The grain size distribution is a representation of the approximate distribution of soil grain sizes for a soil. The sieve analysis, also called mechanical method, measures the dry mass of soil retained on each sieve in a stack of sieves, where the sieve opening sizes vary from the largest to smallest going from the top to the bottom of the stack. All the soil particles retained on a particular sieve will have an ‘intermediate size’ or ‘average diameter’ that is smaller than the opening of the sieve above and larger than all the sieves below. Thus the individual particle sizes of the soil are not measured but the range of sizes (i.e. smaller than the sieve above and larger than the sieve retaining the particle) is determined. The grain size distribution is obtained by plotting the percent finer by dry mass, the percent of all the soil below a particular sieve, versus the log of the particle diameter, taken as the opening size of the sieve. A smooth curve is drawn to represent the grains size distribution. The grain size distribution is used to classify soils and to determine the suitability of soils for various engineering purposes.
Weight Before Sieve
Pot
|
Weight before sieve
(g)
|
A
|
179.57
|
B
|
258.21
|
C
|
350.00
|
D
|
176.46
|
E
|
153.23
|
Calculation:
(Rn) = Sieve Weight
× 100％
Total Weight
Cumulative Percentage％ = 100％ × Cumulative Weight
Total Weight
Passing Percentage％ = 100％ - ％Cumulative Retained
Coefficient of Uniformity (CU) = D60
/ D10
Coefficient of Curvature (CC) = (D30)2
/ D60 × D10
Weight After Sieve
Pot A
Weight Total = 239.16 g
Sieve opening mesh
size (mm)
|
Mass of soil retained
on each sieve (g)
|
Percent of mass
retained on each sieve (Rn)
|
Cumulative weight
retained (g)
|
Cumulative percent
retained (g)
|
Pass Percentage ％
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
|
1
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
0.212
|
99.34
|
41.54
|
99.34
|
41.54
|
58.46
|
0.125
|
48.79
|
20.40
|
148.13
|
61.94
|
38.06
|
0.063
|
29.40
|
12.29
|
177.53
|
74.23
|
25.77
|
Pan
|
61.63
|
25.77
|
239.16
|
100
|
0
|
Semi-log Graph
Calculation:
From the Sieve Analysis Results Distribution Curve:
％ Gravel = 0 D10 = 0.02
％ Sand
= 74.23 D30
= 0.09
％ Fines
= 25.77 D60
= 0.22
Coefficient:
CU = 0.22 / 0.02 = 11 CC = (0.09)2 / 0.22
× 0.02 = 1.84
Pot B
Total Weight = 194.06 g
Sieve opening mesh
size (mm)
|
Mass of soil retained
on each sieve (g)
|
Percent of mass
retained on each sieve (Rn)
|
Cumulative weight
retained (g)
|
Cumulative percent
retained (g)
|
Pass Percentage ％
|
2
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
1
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
0.212
|
99.28
|
51.16
|
99.28
|
51.16
|
48.84
|
0.125
|
48.76
|
25.13
|
148.04
|
76.29
|
23.71
|
0.063
|
29.40
|
15.15
|
177.44
|
91.44
|
8.56
|
Pan
|
16.62
|
8.54
|
194.06
|
100
|
0
|
Semi-log Graph
Calculation:
From the Sieve Analysis Results Distribution Curve:
％ Gravel = 0 D10 = 0.08
％ Sand
= 91.46 D30
= 0.10
％ Fines
= 8.54 D60
= 0.3
Coefficient:
CU = 0.3 / 0.08 = 3.75 CC
= (0.10)2 / 0.3 × 0.08 = 0.42
Pot C
Total Weight = 456.23 g
Sieve opening mesh
size (mm)
|
Mass of soil retained
on each sieve (g)
|
Percent of mass
retained on each sieve (Rn)
|
Cumulative weight
retained (g)
|
Cumulative percent
retained (g)
|
Pass Percentage ％
|
2
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
1
|
0.14
|
0.03
|
0.14
|
0.03
|
9.97
|
0.212
|
151.97
|
23.31
|
152.11
|
33.34
|
66.66
|
0.125
|
253.72
|
55.61
|
405.83
|
88.95
|
11.05
|
0.063
|
37
|
8.11
|
442.83
|
97.06
|
2.94
|
Pan
|
13.40
|
2.94
|
456.23
|
100
|
0
|
Semi-log Graph
From the Sieve Analysis Results Distribution Curve:
％ Gravel = 0
D10 = -
％ Sand
= 97.06 D30
= -
％ Fines
= 2.94 D60
= -
Coefficient:
CU = - CC
= -
Total Weight = 168.85 g
Sieve opening mesh
size ( µm)
|
Mass of soil retained
on each sieve (g)
|
Percent of mass
retained on each sieve (Rn)
|
Cumulative weight
retained (g)
|
Cumulative percent
retained (g)
|
Pass Percentage ％
|
2
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
1
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
0.212
|
111.50
|
66.04
|
111.50
|
66.04
|
33.96
|
0.125
|
33.65
|
19.93
|
145.15
|
85.96
|
14.04
|
0.063
|
13.46
|
7.97
|
158.61
|
93.94
|
6.06
|
Pan
|
10.24
|
6.06
|
168.85
|
100
|
0
|
Semi-log Graph
Calculation:
From the Sieve Analysis Results Distribution Curve:
％ Gravel = 0 D10 = 0.10
％ Sand = 93.94 D30 = 0.2
％ Fines = 6.06 D60 = 0.4
Coefficient:
CU = 0.4 / 0.10 = 4.0 CC = (0.2)2 / 0.4 × 0.10 = 1.0
Pot E
Total Weight = 136.78 g
Sieve opening mesh
size ( mm)
|
Mass of soil retained
on each sieve (g)
|
Percent of mass
retained on each sieve (Rn)
|
Cumulative weight
retained (g)
|
Cumulative percent
retained (g)
|
Pass Percentage ％
|
2
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
1
|
0.0
|
0.0
|
0.0
|
0.0
|
100
|
0.212
|
78.08
|
57.08
|
78.08
|
57.08
|
42.92
|
0.125
|
37.33
|
27.29
|
115.41
|
84.38
|
15.62
|
0.063
|
18.00
|
13.16
|
133.41
|
97.54
|
2.46
|
Pan
|
3.37
|
2.46
|
136.78
|
100
|
0
|
Semi-log Graph
Calculation:
From the Sieve Analysis Results Distribution Curve:
％Gravel = 0 D10 = 0.10
％Sand = 97.54 D30 = 0.15
％Fines = 2.46 D60 = 0.35
Coefficient:
CU = 0.35 / 0.10 = 3.5 CC = (0.15)2 / 0.35 × 0.10 = 0.64
Discussion
Soil texture is a qualitative classification tool used in both the field and laboratory to determine classes for agricultural soils based on their physical texture. The classes are distinguished in the field by the "textural feel" which can be further clarified by separating the relative proportions of sand, silt, and clay using grading sieves. The Particle-size distribution (PSD). The class is then used to determine crop sustainability and to approximate the soils responses to environmental and management conditions such as drought or calcium (lime) requirements. A qualitative rather than a quantitative tool, it is a fast, simple and effective means to access the soils physical characteristics. Below is the soil particle size distribution table.
Particle type Equivalent Diameter (mm)
Particle type
|
Equivalent Diameter (mm)
|
Coarse Sand
|
2 – 0.2
|
Fine Sand
|
0.2 – 0.02
|
Silt
|
0.02 – 0.002
|
Clay
|
<0.002
|
Based on the soil texture analysis that we previously conducted through the jar test analysis and the calculations done using the soil texture triangulation, the texture for A is sandy loam, B is sandy clay loam, C is sand, D is sandy clay loam and E is loam.
From the results of the sieve analysis that we conducted, we found out that our soil samples are mostly composed of sand while the other remaining portion is clay and silt with Pot A having the highest amount of silt and clay. This is because sand is larger than 63 µm hence it will pass through the sieve opening mesh sizes that are 2mm, 1mm, 600 µm, 212 µm and 63 µm, while the remaining particles that fall to the pan are smaller than 63 µm. The remaining particles are silt and clay.
Week 3
Pots
|
Plant’s height (cm)
|
Number of nodules
|
Amount of leaves
|
A
|
0
|
0
|
0
|
B
|
36.5
|
10
|
69
|
C
|
34.0
|
2
|
80
|
D
|
35.5
|
3
|
75
|
E
|
0
|
0
|
0
|
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