AUENV 233 Lecture Notes - Lecture 1: Hydrosphere, Colluvium, Lithosphere
30 May 2018
School
Course
Professor
Soil Science Notes
Lecture 1 AUENV 233
• Soil – natural body made up of
→
definition is broad
o Solids – minerals, organic matter
o Liquid
o Gas
That occurs on the land surface, occupies space, and is characterized by one or both of the
following:
o Ability to support rooted plants in a natural env
o Horizons, layers, that are distinguishable from the initial material as a result of:
▪ Additions, losses, transfers, and transformations of energy and matter
• Esker – sand left behind from a glacier
o Is a soil because it can house plant roots, but has no horizons
6 Critical soil functions
1.) Home for plant growth
• habitat for plant roots,
• air and water,
• nutrients
• soil properties that determine nature of vegetation
• indirectly impact the number and type of animals that can be supported → PEOPLE – 10% of
the land on earth is capable of food production
2.) Regulation of water supplies
• every drop of water has travelled through or over soil at one point
• storage and flow regulation → can prevent floods [vegetation]
i. eg – mud slides are a result of forest fires. No veg to soak up water.
• Purification → cleans the water
3.) Recycling of raw materials
• Decomposition of materials
• Creation of soil matter
• Nutrient re-release → converts from unusable forms [dead body] into more accessible forms
[nutrients – C, N, P]
4.) Fosters unimaginable biodiversity
• Ecosystem unto itself
• Handful of soil = billions of organisms
5.) Influence the atmosphere composition
• Storage and release of gases – such as CO2
• Key role in C cycle
i. 3rd largest pool on Earth! [next to ocean, rocks/parent material]
ii. can act as a sink or source [organisms within breathing]
• management intensity has an influence. Eg - tilling can release C
• dust storms – large scale transfer
6.) Engineer medium
• Can live in it – build out of it
i. Eg - Rammed earth construction – good insulation
find more resources at oneclass.com
find more resources at oneclass.com
• (-) can cause buildings to collapse. eg – earthquakes. Geotechnical engineers.
History of soil science – very young science – not more than 150 yrs
*dot need to know names/dates
• 1870s – V. V. Dokuchaev father of soil siee → Russia
o soils = natural bodies
• 1920s – CF Marbut
o US department of Ag
o Soil profiling & soil mapping
• 1940 – Hans Jenny
o quantitative analysis – math formula to predict soil form
o soil = fCl, O, R, P, T… → none act independently.
• 1960 – Guy Smith – redid soil class sys
Influences on soil
• war
• crime
• food
• climate change
• cities
Soils and Scales
Spheres [scales]
→ soil eists at eer sale…
1.) atmosphere
2.) biosphere
3.) lithosphere
4.) hydrosphere
Geographical context
• soils = otiuous ut proide otiuall arig oer oer the earth’s lad surfae
• soil properties vary over spatial [vertical, horizontal] & temporal scales
o chemical, biological, physical
Looking at soil
• upper boundary of soil – boundary between:
o air
o shallow water
o live plants
o or plant materials that have begun to decompose
• lower boundary of soil – ofte diffiult to defie…
o parent material and bedrock interface
Vertical Variations
• podzol
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Lecture 1 auenv 233: soil natural body made up of definition is broad, solids minerals, organic matter, liquid, gas. Is a soil because it can house plant roots, but has no horizons. Regulation of water supplies: every drop of water has travelled through or over soil at one point storage and flow regulation can prevent floods [vegetation, eg mud slides are a result of forest fires. No veg to soak up water: purification cleans the water. Recycling of raw materials: decomposition of materials, creation of soil matter, nutrient re-release converts from unusable forms [dead body] into more accessible forms. Fosters unimaginable biodiversity: ecosystem unto itself, handful of soil = billions of organisms. Influence the atmosphere composition: storage and release of gases such as co2, key role in c cycle, 3rd largest pool on earth! [next to ocean, rocks/parent material: can act as a sink or source [organisms within breathing, management intensity has an influence.
