DASAR ILMU TANAH K TANAH DINAMIKA Perilakunya

DINAMIKA KALIUM
DALAM TANAH
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Dinamika K dalam Tanah
 Introduction
 The Potassium Cycle
 Forms of Potassium in soil
 Ketersediaan K dalam tanah
Manajemen K tanah
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Pendahuluan
K is the third most likely element after nitrogen
and phosphorus to limit plant productivity.
Biasanya diaplikasikan sebagai pupuk
K ada dalam larutan tanah sebagai kation K+
K tidak membentuk gas yang hilang ke udara
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Pendahuluan
Its behavior in soil is influenced more by
cation exchange reactions than by
microbiological processes
K tidak menyebabkan pencemaran lingkungan
eksternal
K tidak toksik dan tidak menyebabkan
problematik eutrofikasi
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
K dalam nutrisi tanaman dan hewan
Potassium activates many enzymes in
plants and animals that are responsible
for energy metabolism, photosynthesis
and other processes
As a component of the cytoplasm of plant
cells, it helps to lower cellular osmotic
water potential thereby increasing the
ability of root cells to take up water.
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
K dalam nutrisi tanaman dan hewan
K sangat penting untuk fiksasi nitrogen pada legume
Kecukupan K telah terbukti membantu tanaman
beradaptasi terhadap cekaman lingkungan
In animals including humans, K is important in
regulating the nervous system and maintenance of
good blood vessels.
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Gejala Defisiensi K
Mengurangi kemampuan tanaman untuk
beradaptasi terhadap cekamam lingkungan
mis. Kekeringan, Genangan banjir, dll.
Pucuk dan tepian daun menguning (chlorosis)
dan kemudian mati (nekrosis).
In some crops, K deficiency produces white
necrotic spots that looks like insect damage.
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Siklus K
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Siklus K
Sumber Original K adalah mineral primer
 Mineral Mica (biotite dan muscuvite)
 Potassium feldspar (orthoclase dan microcline)
Potassium is released from the minerals during
the weathering process
When available for plant uptake, it is taken up by
plants in large quantities
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Siklus K
Dalam ekosistem alamiah, K is returned to
the soil by rainwater leaching of foliage and
by plant residue or as waste from animals
that feed on plant
Potassium is lost by soil erosion and runoff,
and leaching to the groundwater
Most potassium in agricultural ecosystems
are lost through removal of crops and crop
residues from soil
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Bentuk-bentuk K dalam tanah
Empat bentuk K dalam tanah adalah:
– K dalam struktur mineral primer
– K dalam posisi tidak dapat ditukar dalam mineral
sekunder
– K in exchangeable form on soil colloid surfaces
– K ions larut dalam air
Total K in soil and its distribution as shown in
the K-cycle is a function of the clay minerals
present in soil
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Ketersediaan bentuk-bentuk K
K dalam struktur mineral
primer
K dalam posisi tidak dapat
ditukar pada mineral
sekunder
Unavailable (90-98% of all
soil K)
Slowly available
-fixed K is not easily exchangeable
-In equilibrium with more available forms
K dalam bentuk dapat ditukar Readily available (1-2% of all
pada permukaan koloid
soil K)
-90% of readily available
tanah
Readily available
Ion K+ larut dalam air
-Subject to leaching
-Equilibrium with exchangeable form
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Fiksasi K oleh Koloid Tanah
Nonexchangeable-K  Exchangeable-K  Soil Solution-K
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Faktor Ketersediaan K dalam tanah
1. Tipe Koloid Tanah
Ability of various colloids to fix K varies (2:1)
2. Pembasahan & Pengeringan Tanah
Physically affects the structure of colloids
3. Pembekuan & Pencairan Tanah
Physically affects the structure of colloids
4. Kemasaman tanah (pH)
High pH increases the fixation of K because of less H+ and
Al3+ at exchange sites.
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Problem K dalam Kesuburan Tanah
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Pengelolaan Kalium
The main problem with managing soil K is that of
converting the unavailable forms of the element
to available forms
 Available K is usually supplemented by fertilization
Another problem is removing a lot of crops from
the soil without returning the crop residues
 Attempts should be made to return as much residue as
possible for the natural plant-soil cycling of K to
continue
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Pengelolaan Kalium
Growing high K content plants places demand on the
soil supply of potassium
 To have high yields of such crops, e.g., alfalfa, it needs to planned in
advance to supply soil with enough K to last the cropping season –
fertilization
Pemupukan dengan dosis ringan dan sering ternyata
lebih baik daripada dosis tinggi sekali aplikasi, hal ini
dapat mengurangi konsumsi mewah K
Pengapuran tanah ternyata meningkatkan retensi K
dalam atanah.
SUMBER: myspace.aamu.edu/users/monday.mbila/soils/SPS251Lecture15.ppt
Kalium Tanah
Efek status K-tanah thd hasil tanaman dan efisiensi pupuk N
(JOHNSTON et al., 2001)
SUMBER: http://www.ipipotash.org/en/presentn/aspcwdb.php
Kalium Tanah
Respon tanaman thd K dalam percobaan jangka panjang (1949-91)
(MERBACH et al., 1999)
SUMBER: http://www.ipipotash.org/en/presentn/aspcwdb.php
Kalium Tanah
Siklus kalium dalam sistem tanah-tanaman-ternak (SYERS, 1998)
SUMBER: http://www.ipipotash.org/en/presentn/aspcwdb.php
Kalium Tanah
Bentuk-bentuk K-tanah dan ketersediaannya bagi tanaman.
SUMBER: http://www.depi.vic.gov.au/agriculture-and-food/dairy/pastures-management/fertilisingdairy-pastures/what-nutrients-do-plants-require
Siklus Kalium dalam Tanah
Status K-tanah
mempengaruhi
penyerapan K oleh
akar tanaman.
Jumlah K dalam
tanah tergantung
pada tipe-tanah,
produksi tanaman,
retensi atau panen
biomasa residu
tanaman,
pemupukan K dan
irigasi.
SUMBER: http://www.ipipotash.org/en/eifc/2011/29/3
Kalium Tanah
Penyerapan
NO3- oleh akar
tanaman
dikendalikan
oleh hasil
reduksi NO3dalam tanaman
dan siklus K+
dalam tanaman.
SUMBER: Ben Zioni et al., 1971; Physiolgia Plantarum 24:288-290.
Kalium Tanah
Model mineral liat tipe 1:2 (illite) yang menunjukkan posisi
penjerapan K+
SUMBER: http://www.intechopen.com/books/soil-processes-and-current-trends-in-qualityassessment/potassium-in-soils-of-glacial-origin
Kalium Tanah
Model pelepasan K dalam proses pelapukan mineral primer tanah
SUMBER: http://www.intechopen.com/books/soil-processes-and-current-trends-in-qualityassessment/potassium-in-soils-of-glacial-origin
Kalium Tanah
Kesetimbangan bentuk-bentuk K dalam tanah.
SUMBER: http://people.umass.edu/psoil120/guide/chapter7.htm
Siklus Kalium Tanah
Sekitar 90 -98 % total K dalam tanah dalam bentuk ineral primer tidak-larut,
mineral ini thaan terhadap pelpaukan kimiawi. Pelepasan K dari mineral primer
ini sangat lambat, dan jumlahnya sangat kecil dibandingkan dnegan kebutuhan
tanaman.
SUMBER: http://www.cropnutrition.com/efu-potassium#in-soil
Kalium Tanah
K dalam larutan
tanah mudah
diserap oleh akar
tanaman.
K-larutan tanah ini
jumlahnya sangat
kecil.
Uji K untuk larutan
tanah tidak
mencerminkan
total K yang
tersedia bagi
tanaman.
SUMBER: http://www.smart-fertilizer.com/articles/potassium-in-soil
Kalium Tanah
Faktor penyerapan K oleh tanaman:
1. Kandungan Oksigen Tanah – oxygen is necessary for
proper root function, including uptake of potassium
2. Air tanah - the more moisture found in the soil, the
easier it is for plants to absorb potassium.
3. Olah-tanah – research has shown that regularly tilled
soil allows for better potassium uptake.
4. Suhu Tanah – 60-80 degrees Fahrenheit is the ideal
soil temperature range for root activity and most of
the physiological processes in plants. The lower the
temperature, the slower absorption becomes.
SUMBER: http://www.smart-fertilizer.com/articles/potassium-in-soil
Siklus Kalium
Tanah
SUMBER: http://www2.ca.uky.edu/agc/pubs/agr/agr11/agr11.htm
Fiksasi Kalium oleh mineral liat Tanah
SUMBER: http://www2.ca.uky.edu/agc/pubs/agr/agr11/agr11.htm