Strategies to Increase Food Production & Crop Yield (Cambridge (CIE) IGCSE Environmental Management): Revision Note

Types of cropping

• Farmers use many strategies to increase crop yield and food production

• These strategies aim to improve soil fertility, water supply, pest control, plant health and growing conditions

• Key strategies include:

  • Improved cropping systems

  • Irrigation

  • Mechanisation

  • Genetic modification

  • Controlled environments

  • Managed grazing

  • Urban farming

  • Agroforestry

  • Fertilisers

  • Pest control

Mixed cropping, intercropping and crop rotation

Mixed cropping

• Growing two or more crops together on the same land

• Reduces the risk of complete crop failure because different crops respond differently to pests or weather

Intercropping

• Growing different crops in alternating rows

• Reduces pest spread because pests may not easily move between plant types

• Makes better use of sunlight, water and nutrients

Crop rotation

• Growing different crops in a planned sequence over several seasons

• Helps prevent nutrient depletion because different crops remove different nutrients

• Reduces the build-up of pests and diseases linked to a single crop

Irrigation & crop yield

Trickle/drip irrigation

• Delivers small amounts of water directly to plant roots

• Reduces water loss through evaporation and increases irrigation efficiency

Rainwater harvesting

• Collecting and storing rainwater for later use in irrigation

• Reduces pressure on groundwater or river supplies

Automated watering systems

• Timed or sensor-controlled irrigation systems

• Can use soil moisture sensors to detect when the soil becomes too dry

• Some systems monitor temperature and humidity, adjusting watering to match plant needs

• Provide consistent and accurate watering, reducing stress on crops

• Reduce water waste by applying only the amount needed

• Lower labour requirements because watering happens automatically

Mechanisation & crop yield

• Using machinery such as tractors, ploughs and harvesters

• Speeds up planting and harvesting, increasing efficiency

• Reduces labour requirements on large farms

• Machines can work large areas quickly, helping farmers grow more food in less time

Genetic modification & crop yield

• Genetic modification involves changing the genetic material of an organism by inserting, removing or altering genes

• Creates crops with favourable characteristics, such as:

  • Resistance to pests or diseases

  • Tolerance to drought, heat or salinity

  • Higher crop yields

Controlled environments & crop yield

Greenhouses

• Enclosed structures where temperature, humidity and light can be controlled

• Protect crops from extreme weather and pests

• Allow year-round production

Hydroponics

• Growing plants in nutrient solutions instead of soil

• Gives precise control of nutrients and water

• Suitable for crops such as lettuce or tomatoes

Aeroponics

• Growing plants with roots suspended in air

• Roots are sprayed with nutrient mist, improving oxygen supply

• Uses very little water and allows fast growth

Managed grazing & livestock rotation

• Rotating livestock between fields prevents overgrazing

• Allows vegetation and soil to recover

  • This helps to maintain soil fertility

• Reduces soil erosion

• Improves long-term productivity of fields

Urban farming & crop yield

• Urban farming involves growing crops in urban areas

  • This could include use of community gardens and allotments, or even rooftops and balconies

• Makes use of unused city spaces

• Shortens the distance food travels, keeping produce fresh

• Helps supply local communities with small-scale food production

Agroforestry & crop yield

• Agroforestry involves growing trees and crops on the same land at the same time

• Trees improve soil fertility by adding organic matter

• Tree roots help prevent soil erosion

• Trees provide shade, reduce wind damage and support biodiversity that may be beneficial for crops, like insect pollinators.

Fertilisers & crop yield

Inorganic NPK fertilisers

• Inorganic fertilisers are man-made chemical fertilisers produced in factories

• They contain nutrients in a ready-to-use form, so plants can absorb them quickly

• They provide the three main nutrients needed for healthy growth:

  • Nitrogen (N)

  • Phosphorus (P)

  • Potassium (K)

• Nutrients are precisely measured, so farmers can apply the exact amount needed

• Inorganic NPK fertilisers improve crop yield by supplying nutrients rapidly during key growing stages

• They are useful when soils are nutrient-poor or when crops need a quick boost

• They replace nutrients removed during harvesting

Organic fertilisers

• Organic fertilisers include natural materials from plants or animals added to soil to improve fertility

• These fertilisers add organic matter, which improves soil structure and water retention

• They release nutrients slowly, supporting long-term plant growth

• They increase soil biodiversity, helping decomposition and nutrient cycling

Crop residue

• Crop residue—leftover plant material such as stalks, leaves and husks after harvesting

• Can be ploughed back into the soil

  • Adds organic matter that improves soil structure and water-holding capacity

• Slowly releases nutrients as it decomposes, improving soil fertility

• Helps reduce soil erosion by covering the soil surface

Manure

• Manure—animal waste (may be mixed with bedding material such as straw)

• Rich in organic matter and nutrients like nitrogen, phosphorus and potassium

  • These nutrients support healthy leaf growth, strong roots and better yields

• Improves soil structure

• Encourages soil organisms such as worms, which help mix and aerate the soil

Mulch

• Mulch—a layer of organic material spread on top of the soil (e.g. straw, wood chips, leaves)

• Helps soil retain moisture by reducing evaporation

• Reduces the growth of weeds, which compete with crops for nutrients

• Protects soil from erosion caused by wind and rain

• As mulch breaks down, it adds organic matter back into the soil

Pest control & crop yield

Chemical control of pests (pesticides)

• Insecticides kill insects

• Herbicides kill weeds

• Fungicides kill fungal diseases

• Chemicals give quick and effective pest control, improving crop yields

Biological control of pests

• Biological control involves using natural predators or parasites to control pest species

• For example: releasing ladybirds to eat aphids that damage crop leaves

  • Ladybirds feed on large numbers of aphids, reducing the pest population naturally

• Reduces the need for chemical pesticides