Form , Source and function in Plant

++
++
4
--

1. Essential Nutrietns of Plants
Chemical Atomic Ionic forms Approximate dry
Element symbol weight Absorbed by plants ____ concentration_____
Mccronutrients
Nitrogen
Phosphorus
Potassium
Magnesium
Sulfur
Calcium
N
P
K
Mg
S
Ca
14.01
30.98
39.10
24.32
32.07
40.08
NO
PO
K +
3
-
4
3-
Mg 2+
, NH
4
+
, HPO
4
2, H
2
PO
4
-
SO
Ca
4
2-
2+
4.0 %
0.5 %
4.0 %
0.5 %
0.5 %
1.0 %
Micronutrients
Iron
Manganese
Zinc
Copper
Boron
Molybdenum
Chlorine
Fe
Mn
Zn
Cu
B
Mo
Cl
55.85
54.94
65.38
63.54
10.82
95.95
35.46
Fe 2+ , Fe 3+
Mn 2+
Zn 2+
Cu
BO
2
+
3
2-
MoO
Cl -
, B
4
2-
4
O
7
2-
200 ppm
200 ppm
30 ppm
10 ppm
60 ppm
2 ppm
3000 ppm
Essential But Not Applied
Carbon
Hydrogen
Oxygen
C
H
O
12.01
1.01
16.00
CO
2
H
2
O
2
O
, H
2
O
40 %
6 %
40 %
________________________________________________________________
Plant tissues also contain other elements (Na, Se, Co, Si, Rb, Sr, F, I) which are not needed for the normal growth and development.

Element Main Function Primary Source
Approx.
Conc. in
Plants
0.1-3% Calcium (Ca) Structural component of cell walls; cell elongation; affects cell permeability
Magnesium
(Mg)
Component of chlorophyll; enzyme activator; cell division
Sulfur
(S)
Constituent of proteins; involved in respiration and nodule formation
Soil minerals, limestone
Soil minerals, dolomitic limestone
Soil organic matter, rainwater
0.05-1%
0.05-1.5%

Form , Source and function in Plant

KALSIUM
(Ca)
Penyusun lamela tengah dinding sel.
Kofaktor bbrp ensim dlm hidrolisis ATP & fosfolipida.
Berperan sbg messenger ke 2 dlm pengaturan metabolisme.

1) Soil Relations
- Present in large quantities in earth’s surface (~1% in US top soils)
- Influences availability of other ions from soil
2) Plant Functions
- Component of cell wall
- Involved in cell membrane function
- Largely present as calcium pectate in meddle lamela
Calcium pectate is immobile in plant tissues
3) Deficiency and Toxicity
- Deficiency symptoms in young leaves and new shoots (Ca is immobile)
Stunted growth, leaf distortion, necrotic spots, shoot tip death
Blossom-end rot in tomato
- No Ca toxicity symptoms have been observed
4) Fertilizers
- Agricultural meal (finely ground CaCO
3
·MgCO
3
)
- Lime (CaCO
3
), Gypsum (CaSO
4
)
- Superphosphate
- Bone meal-organic P source

– Plant available form: Ca +2
– Plant immobile, very limited soil mobility
– Functions: Cell membrane integrity, co-enzyme
– Excess:
• Mg uptake interference
– Deficiency:
• Inhibited bud growth, root tip death, mature leaf cupping, weak growth, blossom end rot and pits on fruits
– Notes:
• Usually corrected with pH, Water stress affects Ca relationships.

•
– Moves to root by mass flow
– Can be leached – particularly sandy soils
– Deficiency sometimes seen in dry soils when there isn’t enough water to transport
Ca
•
•

• Total Ca supply & % Ca saturation of CEC
– Low CEC soil with 1000 ppm Ca supply more Ca to plants than high CEC soil with 2000 ppm Ca
• Soil pH
– Low soil pH impedes Ca uptake
• Type of soil clay
– 2:1 clays require > Ca saturation of CEC compared to
1:1 clays to supply adequate Ca
• Ratio of solution Ca 2+ to other cations
– Uptake depressed by NH
4
+ , K + , Mg + , Mn 2+ , Al 2+
– Absorption increased by NO
3
-

Growth fairly good; young leaves chlorotic, forward roll and marginal scorch.
This plant failed to form tubers of appreciable size.
Potato Plant in Sand Culture

Blossom End Rot of Tomato
Calcium Deficiency
Right-Hydroponic tomatoes grown in the greenhouse, Left-Blossom end rot of tomato fruits induced by calcium (Ca ++ ) deficiency

Form , Source and function in Plant

MAGNESI-
UM (Mg)
.

Magnesium (Mg)
1) Soil Relations
- Present in soil as an exchangeable cation (Mg 2+ )
- Similar to Ca 2+ as a cation
2) Plant Functions
- Core component of chlorophyll molecule
- Catalyst for certain enzyme activity
3) Deficiency and Toxicity
- Deficiency: Interveinal chlorosis on mature leaves
( Mg is highly mobile )
- Excess: Causes deficiency symptoms of Ca, K
4) Fertilizers
- Dolomite (mixture of CaCO
3
·MgCO
3
)
- Epsom salt ( MgSO
4
)
- Magnesium nitrate [ Mg(NO
3
)
2
]
- Magnesium sulfate (MgSO
4
)

– Plant available form: Mg +2
– Plant mobile, limited soil mobility
– Functions:
• Chlorophyll compound, co-enzyme, seed germination
– Excess:
• Ca uptake interference
– Deficiency:
• Growth Reduction, marginal chlorosis, interveinal chlorosis in mid and lower leaves, reduced seed production, cupped leaves
– Notes:
• leaches with irrigation, usually corrected with Lime in fields, chelates and sulfates in pots

– Leaches somewhat more than Ca

• Total Mg supply
• CEC
• pH
• Excess K applications on sandy soil
– Cause Mg leaching
– K interferes with Mg uptake
• Continuous use of high Ca lime increases Ca:Mg ratio
– May induce Mg deficiency in certain crops
• NH
4
+ induced Mg deficiency
– High rates of NH
4
+ on soils with low exchangeable Mg

Magnesium (Mg) Deficiency on Poinsettia
Interveinal Chlorosis on Mature Leaves

Chlorosis and necrosis of leaves defoliation
Growth fairly good foliage chlorotic and with intervenal necrosis death of older foliage

Purple tinting intervenal necrosis developing from marginal areas.
Apple Leaves

From Havlin et al., 2005

Form , Source and function in Plant

BELERANG (S)
Penyusun asam amino sistein, sistin, metionin & protein. Penyusun asam lipoat, koensim A, tiamin, pirofosfat, glutation, biotin, adenosine-5’fosfosulfat & 3-fosfoadenosin.

Sulfur (S)
1) Soil Relations
- Present in mineral pyrite ( FeS
2
, fool’s gold ), sulfides ( S-mineral complex ), sulfates (involving SO
4
-2 )
- Mostly contained in organic matter
- Acid rain provides sulfur
2) Plant Functions
- Component of amino acids (methionine, cysteine)
- Constituent of coenzymes and vitamins
- Responsible for pungency and flavbor ( onion, garlic, mustard )
3) Deficiency and Toxicity
- Deficiency: light green or yellowing on new growth ( S is immobile )
- Toxicity: not commonly seen
4) Fertilizers
- Gypsum ( CaSO
4
)
- Magnesium sulfate ( MgSO
4
)
- Ammonium sulfate [ (NH
4
)
2
SO
4
]
- Elemental sulfur ( S )

– Plant available form: SO
4
-
– Plant immobile, very soil mobile
– Functions:
• structural compound of AA’s, etc. and chlorophyll production
– Excess: very limited information
– Deficiency:
• Rarely deficient due to pollution and impurities: symptoms include growth reduction, overall chlorosis
– Notes:
• leaches with irrigation, usually corrected with other nutrients, true toxicity is rare and difficult to control, very high levels in low pH soils

– Sulfate dominates (SO
4
2)
– Sulfides (flooded conditions)
– Elemental S
– Thiosulfates
– Range in oxidation states (-2 to +6)
– Carbon-bonded S
– Ester sulfates (organic sulfates)
• 30 to 75% of organic S

Volatile S
CH
3
CH
CS
3
2
SH
SCH
3
Volatilization

• Biological
– Cleavage of C-S bonds to produce S 2-
– Cysteine desulfhydolase
– Driven by need for C
• Biochemical
– Cleavage of C-O-S (ester) bonds to produce SO
4
2-
– Sulfohydrolases (sulfatases), associated with microbial cell walls
– Driven by need for S, regulated by SO
4
2-
• C:S ratio
– C: S < 200, net S mineralization; > 400 immobilization
• Volatilization
– Anaerobic mineralization

SO
4
2-
Serine
PAP + Tr
(ox)
SO
3
2S 2Cysteine
SO
ATP PP i
4
2-
3NADPH 3NADP
APS
Tr
(red)
PAPS COS
ATP ADP
GSH
APS
P i
Cysteine
O-acetyl-serine Acetate + H
2
O
AMP + H +
GSSO
3
GSSH
6Fd
(red)
+7H + 6Fd
(ox)
+3H
2
O GS
Cysteine

S 2-
2 e -
S 0
S
2
O
3
2-
4 e -
SO
3
2-
AMP
2 e -
2 e -
APS
SO
4
2-
ADP
P i
Chemoautotrophic (Lithotrophic)
• Energy generated (-189.9 kcal mol -1 S
2
2; -139.8 kcal mol -1 S 0 )
• Acidifying (2H + per S 0 )
• Generally aerobic; attached to S granules
Photoautotrophic (Lithotrophic)
Chemoheterotrophic (Organotrophic)
• No energy produced; dominant in neutral to alkaline soils
• Many bacteria ( Arthrobacter, Bacillus, Pseudomonas )
• Many fungi ( Aspergillus, Mucor, Trichoderma )

Overall light green color, worse on new leaves during rapid growth.

Form , Source and function in Plant

Element
Chemical Atomic symbol concentration_____ weight
Mccronutrients
Nitrogen
Phosphorus
Potassium
Magnesium
Sulfur
Calcium
N
P
K
Mg
S
Ca
14.01
30.98
39.10
24.32
32.07
40.08
Ionic forms Approximate dry
Absorbed by plants ____
NO
PO
-
3
4
3-
, NH
4
+
, HPO
4
2, H
2
PO
4
K +
Mg 2+
SO
4
2-
Ca 2+
-
4.0 %
0.5 %
4.0 %
0.5 %
0.5 %
1.0 %
Micronutrients
Iron
Manganese
Zinc
Copper
Boron
Molybdenum
Chlorine
Fe
Mn
Zn
Cu
B
Mo
Cl
55.85
54.94
65.38
63.54
10.82
95.95
35.46
Fe 2+ , Fe 3+
Mn 2+
Zn 2+
Cu
BO
MoO
Cl -
2
+
2-
3
, B
4
2-
4
O
7
2-
200 ppm
200 ppm
30 ppm
10 ppm
60 ppm
2 ppm
3000 ppm
Essential But Not Applied
Carbon
Hydrogen
Oxygen
C
O
H
12.01
1.01
16.00
CO
O
2
2
H
, H
2
O
2
O
________________________________________________________________
40 %
6 %
40 %
Plant tissues also contain other elements (Na, Se, Co, Si, Rb, Sr, F, I) which are not needed for the normal growth and development.

Different types of plants have different soil pH requirements ( truffle link )

UNSUR MIKRO
Menjadi perhatian sebab
:
1. Diangkut Tanaman
2. Penggunaan varietas unggul & pupuk makro
3. Penggunaan pupuk makro analisis tinggi
4. Kemampuan mengenal gejala kekahatan unsur
Keadaan unsur mikro dapat membatasi pertumbuhan tanaman :
1. Tanah Pasir
2. Tanah organik/Gambut
3. Tanah ber-pH tinggi
4. Tanah yang terus menerus ditanami dan dipupuk berat

Besi (Fe)
• Di kerak bumi + 5 %
Fe dalam tanah + 3,8 %
Mineral mengandung Fe : olivin, pirit, siderit, hematit, geotit, magnetit, limonit
Kahat Fe :- Tanah pasiran
- Tanah organik
Larutan Fe tanah - diserap sebagai Fe +2
- dapat ditransportasi ke akar sebagai kelat
- diserap secara mass flow & difusi
- tidak mobil dalam tanaman

Faktor-faktor yang mempengaruhi ketersediaan Fe
:
1. Keseimbangan ion
Pengaruh keseimbangan ion-ion Cu, Fe & Mn
Rasio Fe / (Cu + Mn) rendah  kahat Fe
2. pH
Kahat Fe  pada daerah pH tinggi ( pada tanah calcareus)
• tanah masam dengan total Fe
• Kelarutan Fe minimum pada pH 7,4 – 8,5
3. Daerah dingin, curah hujan tinggi, kelembaban tinggi, aerasi kurang  kahat Fe
4. Penambahan b.o. Mengatasi kekurangan Fe
5. Hubungan dengan unsur lain
• Nutrisi N mempengaruhi klorosis Fe
• Kahat Fe atau Zn menggaggu pergerakan Fe dalam tanaman

• Peran Fe :
 Mengaktifkan sistem enzim-enzim (fumarie, hidrogenase, katalase, oksidase & sitokrom)
 Sintesa protein kloroplas
• Defisiensi Fe ;
 Nampak pada daun muda
 Klorosis di antara tulang daun muda  menyebar ke helai daun
 daun putih

Mangan (Mn)
Mangan (Mn)
Di kerak bumi + 1.000 ppm
Dalam tanah 20 – 3.000 ppm (rata-rata 600 ppm)
Terkandung dalam feromagnesium, pirolusit, hausmanit, manganit, rodokrosit, rodonit
• Daerah yang kurang Mn :
 Tanah gambut di atas calcareus
 Aluvial debuan, tanah lempungan
 Tanah calcareus drainase jelek
 Tanah pasiran dengan mineral masam
Bentuk Mn tanah
 Larutan Mn +2
 Organik – Mn
 Mn oksida

Faktor-faktor yang mempengaruhi ketersediaan Mn
:
1. Keseimbangan dengan ion logam berat lain
2. pH dan karbonat pengapuran  Mn rendah
3. Bahan organik, Menambah Mn
4. Korelasi dengan unsur lain
Sumber N mempengaruhi ketersediaan Mn
` Penambahan NH
4
Cl
(NH
4
)
2
SO
4
NH
4
NO
3
NH
4
H
2
PO
4
CO(NH
2
)
2
Penyerapan Mn meningkat
5. Musim & iklim
6. Mikroorganisme

Larutan Mn
Sebagai larutan ion
Konsentrasi berkurang dengan naiknya pH
[Mn] larutan 0,01 – 13 ppm pada tanah masam – netral
(Umumnya 0,01 – 1 ppm)
• Peranan Mn :
•  Mengaktifkan enzim-enzim
• Defisiensi Mn :
•  Klorosis di antara tulang daun

Seng (Zn)
Litosfer + 80 ppm
Tanah 10
– 300 ppm (rata-rata 50 ppm
• Daerah kurang Zn :
 Tanah berpasir masam
 Tanah netral / basa
 Tanah calcareus
 >>> lempung & debu
 >>> P tersedia
 >>> tanah organik
• Bentuk Zn :
 Larutan Zn +2
 Zn dapat ditukarkan

Zn diadsorbsi

Zn organik
 Zn yang mensubstitusi Mg di kisi krist

Faktor-faktor yang mempengaruhi ketersedian Zn :
1. pH -> pH tinggi  Zn rendah
2. Adsorbsi oleh mineral oksida
3. Adsorbsi oleh mineral lempung
4. Adsorbsi oleh mineral karbonat
5. Membentuk kompleks dengan b.o.
•
•
•
6. Interaksi dengan unsur lain
P >>  kahat Zn
Sulfat / gipsum >>>
N 

Mn <<<

Zn tinggi pupuk N meningkatkan kebutuhan Zn
•
• Jumlah dan sifat sumber N berhubungan dengan ketersediaan Zn
•
Pupuk N masam meningkatkan penyerapan Zn netral / basa

Zn turun
7. Penggenangan  Anaerob  kahat Zn
8. Iklim yang dingin  kahat Zn

Peranan Zn :
 Aktifator enzinm-enzim
• Defisiensi Zn :
 Pada daun muda
 Klorosis di antara tulang daun
 Pertumbuhan tunas terhambat
 Pada jagung dan sorghum  pita putih sebelah, menyebelah tulang daun

Boron (B)
Unsur hara mikro non esensial valensi +3
Radius ion sangat kecil
[B] dalam tanah 2 – 200 ppm (rata-rata 7 – 80 ppm)
Hanya < 5 % yang tersedia bagi tanaman
• Bentuk B dalam tanah
1. Dalam batuan dan mineral
2. Diadsorbsi di permukaan lempung dan Fe hidrous & oksida Al
3. Bergabung dengan b.o.
4. Sebagai H
3
BO
3 dan B(OH
4
) bebas dalam larutan tanah
• B diserap dalam bentuk BO
3
-3
• melalui mass flow & difusi
• tidak mobil

Faktor-faktor yang mempengaruhi ketersediaan B :
1.
Tekstur tanah
Tekstur kasar, drainase baik, tanah pasiran  B <<<
2.
Jumlah dan tipe lempung
[B] tersedia >>> pada tanah berat dp tanah kasar
Illit, montmorilonit adsorbsi B > kaolinit
3.
pH tanah dan pengapuran pH tinggi  B rendah
Penyerapan B tinggi pada pH 6,3 – 6,5
Pengapuran tinggi  B rendah sebab Al(OH)
3 mengadsorbsi B lebih banyak
4.
Bahan organik
B dan b.o.  kompleks (sumber B pada tanah masam)
Pemberian b.o. Meningkatkan B tanah
5.
Hubungan dengan unsur lain
Ca,  Ca rendah  B rendah demikian juga dengan Overlime  B terbatas
K,  Pada tanah B sangat rendah, dengan pemberian K maka gejala kahat B menonjol
N,  Pemberian N mengontrol kelebihan B dalam jeruk tanaman lain
6.
Kelembaban tanah
Kahat B pada musim kering / kelembaban renda h

Faktor tanaman  tiap tanaman berbeda-beda kebutuhan B
 Bit gula
 Apel, asparagus, brokoli, kubis  perlu B banyak
Peran B dalam tanaman :
 Metabolisme karbohidrat dan pergerakan gula
 Perkembangan sel
 Berperan dalam sistem enzim
Kekurangan B :
 Pada pucuk-pucuk muda
 Daun muda hijau pucat (terutama dasarnya)
 Jaringan pada pangkal daun pecah, bila tumbuh seakan terpilin

Tembaga (Cu)
 Di kerak bumi 55 – 70 ppm
 Batuan beku 10 – 100 ppm
 Batuan sedimen 4 – 45 ppm
 Dalam tanah 1 – 40 ppm (rata-rata 9 pmm)
 1 – 2 pmm  kahat
Mineral yang mengandung Cu :
 Kalkoporit (CuFeS
2
)
 Kalkosit (Cu
2
S)
 Bornit (CuFeS
4
)
Mineral sekunder yang mengandung Cu dalam bentuk-bentuk oksida, karbonat, silikat, sulfat, clorit
Kahat Cu : histosol

Faktor-faktor yang mempengaruhi ketersediaan Cu :
1. Tekstur
Tanah pasir podsol  Cu rendah
Tanah pasir calcareus  Cu rendah
2. pH pH tinggi  adsorbsi koloid tinggi  Cu rendah
3. Interaksi dengan unsur hara lain
• Aplikasi pupuk N  defisiensi Cu lebih buruk
• Tingginya konsentrasi Al dan Zn akan menekan penyerapan Cu oleh tanaman lain
4. Penanaman tanaman pada residu tanaman lain
5. Faktor tanaman

Bentuk Cu dalam tanah :
 Larutan ion dalam tanah
 Kisi pertukaran lempung dan ikatan dengan b.o.
 Akumulasi dalam bahan oksida tanah
 Kisi adsorbsi spesifik
 Sisa-sisa biologis & organisme hidup
Larutan Cu tanah :
Cu dd
Cu adsorbsi Cu – b.o.

Peran Cu :
 Sebagai aktivator berbagai enzim (tirosinase, laktose, oksidase asam askorbat, polifenol oksidase)
Gejala defisiensi Cu :
 Daun menggulung
 Daun mengalami distorsi berkembang tidak normal
 Layu daun muda

Molibdenum (Mo)
 Di kerak bumi <<<
 Di tanah 0,2 – 5 ppm (rata-rata 2 ppm)
Bentuk Mo :
 Tak tertukarkan
 Anion tertukarkan
 Ikatan dengan Fe & Al oksida
 Ikatan dengan b.o.
Kahat Mo :
 Tanah berpasir
 Tanah masam
Larutan Mo :
 pH 4,2  MoO
4
=  diserap tanaman

Faktor-faktor yang mempengaruhi :
1. pH
2. Jumlah Al & Fe oksida
3. Korelasi denagn unsur lain
P meningkatkan absorbsi dan translokasi Mo
SO
4
= >>>  Mo turun
Transport Mo : - mass flow
- difusi
Faktor tanaman : - legum sensitif terhadap Mo
- padi-padian toleran terhadap Mo <<<
Peran Mo :
 Fikasai N
2
 Asimilasi
 legum
 Reduksi nitrat
 Sintesa asam amino & protein
Defisiensi Mo  klorosis di antara tulang daun

Cobalt (Co)
 Co esensial dalam simbiose fiksasi N
2
 Dalam hewan, Co  makanan ternak. Perlu Co untuk sintesa B
12
 [Co] di kerak bumi 40 ppm
• Granit, feromagnesian Co rendah (1 – 10 pmm)
• Sandstone, shale Co < 5 ppm
• Batuan sedimen 20 – 40 ppm
 [Co] dalam tanah 1 – 70 ppm (rata-rata 8 ppm)
 < 5 ppm  kahat
 Perangai Co dalam tanah :
• Adsorbsi (muskovit > hematit > bentonit = kaolinit)
• Kompleks dengan b.o. (membentuk kelat)

Clor (Cl)
 Sebagai anion Cl dalam tanah, pada pH cukup masam sampai mendekati netral
 Pada kemasaman tinggi diikat / diadsorbsi oleh kaolinit
 Cl dalam tanah sangat mobil
Perpindahan dan akumulasi Cl tergantung sirkulasi air
Cl dalam air bawah tanah dapat berpindah secara kapiler ke daerah perakaran
Masalah :
1. Jumlah dalam air irigasi
2. Akumulasi di daerah perakaran
3. Sifat fisik tanah & drainase
4. Tingginya water table dan kapiler ke akar
Cl < 2 ppm  rendah

TERIMAKSIH