Soils Flashcards
Why are soils important ?
As they’re the foundation of global food production.
Essential for achieving food security and nutrition.
Mitigate negative impacts
of climate change - play a role in carbon cycle.
Pharmaceuticals
How much foood production do souls sustain ?
95%
How much biodiversity do soils host?
1/4
What % of soil degradation is there ?
33% globally.
Threaten food security and send people in poverty.
Why do we need to make sustainable soil management ?
Makes more healthy food globally.
What does the FAO want ?
International soil community and policy makers to work together and reduce soil degradation
And restore degraded land
What 5 functions does soil perform.
- Cycling nutrients
- Regulating water
- Sustaining plant and animal life
- Filtering/ buffering pollutants
- Physical stability / support
Cycling nutrients
Carbon
Nitrogen
Phosphorus
Stored / transformed and cycled
Regulating water
It helps control where rain and snow melt and irrigation water goes.
Either flow over land or into through soils
Sustaining plant and animal life
Diversity and productively of living things depends on soil.
Habitat.
Filtering / buffering pollutants
Minerals and microbes in soil responsible for filtering , buffering , degrading and detoxifying organic and inorganic materials.
Like industrial by products
Physical stability and support
Soil structure provides medium for plant roots
What is a ZONAL soil?
Major soil group classified as covering a wide geographic region and are well developed and mature.
Dynamic equilibrium with climate , vegetation and parent matter.
Name 2 zonal soils
Chernozem
Red/ yellow latosols of tropical rainforests
Where are chernozem soils found?
Continental climate ( cold winters / hot summers)
Flat plains with tall grass natural vegetation.
Eurasia / N America
How much land for chernozem soils cover ?
230 million ha worldwide.
What are chernozem soils ?
Deep black rich in organic matter.
Mineral content comes from wind blow sediments.
High organic Mayer and nutrient content. Ammonia.
1m deep and clay like structure.
Why is a clay like structure good?
Retains water.
Where is a location where chernozems are found ?
Russia - steppes.
Allows planting in both winter and spring.
Chernozem crops include ??
Cereal - wheat / barley.
Oilseed plants - sunflower
Potatoes
What agriculture uses do chernozems have ?
Arable cropping.
Cattle ranching
Where are latosols found ?
Hot
Wet
Thick forested areas
Where are nutrients stored in latosols ?
Vegetation and not the soil
Name a way of farming on latosols ?
Shifting cultivation.
Indigenous people clear areas of vegetation.
Burn it as ash provides nutrients for fertile soil.
Land is then farmed for 2/3 years before they love on to another area of rainforest.
Allows forest / soil to recover
How deep are latosols ?
40m
The hot wet climate of rainforest provides perfect conditions for latosols why?
Allows chemical weathering of bed rocks
Constant supply of minerals from latent rock to soil.
What is ferrallitisation?
Process by which bedrock is broken down by chemical weathering into clays and minerals
Latosols ^
Colour of latosol ?
Red
Iron and aluminium minerals
Because in rain forests there is a lot of precipitation which exceed potential evaporation, what does this mean for latosol?
Soil moisture surplus.
Soil saturated.
Water cannot infiltrate down into soil so leads to surface run off.
Rivers flooding
How is nutrient cycling better for latosols?
As hot wet conditions of forest floor allow for rapid decomposition of deal plant material - provides nutrients and absorbed by roots.
What happens in upper limit of soil ?
(Boundary between soil and air)
Shallow water / live plants where they haven’t begun to decompose
What happens in lower boundary of soils?
Separates soils from weathering rock layer underneath.
Less well defined.
