Soil Flashcards
Soil
Upper (1-2m) loose part of earth’s crust. Mineral + Organic Components.
Soil Composition (WAMO)
- Minerals
- Air
- Water
- Organic Matter
*Soil Formation Factors (C-PORT)
Climate Parental Material Organisms Relief Time
Soil Quality
Capacity of soil to sustain biological productivity, maintain environmental quality, and promote plant/animal health
Soil Quality Indicators (POW)
pH
organic matter
water storage
Soil Stability
capacity of soil to carry out normal functions even in presence of environmental disruption
Earthworm Benefits
Improve soil quality:
- Pore-creation (aeration + drainage)
- Nitrogen-rich casts
Mycorrhizae
Symbiotic association between a fungus and a plant (roots). Allow plants to draw more nutrients and water from the soil. Increase plant tolerance to different environmental stresses.
Soil Function (Dubbin)
- Plant Growth
- Habitat
- Breakdown/Recycling Organic Materials
- Water Purification
- Engineering Medium (roads + building foundations)
Soil Formation Processes (ALTT)
- Additions
- Losses
- Transformations
- Translocations
Soil Profile
Interaction between soil forming factors + processes
Organic Matter (functions)
- Nutrient Supply
- Soil structure
- Water-holding capacity
- Soil Colour/Temperature
(Humus)
Soil Structure
Arrangement of sand, silt, clay and organic matter into larger units. Determined by Biological (polysaccharides or earthworms) or Abiotic factors (humus).
Biological nitrogen fixation
legumes, alfalfa, grass clover, pulses, cover crops.
Soil pH
pH <7 = acid, pH > 7 =alkaline.
Soil Acidity (causes)
- Heavy rainfall
- Leaching
- intensive Nitrogen fertilizers (amonia-based)
Micro-Organism (Bacteria) Benefits for Soil
- Produce antibiotics
- Clean polluted soils
- Nutrient transfer
- control insects
Rhizobium allow for fixation of atmospheric Nitrogen. In return, bacteria receives carbs from legume.
Soil Organisms
- Micro-organisms
- Fungi
- Plants
- Animals
- ->all interact in food web
Rhizobium
Bacteria associated with the formation of root nodules on plants. symbiosis with legumes. They take in nitrogen from the atmosphere and pass it on to the plant.
Loam
Textural classification where no single soil (sand, silt, clay) dominates
Soil Texture Importance
determines fertility, water-holding capacity & susceptibility to erosion
Bulk Density
Mass of specific volume of dry soil (includes pores + solids). Organic matter decreases bulk density.
Soil Compaction
increased bulk densities; reduced macro-pore space, leads to:
- restricted root growth
- reduced water infiltration
- surface run-off
- water erosion
Fallow
ploughed and harrowed but left for a period without being sown in order to restore its fertility or to avoid surplus production
Humus
Decomposed organic matter (healthy soil life!)
How to: Improve Soil Quality
Green + Animal Manure Organic Matter Crop Rotation Cover Crops Reduce tillage
Alkaline soil
ph > 7. Poor soil structure and a low infiltration capacity. Correct using Sulphur.
Acidic soil
ph < 7. Decreases nutrient availability. Correct using Lime, bonemeal, wooden ash.
