soilsci

• Soil


  A natural and dynamic body formed on the land surface from weathering of rocks and minerals and made up of porous mixture of inorganic matter, organic matter, water, and air whose composition and properties influence the growth of plants
• Subaqueous soils


  Soils that differ from subaerial or terrestrial soils by having perennial water on the soil surface, occurring in shallow freshwater and marine environments such as ponds, lakes, and the subtidal areas of estuaries and tidal embayments
• Shallow


  Approximately 2.5 m
• Human-altered and Human-transported Soils (HAHT)


  Soils that were intentionally and substantially modified by humans for an intended purpose, commonly for terraced agriculture, building support, mining, transportation, and commerce
• In defining soil, remember P-I-S-O-N
• Soil


  • Supplies air, water, mechanical support & nutrients for crops
  • Covers the Earth in thin layer (crust)
  • Synthesized in a "profile form"
  • Mixture of broken & weathered rocks & minerals, and decayed OM
• Purpose/Function


  Supplies air, water, mechanical support & nutrients for crops
• Importance

  Covers the Earth in thin layer (crust)
• Structure


  Synthesized in a "profile form"
• Origin


  Mixture of broken & weathered rocks & minerals, and decayed OM
• Nature


  Natural Body
• Soil controls the fate of water in the hydrologic system
• Infiltration


  The downward entry of water into the soil
• Percolation


  The downward movement of water through the soil
• Capillary rise


  Upward movement of water
• Runoff


  Water lost by surface flow
• Soil functions as nature's recycling system
• Soil provides a habitat for soil organisms, both macro or micro
• Soil is an engineering medium which provides foundation for roads, airport, building or houses
• Soil is where food, clothing, shelter, and medicines are derived
• Geophagy (deliberate "soil eating") is practiced in some societies
• Soil


  • It is a natural body
  • It is dynamic
  • It is a three-dimensional entity
• Length


  Distance of an object to the other, normally the longest dimension
• Width


  Distance from side to side
• Depth


  Distance from the top downwards or from the surface inwards
• Soil components


  • Soil solids (inorganic or mineral and organic matter or particles)
  • Soil pore spaces (contain air and water at inverse relations)
• Soil as a three-phase system

  • Solid phase (mixture of mineral and organic matter)
  • Liquid phase (water)
  • Gaseous phase (soil air)
• Solid


  Has definite shape and definite volume
• Liquid


  Volume remains constant but the shape depends on that of its container
• Gas


  A form of matter that has no fixed shape
• Land


  A broader term than soil embodying the total natural environment of the areas of the earth not covered by water
• Soil Science


  An organized body of knowledge that has accumulated from the study of soils through the application of basic science of geology, biology, physics, and chemistry
• Geology


  The study of the earth or earth science, treating of the origin and structure of the earth including the physical forces which have shaped it and its physical and organic history especially as shown by rocks and rock formations
• Biology


  The science of life in all its manifestations and of the origin, structure, reproduction, growth and development of living organisms collectively, including botany and zoology
• Physics


  The science that treats of motion, matter, and energy and their interactions, the scientific study of the properties and inter-relationships of matter, energy, force and motion
• Chemistry


  The study of matter, its properties and composition, structure, changes and the laws and principles which govern such changes, the scientific study of the composition, properties, and reactions of chemical elements and their compounds
• Fields of specialization in Soil Science

  • Soil chemistry
  • Soil mineralogy
  • Soil microbiology
  • Soil survey and classification
  • Soil physics
  • Soil fertility
  • Soil genesis
  • Soil conservation and management
• Edaphological approach


  Study of soil in relation to higher plants, soil properties versus plant growth, variability of soil productivity, methods of conserving and improving productivity
• Pedological approach


  Study of the origin and classification of soils, soil as a natural body
• Mineral matter or Inorganic matter


  45% of soil composition