How do Food Production & security issues impact people & the physical environment? Flashcards
Key Idea ~ imbalance in the global food system has physical & human impacts
What is SALINISATION?
- a form of land degradation in arid and semi-arid climates
- the increase in the amounts of SALTS in the soil
- Salts appear naturally in soil , streams , rivers & groundwater
Brought to the surface when :
- High rate of evaporation & transpiration
- Low precipitation
- Poor soil drainage
- This salt layer is POISNOUS to plants and can INHIBIT water absorption
Why does IRRIGATION cause salinisation?
Gravity flow methods of irrigation supply more water than crops can use , meaning :
- The excess water is evaporated in dry conditions
- CAPILLARY FORCE brings water to the surface of the soil & deposits salts
In COASTAL AREAS:
- Excessive withdrawal of underground water for irrigation
- causes the infiltration of saline water into fresh groundwater supplies
Aral Sea ~ Asia
- Rise in food security pressures = heavy reliance on lake for irrigation of crops,
- Land irrigated with water used from the lake has LOST FERTILITY due to SALT BUILD-UP.
- VOLUME of the Aral Sea has fallen by 90%
Land-management solution to salinisation
ALTERNATIVES TO OVER-IRRIGATION:
- drip feed irrigation ~ direct to root
- soil moisture monitoring
- accurate determination of water requirements
GOOD SOIL MANAGEMENT:
- maintain pH levels
- correct structure of soils
SALT-TOLERANT CROPS:
- sugar beet
- barley
MAXIMISE SOIL SURFACE COVER:
- use multiple crops with different growth habits
- maintain trees & shrubs to maintain water table
Deforestation STATISTICS & REASONS
- Each year an area the size of COSTA RICA is destroyed globally (FAO)
- 420 million acres of forest could be lost between 2010 & 2030 (WWF)
Reasons:
EXPANDING AGRICULTURE~
- Increased food demand for growing
population
- Changing diets
Biodiversity & its loss
BIODIVERSITY ~ the variability among living organisms from all sources : air, land & water.
- Loss of biodiversity owing to agriculture continues UNABATED, even in countries where nature is highly protected (FAO)
WAYS ITS REDUCED:
- Acquisition of agricultural land
- Hedgerow removal
- Overgrazing
- Drainage of wetlands
AGRICULTURAL LANDSCAPE CHANGE ~ The driving forces
FARM PRACTICES:
- Extensive deforestation
- Formation of terraces
- Large fields
- Fences, wells & hedgerows
EXTERNAL POWER PLAYERS:
- Agribusiness
- TNC’s
POLICY:
- EU common agricultural policy, e.g woodland management
- National, regional & local policies
CLIMATE CHANGE:
- Desertification
- Biofuel crops
- Increasing agricultural production
The growth of agribusiness & the industrialisation of farming in the UK has lead to changes such as:
INCREASED FIELD SIZE:
- accommodates the mechanisation of agriculture
- involves removing hedgerows & ditches
CONVERSION OF NATURAL HABITATS FOR FOOD PRODUCTION:
- Draining wetlands
- Felling small woodland
- Ploughing moorlands
MONOCULTURE:
- gives rise to less varied & diverse landscape pattern
MANAGEMENT ~ Changes in landscape in Europe
UK:
- Defra introduces Entry Level Stewardship
scheme
- Farmers receive £30 per hectare for small-scale environmental management
- E.G hedgerows, pond management
BELGIUM:
- Strict guidelines on hedgerows ~
- specific length & width
- contain native species
The IMPACT of AGRICULTURAL INPUTS on WATER QULAITY
(surface & ground water)
FERTILISERS:
Surface water~
EUTROPHICATION ~Caused by run-off nutrients, leads to taste & odour in public water supply
EXCESS ALGAE GROWTH ~ leads to deoxygenation of water & fish death
Groundwater~
LEACHING OF NITRATE ~ excess levels are a threat to public health
MANURE SPREADING:
Surface Water~
EUTROPHICATION ~ caused by high levels of contamination from pathogens, phosphorus & metals
Ground water~
NITROGEN ~ soluble compound in soil that leaches into deep aquifers by percolation
PESTICIDES:
Surface water~
CONTAMINATION ~ of fish which is ingested by humans leading to health risks
CARRIED AS DUST ~ ravels large distances contaminating many aquatic systems
Groundwater~
LEACHING ~ into wells causing human health problems
THE NUTRITION SPECTRUM ~ extremes of high & low consumption
HIGH CONSUMPTION:
- Examples ~ North America, Europe,
Australia & New Zealand
- Sedentary (inactive) lifestyle
LOW CONSUMPTION:
- Examples ~ Africa, Central & Southern
Asia
- Inadequate energy for normal activity
- Nutrient deficiencies
GLOBESITY
GLOBESITY ~ obesity and overweight are no longer confined to developed nations.
- The number of overweight people EXCEEDS underweight
Developing nation with high levels of obesity:
- Columbia ~ 41%
- Brazil ~ 36%
- Zimbabwe ~ 23%
Obesity ~ CAUSES
- Energy imbalance between calories consumed & calories expended
- GLOBAL increase in consumption of foods high in FAT & SUGARS but low in vitamins and minerals
- POVERTY in AC’s ~ dependence on fast-food, ready meals , takeaway foods.
Obesity ~ HEALTH CONSEQUENCES
A risk of NON-COMMUNICABLE diseases:
- cardiovascular disease
- diabetes
- musculoskeletal disorders
- cancer
In CHILDREN:
- breathing difficulties
- hypertension
- increased risk of fractures
- psychological effects
Double Burden of food distribution
ONE END OF SPECTRUM ~ OBESITY:
- Rapidly urbanisation ~ sedentary lifestyles, changing diets
- Sugar and fat content increases
- Increasing costs of treating illnesses
OTHER END OF SPECTRUM ~ UNDERWEIGHT:
- Developing nations ~ struggling to feed their people
- UNDERNUTRITION & OBESITY are often found existing in the same country , region or community
Harmful impacts on human health due to the increased use of chemicals & pesticides
- Increased over the last 50 years due to:
- The Green Revolution
- Increase crop yields due to increased
demand - Controls disease
- Enhances soil nutrients
GREATEST USERS:
- Columbia
- Japan
- Chile
- Impacts have led to a range of HEALTH SCARES, becoming more frequent inn the media
- USA is the second highest source of contamination due to unauthorised ingredients in soft drinks & body building products
Examples of HEALTH SCARES in the media due to agrochemicals
USA ~ February 2020
- Recall of peanut butter contaminated with listeria
UK ~ November 2019
- Nearly 200 people fallen ill after eating contaminated oysters
INDIA ~ June 2015
- Noodles withdrew from shelves with excess lead & chemical contamination
