Dirtier Dirt

This topic submitted by Rob Dolan, Megan Evans, Andy Gemperline, Matt Rowe ( dolanre@muohio.edu ) on 10/11/04 .

Natural Systems 1 Syllabus---Western Program---Miami University

Introduction
Purpose
In this lab our group intends to explore the relationship between the composition and pH of soil and the location of such things as dumpsters, man-mad buildings, man-made water structures, and natural areas such as near trees. We would like to know if the composition and chemistry in soil is greatly affected by close proximity to both man placed objects and natural ones.

Hypothesis
We hypothesize that soils near dumpsters will have a higher mineral content and pH. Because of rust and other occurrences related to dumpsters, the soil will have absorbed more metals, such as iron, from the dumpster. We also believe that because of garbage overflow, there will be higher concentrations of other minerals and elements. We predict the pH of the soil will increase due to this overflow of different elements.
Through our experiments, we expect to gather data on the effects of man made objects on the soil. We also expect to compare this data with the effects of nature on soil. This research could be used to find better placement of dumpsters to better control pollution of soil, a point our group believes to be highly important.

Background & Prediction
As written by Henry Foth, "soilÉis any unconsolidated material composed of discrete solid particles with liquids and gases occupying the spaces between the particles." (1978, p.3) A unit of soil is called a pedon, and varies in size from 1 to 10 square meters. A soil body is composed of many pedons, and is called a polypedon, which ranges in size from 1 to 10 acres. Finally, landscapes are composed of many polypedons. All polypedon have a series name, and all soil of the same series have similar structures and compositions (Foth, pp. 9-10).
Layers of soil are divided into many horizons, and when looked at vertically compose the profile of soil. For example, when looking at a sample of soil, the first layers of topsoil would be labeled the A horizon, the second layers of clay the B horizon, and the layers of rock beneath would be called the C horizon. Polypedon of the same series all have the same profile. These series are given names common to the area they are most commonly found in (Foth, pp. 6-10).
In the area of the Miami campus, the most commonly found series of soil are the Miami, Kokomo, and Eldean series. Soils in the Miamian series, the most common series to our area, are "well drained, [and] typically have a very dark grayish brown to brown silt loam or loam topsoil layer (ÔA horizon') and are 5 to 10 inches thick. They commonly have a brown or yellowish brown subsoil layer (ÔB horizon'), 8 to 35 inches thick, with higher clay content than the A horizon. Below the subsoil, soils in the Miamian series have a brown to light olive brown substratum (ÔC horizon') that is slightly or moderately alkaline and has lower clay content than the B horizon." (http://www.dnr.state.oh.us/soilandwater/soils/soilreg2.htm) These factors are important to keep in mind when comparing the content of soils near dumpsters to the content of other soils.
It is generally understood that a large amount and wide variety of elements are found within soil. Things such as plant growth and the types of plants affect things such as the pH, the amount of carbon-dioxide diffused in the soil, and the amount of nutrients taken out of the soil. When soil is classified into series, the composition is also taken into account, which may cause variations around the same polypedon areas. Therefore, a mean must be established about which the soil of a polypedon is composed before it may be classified into a series.
Those elements most predominant in soil are carbon and nitrogen, both results of plant-life. Calcium and phosphors are often also found in high quantities within soil, depending upon the flora of the polypedon. Iron is another element common to soil. These are several of the elements to be tested for when taking samples. It is obvious that many other minerals are abundant within soil. However, this is largely subjective to a variety of factors, including flora, climate, and region.
The texture of soil also must be taken into account when classifying soil. For example, because clay has a thick texture, less water is able to be held in the soil. Thus, more nutrients are held within the soil because it is unable to drain. Also, it is more difficult for plants to take root within thicker textures of soil. Therefore, texture also plays an important role when classifying a series or soil.
Because the relative size of each polypedon and pedon, it is impossible for our group to be able to fully look at the entire area in the depth usually required to fully understand the soil. However, it we are still likely to observe slight variations within the soil near man-made objects. Although we predict to not see any major deviations from the soil series of the area, it does not rule out the possibility that even taking our small samples deviations will be shown.

Design
To compare the composition of soil near dumpsters with other man-made sites, our group will gather several samples of soil from under or near one or two dumpsters and buildings. The sample sizes do not need to be large, but should not be any smaller than a cup full (about Dixie cup size). About 5 samples should be taken from each site. Each sample should be labeled according to location and be given a number to identify it from the other samples of the same site. After collecting soil from near man-made sites, a number of soils should also be taken near natural objects such as trees and the duck pond. It should be noted that the duck pond near Peabody hall is a man made pond, but because all water would likely have a common effect on soil, we will be treating it as a natural site. Once all samples have been collected and labeled, samples should be covered to ensure the preservation of moisture.
To begin testing for different elements and the pH of each sample, samples should be diluted in a test tube with de-ionized water. The ratio of water/soil will begin at about 50mL/1 g. However, these numbers may vary depending upon the test and how well the results are shown, and the ratio may need to be tinkered with until a good ratio is found for each test. Tests should be given to find pH, iron content, phosphate content, alkalinity, and calcium content. These tests will show whether more metals are found in soils near man-made sites than in natural site.
To ensure the ability to find a mean composition from each site, no less than five samples should be taken per site. Each sample should be tested for pH and mineral content at least five times to find the mean content of each sample. With these numbers, a mean average may be found for each site with which to compare to Miamian soil and show any major deviances between the two.

Materials
For the purposes of our lab, we will need to have 2 gallons of de-ionized (spring) water with which to mix the soil in. We will need a number of test tubes or beakers to mix the soil and water in and perform tests with. To collect samples, we will need some form of trowel, cups, and covers for the cups to keep the samples air-tight. To find the content and pH of the soil, tests from the science lab will be used.

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