Test 3 Flashcards
Increase whc
Increase om
Water captured be improved?
Maintain om and vegetation
Fresh water used in agr?
70-80%
Ways to save irrigation water?
Use high efficiency irrigation system water based on need not time
Soil aeration important?
Reduce toxic gas in soil
Factors that determine oxygen availability to roots?
Organisms in soil
Water flow through the soil
Water content important in soil aeration?
Water can block airflow
How does co2 differ in soil vs atmospher?
Soil is higher
Oxygen levels in soil profile?
Down less oxygen
Role of o in oxidation?
It is an oxidizing agent
What molecule acts as an oxidizing agent?
Sulfate (SO4)
Poor aeration
Toxic gas is trapped
Effects microorganisms
Effects of soil temps on plants
Biochemical reaction rates
Soil solarization
Increase temp to kill microorganisms
Freezing thawing cycles
Breaks rocks down
Pushes objects in soil to surface
Manage soil temps
Mulch prevent temp changes
Irrigate to cool
Soil colloid
Small partials usually negative in acid soils and play role in cation exchange
Name mineral colloid
Non-crystalline silacates
Most abundant colloid
Crystalline silicates
Composition and # of sheets tells us?
Type of clay particles
Charges appear on colloids
Along the edges
Development of mineral colloids
Breaking of the edges
Characteristic of a crystalline clay?
Expanded-2:1 space between the sheets
How ate humus colloids created?
Decomposition and altering of plant residues through microorganisms
Process of cation exchange
Reverse process where you change positively charged ions
For Cation exchange what needs to be present?
Water
Cation exchange principals
Reactions are reversible
charges must match ratios
CEC
The ability of the soil to hold or substitute cations
Important a of CEC?
General idea of liming needs
Soils hold on nutrients
Why does low ph reduce CEC?
Because hydrogen occupies all the the negative charges
CEC release to plants by?
Cations must be released from CEC before they can be taken up by plants
Base saturation and why important?
The presence of base cations in soil
Shows how much leaching and liming needs
Basic and acid cation
Ca base al acid
Legume roots deficiency?
They like to absorb 2+ ions and k+ is only 1
Bonding of biomolecules to clays info?
Bonds rapidly and strong
