sifat-sifatfisiktanah-221123013107-eda4fe73.ppt

Sifat fisik tanah

1. Interaksi Tanah dan Mesin
Pertanian
Sifat-sifat fisik tanah
Texture
Structure
Soil density
Bulk density
Moisture content
Porosity
Measurement methods

2. Interaksi Tanah dan Mesin
Pertanian
Physical properties of a soil
The physical properties of a soil are those
characteristics which can be seen with the eye or felt
between the thumb and fingers.
They are the result of soil parent materials being
acted upon by climatic factors (such as rainfall and
temperature), and affected by topography (slope and
direction, or aspect) and life forms (kind and amount,
such as forest, grass, or soil animals) over a period of
time.
A change in any one of these influences usually
results in a difference in the type of soil formed.
Important physical properties of a soil are color,
texture, structure, drainage, depth, and surface
features (stoniness, slope, and erosion).

3. Interaksi Tanah dan Mesin
Pertanian
Four Major Components of Soil
Mineral –Serves as the
solid fraction of the soil.
45% of the Soil Volume
Organic Material –1-5% of
the Soil Volume
> Dead organic material making
up the humus
> Microbial Activity of the Soil
Air – Found in pore space
of soil
Water – Found in the pore
space of soil

4. Interaksi Tanah dan Mesin
Pertanian
Profil Tanah
Lapisan Atas (Olah)
Horison A
Horison
B
Horison
C

5. Interaksi Tanah dan Mesin
Pertanian
Texture
Texture refers to the relative amounts of
differently sized soil particles, or the
fineness/coarseness of the mineral particles in
the soil.
Soil texture is a term commonly used to
designate the proportionate distribution of the
different sizes of mineral particles in a soil.
Soil texture is the relative proportion of sand, silt
and clay sized particles in the soil.
Soil texture depends on the relative amounts of
sand, silt, and clay.
In each texture class, there is a range in the
amount of sand, silt, and clay that class contains.

6. Interaksi Tanah dan Mesin
Pertanian
P
e
r
s
e
n
t
a
s
e
l
e
b
i
h
h
a
l
u
s
(
%
)
Diameter partikel (mm)
Liat Debu Pasir Gravel

7. Interaksi Tanah dan Mesin
Pertanian
Partikel Tanah
Ukuran partikel tanah: halus kasar
Klasifikasi partikel tanah:

8. Interaksi Tanah dan Mesin
Pertanian
Versi Internasional
Clay Silt Fine Coarse
Sand Sand Gravel
Clay Silt Fine Medium Coarse Very Coarse
Sand Sand Sand Sand Gravel
Clay Silt Fine Medium Coarse Sand
Sand Sand Gravel
1) International (Atterberg) System
2) USDA System 3) British Standard
0.002 0.02 0.2 2.0 mm
0.002 0.05 0.1 0.5 1.0 2.0 mm
0.002 0.06 0.2 0.6 2.0 mm

9. Interaksi Tanah dan Mesin
Pertanian
Particle size classification
Soil
Separate
Particle diameter (mm)
USDA ISSS
Sand 2.0-0.05 2.0-0.02
Silt 0.05-0.002 0.02-0.002
Clay less than 0.002 less than 0.002

10. Interaksi Tanah dan Mesin
Pertanian
Clay: .. - 0.002 mm
Silt: 0.002 – 0.05 mm
Sand: 0.05 mm - ….
USDA

11. Interaksi Tanah dan Mesin
Pertanian
Tabel : Kelas ukuran utama butiran anorganik
Ukuran
Nama
Umum
Dapat
dilihat
dengan
Susunan dominan
Sangat
kasar
Batu,
kerikil
Mata Pecahan batuan
Kasar Pasir Mata Mineral primer
Halus Debu Mikroskop
Mineral primer dan
sekunder
Sangat
halus
Liat Miskroskop
Umumnya mineral
sekunder
Ukuran butir/partikel tanah berkaitan dengan sifat-sifat tanah;
sifat individu maupun sifat gabungan (lihat segitiga tekstur)

12. Interaksi Tanah dan Mesin
Pertanian
Klasifikasi Tekstur Tanah
Berdasarkan distribusi ukuran partikel tanah dan plastisitas
Menggunakan:
Segi-tiga tekstur  untuk pertanian
1.International Society of Soil Science (ISSS)
2.US Department of Agriculture (USDA)
100
0
0
90
10
10
80
20
20
70
30
30
60
40
40
50
50
50
40
60
60
30
70
70
20
80
80
10
90
90
0
100
100
X%
Y% Z%
1
2
3
45
6
7
8
9
10
11
12
ISSS:
1: heavy clay
2: sandy clay
3: sandy clay loam
4: sandy loam
5: loamy sand
6: sand
7: light clay
8: clay loam
9: loam
10: silty clay
11: silty clay loam
12: silt loam
Contoh:
Leuwikopo : Pasir (x) 25%, Liat (y) 62%, Debu (z) 13%
100
0
0
90
10
10
80
20
20
70
30
30
60
40
40
50
50
50
40
60
60
30
70
70
20
80
80
10
90
90
0
100
100
X%
Y% Z%
1
2
3
4
5
6
7
8
9
10
11
12
USDA:
1: cl ay
2: si lty cl ay
3: si lty cl ay l oam
4: sandy cl ay
5: sandy cl ay loam
6: cl ay l oam
7: si lt
8: si lt loam
9: loam
10: sand
11: loamy sand
12: sandy loam

13. Interaksi Tanah dan Mesin
Pertanian
100
0
0
90
10
10
80
20
20
70
30
30
60
40
40
50
50
50
40
60
60
30
70
70
20
80
80
10
90
90
0
100
100
X%
Y% Z%
1
2
3
45
6
7
8
9
10
11
12
ISSS:
1: heavy clay
2: sandy clay
3: sandy clay loam
4: sandy loam
5: loamy sand
6: sand
7: light clay
8: clay loam
9: loam
10: silty clay
11: silty clay loam
12: silt loam
PASIR
L
I
A
T
D
E
B
U
Pasir 20%
Liat 30%
Debu 50%
10. Silty Clay
10

14. Interaksi Tanah dan Mesin
Pertanian
Soal latihan
Through mechanical analysis, a
particular soil comes up with:
35% Clay
52% Silt
13% Sand
What is the soil texture of the soil?

15. Interaksi Tanah dan Mesin
Pertanian
100
0
0
90
10
10
80
20
20
70
30
30
60
40
40
50
50
50
40
60
60
30
70
70
20
80
80
10
90
90
0
100
100
X%
Y% Z%
1
2
3
4
5
6
7
8
9
10
11
12
USDA:
1: clay
2: silty clay
3: silty clay loam
4: sandy clay
5: sandy clay loam
6: clay loam
7: silt
8: silt loam
9: loam
10: sand
11: loamy sand
12: sandy loam
Sand
Silt
Clay

16. Interaksi Tanah dan Mesin
Pertanian
Ukuran Fraksi
Domain : kelompok partikel liat (< 5 mikron)
Granules: kelompok domain, debu, pasir halus
(< 0.5 mm)
Crumbs : kumpulan granules (> 0.5 mm)
Clods : agregat tanah (> 1 cm)

17. Interaksi Tanah dan Mesin
Pertanian
Soil structure
Granular Blocky Prismatic Columnar
Platy Single
grained
Massive

18. Interaksi Tanah dan Mesin
Pertanian
Struktur Tanah
Pori di antara partikel padatan
disebut PORI :
1) Pori makro dan 2) pori mikro
2) Distribusi ukuran pori
1)Susunan ketiga komponen pembentuk
tanah (padatan, cairan dan udara/gas).
Padatan
Cairan
Gas/udara

19. Interaksi Tanah dan Mesin
Pertanian
Illustration
Air
Water
Solid
V
a
V
w
V
s
V
v
V
W
w
W
s
W

20. Interaksi Tanah dan Mesin
Pertanian
Porosity (n)
Porosity is a measure of the relative
amount of voids in the soil.
It is the ratio of the voids volume (V
v
) to
the total volume (V) of the soil sample
V
V
n
v


21. Interaksi Tanah dan Mesin
Pertanian
Void ratio (e)
The void ratio (e) is the ratio of the void
volume (V
v) to the volume of the solids
(V
s) in a soil sample.
s
v
V
V
e

22. Interaksi Tanah dan Mesin
Pertanian
Water content (w)
Water content of the soil (w) is the ratio
of the weight of water (W
w
) to that of the
solids (W
s
).
100
s
w
W
W
w

23. Interaksi Tanah dan Mesin
Pertanian
Degree of saturation (S
r)
The degree of saturation (S
r) is the
percentage of void space that is occupied
by water
100
v
w
r
V
V
S

24. Interaksi Tanah dan Mesin
Pertanian
Unit Weight of density ()
The unit weight of density () is defined
as the weight divided by the volume.
aws
ws
VVV
WW
V
W




25. Interaksi Tanah dan Mesin
Pertanian
Dry density (
d)
The dry density (
d) is the weight of solids
divided by the total volume.
V
W
s
d


26. Interaksi Tanah dan Mesin
Pertanian
Density of solid particles (
s)
The density of the solids in the soil (
s) is
expressed as follows.
The density of the solids in soils is found to be
somewhat constant.
It is generally remains between 2.6 and 2.8 g/cc.
The average value is 2.65 g/cc for sand and silt;
and 2.75 g/cc for clay.
s
s
s
V
W


27. Interaksi Tanah dan Mesin
Pertanian
Example
A 100 cc soil sample weighs 165 g
and its water content was found to be
49%. If the specific gravity of the
solids is assumed to be 2.6 g/cc.
Find the void ratio, porosity, degree
of saturation, and dry density.

28. Interaksi Tanah dan Mesin
Pertanian
Soil texture analysis
40 s
6 h

29. Interaksi Tanah dan Mesin
Pertanian

30. Interaksi Tanah dan Mesin
Pertanian
Soil sampling – bulk density

Pisau
Ring sample
Alat bantu pengambil
contoh tanah
Timbangan