Land management lecture 3 Flashcards
Sandy soil
Poor (low nutrients status), permeable dusty, low moisture holding capacity, not easy to work on
Loamy (silty) soils
Low permeability, quite fertile, sensitive for erosion, sometimes very slippery
Clay soils
Rich (high nutrients status), difficult to work on, often slippery, coarse structure
Peat soils
Very wet, mostly good fertility (due to organic matter), only grass is possible, low bearing capacity
A horizon
AH
AP
AH: mineral horizon with organic matter.
AP: Mineral horizon that is ploughed
O horizon
Superficial layer with organic material, formed under wet conditions
H horizon
Pear or clayey peat
Gleying
Saturation of the soil pores with water, leading to greyed and or red brownish
Browning
Chemical and biological processes in sandy soils
Browning lead to the following:
erosion of iron
Formation of black hummus sand particles
Organe + black= brown
Podzolization
Chemical and physical processes of leaching, transport and precipitation of humus, with Fe and or Al
Clay redistribution
Chemical and physical processes of mobilization, transport and precipitation of clay
Weathering
Due to weathering soil is formed. It can be caused by physical, chemical and biological forces where large rocks slowly breakdown into smaller particles
Erosion
Movement of material at the surface of land in general. Loose particles on rock stones, by wind or water or earthquakes
Soil loss due to physical reactions
- Pressure
- Strong temperature fluctuations
- Chemically unchanged
Soil loss due to chemical reactions
- Transformation of primary to secondary minerals
- Chemically different
Soil loss due to biological activities
- Impact of organisms
- Tree roots growth in cracks
Significance for plant growth
- Formation of soil particles
- Possibility for root growth
- Water storage and underground transport
- Increased effect of chemical erosiveness via larger surfaces
Chemical watering/ erosiveness; condition:
- Contact of primary minerals with water (CO2,O2 and organic acids)
- Given formation of secondary minerals
Biological weathering/ erosiveness
- Make nutrients available for plants (phosphate)
- Contribute to formation of clay hum complex
GIS
Geographical information system. Can combine different layers of the moisture content in Europe
