14
Soil Structure & Texture Cations attracted to clay particles partially available to plants Exchange between particles, soil water Ions can be taken up by plants from water, leached, or reattach to other particles

39
Phosphorus in Soils Availability not directly related to amount present in soil Phosphorus bound in ways that make it unavailable to plants Bound to clay particles, metal ions, immobilized by microbes

49
Mutualism or Parasitism? Fungi get carbon, energy from plant host Plant gets nutrients, other benefits Either “partner” can function as parasite at times - plant sheds fungus when times are good, or fungus gives little to plant