Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
19 Cards in this Set
- Front
- Back
|
3 elements of the soil matrix |
-soil particles -water -air |
|
|
4 functions of soil |
-regulator of water supplies -recycler of raw materials -habitat for soil organisms -medium for plant growth |
|
|
3 soil conditions that affect plant growth |
-soil type (particle size and pore space) -soil water -compaction |
|
|
Difference between soil profile and soil horizon |
-profile is made up of a series of different horizons -horizons are a record of the processes affecting the soil profile |
|
|
Describe 3 types of chemical weathering |
-dissolution- water places the mineral in solution -carbonation- acids increase the activity of the hydrogen ions which affects limestone -oxydation- iron and other elements may lose an electron when exposed to oxygen and water |
|
|
Describe 3 types of physical weathering |
-abrasion- sediment carried by water, wind, or ice can wear away less resistant materials -plants and animals- actions of plant roots and animals burrowing can weather rocks -temperature- different heating and cooling rates causes stress and cracks |
|
|
3 factors affecting soil formation |
-patent materials- ultimate source of soil -biota- living organisms that affect soil processes and the distribution of soil -time- amount of time since parent materials were first exposed to weathering |
|
|
Examples of 4 major types of deposits of soil material |
alluvial stream deposits- material transported by flowing water colluvial deposits- materials transported primarily by gravity Glacial deposits- deposits created by the action of glacial ice and meltwater Eolian deposits- well sorted deposits resulting from transportation by wind |
|
|
4 processes of soil genesis |
Transformers- soil constituents are destroyed and synthesized Translocations- movement of materials from one horizon to another Additions- materials added to the profile from outside sources Losses- loss of materials from the profile |
|
|
Difference between particle density, bulk density, and porosity |
Particle density- mass or weight of soil solid without pore space Bulk density- mass or weight of dried soil (no soil water) Soil porosity- measure of soil volume that holds either air or water |
|
|
Calculate particle density, bulk density, and porosity |
Bulk density- (weight of dry soil (g))/(volume of dry soil (cm3)) Porosity- (wet weight-dry weight)/volume × 100 Particle density- |
|
|
Describe 4 of the 7 physical properties of soil |
Texture- size of soil particles which determines internal area and spacing between particles Permeability- ease through which water, air, or plant roots move through the soil Tilth- how easily a soil can be tilled Color- color of the soil |
|
|
3 major soil fractions from largest to smallest |
Sand Silt Clay |
|
|
Difference between sand and clay in terms of the size of soil pores and the amount of total pore space |
Sand has larger soil pores than clay but clay has more total pore space |
|
|
Define mottles and what they indicate |
Patches of different colors, indicates waterlogged soils for at least part of the year |
|
|
Describe 3 forces that contribute to the soil water potential |
Matrix potential- sum of energy present in the adhesive and cohesive water within the soil Gravitational potential- the height the water is above the water table Osmotic potential- ability of dissolved ions to attract water |
|
|
List 3 forces at work upon soil water |
-adhesive -cohesive -gravity |
|
|
Describe how a potentiometer measures soil moisture |
Water is drawn from the potentiometer by soil water forces and creates a vacuum making a dial move which measures the water taken and soil water potential |
|
|
How does capillary water move against the force of gravity |
A small space can be created within the pore space of closely positioned soil particles. Cohesive and adhesive forces are then able to draw water into these spaces against the force of gravity |
