Soils undoubtedly are a product of a complex combination of weathered and eroded rock materials on one hand and organic resides on the other instrument. Weathering changes consolidated rock for an unconsolidated (loose) material. The decomposition of plants and micro-organisms releases organic chemicals (humus) that connect to the loose material, giving rise to be able to types of soils.

Types of Soils

Soil Forming Processes

  • Eluviation is the mechanical translocation of clay or other fine material down the profile.
  • Illuviation is the accumulation of the washed down (elevated) material in the lower horizons of soil profile.
  • Cheluviation is the downward movement of material, similar to leaching but under the influence of organic complex compounds.
  • Leaching is the removal and downward movement of material from horizon in solution

Soil Horizons

Horizons are soil layers that are approximately parallel to the soils surface. Boundaries between horizons range from indistinct to abrupt and clear. Horizons are formed because of difference in the degree of depth, amounts of humus accumulated, translocation of colloids by water and loos of colloids.

SOIL : FACTS FILE

  • The branches of science which study soil is called “pedology”.
  • The “Soil profile” refers to the arrangement of the soil into lyserline horizons of differing texture color and consistency.
  • “Brunizem” soils are also termed as “praire’ soil.
  • The “Hydromorphic” soils are soil associated with marshes, swamps, bag or poorly drained flat uplands.
  • “Calcification” is a pedogenic regime of climate in which evaporation on the average exceeds precipitation.
  • The deposition of colloids and bases in the underlying B horizon is a process known as “illuviation”.
  • “Chernozem” soils are rich in calcium and climate has long been thought to be a determining factor in the development of such a soils.
  • The grey-brown podzolic soil differs from podzols, in that leaching is less intense and contain more of the important base than podzols.
  • The pedogenic regime of “gleization” is characteristic of poorly drained environments under a moist and cool cold climate.
  • The maximum soil temperature of plant to grow is 6 °C or 42 °F.
  • The effect of soil temperatur on plants is most profound in the temperate lands where the farming year is governed by seasons.
  • The dark colored soil absorbs more of sun’s heat than the light colored one.
  • “Bare Soil” loses heat much faster than those covered with vegetation.
  • Most matured soils have ea layered arrangement of strata called “horizon”.
  • “Podsolization” commonly occurs in area of humid temperate climate and in a typical regime of coniferous forest regions.
  • “Leaching” is a process of removal of minerals in solution from the upper layers to the lower layers of soils e.g. “Podzols” type of soils.
  • The “Zonal Soils” are mature soils, the development of which has been influenced by the local climate and vegetation.
  •  “Intrazonal Soil” are those soil, the development of which has been influenced by factor like terrain or the parent material and the role of the vegetation has been limited e.g. “calcimorphic” and “hydromorphic” type of soil.
  • “Latosols” are the soil of rainy tropical areas which have accumulation of iron and aluminium oxides.
  • “Prairie Soil” develops in area of humid continental climate and they are also called “brunizems”.
  • Calcimorphic soils are intrazonal which develop from lime and it is found in south America and Mediterranean sea.
  • The “Thundra Soils” are found in cold-zone and it is stony in texture e.g. Eruasia and North America
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