Morphology tanah menunjukkan bentuk dan susunan penampakan tanah

Di lapangan, pengenalan bentuk morphology dilakukan melalui pengamatan, pendeskripsian dan analisa.

Observasi kadang dilakukan dengan bantuan lensa dan uji kimia sederhana (ph, keberadaan karbonat dll).

Pengamatan dan pengukuran kadang perlu dilakukan di laboratorium (kimia, biologi dan fisik)

Penyipfatan morphology diawali di profil tanah.

Deskripsi dilakukan dengan membatasi profil tanah berdasarkan horizon atau lapisan yang terlihat jelas.

Pembatasan horizon kadang bersifat subjectif karena batas antar horizon yang tidak jelas.

Interval kedalaman horizon atau lapisan (diukur dari bagian atas horizon)

Karakteristik batas horizon Warna Tekstur Struktur Porositas Konsistensi Perakaran pH Penampakan khusus; seperti selaput, nodul dan konkresi

E horizon

A horizon

B horizon(Illuvial)

(Elluvial)

C horizon

R horizon

O horizon

B horizon

Master HorizonsMaster HorizonsO organic A topsoil, O.M., cyclingE elluvialB developed/accumulationC parent materialR bedrock

A horizon

B horizon

C horizon

O horizon

E horizon

Organic matter

Sandy

Clays/iron

Parent

Didominasi oleh bahan organic Terdiri atas sebahagian litter yang sudah terdekomposisi pada bagian permukaannya

Merupakan bahan organic yang terkumpul pada lingkungan yang lembab dan sudah terdekomposisi.

Lapisan kaya bahan organic yang terbentuk dari translokasi bahan organic di dalam bahan mineral tidak disebut sebagai horizon O

Horizon mineral yang terbentuk di permukaan atau dibawah horizon O.Horizon A menunjukkan :•Akumulasi humus b.o yang bercampur dan fraksi mineral

•tidak menunjukkan dominasi horizon E atau B,

•akibat pengolahan tanah, penggembalaan atau berbagai hal yang mengubah tanah.

Horizon mineral yang kehilangan silikat liat, besi, alumunium atau kombinasinya

Mengandung partikel pasir dan debu serta berwarna cerah.

konsentrasi illuvial dari liat silikat, besi/ setrika, aluminium, karbonat, gypsum, atau humus

hilangnya karbonat silikat liat atau sesquioksida Warna lebih gelap atau merah dibanding bagian atas dan bawah tanpa adanya illuviasi besi

Horizon mineral yang masih sedikit mengalami proses pembentukan tanah

Horizon ini bisa mirip atau bahkan tidak menyerupai horizon A, E dan B

Distinctness

Abbreviation [cm]

Abrupt a < 2 Clear c 2 - 5

Gradual g 5 - 15

Diffuse d > 15

Topography Abbreviation Description

Smooth s Nearly a plane

Wavy w Waves wider than deep

Irregular i Depth greater than width

Broken b Discontinuous

Soil color Soil attributes Environmental conditions Brown to black (surface horizon)

accumulation of organic matter (OM), humus

low temperature, high annual precipitation amounts, soils high in soil moisture, and/or litter from coniferous trees favor an accumulation of OM

Black (subsurface horizon)

Accumulation of manganese or Parent material (e.g. basalt)

-

Bright-light Eluvial horizon (E horizon)

In environments where precipitation > evapotranspiration there is leaching of sequioxides, carbonates, and silicate clays. The eluviated horizon consists mainly of silica

Yellow to reddish Fe3+ (oxidized iron) Well-aerated soils

Gray, bluish-green Fe2+ (reduced iron)

Poorly drained soils (e.g. subsurface layer with a high bulk density causes waterlogging, or a very fine textured soil where permeability is very low), anaerobic environmental conditions

White to gray Accumulation of salts

In arid or subhumid environments where the evapotranspiration > precipitation there is an upward movement of water and soluble salts in the soil

White to gray Parent material: marl, quartz -

Soil texture Abbreviation

Gravel g Very coarse sand vcos Coarse sand cos Sand s Fine sand fs Very fine sand vfs Loamy coarse sand lcos Loamy sand ls Loamy fine sand lfs Sandy loam sl Fine sandy loam fsl Very fine sandy loam vfsl Gravelly sandy loam gsl Loam l Gravelly loam gl Stony loam stl Silt si Silt loam sil Clay loam cl Silty clay loam sicl Sandy clay loam scl Stony clay loam stcl Silty clay sic Clay c

Soils different in texture

Pore volume [%]

Macropores [%]

Medium-sized pores [%]

Micropores [%]

Sandy soils

46 (+/- 10)

30 (+/- 10)

7 (+/- 5)

5 (+/- 3)

Silty soils

47 (+/- 9)

15 (+/- 10)

15 (+/- 7)

15 (+/- 5)

Clayey soils

50 (+/- 15)

8 (+/- 5)

10 (+/- 5)

35 (+/- 10)

Organic soils

85 (+/- 10)

25 (+/- 10)

40 (+/- 10)

25 (+/- 10)

Grade Abbreviation Description

Structureless 0

No observable aggregation or no orderly arrangement of natural lines of weakness

Weak 1 Poorly formed indistinct peds

Moderate 2

Well-formed distinct peds, moderately durable and evident, but not distinct in undisturbed soil

Strong 3

Durable peds that are quite evident in undisplaced soil, adhere weakly to one another, withstand displacement, and become separated when soil is disturbed

Form Abbreviation Description

Granular gr Relatively nonporous, spheroidal peds, not fitted to adjoining peds

Crumb cr Relatively porous, spheroidal peds, not fitted to adjoining peds

Platy pl Peds are plate-like. The particles are arranged about a horizontal plane with limited vertical development. Plates often overlap and impair permeability

Blocky bk Block-like peds bounded by other peds whose sharp angular faces form the cast for the ped. The peds often break into smaller blocky peds

Angular blocky abk Block-like peds bounded by other peds whose sharp angular faces form the cast for the ped

Subangular blocky sbk Block-like peds bounded by other peds whose rounded subangular faces form the cast for the ped

Prismatic pr

Column-like peds without rounded caps. Other prismatic caps form the cast for the ped. Some prismatic peds break into smaller blocky peds. In these peds the horizontal development is limited when compared with the vertical

Columnar cpr

Column-like peds with rounded caps bounded laterally by other peds that form the cast for the peds. In these peds the horizontal development is limited when compared with the vertical

Single grain sg Particles show little or no tendency to adhere to other particles. Often associated with very coarse particles

Massive m A massive structure show little or no tendency to break apart under light pressure into smaller units. Often associated with very fine-textured soils.

Size

Angular and subangular blocky

structure[mm]

diameter

Granular and crumb structure

[mm] diameter

Platy structure[mm] width

Prismatic and

columnar structure

[mm] diameter

Very fine < 5 < 1 < 1 (very thin) < 10

Fine 5 - 10 1 - 2 1 - 2 (thin) 10 - 20

Medium 10 - 20 2 - 5 2 - 5 20 - 50

Coarse 20 - 50 5 - 10 5 - 10 (thick) 50 - 100

Very coarse > 50 > 10 > 10 (very thick) > 100

Moisture status Consistence Abbrev

iation Description

wet Nonsticky wso Almost no natural adhesion of soil material to fingers

Slightly sticky wss Soil material adheres to only one

finger

Sticky ws Soil material adheres to both fingers

Very sticky wvs Soil material strongly adheres to both fingers

Nonplastic wpo No wire is formable by rolling material between the hands

Slightly plastic wps

Only short (< 1cm) wires are formed by rolling material between the hands

Plastic wp

Long wires (>1cm) can be formed and moderate pressure is needed to deform a block of the molded material

Very plastic wvp Much pressure is needed to deform a block of the molded material 

Moisture status Consistence Abbreviation Description

Moist Loose ml Soil material is noncoherent

Very friable mvfr Aggregates crush easily between thumb and finger

Friable mfr Gentle pressure is required to crush aggregates

Firm mfi Moderate pressure is required to crush aggregates

Very firm mvfi Strong pressure is required to crush aggregates

Extremely firm mefi Aggregates cannot be broken by

pressure

Moisture status Consistence Abbreviat

ion Dry Loose dl

Soft ds Slightly hard dsh Hard dh Very hard dvh Extremely hard deh

Moisture status Consistence Abbreviat

ion Cementation Weakly cemented cw

Strongly cemented cs Indurated ci

Root quantity classes Per unit area Very few < 0.2 Moderately few 0.2 to 1 Few < 1 Common 1 to < 5 Many >= 5

Size classes of roots Diameter in mm

Very fine < 1 Fine 1 - 2 Medium 2 - 5 Coarse 5 - 10 Very coarse > 10

Concentrations : Wajah tanah yang terbentuk oleh akumulasi bahan selama proses pedogenesis,; pelarutan, oksidasi, reduksi, fisik dan kimia, perpindahan dan penimbunan•  Types:

Halus Massa Nodule Konkresi Kristal Biologis

Ped & Void Surface Features : merupakan selaput yang terbentuk oleh translokasi dan deposisi, atau proses mengembang mengerut, dijabarkan menurut jenis, banyaknya, tempat dan warna

b – buried horizon c – concretions d – root restrictive g – gleying h – illuvial organic matter k – carbonates m – cementation o - oxic p – plowing/disturbance q – secondary silica r – soft bedrock (saprolite) s – illuvial sesquioxides and O.M. t – clay accumulation v – plinthite w – development of color/structure x - fragipan

Subordinate Distinctions

g – gleying h – illuvial organic matter p – plowing/disturbance t – clay accumulation w – development of color/structure o – oxic

• Keadaan reduksi, jenuh air.• Reduksi Besi (Fe III to Fe II)• Chroma rendah• Ditemui pada horizon master B (Bg horizon), E dan C.

gleyedmaterial

oxidizedmaterial

oxidizedFe3+

Fe2+

Subordinate Distinction

• Akumulasi illuvial organic matter-metal complexes•h = “humic”• value dan chroma < 3• Digunakan pada master horizon B (Bh)

Bh horizon“spodic horizon”

*

Subordinate Distinction

Horizon permukaan yang terganggu (pengolahan, peternakan, kehutanan)Digunakan pada master horizon A (Ap)

Ap horizon

Subordinate Distinction

• Translokasi liat• Fgunakan pada master horizon B (Bt)• dapat digunakan pada sub horizon g (Btg)

Subordinate Distinction

“w” = “weak”

Digunakan pada horizon master B (Bw)

Bw

Subordinate Distinction

o = oxic horizon

Akticitas liat rendahMaterial terlapukkan sedikitStruktur batuan sedikitOksida Fe dan Al

Subordinate Distinction

Subordinate Distinctions and Organic Matter

Menunjukkan tingkat pelapukan bahan organik pada horizon O.

Oa – highly decomposed (sapric)Oe – moderately decomposed (hemic)Oi – slightly decomposed (fibric)

Sapric –most decomposed, low plant fiber, low water contentHemic – intermediate decompostionFibric – least decomposed, recognizable fibers

Subordinate Distinction

Master: O, A, E, B, C, R

Subordinate symbols: g, h, p, t, w dan a,e,i

Contoh: Oa, Oe, OiBtBgBtgBwAp

Other Designations

Characterized by similar master and/or subordinateproperties separated by “degree”.

Bt1

Bt2

Bt3

Bt horizons

Transitional layers between master horizons.

AEEBBE

Dominantcharacter

SubordinateCharacter

SynthesisAp

AE

E

Bh

Bt

Btg1

Btg2