2 makeup science activitites

Properties of soil

Catherine Baulkman

SCI 207: Our Dependence Upon the Environment

Instructor Maybruck

July 2, 2020

Properties of soil

Introduction

Background paragraph:

Various soil properties including shape, particle aggregation and texture are crucial in determine whether soil is good for various activities. Different types of soils have different abilities of retaining water. They can also affect the surroundings. For example, pH balance affects soil fertility. This is because soils are productive at certain pH ranges. Particle sizes affect texture of the soil. “Texture is determined by the ratio of clay, slit and sand in a specific soil sample” (Almendro-Candel et al, 2018). Particle sizes of soil are largest in sand and smallest in clay. Clay has a higher water-holding capacity than sand. Nutrients such as nitrogen and phosphorus are useful in plants.

Objectives paragraph:

The purpose is to test the water-holding capacity of various soils and the levels of nitrogen, phosphorus and potash. The lab is to compare soils on the amount of nutrients they have. It also tests the pH of the soils. It examines the usefulness of various soils collected from various sources in agriculture.

Hypotheses paragraph:

Hypotheses

Activity 1 As the soil is dug, there will be little sand followed by more silt and the next one will be clay. This is because larger soil particles are expected to be at the top while the smaller ones at the bottom.	Activity 3: Soil sample A is expected to be acidic because it was taken from the drainage area.
Activity 2: Water takes the longest time to pass the clay. This is because clay had smaller particles that would make it difficult for water to pass through.	Activity 4: Soil sample A is expected to be having a higher level in the plants food chart as compared to the soil sample B. This is because soil sample A was taken from a drain that was not expected to have much nutrients.

Materials and Methods

Test-tubes

Bag of clay

Test-tube rack

Graduated cylinder

Ruler

Rapitest Soil Tester kit

Rubber bands

Marker pen

Plastic cup

Distilled water

Tap water

Cell phone camera

Stopwatch

Results

Two soil samples were taken from two different locations and used together with a bag of clay. Three test-tubes were filled with the three different soil samples. There were two vials with soil sample A, of which one of them had a drop of dawn soap. The water above the vials was tested using the rapitest. A ruler was used to measure the dirt to water ratio and a sharpie used to mark it. Three tests were conducted with the soils by use of the pipettes. Three 3cm cuts were made from the cheese cloth and the rubber bands were used to secure them. They were put in the cylinder with twist ties. The cylinder was used to measure the amount of water that was poured in the pipettes. A smart phone was used to record time and take pictures.

Data Tables:

Observations/Data Tables

Data Table 1. Particle Size Distribution and Soil Type

	Depth of Clay Layer (cm)	Depth of Silt Layer (cm)	Depth of Sand Layer (cm)	Total Depth (cm)	% Clay	% Silt	% Sand	Soil Texture
Soil Sample A	0.2cm	3.0cm	1.50cm	4.65cm	3.9%	64.3%	32.0%	Silt loam

Data Table 2. Determination of Soil Porosity

	Time Taken for First Drop to Emerge from Column (s)
Sand Sample	17.21
Clay Sample	28.30
Soil Sample A	19.21

Data Table 3. pH Comparison of Soil Samples

	Soil Sample A	Soil Sample B (Location Description: lawn )
pH	Alkaline	Neutral

Data Table 4. Nitrogen, Phosphorus, and Potash Comparison in Soil Samples

	Nitrogen	Phosphorus	Potash
Soil Sample A	Low	medium	Low
Soil Sample B	Low	low	high

Observations:

Sample A was alkaline while the sample B taken from the lawn was neutral. The time taken for the first drops to emerge was lowest in the sand soil and highest in soil sample A.

Graphs:

Photographs:

Figure 1 SAND

Figure 2 clay

Figure 3 soil sample A

Discussion

The first hypothesis was that as the soil is dug, there would be little sand followed by more silt and the next one will be clay. There was a larger depth of the silt layer followed by the depth of sand layer and finally the depth of the clay. The hypothesis was accepted because the depths indicated that clay and silt would be found as one dug deeper. The second hypothesis was that soil sample A would be acidic. However, the soil sample A was alkaline, leading to the rejection of the hypothesis. The third hypothesis was that water would take the longest time to pass clay soil. This was accepted because it actually took longer to pass clay. The fourth hypothesis was that soil sample B would have more nutrients than soil sample A. However, A had more phosphorus than B. Hypothesis was; therefore, rejected.

What I have learned paragraph:

I learned that the water retention of different soils is determined by their particle sizes. Some soils are able to hold water for a longer time than others. “soil permeability is related to particle sizes and their aggregation” (Gorbov et al, 2016). I also learned that the location of soil influences its properties such as the nutrients in the soil and its ability to hold water for a long time. The type of soil in a specific area determines whether the area is suitable for agriculture. If the soil does not have nutrients, it might be difficult to practice agriculture.

Sources of error paragraph:

Collecting the samples was difficult because of bad weather. The soils were clumpy due to frequent rains so it was difficult to break them. Because the soils had a high moisture content, it would affect the experiment on determining the amount of time water would take to pass through them.

Future research paragraph:

How do you determine the organic matter present in soils? How does the presence of organic matter affect its water retention capacity?

An experiment would be designed to collect the soils and determine whether there is organic matter using various tests. After determining the amount of organic matter in various soils, there ability to hold water would be determined and this would finally be compared with their organic matter content.

References

Almendro-Candel, M. B., Lucas, I. G., Navarro-Pedreño, J., & Zorpas, A. (2018). Physical properties of soils affected by the use of agricultural waste. Agric. Waste Residues, 2, 9-27.

Gorbov, S. N., Bezuglova, O. S., Abrosimov, K. N., Skvortsova, E. B., Tagiverdiev, S. S., & Morozov, I. V. (2016). Physical properties of soils in Rostov agglomeration. Eurasian Soil Science, 49(8), 898-907.