Soil Properties

There are three types of soil properties: physical, biological and chemical.

Physical Properties

Physical properties are the most visible and can be observed without using equipment like scanners or microscopes. They are reflective of the solid soil particles such as sand, silt and clay and the manner in which they are arranged. They can be used to define and classify soil types and horizons. In addition, they are very effective for field/lab demonstrations. They include:

  • Structure
  • Texture
  • Infiltration and Permeability
  • Aggregation and Aggregate Stability
  • Porosity
  • Bulk Density
  • Compaction
  • Crusting
  • Water Holding Capacity and Available Water
  • Moisture
  • Temperature

Biological Properties

Biological Properties represent the direct and indirect influence of the living organisms habitating a particular soil. Soil biological properties reflect how well-suited a soil is to support life. Most of the properties require specialized and high powered equipment for observations or measurements. They include:

  • Active and Total Carbon
  • Organic Matter
  • Enzymes
  • Earthworms
  • Nematodes
  • Respiration
  • Fungi and Bacteria
  • Microorganisms
  • Nitrogen Fixation

Chemical Properties

Chemical properties represent the complex chemical reactions and processes occurring in the soils. They represent nutrient availability, deficiency, toxicity, salinity and sodicity just to name a few. Almost all of the properties require field equipment or lab analysis for measurement. They include:

  • Electrical Conductivity
  • pH
  • Nutrient Content
  • Cation Exchange Capacity
  • Sodium Adsorption Ratio
  • C:N Ratio
  • Base Saturation
  • Exchangeable Cations
  • Exchangeable Acidity
  • Trace Elements and Heavy Metals

Learn more about specific soil physical, biological and chemical properties.