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MK. DASAR ILMU TANAH TEKSTUR TANAH . Diabstraksikan oleh : smno.jursntnh.fpub.febr2013 . TEKSTUR TANAH. Definisi Tekstur Tanah Texture indicates the relative content of particles of various sizes, such as sand, silt and clay in the soil.
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MK. DASAR ILMU TANAHTEKSTUR TANAH Diabstraksikanoleh: smno.jursntnh.fpub.febr2013
TEKSTUR TANAH DefinisiTekstur Tanah Texture indicates the relative content of particles of various sizes, such as sand, silt and clay in the soil. Texture influences the ease with which soil can be worked, the amount of water and air it holds, and the rate at which water can enter and move through soil. Diunduhdari: ftp://ftp.fao.org/fi/cdrom/fao_training/FAO_Training/General/x6706e/x6706e06.htm ……… 3/3/2013
KelasTekstur Tanah menurut USDA Diunduhdari: ftp://ftp.fao.org/fi/cdrom/fao_training/FAO_Training/General/x6706e/x6706e06.htm ……… 3/3/2013
Definition • Teksturtanahdidefiniskansebagaiproporsirelatifpasir, debudanliat. • Kisaran diameter dariketigaseparat: Pasir(2.0- 0.05 mm), Debu (0.05-.002 mm), Liat (<0.002 mm). http://science.kennesaw.edu/~jdirnber/limno/LecPhy/SiltSandClay.jpg
SEPARAT TANAH = SOIL SEPARATES • Tanah mineral dianggapsebagaisuatucampuranporuspartikel-pertikelanorganik, bahanorganik, air danudara. • particle size and particle size distribution of these inorganic particles have an important bearing on the physical properties of soil.
SEPARAT TANAH = SOIL SEPARATES • mineral fraction of soil is divided into are called soil separates. three major size groups. These groups • Pasir : diameternya 0.05 - 2 mm • Debu : 0.002 mm to 0.05 mm in diameter • Liat : <0.002 mm • Kerikil: 2 mm to 2 cm • Batu:- >2 cm. • Particles of <0.001 mm are designated as colloids - clay, a colloid is unique because of its large surface area.
TEKSTUR TANAH = %Pasir, Debu & Liatdalamtanah. Teksturtanahmerupakansifatfisika-tanah yang sangatpenting. Knowing the soil texture alone will provide information about: 1) Pergerakan (aliran) air, 2) Dayasimpan air, 3) Potensialkesuburan, 4) Kesesuaiantanahuntukberbagaipenggunaan
TEKSTUR TANAH Good soil and water conservation practices are always recommended for all soils; however, there are a number of risks associated with particular soil textures that good farm managers should consider. There are management practices that can be adopted to reduce these risks. • Persentasepasir, debu, liatdalamsuatutanah • Teksturtanahsangatpentinguntukmemahamiperilakutanahdanpengelolaantanah • Soil texture is not subject to change in the field but can be changed in potting mixes. Sumber: http://www4.agr.gc.ca/AAFC-AAC/display-afficher.do?id=1197483793077
Ukuran Diameter Partikel Soil particle diameters range over 6 orders of magnitude: • Batubesar 2 m • Fragmenkasar > 2 mm • Pasir < 2 mm - 0.05 mm • Debu < 0.05 mm - 0.002 mm • Liat < 0.002 m
PARTIKEL PASIR PARTIKEL PASIR Sand is the biggest soil particle. If blown up to an easily visible size, compared to other soil particles, a sand particle would be the size of a basketball. Soils classified as sandy typically contain 80 to 100 percent sand, zero to 10 percent silt and zero to 10 percent clay by volume. Tanah-tanahberpasir, karenaukuranpartikelnyabesar-besar, iatidakmampumenyimpanbanyak air dannilaiharanyarendah. Segenggamtanahberpasirakanmudahhancurberderaikalaugenggamandilepaskan. Read more: 3 Types of Soil Particles Sized From Biggest to Smallest | eHow.com http://www.ehow.com/list_7352275_3-particles-sized-biggest-smallest.html#ixzz2MX2C8vft • Terasasepertiberpasir (kasar) • Tidak-kohesif – tidakmelekatbersamadalamsuatu mass kecualidalamkondisisangatbasah.
PARTIKEL PASIR • Pasirmengandunglebihsedikitharatanamandibandingkandenganpartikelyglebihhalus • Voids between sand particles promote free drainage and entry of air • Menahansedikit air danmudahmengalamikekeringan
PARTIKEL PASIR • < 2 mm hingga > 0.05 mm • Tampaktanpamikroskop • Bentuknyamembulatataubersudut • Sand grains usually quartz if sand looks white or many minerals if sand looks brown, • Some sands in soil will be brown, yellow, or red because of Fe and/or Al oxide coatings.
PARTIKEL PASIR • Luas-permukaanjenisnyarendah • Sand has less nutrients for plants than smaller particles • Voids between sand particles promote rapid permeability of water and entry of air • Holds little water and prone to drought
PARTIKEL DEBU • < 0.05 mm - > 0.002 mm • Tidaktampaktanpamikroskop • Mineral Kuarsadominandalamdebukarenaminrallainnyatelahlapuk.
PARTIKEL DEBU • Tidakterasakasar • Terasabertepung – haluslumer Silt is the next largest soil particle. If blown up to an easily visible size, compared to other soil particles, a silt particle would be the size of a baseball. Soils classified as loam have the largest amount of silt particles and typically contain 25 to 50 percent sand, 30 to 50 percent silt and 10 to 30 percent clay by volume. High-silt-content soils are often found along riverbanks. Silt soils feel smooth when wet and powdery when dry. Genggamlahsegenggamtanahlempungatautanahberdebu, makabentuk yang terjaditidakakanhancur (lembab) kalaugenggamandilepaskan, kalaukeringmakabentukgenggamantanahakan “crumble away”. Read more: 3 Types of Soil Particles Sized From Biggest to Smallest | eHow.com http://www.ehow.com/list_7352275_3-particles-sized-biggest-smallest.html#ixzz2MX0MXG9L
PARTIKEL DEBU • Smaller particles – retains more water for plants and have slower drainage than sand. • Mudahterangkutoleh air yang menmgalir – sangaterosif. • Menahandanmenyimpanlebihbanyakharadibandingdenganpasir.
PARTIKEL DEBU Debuberperandalamprosessedimentasi (silting) diatas material kerikildidasarsungai yang diperlukanolehikanuntuk “bertelur”. www.pedrocreek.org/ fishcommittee.html
PARTIKEL LIAT • < 0.002 mm • Bentuknyapipihatauserpihan-serpihanhalus • Partikelliat yang berukurankeciladalahkoloid • Kalautersuspensidal;am air tidakakanmengendap
PARTIKEL LIAT Clay is the smallest soil particle. If blown up to an easily visible size, compared to other soil particles, a clay particle would be the size of a golf ball. Soils classified as clay typically contain zero to 45 percent sand, zero to 45 percent silt and 50 to 100 percent clay by volume. Because of the small size of clay particles, clay traps water and air, making it difficult for plants to grow. Segenggamtanahliatakantetapmempertahankanbentuknyakalaugenggamandilepaskan, padakondisilembab. Kalaukering, seringkalisangatkerasuntukdapatditembusdengansekop “a shovel”. Read more: 3 Types of Soil Particles Sized From Biggest to Smallest | eHow.com http://www.ehow.com/list_7352275_3-particles-sized-biggest-smallest.html#ixzz2MX3ToTqZ • Padakondisibasah, liatsangatlekatdanplastis, ataudapatdigelintirdenganmudahmembentuk bola, silinderataubentuklainnya. • Jugamudahdibentukmenjadi pita-pita yang panjang.
PARTIKEL LIAT Certain types of clay are capable of absorbing water. Water molecules can actually squeeze into the chemical structures of the clay minerals that make up the soil. When this happens, the clay can actually expand in order to accommodate the water. Expansion can cause significant volume increases in the soil. Swelling can actually cause the ground and anything constructed upon the ground to gradually to be effected. Expansive soils can also shrink when water is removed from the chemical structure within the clay contained within the soils. Dapatmengembangdanmengkerut – sampaibatastertentusifatinijugatergantungpadajenisliat. Diunduhdari: http://www.geology.ar.gov/geohazards/expsoils_geninfo.htm ...... 4/3/2013
PARTIKEL LIAT • Pores spaces are very small and convoluted • Movement of water and air very slow • Water holding capacity • Tremendous capacity to adsorb water- not all available for plants. • Kapasitasjerapankimiawinyasangatbesar
PARTIKEL LIAT • Ronggaporisangatkecil-kecildanberbelit-belitrumit • Pergerakan air danudarasangatlambat • Kapasitassimpan air • Tremendous capacity to adsorb water- not all available for plants. • Soil strength- shrink/swell affects buildings, roads and walls. • Jerapankimiawinyasangatbesar.
PARTIKEL LIAT • < 0.002 mm • Pipihatauserpihanhalus • Partikelliathalusadalahkoloid • If suspended in water will not settle • Permukaannyasangatluas • spoonful = football field
TEKSTUR TANAH • Proporsirelatifdariberbagaiukuranseparatdalamsuatutanah ……. tekstur • Sangatpentingkarena : it affects and is related to several soil properties such as soil structure, aeration, water holding capacity, nutrient storage, water movement, and bearing strength.
TEKSTUR TANAH • Separattanahtidakberfungsisecara individual, tetapisebagai partner atauagregat. Aggregates are the clumps of soil separates. When aggregates are bound together into large masses they are called peds • Sulitmengubahteksturtanahpadasekalalapangan.
TEKSTUR TANAH Ada 12 kategoriteksturtanah, tetapiadatigakelasbesar : • Pasir– Tanah teksturkasar – tanah-tanahringan • Lempung- intermediate texture - happy soils - most productive • Liat- tanahberteksturhalushinggatanahberat
TEKSTUR TANAH • Soil texture can be determined by the “Textural Triangle” - based on feel of soils. • Textural grade is not determined or based on the major soil separates but on the separate that exerts the dominant influence. • TeksturPasirmengandung50-60% fraksi (separat) pasirataulebihdari total beratnya.
PentingnyaTekstur Tanah • Soil texture is one of the most important properties of a soil, and it greatly affects land use and management. • Teksturtanahmempengaruhijumlah air danhara yang dapatditahantanahdandisediakanbagitanaman. • Teksturtanahjugamempengartuhistrukturtanah, pergerakanudaradan air dalamtanah.
What affects soil texture? The parent material, as modified by weathering and soil- forming processes, determines a soil horizon’s texture. Residuum (or bedrock) Marine Sediments http://soils.ag.uidaho.edu/soilorders/aridisols_07.htm http://soils.ag.uidaho.edu/soilorders/ultisols_01.htm
Dapatkahteksturtanahdiubah ? • Texture is a relatively permanent physical property under natural conditions, and, for most agricultural or forestry uses, it is not practical to change soil texture. • Dalamsistempertanianintensif, teksturtanahdapatdiubahdneganmenambahkan material kasaratau material halus. http://www.gov.mb.ca/iedm/profiles/images/alfalfa_lg.jpg
MENGUBAH TEKSTUR TANAH Teksturtanahhanyadapatdiubahdenganmencampurkan material tanah lain yang teksturnyaberbeda, dalamjumlah (sekala) terbatas.
MENGUBAH TEKSTUR TANAH • Adding sand to a clay soil creates a cement like substance • Adding peat or compost to a mineral soil is not considered changing the texture – since it only adds organic matter not sand, silt or clay. • Mengapamenambahkomposataugambut?
MENGUBAH TEKSTUR TANAH • Dalamjanghkapanjang (1000 tahun) prosespedologismengubahteksturhorisontanah. • As soils get older sand weathers to silt and silt weathers to clay …………therefore old soils have more clay.
TranslokasiLiat= Pembentukanhorison B • Liatjugadiangkutkearahbawahdariprofiltanah, sehingga subsoil lebihbanyakmengandungliatdibandingkan topsoil. 2. Thus ‘Argillic’ horizons form and are zones of clay accumulation Argillic =
Profil-Tekstursuatu Tanah • The graph of the % clay from the surface to the parent material will show if a soil has a clay bulge or an increase in clay. • “Textural Profiles” sangatmembantudalammencarikeberadaan “akumulasi” liat. Argillic =
MenentukanteksturtanahdiLaboratorium • Soil textures can be determined in laboratory analyses where the amount of sand, silt, and clay are measured quantitatively. • We will do this in the laboratory activities. http://earthobservatory.nasa.gov/Newsroom/NasaNews/ReleaseImages/20040730/06_LabTestingSoil.jpg
MenentukanTekstur Tanah – MetodePerasaan • Membasahitanahditelapaktangan • Membuat pita tanah • Panjangnya pita tanahmencerminkankandunganliatnya • Kasarataukurang-kasarmencerminkanpasirataudebu • Halusmenyatakandebu.
KLASIFIKASI TEKSTUR TANAH Texture refers to the amount of sand, silt,and clay in a soil sample. The distribution of particle sizes determines the soil texture, which can be assessed in the field or by a particle-size analysis in the laboratory. A field analysis is carried out in the following way: a small soil sample is taken, water is added to the sample, it is kneaded between the fingers and thumb until the aggregates are broken down. Pedomanuntukmenentukankelaspartikel: PASIR: Sand particles are large enough to grate against each other and they can be detected by sight. Sand shows no stickiness or plasticity when wet. DEBU: Grains cannot be detected by feel, but their presence makes the soil feel smooth and soapy and only very slightly sticky. LIAT: A characteristic of clay is the stickiness. If the soil sample can be rolled easily and the sample is sticky and plastic when wet (or hard and cloddy when dry) it indicates a high clay content. Note that a high organic matter content tend to smoothen the soil and can influence the feeling for clay. DIUNDUH dari: http://www.cartage.org.lb/en/themes/sciences/earthscience/geology/Soils/SoilMorphology/SoilMorphology/SoilTexture/SoilTexture.htm……. 3/3/2013
KELAS TEKSTUR TANAH DIUNDUH dari: http://www.cartage.org.lb/en/themes/sciences/earthscience/geology/Soils/SoilMorphology/SoilMorphology/SoilTexture/SoilTexture.htm……. 3/3/2013
KLASIFIKASI TEKSTUR TANAH DalamsistemU.S.D.A., klasifikasiukuranpartikeladalah (units: mm): LIAT : < 0.002 mm DEBU: 0.002 - 0.05 PASIR HALUS: 0.05 - 0.1 PASIR MEDIUM: 0.1 - 0.5 PASIR KASAR: 0.5 - 1.0 PASIR SANGAT KASAR : 1.0 - 2.0 KERIKIL: 2.0 - 762.0 BATU : > 762.0 DIUNDUH dari: ……. 3/3/2013
KLASIFIKASI TEKSTUR TANAH Teksturtanahdilapanganditentukan dg menggunakansegitigatekstur. Misalnya, distribusiukuranpartikel 33 % liat, 33 % debu, dan33 % pasir …….. akantermasukkedalamkelasteksturtanah “LEMPUNG LIAT” . DIUNDUH dari: ……. 3/3/2013
KLASIFIKASI TEKSTUR TANAH HubunganantaraTekstur Tanah danUkuran Pori Tekstur Tanah PasirDebuLiat DIUNDUH dari: http://www.cartage.org.lb/en/themes/sciences/earthscience/geology/Soils/SoilMorphology/SoilMorphology/SoilTexture/SoilTexture.htm……. 3/3/2013
TEKSTUR TANAH MENDUGA TEKSTUR TANAH SECARA CEPAT Soil texture is the "feel" of the soil when a moist quantity is manipulated. Some soils are sticky, others will not stick together at all, and others feel "doughy" or "spongey". Some soils can be played with like plasticine. These differences in properties gave rise, in agriculture, to soils being called clays, loams or sands. Clays stick to your boots, loams are easily moulded but non-sticky, sands are not cohesive at all and cannot be moulded when moist.When moist soil is manipulated in the hand, sands, loams and clays feel very different. You can use one of the two methods outline below to match up how the soil feels in your hand with the texture of the soil. For more information on what texture means for your soils, refer to ‘Practical Note – Soil Texture’.Andamemerlukan: Soil (with any coarse organic matter and stoney material removed) Rain water or distilled water DIUNDUH dari: http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_texture_qrg ……. 3/3/2013
TEKSTUR TANAH MENDUGA TEKSTUR TANAH SECARA CEPAT PENYIAPAN CONTOH TANAH Take a sample of soil sufficient to fit comfortably into the palm of the hand. Moisten the soil with water, a little at a time, and work the water into the soil. Water is added until the soil reaches a consistency where further water added would cause the soil to stick to the hands. Knead and moisten the soil until there is no further change in the soil ball - very dry clayey samples may need considerable working to break down fine aggregates. A working time of one to ten minutes may be needed depending on the material. Usually 1 - 2 minutes is sufficient. The behaviour of the bolus during manipulation indicates soil texture; you can either use the ribboning method (particularly useful for assessing clay samples/soils) or the flowchart over the page. DIUNDUH dari: http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_texture_qrg ……. 3/3/2013
TEKSTUR TANAH MENDUGA TEKSTUR TANAH SECARA CEPAT METODE PITA-TANAHAttempt to make a ribbon by using your thumb to squeeze the bolus of soil over the side of your first finger - this is best learnt by demonstration. The tendency of a soil to form a thin, strong ribbon is what is known as "resistance to shearing". Using Table 1, identify which field texture best suits the behaviour of the moist bolus of soil you are manipulating. This technique can take some practice. DIUNDUH dari: http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_texture_qrg ……. 3/3/2013
PERILAKU BOLA TANAH LEMBAB KALAU DIMANIPULASI DENGAN TANGAN DIUNDUH dari: http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_texture_qrg ……. 3/3/2013
PERILAKU BOLA TANAH LEMBAB KALAU DIMANIPULASI DENGAN TANGAN DIUNDUH dari: http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_texture_qrg ……. 3/3/2013
PERILAKU BOLA TANAH LEMBAB KALAU DIMANIPULASI DENGAN TANGAN DIUNDUH dari: http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_texture_qrg ……. 3/3/2013
The Flowchart Method:Follow the flowchart by manipulating the soil and answering each question ‘yes’ or ‘no’. Apaygterjadikalau bola tanahditekandiantaraibujaridantelunjuk ? Apakahtanahmembentuk bola koheren? Ya, mudah Tidak PASIR Bola tanahmemipih Bola hancur LEMPUNG BERPASIR Ya, tetapi dg carahati-hatisekali PASIR BERLEMPUNG Dapatkah bola digelintirmenjadisilinderygtebal? Tidak Ya Dapatkah bola digelintirmenjadibenangygtebal? Ya Tidak Dapatkahbenangdibentukmenjaditapal-kuda-U tanparetakan ? Dapatkahbenangdibentukmelingkarmenjadi “sawanlengkung”? Ya Tidak Ya Dapatkahdibentukcincin diameter 2.5 cm denganmenggabungkanujung-ujungbenangtanparetakan? Apakah “rasa” tanahsecaraumum? Kasardan gritty LEMPUNG Sepertisutera – LEMPUNG DEBU atau -- DEBU Tidak Ya Digelintirekmbalimenjadi bola dandielus-elus dg jarisupayapermukaannyamengkilaphalus – apakah “rasa” tanahsecaraumum ? Apakah “rasa” tanahsecaraumum? Lumer LEMPUNG LIAT BERDEBU Sangatkasar LEMPUNG BERPASIR Permukaansangathalus-mengkilap LIAT atau LIAT BERDEBU (Pembedaannyasecarasubyektifberdasarkelekatan) Permukaanhalus, denganbentuktidakteratur LEMPUNG LIAT Permukaansangathalus-mengkilap, tetapiadabeberapapartikelkasar yang menonjol LIAT BERPASIR Agakkasar LEMPUNG LIAT DIUNDUH dari: http://vro.dpi.vic.gov.au/dpi/vro/vrosite.nsf/pages/soilhealth_texture_qrg ……. 3/3/2013