5.4 tonnes per hectare.

(b) [3]

Yield increases as nitrogen applied increases, from 2.1 to 5.9 tonnes per hectare between 0 and 180 kg per hectare (1). The increase gets smaller each time: +1.9, then +1.4, then +0.5 tonnes per hectare for each extra 60 kg of nitrogen (1). Beyond 180 kg per hectare the yield stops rising and falls slightly, from 5.9 to 5.8 tonnes per hectare (1).

Working: 26 − 7 (1). Answer: 19 mg per dm³ (1). The unit is worth a mark on its own here, and it is the mark most often dropped.

(d) [4]

A rate of 120 kg per hectare is a defensible recommendation (1 — a clear choice). It gives 5.4 tonnes per hectare, which is only 0.5 tonnes per hectare below the highest yield in the table, so almost no crop is given up (1). Going on to 180 or 240 kg per hectare buys at most 0.5 tonnes per hectare more but takes stream nitrate from 7 to 26 mg per dm³, an increase of 19 (1). That surplus nitrate is leached into the stream and enriches it with nutrients, so algae grow rapidly, block the light, and the plants below die; bacteria then decompose them and use up the dissolved oxygen, so fish and other organisms die — eutrophication (1). 180 kg per hectare is also creditable if the candidate argues for maximum yield and acknowledges the nitrate cost.

What the table does not show

Nothing about the cost of the fertiliser, the weather in that season, the soil at the start, or what happens over several years. One season on one field. Saying so is creditable in the evaluation.

A recommendation question wants a number, evidence from both columns, and the mechanism behind the harm — not just "too much fertiliser is bad".

Checkpoint — the practice sets

Two questions on what the sources do and do not say.

Score: 0 / 2

Question 1

In Figure 1, soil loss from bare soil rises from 6 to 55 tonnes per hectare between 5° and 20°. Which statement is fully supported by the figure?

A Doubling the slope angle doubles the soil loss

B Soil loss rises with slope angle, and rises more steeply at the steeper angles

C Vegetation cover stops soil loss completely

D Soil loss would be zero on flat ground

The steps are 12, 16 and 21 tonnes per hectare for each 5°, so the rise is accelerating — that is B. A is wrong: from 5° to 10° the loss goes 6 to 18, which is three times, not double. C is contradicted by the vegetated bars, which are 1, 3, 6 and 10, all above zero. D is off the end of the data — nothing below 5° was measured, and reading beyond the range of a dataset is exactly what an evaluation question wants you to avoid.

Question 2

In Table 2, why is going from 120 to 240 kg per hectare of nitrogen a poor decision on this evidence?

A Because fertiliser is always harmful

B Because the yield falls to zero

C Because yield rises by at most 0.5 tonnes per hectare and then falls back to 5.8, while stream nitrate rises from 7 to 26 mg per dm³

D Because nitrogen is not needed by wheat

C is the answer built out of both columns: a very small yield gain that then reverses, bought with a large rise in nitrate reaching the stream. A is a slogan, not an argument from the data, and it is also untrue — the first 60 kg per hectare added 1.9 tonnes per hectare of wheat. B misreads the table: the yield at 240 kg per hectare is 5.8, not zero. D is wrong: nitrate ions are needed to make proteins and chlorophyll.