Free Essay

Soil

In: Science

Submitted By tweldon
Words 759
Pages 4
The Nature of Soil

Tara D. Weldon
GENS 320 Physical Geography
August 2, 2015
Soil is a nearly infinitely varying mixture of weathered mineral particles, decaying organic matter, living organisms, gases, and liquid solutions. There are five principal soil forming factors responsible for soil development: Geology, climate, topography, biology, and time.
(geologycafe, 2015)
Geologic Factor: Over many years (thousands and/or millions) a stony surface can be broken down by weather, such as rain, wind and ice. This process is known as weathering.
Climatic Factor: Warmer temperatures and an abundance of water have a tendency to speed up the formation of soil. Cooler temperatures and less precipitation slow down soil formation. Topographic Factor: In areas that are flat, soil tends to get deeper quicker than the surface erodes away. Which typically have deeper, more mature soil layer. On steep slopes, erosion takes place quicker than the formation of new soil. Which have thin layer of soil that is immaturely developed.
Drainage is also a factor. Some locations become waterlogged. This blocks oxygen, which is important for soil formation. In those locations soil formation can become severely hindered.
Biological Factor: Living organisms have an extensive impact on soil. A small fraction of soil contains living and dead lifeforms. However, the role of these lifeforms can't be underestimated. Roots from plant life dig deep into the soil, creating passages for water and air. Animals such as ants, earthworms, rodents and snakes dig and till the soil extensively. Plants and animals provide nutrients to the soil in the form of waste products and dead bodies. A variety of micro-organisms perform important jobs in the soil that help to decompose living materials, and that give richness to the soil.

(Cuny, 2015)
Time Factor: Soil forms over thousands and/or millions of years. A newly exposed surface will have little or no soil, while old surfaces will have much deeper soil.
Mollisols (Dark, Soft Soils for Grasslands) The distinctive characteristic of Mollisols is the presence of a mollic epipodon, which is a mineral surface horizon that is dark and thick, contains abundant humus and basic cations, and retains a soft character (rather than becoming hard and crusty) when it dries out. Mollisols can be thought of as transition soils that evolve in regions not dominated by either humid or arid conditions. They are typical of the midlatitude grasslands and are thus most common in central Eurasia, the North American Great Plains, and the pampas of Argentina.
The grassland environment generally maintains a rich clay-humus content in a Mollisol soil. The dense, fibrous mass of grass roots permeates uniformly through the epipedon and to a lesser extent into the subsurface layers. There is almost continuous decay of plant parts to produce a nutrient-rich humus for the living grass.
Mollisols on the whole are probably the most productive soil order. They are generally derived from loose parent material rather than from bedrock and tend to have favorable structure and texture for cultivation. Because they are not overly leached, nutrients are generally retained within reach of plant roots. Moreover, Mollisols provide a favored habitat for earthworms, which contribute to softening and mixing of the soil.
Alfisols (Clay-Rich B Horizons, High Base Status) the widest ranging of the mature soils, Alfisols occur extensively in low and middle latitudes. They are found in a variety of temperature and moisture conditions and under diverse vegetation associations. They tend to be associated with transitional environments and are less characteristic of regions that are particularly hot or cold or wet or dry. Their global distribution is extremely varied. They are also widespread in the United States, with particular concentrations in the Midwest.
Alfisols are distinguished by a subsurface clay horizon and a medium to generous supply of basic cations, plant nutrients, and water. The epipedon is ochric (light-colored), but beyond that, it has no characteristics that are particularly diagnostic and can be considered an ordinary eluviated horizon. The relatively moderate conditions under which Alfisols develop tend to produce balanced soils that are reasonably fertile. Alfisols rank second only to Mollisols in agricultural producti (America, 2015)

Bibliography
America, S. S. (2015, August 2). K-12 Soil Science Teacher Resources. Retrieved from soils4teachers.org: http://www.soils4teachers.org/lessons-and-activities/teachers-guide/world-soils
Cuny, H. (2015, August 2). chapter.4.outline. Retrieved from geography.hunter.cuny.edu: http://www.geography.hunter.cuny.edu/tbw/ncc/Notes/chapter.4.outline.html geologycafe. (2015, August 2). Weathering and Erosion. Retrieved from geologycafe.com: http://geologycafe.com/erosion/weathering.html

Similar Documents

Free Essay

Soils

...Introduction to Soil / Soil Formation LA7014 - Ecology / Technology I What is the difference between dirt and soil? Textbook Definition of Soil • Preferred Definition - “The unconsolidated material at or near the earth’s surface that has properties due to its proximity to the surface” • Long Version - “the unconsolidated mineral or organic matter on the surface of the earth that has been subjected to and shows the effects of genetic and environmental factors of: climate (including water and temperature effects) and macro- and microorganisms, conditioned by relief, acting on parent material over a period of time” Importance of Soil • "Essentially, all life depends upon the soil .... There can be no life without soil and no soil without life; they have evolved together." Charles E. Kellogg • "The nation that destroys its soil, destroys itself." Franklin D. Roosevelt • "While the farmer holds the title to the land, actually it belongs to all the people because civilization itself rests upon the soil." Thomas Jefferson Importance of Soil • Medium in which plants are grown for food and fiber. • Mechanical support for plant roots, such as trees. • Physical support for structures, roads, sidewalks, etc. • Home for millions of organisms. • Air-storage facility. • Mineral supplement for people (in some regions of the world) • Earth’s compost pile. Soil Sphere Theory • Pedo = Soil • Bio...

Words: 769 - Pages: 4

Premium Essay

Soil

...University of Phoenix Material Soil and Glaciers Worksheet From Visualizing Earth Science, by Merali, Z., and Skinner, B. J, 2009, Hoboken, NJ: Wiley. Copyright 2009 by Wiley. Adapted with permission. Part 1 Size grades of soil are named sand, silt, and clay, which includes colloids. Size grades are defined using the metric system. Use Figure 4.8 from the textbook to fill in the following chart. Specify the type and size and description of the particle. In some cases, particle size will be less than some value or greater than another value. For instance, gravel is greater than 2.0 mm. |Name |Size |Description | |Gravel |>2.0 mm |Limestone, dolomite , sand mixture of pebbles and small rocks | |Sand |>2mm |Quartz, gypsum,mollusk shell, coral fragments basalt pumice. colloids | |Silt |>0.01mm |Sedimentary rock, water, wind, ice include colloids. | |Clay |>0.002mm |Plasticity, firm,silicate, granite, alumina limestone, colloids | |Colloids |>0.00001mm |Molecules, colored glass, tiny grain of sand, silt, and clay. | Part 2 Soils have been classified according...

Words: 729 - Pages: 3

Premium Essay

Soil Erosion

...1.0 Introduction Soil erosion has been accelerated in many areas of the world especially Australia. It becomes a biggest problem in Australia which leads Australians have to confront it. Soil erosion means the removal or disappearance of soil by water or wind. It may due to the poor cultivation, overgrazing and stripping of the land. Today, soil erosion is one of the most critical environmental problems in Australia which threatening farmlands, streams and village.  This report below is concentrate on the types, causes and preventing of soil erosion. 2.0 Types of soil erosion There have various types of soil erosion but the two major types of soil erosion that often occur in Australia which is water erosion and wind erosion. 2.1 Water erosion Water erosion is the most widespread erosion in Australia. There have several types of water erosion which is sheet, rill and gully erosion. Firstly, Raindrop can be a main problem for farmers when they strike bare soil. Rain can washes away seed and splashes soil into the air. If the fields are on a slope the soil is splashed downhill which causes deterioration of soil structure (Sydenham & Thomas, 2008). Hence, soil that has been separated by raindrops is more easily moved than soil that has not been separated. Sheet erosion is caused by raindrops whereas rill erosion and gully erosion caused by rainfall. Sheet erosion is defined as the uniform removal of soil in thin layers from sloping land. When rains run off the slope, without...

Words: 459 - Pages: 2

Premium Essay

Soil Conversion

...Soil Conservation Working Group Report This report provided content for the Wisconsin Initiative on Climate Change Impacts first report, Wisconsin’s Changing Climate: Impacts and Adaptation, released in February 2011. THE WISCONSIN INITIATIVE ON CLIMATE CHANGE IMPACTS 1st Adaptive Assessment Report Contribution of the Soil Conservation Working Group July 2010 Contour stripcropping in central Wisconsin Photo by Ron Nichols, USDA Natural Resources Conservation Service Participants of Working Group William L. Bland, Professor, Department of Soil Science, University of Wisconsin-Madison (Working Group Chair and lead author) Kelly R. Maynard, M.S. Agroecology, University of Wisconsin-Madison (Project Assistant) Jeremy Balousek, P.E., Urban Conservation Engineer, Dane County Land and Water Resources Department Denny Caneff, Executive Director, River Alliance of Wisconsin, Inc. Laura W. Good, Associate Scientist, Department of Soil Science, University of Wisconson-Madison Kevin Kirsch, Water Resource Engineer, Wisconsin Department of Natural Resources Patrick Murphy, State Resource Conservationist, Natural Resources Conservation Service John M. Norman, Emeritus Professor of Soil science, Department of Soil Science, University of Wisconsin-Madison James VandenBrook, Water Quality Section Chief, Wisconsin Department of Agriculture, Trade, and Consumer Protection Sara Walling, Water Quality Specialist, Wisconsin Department of Agriculture, Trade, and ...

Words: 12656 - Pages: 51

Free Essay

Soil Investigation

...Soil investigation is often neglected or rejected by most clients on the basis of cost, despite the fact that the cost of carrying out a soil investigation is very little compared to the cost of the project Soil investigation is done for various purposes. In engineering, soil investigation is very necessary. It is essential to investigate the soil of the selected plot on which a structure will be constructed. Based on soil investigation a soil report is prepared for the purpose of designing the building foundation. When an engineer designs building foundation he/she must carefully read the report and design the foundation based on the data provided in the report. Soil investigation is required for the following purposes - To know the allowable bearing capacity of foundation for proposed building. To know the depth and type of foundation for the proposed building. To know the allowable passive resistance for the foundation of proposed building. To know the type, grading and nature of soil. To know the ground water level. Typical steps of soil investigation Soil investigation involves following steps –  Details planning for the sequence of operations.  Collecting the samples of soil from the plot.  Determining the soil characteristics by conducting field tests.  Study the condition of ground water level.  Collecting ground water sample for chemical analysis.  Soil exploration.  Testing all collected samples in the laboratory.  Preparation of drawings...

Words: 1233 - Pages: 5

Premium Essay

Soil and Glacier

...University of Phoenix Material Soil and Glaciers Worksheet From Visualizing Earth Science, by Merali, Z., and Skinner, B. J, 2009, Hoboken, NJ: Wiley. Copyright 2009 by Wiley. Adapted with permission. Part 1 Size grades of soil are named sand, silt, and clay, which includes colloids. Size grades are defined using the metric system. Use Figure 4.8 from the textbook to fill in the following chart. Specify the type and size and description of the particle. In some cases, particle size will be less than some value or greater than another value. For instance, gravel is greater than 2.0 mm. Name Size Description Gravel >2.0 mm Rock that is unconsolidated with fragments that have a general particle size range Sand 0.05 Sand particles are largerly formed by the physical break up of rocks. Sand has small surface areas and have an almost negligible role in the chemical activity of the soil. Sand particles are chemically insert or inactive. Silt 0.002 Silt is formed by physical weathering. Finer silits, which approach colloidal sizes, may exhibit some of the characteristics properties of clay. Clay Below 0.002 milimeters The clay fraction differs from the sands and silts in that it is composed predominantly of minerals formed as products of secondary weathering. The rock mineral will go through change before becoming clay minerals. Colloids 0.0001 – 0.00001 milimeters Like other soil particles, some colloids are minerals, whereas others are organic. Minerals colloids...

Words: 1284 - Pages: 6

Premium Essay

Soil and Glaciers

...University of Phoenix Material Soil and Glaciers Worksheet From Visualizing Earth Science, by Merali, Z., and Skinner, B. J, 2009, Hoboken, NJ: Wiley. Copyright 2009 by Wiley. Adapted with permission. Part 1 Size grades of soil are named sand, silt, and clay, which includes colloids. Size grades are defined using the metric system. Use Figure 4.8 from the textbook to fill in the following chart. Specify the type and size and description of the particle. In some cases, particle size will be less than some value or greater than another value. For instance, gravel is greater than 2.0 mm. |Name |Size |Description | |Gravel |>2.0 mm |Gravel is very small, irregular pieces of rock and stone. Gravel is more rough and rocky than sand, and | | | |smaller than stones. The word gravel comes from the French word gravele, "gravel or sand," which in turn | | | |comes from grave, "seashore or sand ("Gravel ", 2015). | |Sand |0.05 |sedimentary material, finer than a granule and coarser than silt, with grains between 0.06 and 2.0 | | | |millimeters in diameter ("Sand", 2003-2015). | |Silt |0.0002 |Silt is very...

Words: 1793 - Pages: 8

Premium Essay

Soil Science

...CHAPTER 1 1. INTRODUCTION Rice is one of the important food crops in the world, and it is the staple diet of 1.6 billion people in Asia. Average yield of rice in Malaysia is 3.2 t/ha which is low compared to an average of 5.4 t/ha from East Asian countries. Nowadays, people tend to eat more quality foods rather than normal food. An example, most of people will choose the healthy one likes organic rice; Brown Rice. Therefore, in order to handle these situations our government suggests to all farmers to handle the natural farming at their farms. Natural farming is one of the production methods that use the organic crops such as Indigenous Microorganisms, fertilizer and some factors likes air, water and soil. In additions, large sums of money have been invested in providing irrigation and drainage infrastructure facilities to enable double cropping of rice using high yielding varieties with the latest agronomic practices in attempts to attain high rice yields. There is an alarming concern of a future demand for still higher levels of chemical to be used in order to maintain crop yields. Apart from this, the excessive dependence on chemical pose health hazards and are harmful rice agro-ecosystem and methods to sustain yield levels with the minimal use of chemicals. How to find the solutions? For the detail solution we are explain in this report. In this report, we include the best management practices that can be applied in natural...

Words: 3463 - Pages: 14

Free Essay

Soil Erosion

...Soil Erosion Environmental Science Wanda Black 2/12/15 Soil is solid material of geological and biological origin that is changed by chemical, biological and physical processes. This gives the soil the ability to support plant growth. Erosion is the process of soil and humus particles being picked up and carried away by water or wind. Erosion follows when soil is bared and exposed to the elements. This is how soil erosion happens as well as when there are no plants or trees and soil getting swept into the river. The negative impacts of soil erosion, is overgrazing, over cultivation and deforestation. Overgrazing is grassland that is constantly plowed and crops grown on it. The grasslands don’t get enough rain to support cultivated crops or are too steep for cropping and for grazing livestock. It reduces the ability of plants to grow and water to not penetrate the land. Overgrazing can be prevented by farmers getting information from the U.S. Natural Resources Conservation Service (NRCS). They do testing and analysis of soil. The NRSC have helped decrease soil erosion from 2.1 billion tons in 1992 to 1.7 billion tons in 2007 and made consequences of improved conversion practices such as windbreaks, grassed waterways and field border strips of perineal vegetation. If the land is left untreated it could cause a problem with the food chain. Overcultivation is when the soil has been plowed to control weeds and the soil is exposed to wind and water. The soil may...

Words: 373 - Pages: 2

Free Essay

Soil Properties

...The purpose of a site investigation is to identify the ground conditions which might affect the proposed development. It enables better understanding of the site and immediate surroundings, which will enable safe and economic developments. They are a common requirement of the investors as well as the regulatory authorities. In the broadest sense, the ground conditions are understood to include not only the underlying soils and rocks but also the groundwater regime, any contamination and effects of any previous uses of the site The purpose of a site investigation is to identify the ground conditions which ma, any contamination and the effects o 1.1.1 The scale of problem Various reports over the past 25 years have shown that the largest element of technical and financial risk normally lies in the ground. Ground related problems have led to late completions and high cost overruns on the national scale. Lady using a tablet Professional Essay Writers Get your grade or your money back using our Essay Writing Service! ESSAY WRITING SERVICE In an analysis of 8000 building projects, National economic Development office (NEDO) stated that one third of the projects overran by more than a month, a further one third overran up to a month due to delays due to unforeseen ground conditions. Work in groups or pairs, note down a few points on Why carry out site investigation? 1.2 Why carry out site investigation? The characterization of ground conditions whether for...

Words: 3000 - Pages: 12

Free Essay

Soil Horizon

...A soil horizon is a layer generally parallel to the soil surface, whose physical characteristics differ from the layers above and beneath. Each soil type usually has three or four horizons. Horizons are defined in most cases by obvious physical features, chiefly colour and texture. These may be described both in absolute terms (particle size distribution for texture, for instance) and in terms relative to the surrounding material (i.e., "coarser" or "sandier" than the horizons above and below). The differentiation of the soil into distinct horizons is largely the result of influences, such as air, water, solar radiation and plant material, originating at the soil-atmosphere interface. Since the weathering of the soil occurs first at the surface and works its way down, the uppermost layers have been changed the most, while the deepest layers are most similar to the original parent material. Identification and description of the horizons present at a given site is the first step in soil classification at higher levels, through the use of systems such as the USDA soil taxonomy or the Australian Soil Classification. The World Reference Base for Soil Resources lists 40 diagnostic horizons.[1] Soil scientists often dig a large hole, called a soil pit (usually several meters deep and about a meter wide) to expose soil horizons for study. The vertical section exposing a set of horizons, from the ground surface to the parent rock, is termed a soil profile. Most soils, especially...

Words: 400 - Pages: 2

Premium Essay

Essay On Geography Of Soil

...Maeve Upton 14310368 C. ‘In order to understand the geography of soil all one needs is a good map of the solid geology.’ Abstract: It would be naïve to assume that a good map of solid geology is the only resource needed to understand the geography of soils. The geography of soil does not depend solely on the solid geology of the biosphere and lithosphere. When one studies the geography of soil it is important to look at the properties of soils including the parent material which is usually the dominating underlying bedrock. However, one must take into account the factors that affect soil development and the processes in soils that can produce variations. For examples, climate, topography, time, biological agents such as animals and human interference. Pedology provides us with a soil classification system that can be used to determine types of soil but throughout history it has been...

Words: 1667 - Pages: 7

Premium Essay

Essay On Soil Erosion

...Soil erosion poses a significant threat to the environment and agriculture. The repeated loss of fertile topsoil negatively affects the long term sustainability of natural systems. Agricultural productivity faces a significant decline as a result of soil erosion Kusimi et al., (2015). Agricultural land across the world has either been lost or is rapidly experiencing degradation as a result of soil erosion. According to Arekhi et al., (2012), close to 40% of the world’s agricultural land is degraded, this includes 65% for Africa, 74% and 45% for North and South America respectively. Notable is that soil loss by erosion is an ongoing process, it was earlier reported by (Dudal 1981) that, across the globe , approximately 6,000,000 ha of fertile...

Words: 1022 - Pages: 5

Premium Essay

Soil Protection in South Africa

...Soil Protection in South Africa. Soil protection is the protection and management of the quality of soil. It is all about solving the problems of land degradation. It can further be defined as the combination of the appropriate land use and management practices that promote the productive and sustainable use of soils and in the process minimise soil erosion and other forms of land degradation. 3.2.10 Causes of soil degradation in South Africa. Erosion. Erosion is the detachment and transportation of soil materials by wind or water. Soil erosion is a major problem of agriculture in South Africa. Soil erosion is a natural process but it becomes a serious problem when the activities of humans accelerate the process of its occurence. Land degradation caused by soil erosion causes the loss of fertile topsoil and reduces soil productivity. Researches have shown that over 70% of the soil in South Africa has been affected by one form of soil erosion or the other. The annual soil loss due to soil erosion in South Africa is estimated at 300 – 400 million tonnes for each hectare of land. South Africa loses an average of 20 tonnes of soil for each tonne of agricultural products produced. Soil erosion can be caused by water and, or wind. The effects of these factors on the soil are determined by the speed and the soil cover at the time of occurence. It is estimated that 25% of the country is covered by soil that is susceptible to wind erosion. These include the sandy soils in the...

Words: 1745 - Pages: 7

Premium Essay

Cotton Soil Case Study

...Geographical area is covered by expansive ‘Black Cotton Soil’. These soils are characterized by their highly swelling and shrinkage properties. In dry conditions these soils have high strength which is almost completely lost when they come in contact with water. These soils are having high degree of expansion which creates a lot of problems during the execution of work and after completion of it. Hence stabilization of such soil is prime importance. Attempts have been made to stabilize these soils by using different materials such as lime, cement, asphalt etc. Industrial wastes such as fly ash, furnace slag can also be used for this purpose. In order to improve the engineering and index properties of soil, the experiments have been conducted with industrial wastes of steel foundry called as furnace slag plus black cotton soil. The results show...

Words: 1410 - Pages: 6