Download presentation
Presentation is loading. Please wait.
Published byGeorge Lambert Modified over 8 years ago
2
Soil – Biogeochemically weathered product of nature Minerals, Nutrients, Organic Residue Continual Changes Lead to specific properties of a profile Development
3
Temperature Precipitation Atmospheric Gradients that affect development
4
Weather Gradient
5
6
The Soil Horizons Soils are formed in Horizons Soil Horizons differ one from the other The horizons are roughly parallel to the soil surface The boundaries between horizons can usually be seen 6 / 20
7
Soil Morphology Is the physical nature of the soils seen in horizons Horizons are characterized by differences in physical properties Horizons are given letter names 7 / 20
8
The Soil Profile Any cross- section of a soil This Soil Profile is O, A, B, C 8 / 20
9
O: A: E B Bt: R Soil Profile
10
11
Granite Sandstone Shale Limestone NYS Soil Composition
12
Lower case suffix letters Used with Capital letters – never alone Used to indicate a specific characteristic of the master horizon Example: Ap = plowed A horizon Or Bt = illuvial clay 12 / 20
13
Soil profile review Has visible horizon breaks There are no set numbers of horizons in a pedon 13 / 20
14
Began 2.5 mya 4 glacial advances well known Ice records in ocean show more than 30 advances through history. Ice Ages
15
65,000-10,000yBP Scraped away top layers of soil Wisconsin Advance
16
17
Soil Time Table
18
I – Climate II – Vegetation III – Parent Material IV – Topography V - Time Five Factors of Soil Formation
19
Leaching – complete removal of substances from the soil. Translocation – moved from an upper horizon to a lower horizon. Synthesis of new compounds – process of decomposition (ex. Lichens on glacial till) Biological Activity – animals living on top of the soil will help break it down. Formation of Soil Structure – Soils begin to stick together (coagulate) Soil Development Process
20
I. Hydration – water becoming bound to mineral II.Dissolution – dissolving of minerals in contact with H 2 O III. Carbonation – CO 2 reacting with H 2 O (ex. Acid Rain) IV. Oxidation/Reduction – ex.Rust Chemical Processes Zn(s) => Zn 2+ (aq) + 2e - Cu 2+ (aq) + 2e - => Cu(s)
21
Conditions: Temperate Climate Alternating hot and cold / wet and dry High precipitation and High Humidity Deciduous Vegetation Mechanics: Leaching – mineral Salts buffers and nutrients Results: Podzolization – soil becomes infertile, acidic, absorbs tannins and humic substances. NE: gray-brown podzols SE: red-yellow podzols North Eastern US
22
Conditions:Tropical Climate Super-humid Hot temperature Year-round growing season Mechanics: EXTREME leaching Intense Weathering Organic Materials recycled rapidly Rapid root uptake pH = Alkaline Results:Leaching counteracted by root uptake Productive soils (proper growing season) –> fertile(proper nutrients) Fragile productivity – maintained by rapid recycling Tropics
23
Conditions: Grasslands or Chaparral Moderate or Low rainfall Calcification ->Prairie Soil formation Mechanics: Translocation – Cycling of Ca++ Results: Ca++ saturated Clays Nutrients conserved near the surface Limy subsoil – alkaline pH Very Fertile ( may need irrigation) Prairies
24
Continuous long-term annual agriculture (left) and long-term, annual haying of the native prairie (right)
25
Conditions: Gleization – Tundra Soils Cool-cold temperature Low evaporation Supply of organic material Continuously waterlogged “perma-frost” Mechanics: Frost Polygons “patterned” ground Reduction Results: Sticky layers of reduced clays Blue-gray color “bog” iron deposits Arctic
26
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.