Soil Study

Parent Material of Soil Unconsolidated product of weathering from which soil develops is called parent material. Generally there are two groups of parent materials, i.e. sedentary and transported. The transported materials are further subdivided according to transporting agency and place of deposition. Sedentary or Residual                                            The parent material formed in place and still at the original site. Transported                       The parent material carried and deposited by various transporting agencies. By gravity- Colluvial By water- Alluvial By ice- Glacial By wind- Eolian The nature and properties of parent material together with climate are the most important factors affecting the kind and quality of soils. So to understand soils we must know the source of material, mechanisms of weathering and transporting agencies. Sedentary or Residual Parent Material                                                      

Weathering It is process in which different physical and chemical changes are produced in rocks at or near the earth’s surface by atmospheric agents. There are two basic weathering processes. Mechanical/physical weathering                                                                      It causes decrease in size of rocks and minerals without appreciably affecting their chemical composition.  Chemical weathering                                                                 It is a process in which chemical changes take place in rocks and minerals. Soluble materials are released, new minerals are synthesized and some resistant products remain as such. Mechanical/physical weathering (disintegration) Temperature                                           Rocks heat up during day the day and cool down at night, causing alternate expansion and contraction of their constituent minerals. As some minerals expand more than others, temperature changes set up differ

Minerals and rocks Minerals and rocks are the most common material of the earth. Mineral                   It is a natural inorganic substance of definite chemical composition and generally with a definite crystal form. All minerals except water and mercury are solid at normal temperature. Primary Minerals  are the minerals that have not been altered chemically since deposition and crystallization from molten lava are called primary minerals.  e.g. quartz, feldspar and mica etc. Secondary Minerals are the minerals resulting from the decomposition of a primary or from the re-precipitation of the products of primary minerals are called secondary minerals. e.g. calcite, gypsum, and dolomite etc. Rocks It is defined as a natural aggregate of one or more minerals to form an appreciable part of the solid portion of the earth. Rocks are classified into three types according to their origin Igneous rocks Metamorphic rocks Sedimentary rocks Igneous r

Soil Soil is the unconsolidated upper part of the earth's crust which serves as a natural medium for the growth of plants. It is dynamic in nature and composed of minerals and organic materials, water, air and living forms (plants and animals) that support plant growth. Soil Science It is the branch of science or agriculture that deals with soils as a natural resource on the surface of the earth. It includes the study of soil formation, classification and the physical, chemical, biological and fertility properties of soil in relation to their management for growth of plants and sustaining a clean environment.