Unit notes and practice questions

Grade 11 Agriculture unit 10: Introduction to Natural Resources

Everything here is for unit 10 of the Grade 11 Agriculture textbook: what the chapter covers, the short notes, practice questions with their answers, and the lesson video where one exists.

2
Cards: 10
Practice questions on unit 10: 160–178
The textbook pages for unit 10

Start here

The Temari lesson on unit 10

A short video lesson on this chapter, made by Temari. It loads only when you press play.

Acid soil in the highlands, salt in the lowlands · 4 min · 2 past exam questions worked through

Parts of the lesson

Tap a part to play the lesson from there.

What unit 10 covers

1.Definition and importance of natural
2.Major types of natural resources
3.Causes and consequences of degradation

Short notes for unit 10

The cards filed under this chapter on the Grade 11 Agriculture page. Open one at a time.

Forms and Mechanisms of Soil DegradationReference tableWater erosion · Wind erosion · Soil acidification · +2

Degradation Form	Primary Cause	Common Region	Key Impact
Water erosion	High rainfall on exposed soil	Highlands	Topsoil and nutrient loss
Wind erosion	Low vegetation cover and dry soil	Lowlands	Removal of productive topsoil
Soil acidification	Leaching of basic ions ( $K^+$ , $Ca^{2+}$ , $Mg^{2+}$ , $Na^+$ )	Highlands	pH drops below 7, reduced nutrient availability
Soil salinization	Salt-rich irrigation, high evapotranspiration	Lowlands (Rift Valley)	White salt crust, plant dehydration
Physical degradation	Intensive tillage, heavy machinery, overgrazing	Cultivated lands	Soil compaction, reduced root growth and aeration

When you use it

Use when categorizing physical, chemical, and erosion-based soil degradation processes and their regional occurrences.

Watch out

Remember that water erosion and acidification dominate high-rainfall highlands, whereas wind erosion and salinization dominate dry lowlands.

Drafted from Grade 11 Agriculture, pages 163-181, then checked twice before it went up

Quantitative Benchmarks in Natural ResourcesReference tableTypical mineral soil · Ideal soil for most crops · Ethiopian soils · +2

System or Resource	Component or Property	Baseline Value
Typical mineral soil	Minerals	$45\%$
Typical mineral soil	Organic material	$5\%$
Typical mineral soil	Pore space (water and air)	$25\%$ water, $25\%$ air
Ideal soil for most crops	Soil reaction (pH)	$6.5\text{ to }7.2$
Ethiopian soils	Acid-affected soils	Approximately $40\%$
Global water distribution	Oceans and seas	Approximately $97\%$
Global water distribution	Freshwater and ice caps/glaciers	$2\%$ fresh water, $1\%$ ice/glaciers
Atmosphere composition	Nitrogen ( $N_2$ ) and Oxygen ( $O_2$ )	$78\%\text{ }N_2$ , $21\%\text{ }O_2$

When you use it

Use when recalling standard compositions of mineral soils, atmospheric gases, global water fractions, and optimal soil pH ranges.

Watch out

Pore space in a typical soil is evenly divided between water ( $25\%$ ) and air ( $25\%$ ), not minerals.

Drafted from Grade 11 Agriculture, pages 163-181, then checked twice before it went up

Practice questions on unit 10

10 multiple-choice questions written against this chapter, each with its answer and the reason. Try one before you open the answer.

Question 1

Which of the following is an example of a non-renewable natural resource?

A.Forest
B.Coal
C.Water
D.Atmospheric air

Show the answer and why

Answer: B Coal

Why

Non-renewable resources cannot regenerate themselves after being used once. Coal, oil, and minerals are non-renewable, while forests, water, and air are renewable resources.

Question 2

What percentage of a typical mineral soil is made up of mineral particles?

A.5%
B.25%
C.45%
D.70%

Show the answer and why

Answer: C 45%

Why

A typical mineral soil contains about 45% minerals, 5% organic material, 25% water, and 25% air.

Question 3

According to the textbook, what is the source of the Abbay River basin in Ethiopia?

A.Ginchi
B.Sekela, West Gojam
C.Bale mountains
D.Lasta/Gidan

Show the answer and why

Answer: B Sekela, West Gojam

Why

The Abbay River basin originates in Sekela, West Gojam, and flows west toward the Sudan border.

Question 4

A wildlife species that is at risk of total extinction throughout its habitat range is classified as:

A.Threatened
B.Endangered
C.Non-native
D.Degraded

Show the answer and why

Answer: B Endangered

Why

An endangered species is at risk of extinction or disappearance throughout its range of habitats, whereas threatened species are those that may become endangered in the near future.

Question 5

For most agricultural crops, what is the most suitable soil pH range for healthy growth?

A.4.0 to 5.0
B.5.5 to 6.0
C.6.5 to 7.2
D.8.0 to 8.5

Show the answer and why

Answer: C 6.5 to 7.2

Why

The most suitable soil pH for most crops is between 6.5 and 7.2. Values below this range indicate acidic conditions that reduce crop yield.

Question 6

Of the total water available globally, what percentage is found in oceans and seas?

A.97%
B.70%
C.25%
D.2%

Show the answer and why

Answer: A 97%

Why

Approximately 97% of the total global water is found in oceans and seas, 2% is fresh water, and 1% is frozen in ice caps and glaciers.

Question 7

While soil erosion in the Ethiopian highlands is mainly caused by water, what is the main natural force causing soil erosion in the lowlands?

A.Wind
B.Heavy rainfall
C.Leaching
D.Flooding

Show the answer and why

Answer: A Wind

Why

Soil erosion is mainly caused by water in the highlands where rainfall is high, and by wind in the lowlands where vegetation cover is low.

Question 8

According to the textbook, arid areas are defined as areas that receive an annual rainfall of:

A.Less than 25 mm
B.Less than 50 mm
C.Between 100 mm and 200 mm
D.Above 500 mm

Show the answer and why

Answer: A Less than 25 mm

Why

Arid areas receive less than 25 mm of rainfall per year, while semi-arid areas receive less than 50 mm of annual rainfall.

Question 9

Soil acidification in the highland areas of Ethiopia is mainly caused by the leaching of which basic nutrient ions?

A.Nitrogen, phosphorus, and sulfur
B.Potassium, calcium, magnesium, and sodium
C.Iron, aluminum, and zinc
D.Chlorine, copper, and boron

Show the answer and why

Answer: B Potassium, calcium, magnesium, and sodium

Why

Soil acidification develops when water washes away basic nutrient ions, specifically potassium, calcium, magnesium, and sodium, from the topsoil through leaching.

Question 10

What combined percentage of the Earth's atmosphere is made up of nitrogen gas and oxygen gas?

A.78%
B.90%
C.97%
D.99%

Show the answer and why

Answer: D 99%

Why

Nitrogen makes up 78% and oxygen makes up 21% of the atmosphere, which together account for 99% of all atmospheric gases.

The app holds 12 questions on this unit, marked as you go. These are the first 10.

The textbook pages for unit 10

Unit 10 runs from page 160 to page 178 of the Ministry of Education edition.

Ministry of Education edition, English, 270 pages

Download the PDF

All Grade 11 Agriculture short notes

Practise this unit in the app

Temari turns this chapter into timed practice and marks it as you go, with an AI tutor to explain anything that did not land.

Start free

Temari.et is also an Android app, free on Google Play.

About the Temari app