Soil

• 1. What are three important functions served by soils?
  2. Anchor plants
  3. Storage of water and nutrients
  4. Habitat for soil organisms (bacteria fungi, insects, invertebrates)
• 1. Name the five soil-forming factors. (CORPT)
  2. Cl - Climate
  3. O - Organisms
  4. R - Relief
  5. P - Parent material
  6. T - Time
• 1. Name the 7 predominant soil orders in Texas. 
  2. Entisols 
  3. Inceptisols 
  4. Ardisols 
  5. Cerisols
  6. Alfisols
  7. Mollisols
  8. Ultisols  
• 1. What is soil organic matter?
  2. Portion of the soil that includes animal and plant residues in various stages of decomposition
• 1. What are the five different functions of soil organic matter?
  2. Sequestration of nutrients 
  3. Source of nutrients
  4. Soil aggregation and structure
  5. Water storage
  6. Chemical sequestration
• 1. As the C: N ratio increases, what happens to the decomposition rates of plant material?
  2. Decreases 
• 1. What are the three soil particle sizes?
  2. Sand 
  3. Silt 
  4. Clay 
• Know the soil triangle or else!

  Type okay ~ okay
• 1. Gravitational water ~ water drains readily through soil
  2. Water can’t be held by soil and just flows through
• 1. Field capacity ~ water is held in the pore spaces and is readily available to plants
  2. Holds water ready for plants without flowing all teh way through or holding on too tight
  3. Goldilocks between gravitational water and permanent wilting poiint
• 1. Permanent wilting point ~ water is held tightly by soil particles and isn’t available to plants 
  2. Point where water is held by particles so the plant can’t use it
  3. And then it wilts 
• 1. Tilth ~ physical condition of the spil as related to plant growth
  2. Determines how easy you can till through the ground
  3. root penetration
  4. aeration
  5. water infiltration/drainage
• 1. Shrink-swell potential ~ a measurement of the amount of volume change that can occur when a soil wets and dries
• 1. Why is shrink-swell potential important?
  2. Important for ag and engineering
  3. Keeps roads and foundations intact
• What is the total water holding capacity for sand (low, moderate, or high)?

  Low
• What is the total water holding capacity for silt (low, moderate, or high)?

  Moderate
• What is the total water-holding capacity for clay (low, moderate, or high)?

  high
• How quickly does sand drain (slow, moderate, fast)?

  Fast
• How quickly does silt drain (slow, moderate, fast)?

  Moderate
• How quickly does clay drain (slow, moderate, fast)?

  Slow
• 1. Cation exchange capacity (CEC) ~ determines how well your soil will hold on to anything
• What is the CEC level of sand (low, moderate, high)?

  Low
• What is the CEC level of silt (low, moderate, high)?

  Low - Moderate
• What is the CEC level of clay (low, moderate, high)?

  High
• What is the shrink-swell potential of sand (low, moderate, high)?

  Very low
• What is the shrink-swell potential of silt (low, moderate, high)?

  Low
• What is the shrink-swell potential of clay (low, moderate, high)?

  Moderate - very high
• How much can sand store plant nutrients (low, moderate, high)?

  Very low
• How much can silt store plant nutrients (low, moderate, high)?

  Low - moderate
• How much can clay store plant nutrients (low, moderate, high)?

  High
• How easy is it to cultivate sand (easy, moderate, hard)?

  Easy
• How easy is it to cultivate silt (easy, moderate, hard)?

  Moderate
• How easy is it to cultivate clay (easy, moderate, hard)?

  Hard
• 1. How does pH affect plant growth, nutrient availability, and soil organisms?
  2. pH influences availability of nutrients to plants
  3. Soil pH of 5 may limit phosphorus availability to plants even though phosphorus levels are adequate
  4. Low soil pH may cause toxic levels of available Al and Mn 
  5. pH affects the growth of beneficial soil microorganisms
  6. Microorganisms bind the CO2 in the soil and conduct a healthy enviroment for the roots to grow so it’s important you have a pH that makes them happy
• 1. Where do saline soils typically occur and what is the cause?
  2. Occur in dry regions 
  3. Where salts rise to the soil surface during water evaporation
• 17 essential elements needed for plant growth acyronym: C. Hopkin’s café is managed by mine nice close cousin, Moe

  Stands for: [C HOPKNS CaFe Mg] {B Mn Ni Cl Co/uZn Mo}
• 17 essential elements needed for plant growth:

  1. C ~ carbon
  2. H ~ hydrogen
  3. O ~ oxygen
  4. P ~ phosphorus
  5. K ~ potassium
  6. N ~ nitrogen
  7. S ~ sulfur
  8. Ca ~ calcium
  9. Fe ~ iron
  10. Mg ~ magnesium
  11. B ~ boron
  12. Mn ~ manganese
  13. Ni ~ nickel
  14. Cl ~ chlorine
  15. Co ~ cobalt
  16. Zn ~ zinc
  17. Mo ~ molybdenum
• Know the phrase, “Don’t guess, soil test.”

  type okay: okay
• 1. What are the differences between organic and inorganic fertilizers?
  2. Organic ~ derived from living matter contain carbon
  3. Inorganic ~ synthetic or mined elements no carbon
• 1. List and describe the 3 types of organic fertilizers.
  2. Animal manures ~ combination of feces and urine
  3. Compost ~ controlled decomposition of manure, crop residue, or other organic matter by microorganisms in the presence of oxygen
  4. Green manures ~ plants that are grown and plowed under to improve soil and add organic matter and nutrients