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Ca, Mg and S in Soil. Form , Source and function in Plant. Secondary Nutrient Form. 1. Essential Nutrietns of Plants. Chemical Atomic Ionic forms A pproximate dry Element symbol weight Absorbed by plants ____ concentration _____ Mccronutrients
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Ca, Mg and S in Soil Form , Source and function in Plant
1. Essential Nutrietns of Plants Chemical AtomicIonic forms Approximatedry Element symbol weightAbsorbed by plants ____ concentration_____ Mccronutrients Nitrogen N 14.01 NO3-, NH4+ 4.0 % Phosphorus P 30.98 PO43-, HPO42-, H2PO4-0.5 % Potassium K 39.10 K+ 4.0 % Magnesium Mg 24.32 Mg2+ 0.5 % Sulfur S 32.07 SO42- 0.5 % Calcium Ca 40.08 Ca2+ 1.0 % Micronutrients Iron Fe 55.85 Fe2+, Fe3+ 200 ppm Manganese Mn54.94 Mn2+ 200 ppm Zinc Zn 65.38 Zn2+ 30 ppm Copper Cu63.54Cu2+ 10 ppm Boron B 10.82 BO32-, B4O72-60 ppm Molybdenum Mo95.95MoO42- 2 ppm Chlorine Cl 35.46 Cl- 3000 ppm Essential But Not Applied Carbon C 12.01 CO2 40 % Hydrogen H 1.01 H2O 6 % Oxygen O 16.00 O2, H2O 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.
Calsium Form , Source and function in Plant
Calcium (Ca) 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 CaCO3·MgCO3) - Lime (CaCO3), Gypsum (CaSO4) - Superphosphate - Bone meal-organic P source
Calcium (Ca) • 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.
Calcium • Is mobile in the soil • 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 • Is held on the cation exchange • Low pH soils likely to be low in Ca
Factors Affecting Ca Availability • 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 Ca2+ to other cations • Uptake depressed by NH4+, K+, Mg+, Mn2+, Al2+ • Absorption increased by NO3-
Calcium Deficiency — Tip leaves small, rolled and scorched 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 TomatoCalcium Deficiency Right-Hydroponic tomatoes grown in the greenhouse, Left-Blossom end rot of tomato fruits induced by calcium (Ca++) deficiency
Magnesium Form , Source and function in Plant
Magnesium (Mg) 1) Soil Relations - Present in soil as an exchangeable cation (Mg2+) - Similar to Ca2+ 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 CaCO3·MgCO3) - Epsom salt (MgSO4) - Magnesium nitrate [Mg(NO3)2] - Magnesium sulfate (MgSO4)
Magnesium (Mg) • 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
Magnesium • Moves to root via mass flow & diffusion • Leaches somewhat more than Ca • Held on the cation exchange • Deficiency occurs in low pH soils
Factors Affecting Mg Availability • 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 • NH4+ induced Mg deficiency • High rates of NH4+ on soils with low exchangeable Mg
Magnesium (Mg) Deficiency on Poinsettia Interveinal Chlorosis on Mature Leaves
Chlorosis and necrosis of leaves defoliation • Magnesium Deficiency Growth fairly good foliage chlorotic and with intervenal necrosis death of older foliage
Purple tinting • Magnesium Deficiency intervenal necrosis developing from marginal areas. Apple Leaves
Calcium & Magnesium Cycle From Havlin et al., 2005
Sulfur Form , Source and function in Plant
Sulfur (S) 1) Soil Relations - Present in mineral pyrite (FeS2, fool’s gold), sulfides (S-mineral complex), sulfates (involving SO4-2) - 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 (CaSO4) - Magnesium sulfate (MgSO4) - Ammonium sulfate [(NH4)2SO4] - Elemental sulfur (S)
Sulfur (S) • Plant available form: SO4- • 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
Sulfur Forms in Soils • Inorganic S • Sulfate dominates (SO42-) • Sulfides (flooded conditions) • Elemental S • Thiosulfates • Range in oxidation states (-2 to +6) • > 90% of total S in most soils is organic • Carbon-bonded S • Ester sulfates (organic sulfates) • 30 to 75% of organic S
Volatile S CS2 CH3SH CH3SCH3 Volatilization
Sulfur Mineralization • Biological • Cleavage of C-S bonds to produce S2- • Cysteine desulfhydolase • Driven by need for C • Biochemical • Cleavage of C-O-S (ester) bonds to produce SO42- • Sulfohydrolases (sulfatases), associated with microbial cell walls • Driven by need for S, regulated by SO42- • C:S ratio • C: S < 200, net S mineralization; > 400 immobilization • Volatilization • Anaerobic mineralization
Immobilization of S (assimilation) Serine SO32- S2- Cysteine PAP + Tr(ox) ATP PPi 3NADPH 3NADP Tr(red) SO42- SO42- APS PAPS COS Cysteine ATP ADP Pi APS GSH O-acetyl-serine Acetate + H2O AMP + H+ GSSO3- GSSH Cysteine 6Fd(red) +7H+ 6Fd(ox) +3H2O GS
S2O32- 2e- 4e- 2e- S2- S0 SO32- SO42- AMP ADP 2e- Pi APS Microbial S Oxidation • Chemoautotrophic (Lithotrophic) • Energy generated (-189.9 kcal mol-1 S22-; -139.8 kcal mol-1 S0) • Acidifying (2H+ per S0) • 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)
Sulfur Deficiency in Corn. Overall light green color, worse on new leaves during rapid growth.
AVAILABILITY OF NUTRIENTS INFLUENCES GROWTH AND PRODUCTIVITY
HARA MIKRO Form , Source and function in Plant
1. Nutrietns of Plants Chemical Atomic Ionic forms Approximate dry Element symbol weight Absorbed by plants ____ concentration_____ Mccronutrients Nitrogen N 14.01 NO3-, NH4+4.0 % Phosphorus P 30.98 PO43-, HPO42-, H2PO4-0.5 % Potassium K 39.10 K+4.0 % Magnesium Mg 24.32 Mg2+ 0.5 % Sulfur S 32.07 SO42- 0.5 % Calcium Ca 40.08 Ca2+1.0 % Micronutrients Iron Fe 55.85 Fe2+, Fe3+ 200 ppm Manganese Mn 54.94 Mn2+ 200 ppm Zinc Zn 65.38 Zn2+ 30 ppm Copper Cu 63.54 Cu2+ 10 ppm Boron B 10.82 BO32-, B4O72-60 ppm Molybdenum Mo 95.95 MoO42- 2 ppm Chlorine Cl 35.46 Cl- 3000 ppm Essential But Not Applied Carbon C 12.01 CO2 40 % Hydrogen H 1.01 H2O 6 % Oxygen O 16.00 O2, H2O 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.
SOIL pH AND MINERAL NUTRITION Different types of plants have different soil pH requirements (truffle link)
UNSUR MIKROMenjadi perhatian sebab : • Diangkut Tanaman • Penggunaan varietas unggul & pupuk makro • Penggunaan pupuk makro analisis tinggi • Kemampuan mengenal gejala kekahatan unsur • Keadaan unsur mikro dapat membatasi pertumbuhan tanaman : • Tanah Pasir • Tanah organik/Gambut • Tanah ber-pH tinggi • 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, limonitKahat 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 : • Keseimbangan ion Pengaruh keseimbangan ion-ion Cu, Fe & Mn Rasio Fe / (Cu + Mn) rendah kahat Fe • pH Kahat Fe pada daerah pH tinggi ( pada tanah calcareus) • tanah masam dengan total Fe • Kelarutan Fe minimum pada pH 7,4 – 8,5 • Daerah dingin, curah hujan tinggi, kelembaban tinggi, aerasi kurang kahat Fe • Penambahan b.o. Mengatasi kekurangan Fe • Hubungan dengan unsur lain • Nutrisi N mempengaruhi klorosis Fe • Kahat Fe atau Zn menggaggu pergerakan Fe dalam tanaman
Peran dan Defisiensi Fe • 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 ppmDalam 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 : • Keseimbangan dengan ion logam berat lain • pH dan karbonat pengapuran Mn rendah • Bahan organik, Menambah Mn • Korelasi dengan unsur lain Sumber N mempengaruhi ketersediaan Mn ` Penambahan NH4Cl (NH4)2SO4 NH4NO3 Penyerapan Mn meningkat NH4H2PO4 CO(NH2)2 • Musim & iklim • Mikroorganisme
Larutan MnSebagai larutan ionKonsentrasi 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 ppmTanah 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 : • pH -> pH tinggi Zn rendah • Adsorbsi oleh mineral oksida • Adsorbsi oleh mineral lempung • Adsorbsi oleh mineral karbonat • Membentuk kompleks dengan b.o. • Interaksi dengan unsur lain • P >> kahat Zn • Sulfat / gipsum >>> Mn <<< Zn tinggi • N pupuk N meningkatkan kebutuhan Zn • Jumlah dan sifat sumber N berhubungan dengan ketersediaan Zn • Pupuk N masam meningkatkan penyerapan Zn • netral / basa Zn turun • Penggenangan Anaerob kahat Zn • 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 esensialvalensi +3Radius ion sangat kecil[B] dalam tanah 2 – 200 ppm (rata-rata 7 – 80 ppm)Hanya < 5 % yang tersedia bagi tanaman • Bentuk B dalam tanah • Dalam batuan dan mineral • Diadsorbsi di permukaan lempung dan Fe hidrous & oksida Al • Bergabung dengan b.o. • Sebagai H3BO3 dan B(OH4)- bebas dalam larutan tanah • B diserap dalam bentuk BO3-3 • melalui mass flow & difusi • tidak mobil