Strategies to increase agricultural sustainability Flashcards
What is increasingly important with a growing population?
that food supplies also increase
How are population sizes usually controlled?
density dependent factors (disease and food supply)
What happens if population rises above carrying capacity?
death rates will increase and the population will be reduced
What are humans able to do with carrying capacity?
consciously manipulate the environment to produce more food and allow population to rise above natural carrying capacity
What must be done to support a huge global human population? (food)
must direct more energy captured by photosynthesis into the human food chain
what can the development of sustainable agriculture be guided by?
learning form past mistakes
How long ago did agriculture first develop?
12,000 years ago
where did agriculture fist begin?
‘the fertile crescent’
Where is the fertile crescent?
the middle east:
largely in Iraq and Syria
What made the fertile crescent good for agriculture?
forested area with a good climate and fertile soils
What has reduced the fertile crescents ability for food production?
natural climate change and the way it was exploited
Where have reductions in agricultural productivity also be occurring?
mid-west USA
parts of UK
deforested rainforest areas
Large areas of Africa
what are the key features of land degradation?
soil erosion combined with reduction in soil nutrients and water levels
What are some farming strategies that increase productivity but are unsustainable long term?
Reliance on artificial fertilisers for nutrient supplies
Reliance on chemical pesticides for pest control
Irrigation using water from groundwater resources that are not being recharged
How much of earths surface is cultivated for crops?
10%
How much of earths surface is being grazed by livestock?
25%
Why is the potential for cultivating new areas limited?
as much of the remaining areas are:
too dry
too wet
too cold
too hot
too steep
covered in ice
have no soil
What is the negative of food importation on the producer?
food availability may be reduced to those with less money as land they use to farm becomes too expensive to rent and land is used to supply affluent countries
What is organic agriculture?
As natural as possible with little artificial interference
What are some examples of organic agriculture?
not using pesticides or artificial fertiliser
What is the sustainability problem with pest control?
A reliance on chemical pesticides may be unsustainable
Use of some pesticides has been banned or restricted due to their impacts on non-target species many pests have developed resistance to pesticides
What are the selected sustainability strategies for pest control?
Cultural pest control: weeding, mulching, crop rotation, barrier crops, culling, biological control, predator habitats, polyculture/ companion crops and integrated control
Reduced antibiotic use
What is the sustainability problem with nutrient supplies?
Current supplies of rock phosphate to produce phosphate fertilisers are non-renewable
What are the selected sustainability strategies for nutrient supplies?
increased use of natural processes to supply nutrients
Recycling organic matter
Crop rotation
Cultivation of legumes
Conservation of soil biota
What is the sustainability problem with energy inputs? (Agriculture)
Manufacture of nitrate fertilisers requires large energy inputs form fossil fuels
What are the selected sustainability strategies for nutrient supplies? (agriculture)
Reduced use of artificial fertilisers (nitrates)
Low tillage techniques
Low food miles
What is the sustainability problem with gene pool for breeding problems?
Usually quite small which can cause problems like inbreeding which negatively affect the future generations
What are the selected sustainability strategies for gene pool breeding programmes? (plants)
Conservation of habitats that protect CWRs
Seed banks to conserve biodiversity
What is the sustainability problem with water supplies?
Over-exploitation of rivers and groundwater reserves
Soil salinisation caused by using saline irrigation water
What are the selected sustainability strategies for water supplies?
Cultivation of low water-use crops
Maintenance of soil and soil organic matter
Use of reservoir and aquifer recharge
Drip irrigation rather than overhead sprays
What is the sustainability problem with Carbon dioxide emissions? (Agriculture)
Loss of soil organic matter increases atmospheric CO2 levels
CO2 released by fossil fuel use which are still vital until reliable replacement
What are the selected sustainability strategies for Carbon dioxide emissions? (agriculture)
Low-tillage farming to reduce decomposition of soil organic matter
Maintain or increase soil organic matter
Reduced use of machinery
Use of renewable energy sources
What is the sustainability problem with Methane releases?
Methane produced by anaerobic microbes in rice padi fields and digestive system of livestock
what are the selected sustainability strategies for methane releases? (agriculture)
Cultivation of rice varieties that can tolerate drier conditions so fields can be drained earlier
Feeding cattle high carbohydrate diet and grinding their food first reduces methane production (sea weed)
What is the sustainability problem with Wildlife biodiversity?
Loss of species that provide important ecosystem-services such as pest control, nutrient provision, and pollination
What are the selected sustainability strategies for wildlife biodiversity?
Retain natural and semi-natural ecosystems e.g. hedgerow, ditches, ponds, woodlands
Maintenance of soil biota
