Success Criteria
You must:

1. List the natural resources that influence agricultural production.

2. Explain the importance of each of the natural resources in agricultural production.

3. Identify ways in which natural resources that influence agricultural production can be depleted.

4. Define conservation of natural resources.

5. Describe ways of conserving soil, water, air, and vegetation.

6. Explain the effects of rapid population increase on natural resources and the environment.

Natural resources are materials or substances that occur naturally within the environment and are utilized by humans and animals for various purposes. These include:

1. Water

2. Air/Wind

3. Vegetation

4. Soil

5. Sunlight

6. Wildlife

7. Minerals

Water

Water is vital for agricultural production. Its main sources are:

• Rainfall

• Groundwater (springs, boreholes, wells)

• Surface water (rivers, dams, oceans)

Importance of Water:

1. Germination of seeds.

2. Dissolving and uptake of plant nutrients.

3. Cooling of plants and animals via transpiration and evaporation.

4. Soil formation through physical and chemical weathering.

5. Fishing and aquaculture.

6. Hydro-electric power generation.

7. Transportation (water transport).

Problems Associated with Water:

1. Soil erosion.

2. Transmission of diseases in plants and animals.

3. Floods caused by heavy rains.

4. Waterborne diseases (cholera, bilharzia).

5. Crop logging.

6. Hailstorms damaging crops.

7. Leaching of soil nutrients beyond the reach of plant roots.

Air/Wind

Air is a mixture of gases, including oxygen, carbon dioxide, hydrogen, and nitrogen, all essential for agricultural processes.

How Soil Air (Oxygen) is Reduced:

• Increased bacterial activity.

• Soil compaction from heavy machinery.

• Waterlogging due to poor drainage.

• High clay content.

Effects of Reduced Air in Soil:

• Slowed decomposition, affecting humus formation.

• Retarded root growth.

• Poor water and nutrient absorption.

• Increased anaerobic activity.

Improving Soil Air (Oxygen):

• Drain excess water.

• Ridging to remove water in furrows.

• Deep tillage to loosen soil.

Importance of Wind:

• Provides oxygen for respiration and germination.

• Necessary for drying crops like air-cured tobacco.

• Aids microbial activity and soil fertility.

• Helps in plant pollination and seed dispersal.

• Drives windmills.

Problems of Wind:

1. Causes lodging of plants.

2. Transmits diseases and pests.

3. Leads to soil erosion.

4. Increases evaporation and water loss.

5. Disturbs grazing animals.

6. Damages farm structures.

7. Premature fruit fall.

8. Air pollution.

Vegetation

Vegetation refers to plant life such as trees, shrubs, herbs, and grasses.

Importance of Vegetation:

• Protects soil from erosion.

• Traps runoff water, reducing soil erosion.

• Reduces climate change effects by balancing gases in the atmosphere.

• Provides fuel for cooking and tobacco curing.

• Serves medicinal purposes.

• Supplies materials for building.

• Offers shelter in extreme heat.

Soil

Soil is the loose material covering the earth’s surface, essential for plant growth.

Main Components of Soil:

1. Mineral Matter: Includes sand, silt, and clay (45% of soil volume).

2. Organic Matter (Humus): 5% of soil volume.

3. Soil Air: 25% of soil volume.

4. Soil Water: 25% of soil volume.

5. Living Organisms: Microorganisms and animals that contribute to soil structure.

Importance of Soil:

• Anchors plants.

• Provides nutrients and water to plants.

• Retains warmth for seed germination and microbial activity.

Sunlight

• Light that comes from the sun.

Light Intensity

• Measure of the strength and brightness of light reaching Earth’s surface.

Factors Determining Light Intensity

• Cloud Cover: Clear skies have higher light intensity than during dense cloud cover.

• Time of Day: Light intensity is higher at midday than in the morning or evening.

• Shading: Shade reduces light intensity.

Influence of Light Intensity on Plant Responses

• Photosynthesis: Increases with higher light intensity.

• Seed Dormancy: Some seeds need exposure to light to germinate (e.g., lettuce seeds).

• Etiolation: Stem grows long, thin, and pale due to low light intensity, causing long internodes and lower photosynthesis.

• Tillering: Growth of secondary stems at the base of the main stem; influenced by good light intensity. Reduced by close plant spacing.

• Flowering & Grain Filling: Shading affects both processes.

Ways to Improve Light Intensity for Crops

• Pruning: Ensures crops do not shade each other.

• Thinning

• Weed Control

• Use of Ultra-Heat-Sensitive Greenhouse Cover: Enhances light intensity and filters short wavelengths.

• Staking Climbing Crops: E.g., beans.

Importance of Light for Plants

• Photosynthesis: Light is used to produce glucose and release oxygen.

• Heat Energy: Used for proper crop drying.

• Pest Control: Heat can help control pests like eelworms.

Wildlife

• Describes undomesticated animals and plants.

Importance of Wildlife

• Income Source

• Foreign Exchange: Through tourism.

• Climate Change Prevention

• Ecosystem Maintenance

• Biodiversity Reserve

Minerals

• A mineral is an element or compound formed through geological processes.

Importance of Minerals

• Dietary Usage: Essential for human and plant health.

• Energy Source: Coal used on farms (e.g., curing tobacco).

• Income Source: Export of minerals.

Types of Plants Based on Light Requirements

• Long-Day Plants: Thrive in long light periods.

• Short-Day Plants: Thrive in short light periods (e.g., soya beans, tobacco, rice).

• Day-Neutral Plants: Grow irrespective of light periods.

Light Wavelength

• Long Wavelength: Visible light important for plant growth and photosynthesis.

• Short Wavelength: Harmful light like gamma rays, ultraviolet, and microwaves; prevents photosynthesis.

Ways Natural Resources Are Depleted

• Water Evaporation

• Transpiration by Plants

• Irrigation

• Domestic Use

• Mining: Depletes minerals.

Soil Erosion

• Types:

  • Splash Erosion

  • Rill Erosion

  • Sheet Erosion

  • Gully Erosion

Effects of Soil Erosion

• Loss of Nutrients: Reduces crop yields.

• Exposure of Roots: Weakens anchorage.

• Buried Crops: Leads to low productivity.

• Land Degradation: Increases production costs.

Wildlife Depletion Causes

• Deforestation

• Poaching and Hunting

• Wildfires

• Encroachment in Protected Areas

Depletion of Mineral Salts from Soil

• Plant Uptake

• Soil Erosion

• Leaching: Dissolved minerals taken deep into soil.

• Mining

Conservation of Natural Resources

• Cultural Methods:

  • Zero/No Tillage

  • Mulching

  • Correct Plant Population

  • Early Planting & Fertilizer Application

• Physical Methods:

  • Contour Ridging

  • Graded Bunds

  • Fish Ponds

  • Box Ridges

  • Storm Drains

• Biological Methods:

  • Planting Trees & Grass

  • Making Fire Breaks

Water Conservation

• Cultural Methods: Crop rotation, correct plant population, controlled grazing.

• Biological Methods: Planting vegetation to trap water.

• Physical Methods: Structures like box ridges, dams, storm drains to trap water.

Air Conservation

• Restricting CFC Use

• Conservation of Vegetation

• Avoid Bush Fires

• Reduce Emissions from Smoke-Producing Vehicles

Effects of Rapid Population Growth on Natural Resources

• Deforestation

• Pollution

• Marginal Land Cultivation

• Desertification

• Land Degradation

• Bushfires