Dasar Ilmu Tanah Kemasaman Tanah Dan Masalahnya

8/20/2019 Dasar Ilmu Tanah Kemasaman Tanah Dan Masalahnya

1/23

Sumber: classes.uleth.ca/200801/geog3080a/SOILS%20PART%20V%202008.ppt

KEMASAMAN TANAH

&Permasalahannya


2/23

Soil Acidity:

auses and Impacts



3/23



4/23



5/23



6/23

1. Asam KarbonatCarbon dioxide gas from soil air dissolves in

waterRoot respiration and soil decomposition provideextra CO2

CO2 !2O !2CO" !CO"#

!

2. Asam#asam dari $etabolism %iologis$icrobes brea& down organic matter' prod(cing

organicacids s(c) as citric acid' carbox*lic acids andp)enolic acids

RC!2O!+ O2 !2O RCOO! RCOO#

!


roses#proses engasaman /ana)


7/23

0. O&sidasi itrogen ,itrication-itrogen memas(&i tana) sebagai !0

3i(ba) men4adi asam nitrat .

!0 2O2 !2O !

! O"#

5. O&sidasi S(lp)(r6. Asam#asam dalam air )(4an

!2SO0 SO02# 2!

!O" O"#

!

7. lant 8pta&e of Cationslants ex(de ! ions or ta&e (p anions ,eg.SO

0

2#- to

balance o9 cation (pta&eSumber: classes.uleth.ca/200801/geog3080a/SOILS%20PART%20V%202008.ppt

roses#proses engasaman /ana)


8/23

Kation ! *ang di4erap pada perm(&aan liatdapat mer(sa& str(&t(r mineral dan melepas&anAl" dalam prosesn*a

Al(mini(m sangat to&si& bagi &eban*a&an 4enis

tanaman

Al memac( )idrolisis !2O

Al bergab(ng dnegan O!#

' meninggal&an !

dalam lar(tan tana)

/olerant plants secrete organic acids into t)esoil aro(nd

t)e root. Organic acids s(c) as ,eg. malate orSumber: classes.uleth.ca/200801/geog3080a/SOILS%20PART%20V%202008.ppt

/o&sisitas Al.


9/23Sumber: classes.uleth.ca/200801/geog3080a/SOILS%20PART%20V%202008.ppt


10/23

1. Acids are ne(trali:ed in soils wit) available bases

2. Canadian S)ield severel* a9ected in central and easternCanadaSumber: classes.uleth.ca/200801/geog3080a/SOILS%20PART%20V%202008.ppt


11/23

! !SO"#

SO2 SO"sun

O2!2SO0 ↔2!

SO02#

! O"#

22; O20O

!2O

0O2 2!O" 2!O22O2 22O



12/23

•


13/23

>fe& p! tana)/er)adap K/K

K/K mening&atdengan p!

&arena=

,i- %inding andrelease of ! ions on p!#

dependentc)argesites

,ii-!*drol*sisSumber: classes.uleth.ca/200801/geog3080a/SOILS%20PART%20V%202008.ppt


14/23

ersen Ke4en()an %asa ,K%-

? cmol of exc)angeable Ca2 $g2 K

a

cmolc of C>C

? 1;; @ persen &e4en()an asam.

!ote: Percent acid saturation, though less often cited, is determinedbycmolc Al

3+ & H+ ions divided by cmolc of CEC. This is actually more

meaningful, because Ca, g, ! and "a ions are not true bases#



15/23

1. So"ls #"th h"gh cla$ or organ"c content tento ha&e the h"ghest bu'er"ng ca(ac"t$

2. )h$* +m(ortance o, e-changeable an

res"ual ac""t$

Conto) roses en*angga=

,i- Al(mini(m )*drol*sis ,in ver* acid soils-

AlO2 2O → AlO3

A"ng more "ons #"ll r"&e the react"on to the le,t.


roses#proses en*angga dalam tana)

d l t )


17/23

,ii- rotonation and deprotonation of organic matter

"ons "ssoc"ate #hen a base "s ae (re&ent"ng( ,rom r"s"ng as much as e-(ecte.

"ncreases as the "ons are remo&e "ncreas"ngthe negat"&e charges

,iii- p!#dependent c)arge sites in cla*s

Aga"n a"ng a base "ssoc"ates "ons ,rom h$ro-$lgrou(s an o-$gen atoms

,iv- Cation exc)ange

As "ons are ae most en u( attracte to negat"&echarge s"tes so that ( changes less than e-(ecte. +, abase "s ae the$ are re(lace b$ "ons or Al "ons,rom e-change s"tes. most e'ect"&e #hen (45.

,v- Carbonate dissol(tion and precipitation 6. 7.18




18/23

"m"ng"me reacts #"th O2 an 2O to (rouce b"carbonate

O39

Example:O3

9 2 → O2 2O

agO32 22O 2O2↔ a2 2O3

9 g2 2O39

•;"carbonate "s reactive wit) exc)angeableandresid(al soil acidit*

•

a2

an g2

replace !

and Al"

on cla*

H+

Soil Colloid + CaCO3

Soil Colloid-Ca++ + H2

O + CO2

H+


PENGAP!AN



roses#proses *ang mempengar()i p!tana)



>f & ) d ! )


21/23


>fe& engap(ran ter)adap p! tana)

>f & ! t ) t ) d & d ! d


22/23

>fe& p! tana) ter)adap &and(ngan !ara dan$i&roba /ana)


t ! t )


23/23

,i-$etode at ewarnaCertain organic compo(nds c)angecolo(r inresponse to p!

3rops of d*e sol(tion can be placed onw)itespot plate ,in contact wit) soil-

,ii-$etode otentiometri& 3i9erence between ! ion activit* insoil s(spension and glass electrodegives p!

Sumber: classes uleth ca/200801/geog3080a/SOILS%20PART%20V%202008 ppt

enent(an p! tana)

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