Ecology

Agro-ecology

Agro-ecology treats the farm as an ecosystem: crops, animals, soil, water and people in one system, not a factory with no surroundings.

CAPS

Grade 10 · Agricultural Sciences · Ecology

Agricultural Sciences splits animals from plants, soil and management.

The papers
Paper 1 is animal nutrition, animal production, reproduction and protection. Paper 2 is soil science, plant studies, and agricultural management. Each paper is 150 marks.
How to write it
Use the farming term, then the reason: a deficient mineral, a symptom, a management practice, and why it changes the yield or the health of the animal. A list with no cause does not explain.
How a marker reads it
A common mix-up is to treat sustainability as a slogan and still plough one crop, straight down the slope, forever.

Data-response questions want you to read the table first. A general paragraph about farming that ignores the numbers scores as if you did not see them.

Diagram

Worked theory

Worked theory. Two plots, same rainfall. One is maize every year, bare between rows, kraal uphill of the drinking well. Soil leaves in the storms, the well receives the manure, and the pests that like maize never go hungry. The other plot rotates maize with a legume, keeps a grass strip on the contour, and puts the kraal below and away from the well. Yield holds for longer because the soil and the water stay. The difference is the arrangement, not a more expensive seed.

More worked examples

Two plots after three seasons
Plot A grows maize, maize, maize, ploughed downhill, kraal above the well. By season three the topsoil is paler and the well tests dirty after rain. Plot B grows maize, then beans, then maize, with a grass strip on the contour and the kraal downhill of the well. The bean year puts nitrogen back. The strip stops the soil. Yield on B holds. Yield on A falls. The seed was the same variety.
Beans and the nodules
A bean plant has nodules on its roots. Bacteria in the nodules take nitrogen from the air and turn it into a form the plant can use. When the roots rot, that nitrogen is in the soil for the next crop. Maize cannot make those nodules. A field that grows maize after maize mines the nitrogen. A field that puts beans in the rotation puts some back. The nodules are the reason, not a slogan about “resting the land”.

In ordinary words

A sustainable layout puts the homestead and the stores on ground that will not flood, keeps animals out of the cropped land, runs water where it will not gully, and leaves strips of natural veld so pollinators and predators of pests stay. Monoculture is simple and fragile. A mix of plants and a rotation breaks pest cycles and rests the soil. The farm’s waste, such as manure, is an input, not rubbish.

In South Africa

A homestead, a kraal, a contour strip and a well are the plan you can draw for a real small farm.

Part 1 / 4

What it is

Agro-ecology treats the farm as an ecosystem: crops, animals, soil, water and people in one system, not a factory with no surroundings.

More worked examples

Board walkthroughs on this topic. Open one, copy the working, then try the next.

Example 1 / 20

A farm has 2 000 ha of veld with a carrying capacity of 5 ha per large stock unit (LSU). How many cattle (1 LSU each) can it carry?

How we got there

Read this like a teacher at the board. We go slowly, name every number, and say why we take each step.

Explain in another language · 11

1. What is the question asking?

Read the question twice. Circle the unknown. Underline every number and unit. The paper is asking: A farm has 2 000 ha of veld with a carrying capacity of 5 ha per large stock unit (LSU). How many cattle (1 LSU each) can it carry?

In other words — as if you have never seen this before

If you have never seen this before: Number of LSU = areahectares per LSU. We will name a method in words, write the formula with no numbers, then substitute one line at a time.

2. What do we already know?

2 000 ha; 5 haLSU.

3. Which method — and why this one?

Number of LSU = areahectares per LSU.

4. Step-by-step working

01 / 07
Step A — Read the question twice
Slow down. Circle the word that names the unknown. Underline every number and its unit. Do not grab a formula yet — first decide what the paper is actually asking.
Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.
02 / 07
Step B — Write the given in a column
2 000 ha; 5 haLSU.
Why this step: A column with units stops you mixing cm with m, or minutes with seconds. Markers can also see you started correctly.
03 / 07
Step C — Name the method in words
Number of LSU = areahectares per LSU.
Why this step: If you can say the method in a sentence, you will pick the right formula. First-timers skip this and grab the first equation they remember.
04 / 07
Divide
2 0005=400 LSU.
Why this step: We only do one job per line so a marker can follow the marks — and so you can find a slip without starting over.
05 / 07
Step G — Sense-check the size
Ask: is this the kind of number a Grade 10–12 paper would want? A speed of 3 000 ms for a learner walking, or a probability bigger than 1, means a unit or algebra slip. Estimate first: round the numbers and do the sum in your head.
Why this step: Markers write ‘unrealistic’ in the margin when the method is right but the size is wild. A 10-second head check often finds a missing 10² or a unit that never changed.
06 / 07
Step F — Box the answer with its unit
400 cattle.
Why this step: A number without a unit is half a mark on a Physics paper, and a marker can miss a Maths answer that is buried in working.
07 / 07
Step H — What the marker is looking for
On an NSC memo you usually earn: (1) a method mark for naming the right formula or idea in words, (2) an accuracy mark for substituting the given numbers with units, (3) an accuracy mark for the boxed answer with its unit. Write those three lines even if you are unsure of the arithmetic — blank pages score zero.
Why this step: First-timers chase the final number and leave the method blank. The memo still pays out for the idea and the substitution even when the last line is wrong.

5. The answer

400 cattle.

Copy onto your answer sheet — in this order

Answer: 400 cattle.

6. Check it like a marker

Overstocking leads to veld degradation and erosion.

7. A trap first-timers fall into

First-timers often grab the first formula they remember, mix units (cm with m, minutes with seconds), or drop a minus sign. Write the formula in words first: “this equals that, because…”

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