Soils Flashcards
How does soil pH relate to chemical weathering and CEC?
Soil pH, chemical weathering, and CEC are interrelated when it comes to soil chemistry. It determines soil quality and fertility, the lower the pH the more intense chemical weathering is, which can lead to leaching essential cations. The higher the pH the less chemical weathering rates. CEC is also affected by soil pH, this is because the charge on soil particles influences their capacity to retain cations.
How does soil organic matter (SOM) influence soil chemical and physical properties (e.g. CEC, water holding capacity, bulk density)?
SOM influences both soil chemical and physical properties. For example, SOM can increase CEC, this is because it’s rich in negatively charged ions, which can exchange with positively charged ions in the soil. SOM also increases water holding capacity, it prevents excess drainage and it helps plants get water during the dry periods. SOM can also hold/store essential plant nutrients like nitrogen, phosphorus and sulfur which can be released when the plant needs it.
In a soil with strongly negative redox potential would you expect to find methanogenesis or aerobic respiration? Why?
A strong negative redox potential usually means that there is limited or a lack of oxygen, so I would expect to find methanogenesis instead of aerobic respiration. This is because the microorganisms that are involved in the methanogenesis thrive in environments where oxygen is either absent or lacking and are capable of converting organic compounds into methane.
Gelisol
Found in Tundra or bog, they develop in climates that are below 0*C, they have a layer of permafrost
Aridisol
Found in arid climates, dry soils=little leaching
Spodosol
Usually in cold and wet climates, with Sandy leached E horizon, Acidic B horizon.
Mollisol
Usually in grasslands, dark colored A horizon
Oxisol
Usually in hot/humid climates, highly leached horizon.
