part 4

• soil?


  unconsolidated cover on earth's surface
• components of soil?


  organic matter, water, air, and mineral matter
• function?


  supply water to roots, furnish nutrients, produce air
• soil txt?


  sand- loose txt, high infiltration rate, silt- organic matter, heavy txt, improves infiltration rate, clay- mix of both, least infiltration rate
• what is organic matter?


  the glue
• what is large pores?

  air
• what is small pores?


  water
• soil layers?


  o,a,e,b,c,r
• field capacity?


  available water for plant growth
• wilting point?

  no more water avaliable
• swp?

  soil water potential- if water clings to soil- higher in drier conditions
• plant available water?


  water held in soil between field capacity and permanent wilting point
• how to measure?


  electrical resistance blocks, time domain reflectometry, tensiometers