MORPHOLOGY TANAH

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.

Informasi yang diperlukan untuk mendeskripsikan profil : 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

Master Horizons (Elluvial) (Illuvial) O horizon A horizon R horizon E horizon (Elluvial) C horizon B horizon B horizon (Illuvial)

Soil Horizon designations O horizon Master Horizons O organic A topsoil, O.M., cycling E elluvial B developed/accumulation C parent material R bedrock A horizon Organic matter E horizon Sandy B horizon Clays/iron C horizon Parent

Horizon O 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 A 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 E 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 C Horizon mineral yang masih sedikit mengalami proses pembentukan tanah Horizon ini bisa mirip atau bahkan tidak menyerupai horizon A, E dan B

Boundary 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

Environmental conditions Soil Color 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 Parent material: marl, quartz

Soil Texture Soil texture Abbreviation Gravel g Very coarse sand vcos 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

Texture and Pores size distribution 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)

Structure : grade, size dan bentuk partikel Abbreviation Description Structureless 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

Structure : grade, size dan bentuk partikel Form Abbrevia tion 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.

Structure : grade, size dan bentuk partikel Angular and subangular blocky structure [mm] diameter Granular and crumb structure Platy structure [mm] width Prismatic and columnar structure Very fine < 5 < 1 < 1 (very thin) < 10 Fine 5 - 10 1 - 2 1 - 2 (thin) 10 - 20 Medium 2 - 5 20 - 50 Coarse 5 - 10 (thick) 50 - 100 Very coarse > 50 > 10 > 10 (very thick) > 100

Consistency Moisture status Consistence Abbrevia tion 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  

Consistency Moisture status Consistence Abbrevi ation Description 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

Consistency Moisture status Consistence Abbreviation Dry Loose dl Soft ds Slightly hard dsh Hard dh Very hard dvh Extremely hard deh

Consistency Moisture status Consistence Abbreviation Cementation Weakly cemented cw Strongly cemented cs Indurated ci

Roots 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

Special Features Types: 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

Subordinate Distinctions 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

Subordinate Distinction (g = gleying) Keadaan reduksi, jenuh air. Reduksi Besi (Fe III to Fe II) Chroma rendah Ditemui pada horizon master B (Bg horizon), E dan C. oxidized material Fe3+ Photographs showing redoximorphic features (soil mottling) which are color patterns in the soil formed by the oxidation and reduction of iron and/or manganese caused by saturated conditions within the soil. Redoximorphic features are used to estimate the depth to seasonal high watertable oxidized gleyed material Fe2+

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

Subordinate Distinction p = plowed Horizon permukaan yang terganggu (pengolahan, peternakan, kehutanan) Digunakan pada master horizon A (Ap) Ap horizon

Subordinate Distinction t = clay accumulation Translokasi liat Fgunakan pada master horizon B (Bt) dapat digunakan pada sub horizon g (Btg)

Subordinate Distinction w = color or structure “w” = “weak” Digunakan pada horizon master B (Bw) Bw

o = oxic horizon Subordinate Distinction Akticitas liat rendah Material terlapukkan sedikit Struktur batuan sedikit Oksida Fe dan Al The oxic horizon has:           a. a CEC7  < 16cmol(+)/kg of clay and an ECEC < 12 cmol(+)/kg of clay which is due to the low activity clay minerals (1:1 clays, Fe and Al oxides, etc)           b.  < 10% weatherable minerals in the sand fraction           c.  < 5% rock structure

Subordinate Distinctions and Organic Matter

a, e, i Subordinate Distinction 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 content Hemic – intermediate decompostion Fibric – least decomposed, recognizable fibers

Subordinate symbols: g, h, p, t, w dan a,e,i Summary Master: O, A, E, B, C, R Subordinate symbols: g, h, p, t, w dan a,e,i Contoh: Oa, Oe, Oi Bt Bg Btg Bw Ap

Other Designations

Vertical Subdivisions Characterized by similar master and/or subordinate properties separated by “degree”. Bt horizons Bt1 Bt2 Bt3

Transitional Horizons Transitional layers between master horizons. AE EB BE Dominant character Subordinate Character

Synthesis Ap AE E Bh Bt Btg1 Btg2