Laboratory Experiment Summary – Controlling Soil pH Introduction The purpose of
ID: 105462 • Letter: L
Question
Laboratory Experiment Summary – Controlling Soil pH
Introduction
The purpose of this laboratory summary is to ensure that you have a basic understanding of soil pH and liming concepts, and also test your ability to think critically while analyzing, interpreting, and reporting results from an experiment. You will write this lab summary and submit it as a single Word document via K-State Online. It is due by 11:59 PM on April 2 and April 4 for the Tuesday and Thursday labs, respectively. You will use the data collected by your lab section to complete the report.
Using any resource available to you, answer the following questions. Responses should be typed, double spaced and well organized with a neat, professional appearance. Grammar and spelling MUST BE correct (Note: pH is pH not Ph). If you use a resource, be certain to properly cite the resource. You can use the citation builder available on the D.H. Hill Library’s web site: www.lib.ncsu.edu/citationbuilder/
Define active, salt-replaceable, and residual acidity (6 pts)
Describe the various sources of acidity (6 pts)
Define lime and explain how it works (6 pts)
Define buffering capacity and explain how it works (6 pts)
Report the data that was collected by your lab section in a table similar to what is shown for Table 1. Then, using that data, develop the following summary table (part a.) and two graphs (parts b. and c.):
Change in pH – Calculate the change in pH as the result of the liming material (i.e., the difference between the “control” treatment with no lime, and each lime treatment). Copy/paste the attached summary table into your report and complete it in order to report your “change in pH” results. (16 pts)
Effect of Liming Material – Calculate the average, across all soil types, the change in pH resulting from the each lime treatment, then graph the average soil pH change by liming treatment. The resulting figure should display the Treatment Effect. (15 pts)
Effect of Soil Type –For each soil, average the results of all treatments, then graph the average soil pH change by soil type. The resulting figure should display the Soil Effect which is a function of the relative pH buffering capacities of each soil (15 pts)
Checklist for receiving full credit on graphs for parts b & c
Graph title
Graphs should be vertical bar charts (Excel calls these “column charts”) with the response (average pH change) on the Y-axis, and the variable you are comparing (lime type for part b, or soil type for part c) on the X-axis, i.e. the column bar label.
Y-axis has an appropriate title, such as “Change in pH”
Y-axis labels (numbers along axis)
X-axis has an appropriate title, such as “Soil Type” or “Lime Treatment”
Bars are each appropriately labeled
Chart is neat and easily understood by a reader
Discussion – Using your own figures, answer the questions below. Responses should double spaced and well organized with a neat, professional appearance. Grammar and spelling MUST BE correct:
In one or two paragraphs, explain how lime effectiveness is influenced by lime chemistry (think about the chemical formula) (10 pts)
In one or two paragraphs, explain how lime effectiveness is influenced by lime particle size (10 pts)
In one or two paragraphs, explain how lime rate is influenced by soil texture (10 pts)
Table 1. Measured soil pH response data.
Treatment
Clayey
Sandy
pH
Pure reagent CaCO3
7.37
7.9
Pure reagent CaO
8.73
12.5
Pure reagent CaSO4
4.35
4.8
Dolomitic limestone (20-40 mesh)
5.15
6.91
Dolomitic limestone (<100 mesh)
6.58
7.57
Control
5.12
5.17
Table 2. Change in soil pH relative to the control pH
Treatment
Clayey
Sandy
Average
pH
Pure reagent CaCO3 †
Pure reagent CaO
Pure reagent CaSO4
Dolomitic limestone (20-40 mesh)
Dolomitic limestone (<100 mesh)
Average
† Example Calculation: CaCO3 – Control = Change in pH due to CaCO3 treatment)
this is very urgent
please including the charts and explanations in it
thank you so much
Treatment
Clayey
Sandy
pH
Pure reagent CaCO3
7.37
7.9
Pure reagent CaO
8.73
12.5
Pure reagent CaSO4
4.35
4.8
Dolomitic limestone (20-40 mesh)
5.15
6.91
Dolomitic limestone (<100 mesh)
6.58
7.57
Control
5.12
5.17
Explanation / Answer
Active acidity (pH), Salt-replaceable acidity and Residual acidity are the different forms of Soil acidity.
Active acidity reflects the hydrogen ion activity in the soil solution and it’s measured as the soil pH. Salt-replaceable and Residual acidity can be described as the soil’s capacity to resist change in the soil solution pH Salt-replaceable activity are the H+ and Al3+ activity in solution. Residual activity is associated with H+ and Al3+ ions that are bounded non-exchangeable to organic matter and clay.
The main sources for the acidification of soil are
1. Removal of product from the farm.
2. Leaching of nitrogen below the plant root zone.
3. Improper use of Nitrogen fertilizers
4. Build up of organic matter.
Lime is a calcium-containing inorganic material in which carbonates, oxides, and hydroxides predominate. It’s being pulverized from limestone or chalk that can be applied to the farmland in order to:
1. Increase pH of the acidic soil
2. It acts as a good source of Ca and Mg for the plant.
3. Helps in better water penetration in acidic soils.
Buffering capacity of the soil is the capacity to help in the change in pH in the soil when an acid or base is added. At higher values of pH, calcium, magnesium and potassium oxides together with carbonates help in pH change, for intermediate pH level soil organic matter mineral weathering and weathering and exchange reactions help in buffering the soil. In other words, greater the value of buffering capacity the soil will absorb more acid or base without changing the pH, Generally clay soil has higher values than sandy soil additionally with the higher amount of organic matter will tend to increase the buffering capacity.
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