Soil Characteristics

Soil Characteristics

1. TEXTURE

   • determines whether soil can support roots
   • determines water retention ability
   • sandy
     • gritty
     • limestone, granite
     • big air spaces
       • well drained
       • subject to leaching & dehydation
       • need fertilising
   • clay
     • sticky & lump when wet
     • rock hard when dry
     • fine particles
       • few air spaces
         • hard to work with
         • often waterlogged
     • rich in nutrients
       • plants will grow if enough drainage
   • silty
     • minerals & fine organic particles
     • more nutrients
     • good drainge
     • smooth when dry
   • loamy
     • drain well
     • retain moisture
     • nutrient rich

2. COLOUR

   • indicates amount of organic material
   • humus rich
     • black, dark brown
       • absorb sunlight
         • aids germination
   • leached
     • white

3. STRUCTURE

   • shape of grains and particles
   • clusters of particles = peds
     • size & shape determine size &shape of pore spaces
       • controls water retention
       • controls amount of organic activity
   • single grained
     • leaching & drought
     • sandy
   • crumb structure
     • holds water, nutrients
     • suitable for farming
     • loamy
   • massive
     • clay
     • waterlogging
       • hard lumps

4. Water Content

   • sandy soils
     • easy leaching
   • clays
     • limit percolation
       • waterlogged

5. Organic Content

   • dead suff
     • leaves, roots, plans
     • humus
   • darker soil = more organic matte

6. pH Value

   • pH<7
     • peaty
     • lack calcium
     • hard to cultivate
     • low productivity
   • alkaline
     • high Ca conc.
   • neutral
     • encourage growth of bacteria
       • release nutriens
     • good for cultivation