Agricultural Sciences
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Agricultural Sciences
Facilitator’s guide
Grade 10
CAPS aligned
JC Zandberg
UNIT 2: SUSTAINABLE NATURAL RESOURCE UTILISATION
Lesson 11: Agricultural resources
ACTIVITY 11: MEMORANDUM
1. Differences between natural and agricultural resources.
• Water • Soil • Vegetation Cannot be made by people. They form part of nature.
2.1 Soil:
Agriculture relies on soil to grow crops.
Farming equipment
Fuel
People
Those resources that are necessary to farm successfully. Natural as well as man-made resources.
Soil is needed for grazing plants for livestock.
Soil can be damaged by poor agricultural practices. (3)
2.2 Water:
All living things need water.
Water comes from rain, rivers and dams.
Water is scarce in South Africa. (3)
2.3
Natural vegetation:
Natural vegetation is used for grazing.
Indigenous forests are a natural resource. (2)
3.1 Fossil fuels: Natural fuels formed in the geological past. (1)
3.2 Nutrients: Substances that nourish plants and animals. (1)
3.3 Monocultures: Growing of a single plant. mono – one. (1)
4. Improve and protect soil quality,
Farm with crops that are suited to the conditions of the farm,
Let animals graze in different areas of the veld,
Reduce the use of pesticides,
Use natural fertilisers,
Use water carefully,
Avoid pollution. (any FIVE)
5. Mari-culture is the farming of marine organisms, including fish, mollusc, crustaceans and plants for commercial purposes.
Lesson 12: Soil conservation and management
ACTIVITY 12: MEMORANDUM
1. Soil is a permanent resource and cannot be replaced. It can only in a minor way be improved, but it can also easily be totally destroyed.
The management of the farm must be adapted according to the soil characteristics, to prevent the soil characteristics to degrade and so that farming can stay sustainable over a long period of time. (5)
2. Overgrazing causes vegetation to become thinner.
Ploughing up and down instead of following the slope contours.
No wetlands – wetlands slow the flow of water.
Not enough organic matter (humus) in soil.
After veld is burnt, the ground is bare. (5)
3. Control traffic – it can easily re-compact 60% to 80% of the loose cultivated land.
Rain water on the soil surface must be able to infiltrate the plow layer.
Use minimum tillage to prevent compaction,
Break up compacted soil with deep tillage. (5)
4. Soil acidification occurs when: the soil pH decreases over time. (2)
5. A drop in crop and pasture production, some nutrients are less available while other elements reach toxic levels. (3) Sample
6. Soil Pollution occurs when the soil surface or groundwater contaminated by substances that are not in their natural form it occurs.
Soil Pollution leads to the breakdown of total destruction of the ecosystem that lives on earth sustain. (6)
7. Soil can be dug up and removed.
Reduce the use of pesticides.
Grow plants that absorb heavy metals.
Re-use or recycle materials. (4)
8.1 Salination
8.2 Leaching
8.3 Water table
8.4 Hardpan
8.5 Chemical soil degradation (5) [35]
Lesson 13: Water management
ACTIVITY 13: MEMORANDUM
1. Chemical characteristics:
pH: how acidic or alkaline the water is,
The oxygen available in water for organisms,
Pollution by fertilisers,
Pesticides that wash into rivers,
Dissolved metals and salts.
biological characteristics:
Taste and colour are factors important for drinking water quality.
Some organisms can live in polluted water,
Faecal bacteria: causes cholera.
Parasitic organisms. (10)
2. Main sources: Rain and groundwater.
Rainwater is stored in rivers and dams.
Underground water is pumped to the surface.
Water is piped for irrigation. (5)
3. Sprinkler systems:
This method is virtually identical to watering the lawn with a house pipe.
Sprinkler irrigation is mostly used in regions with a moderate climate.
The amount of water used through this system is considerably less as opposed other irrigation systems. (4) Sample
4. ydroponics prevent:
Bad drainage
Bad soil structure
Weeds
Harmful organisms
5. Groundwater cannot be replaced
Droughts
Alien vegetation Global warming
6. Livestock causes water pollution by:
Trampling the riverbanks and causes water pollution
Dams are polluted by organic wastes such as manure
Farmer should rather supply a water trough.
Lesson 14: Agricultural pollution
ACTIVITY 14: MEMORANDUM
1. Health problems in humans and animals
Damage to natural ecosystems
Crop losses
Decreased food production. (4)
2. Natural waste:
Farmyard manures
Carcasses
Washes off fields (3)
Non-natural waste:
Packaging such as plastic and cardboard,
Animal health products
Waste from machinery like used oil, tyres etc.
Building waste. (any THREE) (3)
3. Soil fertility decrease.
Soil and natural nutrients are lost.
Soil yield decrease.
The balance of organism in soil decrease.
Soil structure changes.
Salinity of soil increases – soil is useless. (any FIVE) (5) Sample
4. Slurries: Slurries is a mixture of water and substance (farmyard manures) that cannot dissolve in water.
The spreading of manure and slurries can cause water- and soil pollution.
Manure on the land should be removed. (4)
5. Making use of natural fertilisers,
Making use of natural pesticides,
Applying the correct amount of fertilisers,
Ploughing back crop residues into the soil,
Recycling containers.
6. Natural wastes
Non-natural wastes
7. Crop residues should not be destroyed or removed from the field. They protect the field from erosion, add organic materials to the soil. (any TWO)
Lesson 15: Basic soil components
ACTIVITY 15: MEMORANDUM
1.2 A good source of nitrogen,
That it improves the soil’s capacity to retain water,
That is has a crumbling effect on the mineral component,
That it is the only source of energy-rich nutrients required by micro-organisms in the soil. (4)
2. Being a good source of food and medicine,
The maintaining of soil structure,
Controlling the growth of plants,
Cycling the nutrients needed by plants. (5)
3.1
Hygroscopic water: This is not available to plants or animals.
Apparent capillary water: It is available to both plants and small animals in the soil.
Real capillary water: It is usually available to plants during dry periods. Free water or seepage: This water temporarily fills the larger air spaces in the soil and drains under the influence of gravity. It is available to plant roots.
3.2
Soil texture.
Soil structure.
Humus content of the soil.
Soil depth.
4.1 A good source of nitrogen,
That it improves the soil’s capacity to retain water, That is has a crumbling effect on the mineral component, That it is the only source of energy-rich nutrients required by micro-organisms in the soil.
2.1 Mineral components: These are components derived from rocks. Over a lengthy period rocks break down into very tiny particles. (2)
2.2 Weathering: wearing away by exposure to the effects of the weather. (1)
2.3 Lava: Molten rock that flows or erupts from a volcano. (1)
2.4 Crystallise: The form of crystals. (1)
2.5 Igneous: Igneous is formed by the action of a volcano. (1)
2.6 Precipitate: To be deposited into a solid form from a solution. (1)
2.7 Primary minerals: Are formed deep in a volcano and is not altered chemically. (1)
2.8 Secondary minerals: Minerals formed through the decomposition of a primary mineral. (2) Sample
3. (10)
PRIMARY MINERALS
Present in soil as sand or silt particles.
Crystallised out from magma, deposited as igneous rock.
Formed at high temperatures and pressure.
SECONDARY MINERALS
Present in soil as clay particles.
Formed through the weathering of primary minerals or through re-precipitation.
Formed at low temperature and pressure.
Formed in the absence of free oxygen. Formed in the presence of oxygen.
4. Secondary minerals are formed when primary minerals undergo chemical weathering. The weathering products of primary minerals can also combine to form new minerals with new properties. Secondary minerals are formed at low temperature. (4)
5. Minerals have a definite chemical composition.
The colour is the visible light spectrum radiation reflected. The colour from minerals varies.
Minerals have the ability to transmit light.
ACTIVITY 17: MEMORANDUM
Minerals are tough. (any TWO) (2) [35]
1. A Rock is a hard, compact, non-living material made by different types of minerals. Rock is the basic material that all soils are made of. (4)
2. Igneous rocks form when: molten magma or lava form inside the Earth cools and solidifies or becomes hard rock The texture of these rocks is mainly determined by the speed at which cooling takes place. (6)
3. These rocks are the softest group, These rocks are easy to break, They weather quickly, They can be rough or smooth, They have different colours, They are opaque. (any FIVE) (5) Sample
Lesson 17: Rocks and their formation
4. Granite:
When quarts undergo physical weathering, soils are easy to cultivate.
Micas and veldspars are changed to clay.
Quarts changes and forms the sand fraction of soil. (4)
5. Sedimentary rocks are igneous rocks which undergo weathering and break up into smaller particles.
The weathering products (sand, clay and gravel) of igneous rocks are deposited in rivers, lakes and oceans and combine with living organisms.
Weathering and erosion processes lead to the forming of sediments.
Lesson 18: Weathering of rocks
ACTIVITY 18: MEMORANDUM
1. Physical weathering
Chemical weathering
Biological weathering (3)
2. The parts of rocks that are visible above ground heat up when the sun shine on them.
If sudden changes in temperature occur, such as rain during a thunderstorm, the outer layer of the rock cools down rapidly. The rapid cooling causes contraction of the outer layer, which causes the layer to crack. It puts the top few centimetres of rock under great stress – cracks appear, which deepen and eventually cause the outer layer of the rock to peel away. (6)
3. When water freezes it increases its volume.
Thus, it expands in size with immense power. Therefore, if water freezes in a fissure or a crack in a rock the ice will force the sides of the fissure or crack further apart. (5)
4. Hydrolysis:
It is the splitting of minerals.
UNIT 3: SOIL SCIENCE Sample
It is the atomic structure (H2O) of water where the water splits as well. For example: when we expose feldspars and glimmers to water, they split to form clay and potassium. (4) Hydration:
In hydration, water combines with compounds in rocks, which causes chemical change in a mineral’s structure. For example: Anhydrite chemically changes gypsum when water is added. (4)
5. Oxygen
The minerals that contain iron oxidise and hence become brittle. Increased temperatures and the presence of water speed up the oxidation process.
Rust is an example of an oxide. Rust forms due to the reaction of oxygen with iron to form iron oxide. Soil that contain iron oxides are red in colour. (6)
6. Soil inhabitants such as earthworms and moles make holes and tunnels in the ground and work it onto the surface.
Oxygen, carbon dioxide and water penetrate the narrow passages. This causes chemical weathering. (6)
7.1 Fissures: narrow openings made when something splits.
7.2 Unloading: release of pressure on rocks, causing them to crack.
7.3
Metabolic processes: chemical processes carried out by living things. (6) [40]
Lesson 19: Soil forming factors
ACTIVITY 19: MEMORANDUM
1. Transformations: the formation of clay and the arrangements of soil components.
Translocations: the movement of organic matter from one soil layer to another.
Losses: losses of water through transpiration or evaporation.
Additions: the adding of water, air and organic matter from the plants through processes. (12)
2. Leaching occurs when rainfall exceeds evaporation and there is a free downward movement of water through the soil. It occurs in porous, sandy soils with large airspaces.
Leaching results in the loss of nutrients from the soil. Some dissolved materials may be lost from soil. (4)
3.1
3.4
4. Displacing soil by plant roots
Digging by burrowing animals, such as ants and moles
Pushing sediments aside for example animal tracks
Eating and egesting sediment, as earthworms do. (4) [30]
Lesson 20: Classification of farm animals
ACTIVITY 20: MEMORANDUM
1. Selective breeding. Improvement with respect to production, reproduction, forage utilization, product quality, growth rate and other economical characteristics were introduced gradually. (7)
2. Leather garments made from the skin, Jackets, gloves shoes, Artists’ brushes made from the hair. (5)
3. This is the number of hectares required to maintain an animal Lesson (AU), i.e. a cow and her calf for the duration of one year. (4)
4. Their build, endurance or stamina, growth rate calving percentage. (5)
5. Indigestible food is digested with the aid of micro-organisms in the caecum and enlarged colon. (4) [25]
Lesson 21: Cattle breeds
ACTIVITY 21: MEMORANDUM
1. The Ayrshire’s coat is red and white.
As good pigmentation is important in South Africa, preference is given to Ayrshires with more red than white. This Scottish dairy breed is an excellent producer of high-quality milk and is free of any real shortcomings. Medium build, good adaptability but prefer cooler, humid climate. (6)
2. Bulls are generally much bigger and heavier than cows.
Their bone structure is heavier and muscling is more defined.
Bulls grow faster than cows.
The body conformation of a beef bull is wedge-shaped, with the breast broader than the tail.
A beef bull should have male characteristics, while the cow should appear feminine. (6)
3. Red Poll,
Simmentaler,
Pinzgauer,
Brown Swiss,
Dairy Shorthorn,
South-Devon (any FOUR)
4. The Brahman
Colour is shade from grey to red to black.
Has a hump on top of its shoulders and large, pendulous ears.
Has abundant folds of skin around the neck.
Easy calving due to calves having a low birth weight.
Mothers protect calves.
Excellent for cross-breeding.
Perform despite extreme environmental conditions. (8)
5. Beef cattle breeds are bred for meat production.
Beef breeds have a body conformation that increases good muscle distribution.
They have high fertility and produce as many calves as possible.
A high average daily gain (ADG) and a low feed conversion rate (FCR) are desirable in these breeds.
The carcass should have good meat quality and a good fat distribution. (6) [30]
Lesson 22: Sheep breeds
ACTIVITY 22: MEMORANDUM
1. Rams is bigger and heavier than a ewe.
The bone structure of the ram is heavier.
Rams grows faster than ewes.
They deposit fat at a later stage.
A ram should have male characteristics while the ewe should appear feminine.
The ram should have strong features and a muscled body.
The ewe should have softer head features. (7) Sample
2. The vegetation in this area is sparsely scattered and one can only farm with small livestock.
The wool industry is of particular importance to South Africa.
The shearing produced in Southern Africa is small compared to those of Australia; however South Africa takes the lead in the production of fine wool. (5)
3. Because both mutton and wool are produced.
The large number of dual purpose breeds found all over the world, differ with regards to the fact that some are kept for the production of lamb while others are kept for production of mutton for the market wool production plays an important role in the latter. (5)
4. Early maturity.
Early marketing of slaughter lambs.
Calm temperament.
Produce good slaughter lambs when the ram is used in cross-breed system.
Developed as a mutton-producing breed that could adapt to the cold and wet winter conditions and to produce suitable rams for cross-breeding purposes. (6)
5.1 Karakul lamb (2)
5.2 In the barren areas of North-West Cape and the Southern areas of Namibia.
Farming with Karakul sheep gave rise to a pelt industry which is normally very profitable. (4)
5.3 For its skin. (1) [30]
ACTIVITY 23: MEMORANDUM
1. Goats are well suited for the South African environment, as neither cold not heat have a negative effect on them. Goats are browsers and can also utilise food that is not assessable for grazing livestock, such as sheep or cattle. Goats are free from tuberculosis. (5)
2. A cold wet climate is detrimental especially for sheared goats.
This Angora goat mohair is preferred above other natural animal fibre due to the smooth and shiny character thereof.
This characteristic together with the natural stiffness and durability of the fibre is required for the production of certain materials such as ties, light summer suits, carpets and curtains. (7) Sample
Lesson 23: Goat breeds
3. It is a highly resilient animal and less susceptible to disease.
The animal is resistant to cold and especially heat.
They move easily over rough terrain.
They have a large body structure and a heavy carcass and tend to have little fat that is sparsely distributed- the meat is coarse although soft, juicy and tasty. (6)
4. Goat’s milk is also used for babies who are allergic to cow’s milk, as well as patients with digestive disorders.
The milk contains less lactose than cow’s milk and is less likely to trigger lactose intolerance. (4)
5. The general body conformation of milk goats enhances milk production.
They are medium framed animals with a well-developed udder.
Milk goats are seasonally bound, which means that they kid only in spring.
Milk goats are more efficient milk producers than cows, as they need less feed to produce an equal quantity of milk per body weight. (6)
6. It keeps its shape very well.
It is crease-resistant due to the stiffness of the material. (2) [30]
Lesson 24: Pig breeds
ACTIVITY 24: MEMORANDUM
1. Natural resources to a lesser extent The production of pork requires high quality nutrition in properly equipped pens. This is in contrast to ruminants that are able to survive on minor crude-fibre that is useless to man. (6)
2. Improved pig breeds - example: The Large White and the Landrace with long bodies, heavy hindquarters and high quality meat. Indigenous unimproved pig breeds - They have short bodies, light hindquarters and poor quality meat. (7)
3. Desirable traits in pig breeds are a good feed conversion ratio and fast growth.
Sample
Sows should have high fertility, as the litter size determines the number of pigs you have for slaughtering.
The carcass should have adequate length and depth, as well as a good muscle deposition in the hams, as this will determine the meat on the carcass.
A deep body is preferable to carry a large litter for the optimum feed intake and digestion.
Reproduction organs should be functional.
A good bone structure, strong legs and trotters are desirable for adequate movement. (12)
4. The large white Landras
The SA Landras
The Minnesota
The Hampshire
The Tamworth (any THREE) (3)
5. Increase in human population that resulted in an increase in demand for animal products.
Consumer demand for leaner meat. (2)
6. Pigs are easily stressed, for example if they experience high temperatures. Pigs that are stressed at the time of slaughter produce very poor quality meat. (3)
7. The waste products of industrial dairy farming – i.e. skimmed milk. (2) [35]
Lesson 25: Poultry breeds
ACTIVITY 25: MEMORANDUM
1. Chickens Turkeys
2. Housing conditions
3. Layers start laying at 18 – 20 weeks and produce one egg per day, usually up to 80 weeks.
Egg production decreases as the hens become older. (4)
4. Broiler breeds are kept for meat production.
Due to genetic selection and nutritional modifications, broilers are ready to be slaughtered in 5 – 6 weeks. They are kept in large houses, called batteries. They weigh between 1,3 and 1,8 kg at slaughter age.
Broilers have free access to food and water and can move about freely in the batteries.
Light in the battery are controlled and broilers are provided with light for 14 – 15 hours every day.
Broiler breeds are birds with good genetic potential.
A group of 1 000 – 3 000 day old chicks is put into the battery. (10)
5. Due to high production costs and low profit margin.
Other poultry breeds like ducks and geese are kept for meat and feather production.
Turkeys are kept solely for meat production. (4)
6. Poultry are kept indoors for the entire lives.
Their environment is controlled.
Everything they need is provided for them.
The system is very expensive
This system requires:
Optimum management
Record-keeping
Disease prevention
Feed conversion is very high, as movements of hens are limited. (9)
7. Dual-purpose have a balance between layer and broiler breeds.
These breeds gain enough weight to make them suitable for slaughtering, while they also have a reasonable egg-laying ability.
These breeds are ideal for free-range production as they can survive in the South African environment. (4) [40]
Lesson 26: Horse, donkey and mule breeds
ACTIVITY 26: MEMORANDUM
1. Their temperament
Sensitivity
Keen awareness
2. Cold blood horses such as draught horses are:
Heavier
Calm and steady horses
Patient temperament.
Characteristics of light horse breeds:
Medium-sized animals
Temperaments can vary from very attentive and responsive to very spirited and high strung,
They have a light frame that makes them suitable for horse riding and sports.
3. Large horse breeds
Are used for heavy tasks such as ploughing and farm work.
Traits of strength and stamina
Patience and a calm temperament
Heavy-boned animals
Tall stature and strong,
well-developed muscles.
4. They have a good adaptability.
They are more resilient than the horse - they perform better than the horse under harsh conditions.
They are less subject to digestive problems, lameness and diseases.
With respect to draughting power, the mule is much faster and stronger than the donkey and even faster than certain cart horses.
Mule mares are sterile and can’t become pregnant this is the reason why she is a much more dependable worker than the horse mare.
ACTIVITY 27: MEMORANDUM
1. Grazers
Browsers
Carnivores
2. Trophy hunting for examples elephants,
Meat hunting such as the springbok
Educational purposes
Endangered species
Tourist industry
Lesson 27: Game types
3. The elephant
The buffalo
The rhino
The lion
The leopard
The term “Big Five” does not refer to the size of the animal, but to the fact that they are the most difficult African animals to hunt and the degree of danger involved in hunting them. (8)
4. Conservation
Breeding
Ecotourism
Hunting
5. Tourists will visit game farms for bird watching in their natural habitat.
Nature photography is another growing industry. (3) [25] Sample
