Soil is formed by various processes and originates from parent material.

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1 Soils and sediments usually contain organic matter from decayed vegetation. A majority of the organic matter is humic substances. o Humic substances are naturally formed from the decomposition of vegetation. o Once the humic substance is formed, it is a resistant to degradation. The major soil elements in humic material, C, N, P, and S, have an expected ratio of 100:10:2:1, respectively. Reservoirs of N, P, and S formed in the humic material. The reservoir s elements are available to plants as microorganisms break down soil organic matter. Soils usually have several layers, called horizons, of differing composition that are used in soil classification. Horizons are the result of biological decay, weathering, and leaching. The top layer of soil is known as the A horizon, or topsoil, and it is usually several inches thick. o The topsoil has the most biological activity and contains the most organic matter. Since 1750, there has been an increase in atmospheric carbon dioxide of 31% as a result of fossil fuel combustion and land use changes. From the start of the Industrial Revolution (around the year 1750) to the year 2004, global emissions of carbon have been estimated at 270±30 x g due to fossil fuel combustion and 136±55 x g due to changes in land use and soil cultivation. Land use changes include; deforestation, biomass burning, conversion of natural to agricultural soils, drainage of wetlands, and soil cultivation. The diminishing soil organic content pools have contributed to an increase in carbon to the atmosphere, also. The soil organic matter of the soil is the part that was once a living substance, such as, plant and animal remains. The remains of terrestrial plants compose the largest portion of soil organic matter These remains can vary in levels of decomposition and also contain cells and tissues. Most soils contain an organic matter amount of a little less than 5% (USDA, 1996). o But some soils, such as peat soils, can contain up to about 95% organic matter. o Also, some soils only contain about 1% organic matter. Another common source in soil organic matter is plant roots and soil microbes. o If the organic matter is well decomposed, it will be dark brown in color, spongy, and porous. Much of the organic material comes from plant derived litter, so the amount of organic materials added to soil depends on the main type of vegetation present. The organic materials added to the soil can have different amounts of degradation. Soil is formed by various processes and originates from parent material.

2 The soil s characteristics are formed by five major factors: climate, biological activity, topography, length of time these factors act on the soil, and parent material. The climate and biological activity are active factors of soil formation. The other three factors of soil characterization are passive factors. Active factors develop the soil once the soil has gone through the weathering process of the parent material. Each characterizing factor has a different affect on the soil. The affect of these factors depends on the geographical location. Biological effects can incorporate physical disruption by plant roots, chemical effects from root excretion, and bacterial action. Biological actions cause reactions in the nitrogen cycle and the organic materials. These actions affect the soil ph, therefore, affecting soil solubility and leaching. Leaching is the loss of soluble substances from the top layer of soil. o The substances are carried down through the soil and usually redeposited in the lower layer through percolating precipitation. o As a result, a porous top layer and a dense lower layer is created. The weathering processes can vary depending on the initial composition of the rock and the environmental conditions. Organic matter holds soil particles together and this will lower the amount of soil erosion. Since the soils on the surface have the highest percent of organic carbon content, erosion can reduce the amount of soil organic carbon Weathering patterns differ with climate zones. o The upper layer of soils will weather faster in wetter climates, such as tropical rain forest conditions. o The organic materials in the soil will decay and produce acidic leaching conditions, so the upper layer soil conditions will be less acidic from the leaching. Soil carbon accumulation is also affected by topography. Soil erosion will vary with differing land slopes Soil organic carbon will be more significantly affected by erosion through increased slope in the upper 20 cm of soil. Factors such as temperature influence the level of microbial activity temperate regions with cold winters decrease microbial activity and cause a buildup of organic matter Tropical regions have a much lower amount of organic material below the upper layer The determination of total organic carbon is an essential part of any soil ecological site characterization since its percent content can markedly influence how chemical reactions will proceed in the soil. Total organic carbon contents of soils are typically requested with contaminant analyses as part of an ecological risk assessment data package.

3 Total organic content may be used to qualitatively assess the nature of a sampling location. The amount of organic matter is strongly affected by the availability of oxygen. In waterlogged soils, decaying vegetation does not have easy access to oxygen, so the organic matter accumulates. In cases such as this, the soil organic matter can reach 90%. Organic matter helps the growth of crops, plants, and soil organisms by improving the soil s ability to store and use air/ and water and storing/ supplying nutrients, such as, nitrogen, phosphorus, and sulfur. Organic matter also allows soil to be worked easier because of less stickiness retains carbon from the atmosphere can help reduce the negative effects on the soil by pesticides and pollutants Soils release about 60 billion tons of CO 2 per year. About the same amount is held by land plants. The decomposing plant material is responsible for releasing most of the CO 2 in the upper level soils. Two thirds of the releasing CO 2 comes from the deeper layers, caused by respiration in roots, fungi, and soil microorganisms. Microbial activity converts organic matter to CO 2. About 70% of the carbon added to soil is lost as CO 2 because of, mostly, microbial respiration. o The other 30% of carbon added to soil is incorporated into the microbial biomass and soil humus. Tilled soils organic matter decomposes faster because the organic content is exposed to the elements, such as: change in water air contact temperature conditions Losses of soil organic content are high under aerobic (exposed to O 2 ) decomposition, compared to anaerobic (without O 2 ) decomposition Since plant biomass adds to the soil organic content, the following affect soil organic content: the amount of plant consumption by animals and insects destruction of plants by fire production and harvesting of crops by humans o Some cultivated soils can lose one half to two thirds of the original organic content from the soil Restorative land use and recommended management practices (RMPs) on soils can reduce the rate of increasing atmospheric carbon dioxide can result in a positive impact on:

4 o food security o agro industries o water quality Restoring the land with prairie grass can increase the carbon pool of that terrestrial area. Humans can INCREASE soil organic matter increase the production of plant materials by irrigation introducing plants that produce more biomass restoring grasslands and prairies increasing the supply of organic materials to soils by applying carbon rich wastes, like animal manure decreasing decomposition by reducing tillage o keeps the soil cool by introducing vegetative cover o Keeping the soil cool is effective because soil decomposition is directly related to temperature o The warmer the soil, the faster the soil organic matter will decompose According to Canadian agricultural data, carbon sequestration was increased when conventionally tilled soils were converted to no till soils In 1996, the amount of carbon (C) stored in the soils due to conversion to no till soils was 1.23 x 10 6 mg of C In 2001, the amount was calculated to be 1.72 x 10 6 mg of C The amount of sequestered C in the no till zones is approximately 10% of greenhouse emissions from the Canadian agricultural sector Researchers from the University of Illinois reported in late 2008 that, planting perennial grasses on existing agricultural lands had the most beneficial effect on soil carbon. Although there was an initial drop in carbon as fields were converted from corn to Miscanthus, switchgrass or native perennial grasses, the loss was fairly quickly offset by yearly gains in soil carbon as the grasses became established (Yates, 2008). Many factors must be considered when restoring a land area to prairie form. Open areas, such as fields and pastures, are preferred over a highly wooded area when considering a prairie restoration site. o Trees along a prairie s boundary reduce sun and wind into the prairie. The present nutrients in the soil of interest must also be considered. o A soil high in nutrients is not preferred. The high nutrient content better suites o weed growth over prairie restoration species. With time, the prairie s plant species will add organic matter to the soil, so the nutrient content in the soil will rise. Match restoration prairie plant species with original, regional prairie plant species Match appropriate soil moisture that allows for the proper growth of the plant Two common routes of prairie restoration exist

5 1. no tillage and planting the restoration plants over the existing plants. The existing plants are burned, and the site may or may not be sprayed with a herbicide 2. cultivating existing weeds and plants. The site may or may not be treated with herbicide. Then, plant restoration plants. Three examples of restored prairies in Illinois 1. The Green Oaks Field Station was given to Knox College, in Galesburg, Illinois, in A few years before Green Oaks Field Station came under the control of Knox College, two Knox College professors began to restore the area back to its natural prairie habit. In 1965, another Knox College professor began to finish the restoration process. The appropriate species of plants were planted in the restored prairie. The prairie was burned each year to stimulate growth and to keep out evasive species. The prairie at Green Oaks Field Station is the second oldest restored tallgrass prarie in the United States of America. facilities/green oaks/green oaks history.html facilities/green oaks/prairie burn.html 2. The Nygren Wetlands restoration and preservation began in The Natural Resources Conservation Service (NRCS) entered the wetland into the Wetland Reserve Program. The program separates the restored land from agricultural lands. The owners of the land gave the property to the Natural Land Institute. The Nygren Wetlands are a 705 acre preserve. For over 40 years, the land was used for agricultural purposes, such as corn/ soybean fields and cattle production. Ditches were implemented. Buildings were constructed. The land was tilled. The goal of the restoration was to create a self sustaining system. The Natural Land Institute used expert ecologists to change the landscape. The restoration plan was developed in conjunction with the USDA NRCS The 250 acres that make up the Nachusa Grasslands was purchased in 1986, and the restoration process started. The Nature Conservancy and hundreds of volunteers goal was to re create 1800 Illinois prairies, savannas, and wetlands. Non Illinois plants must be continually removed from the Nachusa Grasslands. The restored prairie is now home to over 600 native plants. achusa grasslands.xml Process for testing the soil organic content: