bab 09 biologi tanah

7/31/2019 Bab 09 Biologi Tanah

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PTT 101, Science of Soils

Soil Biology


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Soil is alive!

GOOD SOIL, MORE DIVERSITY !

TANAH :

a. Bahan inorganik (liat, debu,pasir)

b. Bahan organikHidup (biomas)

Mati (nekromas)

c. Air

d. Udara

Ekologi Tanah, gabungan:

Ekologi (orientasiorganisma)

Ilmu Tanah: klasifikasi,genesis, fisika, kimia,biologi

Overlap ke dua ilmu


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Biology

Soil

Fertility

Organisms (BIOTA) ~ involve inchemical & physical processes

Soil as energy & nutrientsource of biota except:

Plants & mikrobia photo-

autotroph ~ sun lightenergy source

Microbialchemoautotroph ~

inorganic; CO2 from theatmosfer

Symbiont ~plant roots ~fixed N from the air


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Fase 1

2.5>pF>0

KR = 100%

Tt = T0= 100C

Air bebas

Collembola& kutu

Uap air

4.7>pF>2.5

KR =100%

Air

kapiler

Migrasi

Collembola

Fase 2

BIOTA pada berbagai kondisi AIR TANAH


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Component Diameter, m

Sand particle 2000 - 20

Roots 200

Soil pore >50

Silt Particle 20 - 2Root hair 10

Bacterium 1

Storage pore 50

0.5Clay particle < 2

Residual pore


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Animals (Fauna)

Macro Micro

Largely herbivores& Detrivores

Squirells,geopers,woodchucks, mice

Insects, springtail,

ants, beetles, grubs,etc

Millipides, woodlice,mites, slugs, snails,

earthworm

LargelyPredators

Moles,insects, ants,beetles,mites,spiders

LargelyDetrivores,

Predators, orParasites

Nematodes

Protozoa

Rotfers


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Plants (Flora)

Rootsof higher

plants

Algae

Green

Bluegreen

Diatoms

Bacteria

Aerobic

Anaerobic

Autotrophic

Heterotrophic

Fungi

Mushroom

fungiYeast

Molds

Actino-mycetes

of manykinds


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Grouping Body with Organisms

Microflora < 10 m Bacteria, fungi

Microfauna < 100 m Protozoa,nematodes

Mesofauna < 2 mm Collembola, acari,

enchytaeids,termites

Macrofauna


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Beetle larva

Herbi- & detritivores Predators

millipede

termiteearthworm

centipede

scorpionspider

Staphylinid beetlenematoda

bacteriafungi

Collembola

dungbeetle

Isopoda

algae

protozoa

snail

Belowground

ZOO


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Biological function Biological/functional group

Decomposition Residue-borne microorganisms,

C-sequestration Microbial biomass (especially

fungi), macrofauna buildingcompact structures

N-fixation Free and symbiotic N-fixers

OM/ nutrients

redistribution

Roots, mycorrhizas, soil

macrofauna

Nutrient cycling,

mineralization/

immobilization

Soil microrganisms, soil

microfauna

Bioturbation Roots, soil macrofauna

Soil aggregation Roots, fungal hyphae, soil

macrofauna, soil mesofauna

Population control Predators/grazers, parasites,

pathogens

Keybiologica

lfunctions


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Energy+CO2

input

Energy + CO2 loss

SOIL FAUNA

Detritivores Carnivores (predators, parasites)

Primary

consumers

Secondary

consumers

Tertiary

consumers

Soilhumus

Detritus

Soil microflora (ultimate decomposers)

Feces & dead

bodies

Microphytic

feeders

Feces & dead

bodies


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Channeling Water


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Termites

(rayap)Ants (semut)

Earthworms,cacing tanahRoots

(akar)

Natural Soil Mixing (Bioturbation)

Soil engineering


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Old tree rootchannel

Bioturbation


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Karak-

teristik

Epigeic Anecic Endogeic

Lubang tidak ada terbuka permanen ke

permukaan tanah

ekstensif

dalam

Cast tidak ada di permukaan tanah

berdekatan dengan pori-

pori tanah

dalam lubang

atau dalam

pori-poritanah

Pigmen

tasi

tinggi tingkat

samarannya

sedang, hanya di bag.

belakang

tidak

berpigment

Makan-

an

mendekomposisilitter padapermukaan tanah

tidakmencernakkan

tanah

mendekomposisilitter yang diambildari lapisan atas

dibawa ke lapisan

dalam

tidak mencernakkantanah

mencernakkantanah& BO

&akar-akar

mati

Kelompok cacing tanah berdasarkan tipe ekologinya


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Soil Bacteria


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Symbiotic: bacteria and plants (e.g., legumes + rhizobium

Bacteria require plant for growth; plantgains free source of available N

Sengon


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Mycorrhiza

To improve P-uptake by plants:

To extend the volume of soil through itsmycellium

Sollubilising unavailable P


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Nematode

NOT allOrganismsare usefull

for plantgrowth


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bab 09 biologi tanah

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