# SAVING THE SOIL: answers and explanations

Cambridge IELTS 13, Test 4, Reading Passage 2

Source: Passage, questions and answer key from Cambridge IELTS 13, Test 4, Reading Passage 2. © Cambridge University Press & Assessment. Used for educational practice. Explanations and evidence notes are written by Testmigo.

## Answer key

| Q | Answer | Proof |
| --- | --- | --- |
| 14 | minerals | living amid decomposing plants and various minerals. |
| 15 | carbon | they lock in their carbon content, holding three times the amount of carbon as does the entire atmosphere. |
| 16 | water | Soils also store water, preventing flood damage |
| 17 | agriculture | Agriculture is by far the biggest problem. |
| 18 | C | Humans tend not to return unused parts of harvested crops directly to the soil to enrich it |
| 19 | E | Chemical fertilisers can release polluting nitrous oxide into the atmosphere and excess is often washed away with the rain, releasing nitrogen into rivers. |
| 20 | A | a good crop of plants emerged that were not just healthy at the surface, but had roots strong enough to pierce dirt as hard as rock. |
| 21 | D | Like the idea of carbon neutrality, it is an easily understood target that can help shape expectations and encourage action. |
| 22 | E | He came to realise that the best way to ensure his trees flourished was to take care of the soil |
| 23 | C | In the wild, when plants grow they remove nutrients from the soil, but then when the plants die and decay these nutrients are returned directly to the soil. |
| 24 | F | field surveys, drone surveys, satellite imagery, lab analyses |
| 25 | G | Several researchers are agitating for the immediate creation of protected zones for endangered soils. |
| 26 | F | For one thing, there is no agreed international system for classifying soil. |

## Why these answers are right

**14. minerals.** The summary lists what healthy soil contains besides microorganisms and plant remains. Paragraph B says bacteria and other microorganisms live amid decomposing plants and various minerals, so minerals is the word, with plant remains paraphrasing decomposing plants.

**15. carbon.** The gap needs what soil stores that affects the climate. The passage calls soil an ally against climate change because microorganisms lock in the carbon content of dead plants and animals, holding three times the carbon of the atmosphere, so carbon is correct.

**16. water.** The summary says soil prevents damage to property and infrastructure because it holds something. The passage says soils also store water, preventing flood damage to buildings, roads and bridges, so water is the answer, with holds paraphrasing store.

The why and the trap for questions 17 onwards are free with an account on the [answers page](https://testmigo.com/ielts/reading/saving-the-soil/answers).

[Practice SAVING THE SOIL](https://testmigo.com/ielts/reading/saving-the-soil)