explain the factor of formation of soil in detail
Answers
Answer:
Time:
The formation of soils is a continuing process and generally takes several thousand years for significant changes to take place. The soils of Plymouth County began to develop immediately after the ice retreat of the last glaciation (Pleistocene), approximately 14,000 years ago. The soils are considered to be relatively young soils with slight alteration of parent material and weak soil horizon development. Most of the soil orders mapped in Plymouth County are Inceptisols, Entisols, and Spodosols.
Climate:
Climate, particularly temperature, precipitation and frost action have a profound influence on the soil forming processes which occur within a region. The kind of climate largely determines the nature of the weathering processes that will occur and the rates of these chemical and physical processes. It directly affects the type of vegetation in an area which in turn will affect those soil forming processes related to vegetation. Plymouth County is in a transitional climate zone with conditions characteristic of both humid marine and humid continental climates. The winters are quite mild for New England due to the moderating effect of the surrounding Atlantic waters. Temperature and precipitation (approximately 40 in/yr.) govern the rate of chemical and physical weathering of the soils and allows for the accumulation of organic matter in the surface layer of the soils. Moisture is sufficient enough to promote leaching of water-soluble material down through the soil. Cold winter temperatures allow for frost action which physically break apart rock fragments.
Parent Material: Link to General Geology of Plymouth County, Massachusetts
Parent material is the unconsolidated mineral and organic deposits in which soils are developing. It determines the mineralogical composition and contributes largely to the physical and chemical characteristics of the soil. The kind of parent material also influences the rate at which soil forming processes take place.
Due to the effects of the Wisconsinan glaciation, insufficient time has elapsed to significantly alter the glacial deposits. The influence of parent material is very apparent in the soils of Plymouth County. Parent material is roughly divided into two broad groups; glacial (Late Pleistocene) deposits and post glacial (Holocene) deposits. There are four general types of glacial deposits recognized in the survey area, they are; till, fluvial, lacustrine, and ice-contact deposits. Post glacial deposits are sediments which were deposited after the last glacial period which ended approximately 10,000 years ago. Post glacial deposits recognized in the survey area include, eolian silts and sands, alluvial (floodplain) deposits, freshwater and marine organic deposits, and coastal beaches and sand dunes desposits.
Topography and Relief
The shape of the land surface, its slope and position on the landscape, greatly influence the kinds of soils formed. In Plymouth County soils that formed in similar parent materials with the same climatic conditions exhibit differences as a result of their position on the landscape. These differences are largely a result of varying drainage conditions due to surface runoff or depth to water table.
Soils that developed on higher elevations and sloping areas are generally excessively drained or well drained. Depth to groundwater is generally greater than 6 feet and surface runoff is moderate or rapid. Soil profiles within these areas commonly have a bright colored strong brown to yellowish brown upper solum grading to a lighter, grayer, unweathered substratum.
Organisms
All living organisms actively influence the soil forming process. These organisms include bacteria, fungi, vegetation and animals. Their major influence is the effect on the chemical and physical environment of the soils.
Most, if not all of Plymouth County, was originally in native forest of mixed hardwoods and conifers in varying proportions. The mineral element content of leaves and branches varies depending on the type of forest vegetation, and influences the characteristics of the soils that develop beneath it.
Explain the factor of formation of soil in detail?
Factors affecting soil formation:
Soils form from the interplay of five main factors namely are:
1.Parent material
2.Time
3.Climate
4.Relief and Organisms.
Parent Material:
This refers to the mineral material or organic material from which the soil is formed. Soils will carry the characteristics of its parent material such as color, texture, structure, mineral composition and so on. For example, if soils are formed from an area with large rocks (parent rocks) of red sandstone, the soils will also be red in color and have the same feel as its parent material.
Time:
Time: Soils can take many years to form. Younger soils have some characteristics from their parent material, but as they age, the addition of organic matter, exposure to moisture and other environmental factors may change its features. With time, they settle and are buried deeper below the surface, taking time to transform. Eventually, they may change from one soil type to another.
Climate:
This is probably the most important factor that can shape the formation of soils. Two important climatic components, temperature and precipitation are key. They determine how quickly weathering will be, and what kind of organic materials may be available on and inside of the soils. Moisture determines the chemical and biological reactions that will occur as the soils are formed. A warmer climate with more rainfall means more vegetative cover and more animal action. It also means more runoff, more percolation and more water erosion. They all help to determine the kind of soils in an area.
Relief:
This refers to the landscape position and the slopes it has. Steep, long slopes mean water will run down faster and potentially erode the surfaces of slopes. The effect will be poor soils on the slopes, and richer deposits at the foot of the slopes. Also, slopes may be exposed to more direct sunlight, which may dry out soil moisture and render it less fertile.
Organisms:
The source and richness of organic matter are down to the living things (plants and animals) that live on and in the soils. Plants, in particular, provide lots of vegetative residues that are added to soils. Their roots also hold the soils and protect them from wind and water erosion. They shelter the soils from the sun and other environmental conditions, helping the soils to retain the needed moisture for chemical and biological reactions. Fungi, bacteria, insects, earthworms, and burrowing animals help with soil aeration. Worms help break down organic matter and aid decomposition. Animal droppings, dead insects and animals result in additional decaying organic matter. Microorganisms also help with mineral and nutrient cycling and chemical reactions.