dinamika kalium dalam tanah sumber: myspace.aamu.edu/users/monday.mbila/soils/sps251lecture15.ppt

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

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

Pendahuluan

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 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

K dalam nutrisi tanaman dan hewan

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

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 plantPotassium is lost by soil erosion and runoff, and leaching to the groundwaterMost 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

Siklus K

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

K dalam struktur mineral primer

Unavailable (90-98% of all soil K)

K dalam posisi tidak dapat ditukar pada mineral sekunder

Slowly available -fixed K is not easily exchangeable-In equilibrium with more available forms

K dalam bentuk dapat ditukar pada permukaan koloid tanah

Readily available (1-2% of all soil K) -90% of readily available

Ion K+ larut dalam airReadily available -Subject to leaching-Equilibrium with exchangeable form

Ketersediaan bentuk-bentuk K

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 TanahAbility of various colloids to fix K varies (2:1)

2. Pembasahan & Pengeringan TanahPhysically affects the structure of colloids

3. Pembekuan & Pencairan TanahPhysically 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

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

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

SUMBER: http://www.ipipotash.org/en/presentn/aspcwdb.php

Kalium TanahEfek status K-tanah thd hasil tanaman dan efisiensi pupuk N

(JOHNSTON et al., 2001)

SUMBER: http://www.ipipotash.org/en/presentn/aspcwdb.php

Kalium TanahRespon tanaman thd K dalam percobaan jangka panjang (1949-91)

(MERBACH et al., 1999)

SUMBER: http://www.ipipotash.org/en/presentn/aspcwdb.php

Kalium TanahSiklus kalium dalam sistem tanah-tanaman-ternak

(SYERS, 1998)

SUMBER: http://www.depi.vic.gov.au/agriculture-and-food/dairy/pastures-management/fertilising-dairy-pastures/what-nutrients-do-plants-require

Kalium TanahBentuk-bentuk K-tanah dan ketersediaannya bagi

tanaman.

SUMBER: http://www.ipipotash.org/en/eifc/2011/29/3

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: Ben Zioni et al., 1971; Physiolgia Plantarum 24:288-290.

Kalium Tanah

Penyerapan NO3

- oleh akar tanaman

dikendalikan oleh hasil

reduksi NO3-

dalam tanaman dan

siklus K+ dalam

tanaman.

SUMBER: http://www.intechopen.com/books/soil-processes-and-current-trends-in-quality-assessment/potassium-in-soils-of-glacial-origin

Kalium TanahModel mineral liat tipe 1:2 (illite) yang menunjukkan

posisi penjerapan K+

Kalium Tanah

SUMBER: http://www.intechopen.com/books/soil-processes-and-current-trends-in-quality-assessment/potassium-in-soils-of-glacial-origin

Model pelepasan K dalam proses pelapukan mineral primer tanah

SUMBER: http://people.umass.edu/psoil120/guide/chapter7.htm

Kalium TanahKesetimbangan bentuk-bentuk K dalam tanah.

SUMBER: http://www.cropnutrition.com/efu-potassium#in-soil

Siklus Kalium TanahSekitar 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.smart-fertilizer.com/articles/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.

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

SUMBER: http://www2.ca.uky.edu/agc/pubs/agr/agr11/agr11.htm

Siklus Kalium Tanah

SUMBER: http://www2.ca.uky.edu/agc/pubs/agr/agr11/agr11.htm

Fiksasi Kalium oleh mineral liat Tanah