CIE iGCSE Biology-20.1 Food supply- Study Notes- New Syllabus
CIE iGCSE Biology-20.1 Food supply- Study Notes – New syllabus
CIE iGCSE Biology-20.1 Food supply- Study Notes -CIE iGCSE Biology – per latest Syllabus.
Key Concepts:
Core
- Describe how humans have increased food production, limited to:
(a) agricultural machinery to use larger areas of land and improve efficiency
(b) chemical fertilisers to improve yields
(c) insecticides to improve quality and yield
(d) herbicides to reduce competition with weeds
(e) selective breeding to improve production by crop plants and livestock - Describe the advantages and disadvantages of large-scale monocultures of crop plants
- Describe the advantages and disadvantages of intensive livestock production
How Humans Have Increased Food Production
Humans have developed modern agricultural techniques to boost the quantity and quality of food. These innovations help feed a growing global population by enhancing crop and livestock productivity.
1. Use of Agricultural Machinery
✅ What it does: Machines like tractors, seed drills, and harvesters allow:
- Cultivation of larger land areas
- Faster and more efficient farming
- Reduced need for human labour
📌 Result: Greater productivity and quicker food production.
2. Use of Chemical Fertilisers
✅ What it does: Fertilisers add essential minerals to soil:
- Nitrates – promote leaf growth
- Phosphates – support root development
- Potassium – helps flower and fruit formation
📌 Result: Faster plant growth and higher crop yields.
3. Use of Insecticides
✅ What it does: Insecticides kill pests that:
- Damage crops by eating leaves, stems, or roots
- Spread plant diseases
📌 Result: Less crop damage → better quality and more produce.
4. Use of Herbicides
✅ What it does: Herbicides kill weeds that:
- Compete for sunlight, nutrients, and water
📌 Result: Crops have better access to resources → improved yield.
5. Selective Breeding
✅ What it does: Farmers breed organisms with desirable traits such as:
- Disease resistance
- Faster growth rate
- Increased meat, milk, or fruit production
📌 Result: Over generations, this leads to higher-quality and more productive crops and animals.
🧠 Final Summary Table:
| Method | Purpose | Effect on Food Production |
|---|---|---|
| Agricultural machinery | Efficient large-scale cultivation | Faster, large-area farming |
| Chemical fertilisers | Add nutrients to soil | Higher crop yields |
| Insecticides | Protect crops from pests | Better crop quality and quantity |
| Herbicides | Eliminate weed competition | Improved crop growth |
| Selective breeding | Enhance useful traits | Better yield and efficiency |
Large-Scale Monocultures – Pros and Cons
What is a Monoculture?
A monoculture is the farming practice of growing only one type of crop (such as wheat, maize, or rice) across a large area. It is widely used in commercial agriculture to produce food efficiently and at scale.
🌟 Advantages of Monocultures
| Advantage | Explanation |
|---|---|
| Easier to manage | Uniform crop needs uniform care – simpler irrigation, fertilisation, and pest control. |
| Efficient harvesting | Machinery is more effective when the same crop is grown over large areas. |
| Higher yields | Well-managed monocultures can produce large amounts of food. |
| Specialised expertise | Farmers gain deep knowledge of the crop, improving efficiency and techniques. |
| Supports large populations | Helps meet food demands in densely populated areas. |
⚠️ Disadvantages of Monocultures
| Disadvantage | Explanation |
|---|---|
| Loss of biodiversity | Only one species is grown — fewer habitats for insects, birds, and other organisms. |
| Increased pest and disease risk | Diseases and pests spread rapidly through genetically identical crops. |
| Heavy use of chemicals | Fertilisers and pesticides are often needed to maintain productivity. |
| Soil degradation | Repeated planting of one crop can exhaust soil nutrients. |
| Long-term unsustainability | Harmful to ecosystems and soil health over time if not managed sustainably. |
🧠 Final Thought:
Monocultures offer short-term efficiency, but can cause environmental harm if overused. Many modern farms now use methods like crop rotation or intercropping to balance productivity with sustainability.
Intensive Livestock Production – Pros and Cons
What Is Intensive Livestock Production?
This method involves raising large numbers of animals (such as cows, pigs, and chickens) in confined indoor spaces with controlled feeding, breeding, and environmental conditions. The goal is to maximise meat, milk, or egg production efficiently.
🌟 Advantages of Intensive Livestock Production
| Advantage | Explanation |
|---|---|
| Higher productivity | More meat, milk, or eggs produced in a shorter time and smaller space. |
| Efficient land use | Requires less land than traditional grazing methods. |
| Controlled environment | Feeding, temperature, and lighting are optimised for growth. |
| Lower costs per unit | Bulk production often lowers food prices for consumers. |
| Year-round production | Animals can be raised regardless of external weather or seasons. |
⚠️ Disadvantages of Intensive Livestock Production
| Disadvantage | Explanation |
|---|---|
| Animal welfare concerns | Animals may be kept in cramped, unnatural conditions with limited space or movement. |
| Disease spreads quickly | Close quarters allow disease to spread easily, often requiring heavy antibiotic use. |
| Environmental pollution | Large amounts of manure and waste can pollute soil, water, and air. |
| Overuse of antibiotics | Can lead to antibiotic-resistant bacteria that threaten human health. |
| Ethical concerns | Many people oppose treating animals as production units rather than living beings. |
🧠 Final Thought:
Intensive livestock farming boosts food supply and can reduce costs, but it also brings challenges related to animal welfare, public health, and environmental sustainability. Balancing efficiency with ethics and ecology is key for future farming systems.