Kelly Pendergast

BI 341

October 31, 2002

 

“Field study project”

 

Abstract:

 

     Oak Creek, Wisconsin, is recognized as a swampland area, terrible to build or own a home on (Division of Hearings and Appeals 2002). A total of 48 soil samples were obtained and analyzed for a pH value to test the hypothesis that Oak Creek would have more acidic soil than Franklin. This hypothesis was based on the fact that swampland contains higher amounts of water therefore Oak Creek soil pH would be more acidic, as a result of rainwater leaching away basic ions such as calcium, magnesium, potassium, and sodium in the soil (Bickelhaupt 2002). In analyzing the data it was apparent that there was no evidence that supported Oak Creek having more acidic soil than Franklin. All the comparison graphs and P values from the T-tests from O m in vegetation, 9.144 m from vegetation, and 18.288 m from vegetation, proved to not be significant.

Keywords: Soil pH, pH comparison, pH

Introduction:

    

          The objective of this experiment was to determine if there was a difference in soil pH from a location at 3030 W. Minnesota Ave. in Franklin (Fig.1, Map 1), to a site in Oak Creek at 615 W. Riverwood Dr. (Fig. 2, Map 2). The hypothesis tested was that measured areas in Franklin at 0 m in vegetation, 9.144 m from vegetation, and 18.288 m from vegetation would have a greater pH values compared to the same measurements in and away from vegetation made in Oak Creek. This hypothesis was based on the idea that Oak Creek is known to be swampland area, therefore soil pH would be more acidic as a result of rainwater leaching away basic ions such as calcium, magnesium, potassium, and sodium in the soil (Bickelhaupt 2002).

     Soil pH is defined as the negative logarithm of the hydrogen ion concentration. Soil pH is an indication of the acidity or alkalinity of soil and is measured in pH units on a scale of 0 to 14, with 7 being neutral. Soil that is acidic has a pH range of 7 to 0, while alkaline or basic soil has a pH range of 7 to 14.  The pH of soil is very important because soil carries certain nutrients such as Nitrogen, Potassium, and Phosphorus that plants need in specific amounts to grow, thrive, and fight off diseases. If the pH of the soil is above a pH of 5.5, Nitrogen is available to plants. Phosphorus, on the other hand, is available to plants when soil pH is between 6.0 and 7.0 (Bickelhaupt 2002). Bacteria that help plants obtain Nitrogen in usable forms function best when the pH of the plant they live in is growing in soil within an acceptable pH range.

     It is important to know whether soil pH is acidic or basic because if the soil is too acidic, the pesticides, herbicides, and fungicides commonly applied will not be absorbed or held in the soil. This means they will end up in rainwater run off, where they will eventually become pollutants in our streams, rivers, lakes, and ground water. If soil pH is too acidic, plants cannot utilize the Nitrogen, Phosphorus, Potassium, and other nutrients that they need. In some cases plants in acidic soils are more likely to take up toxic metals and some plants ultimately die of toxicity. 

Methods:

 

     On October 17, 2002, 24 soil samples were collected from two different locations and analyzed for a pH value. A total of 48 soil samples were collected and analyzed. Soil samples were collected from 615 W. Riverwood Dr. in Oak Creek (Map2) and 3030 W. Minnesota Ave. in Franklin (Map 1) in exactly the same manner, so a comparison study could be conducted. Both individual areas were measured at 0 m in vegetation, 9.144 m from vegetation, and 18.288 m from vegetation, using a standard measuring tape. While wearing gloves, each soil sample was obtained using a soil core digger to penetrate the soil, to zone B. Soil samples removed from the ground, were then placed into individual plastic bags and labeled according to site location and meters gathered from vegetation. Exactly eight soil samples were collected from each area at each site location, or at 0 m, 9.144 m, and 18.288 m, were 0 m was in the vegetation.

     All forty-eight soil samples obtained were than tested for a pH value using the Lamotte combination soil test kit; model EM 5934 (Fig. 3). Test tubes were filled to line 4 with pH indicator 5701 PT-K, lot # 201801, and approximately 1.5 grams of soil was scooped into each test tube, using a 0.5 gram tool dipper (Fig. 4). Test tubes were then capped and gently shaken for exactly one minute. After the soil settled, or approximately 10 minutes later, the test tubes were compared to a Lamotte pH wide range color chart, code 1352. The site location, soil collection procedure, and method of pH analysis were all documented in a laboratory notebook and photographed for visual comparison.

Results:

 

     P value analysis from the T-Test calculation of the data at each site location, were not significant. Overall the pH values were basically the same regardless of area or site they were obtained from. The pH values ranged from 7.5 to 7.7 and there was no significant decrease in pH in the vegetation at either site. This doesn’t support my hypothesis that Oak Creek would have more acidic soil than Franklin. The pH comparison values at each site location at each measured position were also not significant. The difference in pH values at each site location are as follows; at 0 m there was a 0.025 pH difference, 9.144 m there was a 0.075 difference, and at 18.288 m, there was a 0.1375 difference in pH values (See table 1,2,3). A T-test comparing soil pH of Oak Creek to Franklin sites also was calculated and a P value along with the graphs supported that the differences in pH values were not significant. At 0 m the P value was 0.42, 9.144 m 0.32, and at 18.288 m 0.15 (See table 1,2,3). All of these comparisons can also be observed by the graphs below (See graph 1, 2, 3).

Graph 1: Comparison of Franklin and Oak Creek at 0 m, from vegetation (P value = 0.42)

 

 

 

 

 

 

 

 

 

 

Graph 2: Comparison of Franklin and Oak Creek at 9.144 m, from vegetation (P value = 0.32)

Graph 3: Comparison of Franklin and Oak Creek at 18.288 m from vegetation (P value = 0.15)

 

 

 

 

 

 

 

 

 

 

 

 

Table 1: Analysis of pH values at each site location, 0 m, from vegetation

 

Franklin

Oak Creek

7.5

7.5

7.5

8

7.5

7.5

7.5

7

7.5

7.5

7.5

8

7.5

7.2

Average 7.5

Average 7.525

Difference in averages 0.025

P value = 0.42

 

 

Table 2: Analysis of pH values at each site location, 9.144 m from vegetation

 

Franklin

Oak Creek

7.2

7.5

7.5

7.5

7.2

8

7.5

8

7.5

7.5

7.7

7.3

7.5

7.2

Average 7.45

Average 7.525

Difference in averages 0.075

P value = 0.32

 

 

Table 3: Analysis of pH values at each site location, 18.288 m from vegetation

 

Franklin

Oak Creek

8

7.5

7.5

8

7.5

7.5

7.5

7.5

7.6

7.5

8

7.5

7.5

7.5

Average 7.7

 Average 7.5625

Difference in averages 0.1375

P value = 0.15

 

 

 

 

 

Fig. 1 Site 1, 3030 W. Minnesota Ave. Franklin, Wisconsin

 

 

 

Fig. 2 Site 2, 615 W. Riverwood Dr. Oak Creek, Wisconsin

 

 

 

Fig. 3 Lamotte combination soil test kit, model EM 5934

 

 

Fig. 4 Test tubes were filled to the line with indicator 5701 Pt-K, lot # 201801

 

 

 

Map 1 Site 1: 3030 W. Minnesota Ave. Franklin, Wisconsin

 

 

Map 2 Site 2: 615 W. Riverwood Dr. Oak Creek, Wisconsin

 

 

 

 

 

Discussion:

 

     In analyzing the data it is apparent that there were no values that supported my hypothesis that Oak Creek had more acidic soil than Franklin. Although both sites were visually similar, there may have been several factors that could have affected this experiment. First, the sites were chosen based on their access to dig soil samples. After completing the experiment, I realized that I should have selected locations that were both located in private backyards, with little construction near by. By this, I mean site one soil samples were collected in a homeowner’s private backyard in Franklin, where fertilizers have been most likely added to the grass at some point. If so, the fertilizers could have made the soil at the Franklin location more acidic (Smith 2002). This could explain why the soil samples obtained from this area were lower on the pH scale (See tables 1,2,3). However at site two in Oak Creek, new apartments, houses, and a railroad track surrounded the location, which could have disrupted the soil, vegetation, or animal life in that area. Although the pH values were not significant, this would be something to consider if the experiment were to be re conducted.

    Although my experiment did not support my hypothesis, it is beneficial to know that both Franklin and Oak Creek, in the areas I tested, have good soil conditions for plants to grow in. This means that the vegetation in the area has an acceptable pH range to obtain nutrients to grow, survive, and fight off disease.

 

 

 

 

 

Literature Cited:

 

Bickelhaupt, Donald 2002. Soil pH: What it Means, SUNY College of Environmental  

       Science and Forestry, Instructional Support Specialist, Forest and Natural Resources 

       Managements. <http://www.esf.edu/pubprog/brochure/soilph/soilph.htm>

 

Smith, Tim 2002 WSU extension, Wenatchee & North Washington State University,

        Some Thoughts about soil Ph, Fertilizers and Lime,   

       <http://www.ncw.wsu.edu/lime.htm>

 

Division of Hearings and Appeals 2002 State of Wisconsin-Department of

        Administration <http://dha.state.wi.us/home/>