5 Flashcards
Soil
Complex system.
Holds Minerals, air, liquids, organic material.
Habitat for plant and animals.
Transfers in the Soil System
Biological mixing
Translocation - movement of particles
Leaching - minerals dissolved in water moving through the soil
What does Soil Store
Organic matter
Organisms
Nutrients
Minerals
Air
Water
Transformations in the Soil System
Decomposition
Weathering
Nutrient Cycles
O-Horizon
Upper layer of newly added organic material.
Decomposers start ti break down organic material.
A-Horizon
Humus - partially decomposed organic matter and fine mineral particles.
Water logging slows decompositions, fewer decomposers, leads to a build up of organic material and eventually peat soil.
E- Horizon
Depletion of amount of organic matter. Minerals such as iron, clay and aluminium compounds are present.
B-Horizon
Soluble minerals depsoited here from the layer above. Clay, iron and slats.
C-Horizon
Weathered rock from which the soil forms.
R-Horizon
Parent material, bedrock or other.
Sandy Soils
Gritty and fall apart easily - high air supply and drainage.
Silty Soils
Slippery wet, holds together better than sandy soil. Hold sand and clay particles togehter.
Clay Soils
Sticky and rolled into a ball easily, hold together well. Retains water and nutrients.
Salinisation
Water evaporates on surface.
Water moves upwards carrying dissolved minerals.
Water evaporates on surface.
Dissolved minerals remain.
Occurs in places where E>P, and irrigated places.
Leaching
Water moves down through soil thanks to gravity, bringing dissolved minerals with it. P>E.
Subsistence Farming
Provision of food by farmers for themselves, family or community. Human labour is great, technology rarely used. Susceptible to food shortages.
Cash Cropping
Growing food to sell.
Commercial Farming
Large, profit-making scale, maximising yields per hectare. High technology and energy use. High levels of produciton.
Extensive Farming
More land with lower density of planting, lower inputs and outputs.
Intensive Farming
Uses more crops in the same area of land/land use is more intensive. high inputs and outputs. Animal feedlots.
Pastoral Farming
Raising animals on grass on land that is not suitable for crops.
Arable Farming
Growing crops on good land to feed humans or animals.
Mixed Farming
Raises animals and crops. Animals to eat and to use dung to fertilise crops and increase soil’s structure. Crops feed animlas and humans.
Agribuisness
Business of agricultural production including farming, seed supply, breeding, chemical for agriculture, machinery, food harvesting, distribution, process and storage.
Malnutrition
Nutritional intake is bad.
lacking - under nourishment
Excessive - over nourishment
Unbalanced - wrong proportions of micro-nutrients.
Causes of Food Imbalance
Ecological - climate, severe weather, soil degradation, declining biodiversity.
Economic - lack of food due to more money through exports, or too expensive to grow.
Socio-politcal - globalisation - supports imports to MEDCs, lack of monitoring and deploying food relief, disagreements over transboundary issues.
Factors influencing Crop/Livestock Choices
Climate - what food can grow where, overcome with technology.
Cultural and Religious - Some peoples don’t eat certain foods. Food choice varies.
Political - tariffs or subsidies on foods.
Socio-Economic - Cost of food influences supply and demand.
Livestock
Animals raised to turn food not suitable for human consumption into food suitable for human consumption.
Crops
Plants are sowed onto arable land. Harvesting removes biomass. Growing crops may degrade the soil, crop rotations can minimise this effect.
Efficiency of a Farming System
Energy contained within the crop harvested per unit area of land required. Joules per gram. If it is <1, inputs<outputs.
Extensive Farming
Limited selective breeding.
No genetic engineering.
Polyculture.
Little effect on biodiversity.
Little soil erosion.
Intensive Farming
Strong selective breeding.
Genetically engineered organisms.
Monoculture.
Reduction in Biodiversity.
Strong Soil Erosion.
How to Improve Sustainability of Food Production Systems
Maximise Yield - improved technology, alter what we grow (GMF), recycle nutrients and energy on a farm (Green Revolution).
Reduce Food Waster - LEDCs: Improve production and storage. MEDCs: Improve consumption rates.
Reduce Food processing, Packaging and Transport -
Changing Attitudes - eat different, less mea more insects.
Monitoring and Control - IGOs, GO, MN and N FC, I, NGOs to reduce unsustainable farming.
Overgrazing
Too many animals graze in the same land. Roots can no longer hold together soil. Soil is removed from the land through wind and rain.
Overcropping
Depleted soil nutrients, reduces soil fertility. Friable soil, dry and susceptible to wind erosion.
Deforestation
Removal of forest allows soil to be more easily eroded by wind and rain, less roots and cover.
Urbanisation
Impermeable surface, increasing run-off, may erode other places. Cities encroach on agricultural land.
Unsuitable Agricultural Techniques
Total removal of crops after harvest.
Growing crops in rows.
plowing in the direction of the slope.
irrigation, leaching.
Monoculutres.
Soil Erosion
Sheet wash - large areas of soil washed away by water, landslides.
Gullying - channels on hillsides develop allowing soil to be washed away more easily.
Wind Erosion - Drier soils, high winds remove surface layer.
Desertification
The process of arable land losing productivity, nutrients change, soil loss, and forming a desert.
Peat Soil
water logged, oxygen deficient, high acidity, nutrient deficient.
Terrestrial VS Aquatic
Terrestrial: Consume lower trophic level. Less efficient.
Aquatic: Consume higher trophic level, higher efficiency.
