Explain any two physical factors of soil formation.
Answers
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.