Essential plant nutrients. Classification of essential plant nutrients

Size: px

Start display at page:

Download "Essential plant nutrients. Classification of essential plant nutrients"

Annis Newton
5 years ago
Views:

2 ن آ سک هک دنادب و دهاوبخ هک دنادب دوخ ار هب یادنلب تداعس دناسرب "آن سک هک دنادب و دنادب هک دنادب بسا بلط زا دبنگ "دناهبج نودرگ ن آ سک هک دنادب و دنادن هک دنادب با هزوک ب آ تسا لیو هن شت دنابم "آن سک هک دنادن و دنادب هک دنادن ناگنل کرخ شیوخ هب دصقم "دناسرب ن آ سک هک دنادن و دهاوبخ هک دنادب ناج و نت دوخ ار تلاجه ز دناهرب "آن سک هک دنادن و دنادن هک دنادن لجه رد بکرم رهلدادبا "دنابم ن آ سک هک دنادن و دهاونخ هک دنادب فیح تسا یننچ یروناج هدزن!دنابم

3 Essential plant nutrients Classification of essential plant nutrients

4 Essential plant nutrients Classification of essential plant nutrients on the basis of biochemical and physiological functions in plants Group Nutrients Form in which Biochemical/physiological functions taken up by plants I C CO 2, HCO - 3 Major constituents of organic material, essential H H 2 O elements of atomic groups which are involved in O O 2 N NH 4+, NO 3-, N 2 (in enzymatic process, etc. fixation) S SO 4-2, SO 2 (gaseous absorption in leaves II P H 2 PO 4-1, HPO 4-2 Esterification with native plant alcohol. Phosphate esters B B(OH) 3 are involved in energy transfer.

5 Essential plant nutrients Classification of essential plant nutrients on the basis of biochemical and physiological functions in plants Group Nutrients Form in which Biochemical/physiological functions taken up by plants III K K + Nonspecific functions, involved in establishing osmotic Mg Mg +2 potential. Ca is a component of plant structural parts. Ca Ca +2 Mn Mn +2 Cl Cl -1 IV Fe Fe +2 Present predominantly in a chelated form in prosthetic group, enable electron transport by valency change Cu Cu +2

6 1. ESSENTIAL NUTRIETNS OF PLANTS APPROXIMATE DRY CONCENTRATION MACRONUTRIENTS 4.0 % 0.5 % 4.0 % 0.5 % 0.5 % 1.0 % IONIC FORMSATOMIC ABSORBED BY PLANTSWEIGHT CHEMICAL SYMBOL NO 3-, NH N PO 3-4, HPO 2-4, H 2 PO P Phosphorus K K Potassium Mg Mg Magnesium SO S Sulfur Ca Ca Calcium MICRONUTRIENTS 200 ppm 200 ppm 30 ppm 10 ppm 60 ppm 2 ppm 3000 ppm ESSENTIAL BUT NOT APPLIED Fe 2+, Fe Fe Iron Mn Mn Manganese Zn Zn Zinc Cu Cu Copper BO 2-3, B 4 O B Boron MoO Mo Molybdenum Cl Cl Chlorine Nitrogen 40 % CO C Carbon 6 % H 2 O 1.01 H Hydrogen 40 % O 2, H 2 O O Oxygen ELEMENT PLANT TISSUES ALSO CONTAIN OTHER ELEMENTS (NA, SE, CO, SI, RB, SR, F, I) WHICH ARE NOT NEEDED FOR THE NORMAL GROWTH AND DEVELOPMENT.

7 MOBILE IMMOBILE -1mobile : N P K Mg Zn -2immobile :Ca Fe B Mn Cu S

8 NITROGEN CYCLE

9 SOURCES Lightning Inorganic fertilizers Nitrogen Fixation Animal Residues Crop residues Organic fertilizers

11 AGRICULTURE BREAKS N CYCLE N2 Removed by crops NH3 erosion Losses gains Feeding farm animals cow N2 Artificial fixation Manuring Organic N symbiotic fixation denitrification NH4 NH3 fertilizer

12 FORMS OF NITROGEN Urea CO(NH2)2 Ammonia NH3 (gaseous) Ammonium NH4 Nitrate NO3 Nitrite NO2 Atmospheric Dinitrogen N2 Organic N

13 ROLES OF NITROGEN Plants and bacteria use nitrogen in the form of NH 4+ or NO - 3 It serves as an electron acceptor in anaerobic environment Nitrogen is often the most limiting nutrient in soil and water.

14 NITROGEN IS A KEY ELEMENT FOR amino acids nucleic acids (purine, pyrimidine) cell wall components of bacteria (NAM).

15 NITROGEN CYCLES Ammonification/mineralization Immobilization Nitrogen Fixation Nitrification Denitrification

16 NITROGEN CYCLE

17 N 2 N 2 O NH 4 NO 2 R-NH 2 NO NO 2 NO 3

18 AMMONIFICATION OR MINERALIZATION N 2 N 2 O NH 4 NO 2 R-NH 2 NO NO 2 NO 3

19 Plants die or bacterial cells lyse release of organic nitrogen Organic nitrogen is converted to inorganic nitrogen (NH 3 ) When ph<7.5, converted rapidly to NH 4 Example: Urea NH CO 2

20 NITROGEN FIXATION N 2 N 2 O NH 4 NO 2 R-NH 2 NO NO 2 NO 3

21 Nitrogen in the environment N 2 77% in the air; very stable Industrial fixation Natural fixation: lighting (8% of the nitrogen fixed) N 2 HNO 3 photochemical reactions (2% of the nitrogen fixed) N 2 HNO 3 biological nitrogen fixation (90% of the nitrogen fixed) N 2 NH 3 NH

22 CLASSIFICATION NITROGEN FIXATION NON-BIOLOGICAL BIOLOGICAL SYMBIOTIC NON-SYMBIOTIC

23 NITROGEN FIXATION Energy intensive process : N 2 + 8H+ + 8e ATP = 2NH 3 + H ADP + 16 Pi Performed only by selected bacteria and actinomycetes Performed in nitrogen fixing crops (ex: soybeans)

24 BIOLOGICAL N 2 FIXATION Conversion of elemental nitrogen or gaseous nitrogen into nitrogenous compounds or salts by certain microorganisms like bacteria,blue green algae, fungi etc. is called biological nitrogen fixation. It is carried by two types of micro- organisms. Eg Symbiotic and non-symbiotic.

25 MICROORGANISMS FIXING Azobacter Beijerinckia Azospirillum Clostridium Cyanobacteria Require the enzyme nitrogenase Inhibited by oxygen Inhibited by ammonia (end product)

26 RATES OF NITROGEN FIXATION N 2 fixing system Nitrogen Fixation (kg N/hect/year) Rhizobium-legume Cyanobacteria- moss Rhizosphere associations 2-25 Free- living 1-2

27 NITROGEN (N)A. 1) SOIL NITROGEN CYCLE a) Nitrogen Fixation -Transformation of atmospheric N to nitrogen forms available to plants - Mediated by N-fixing bacteria: Rhizobium (symbiotic) found in legumes (bean, soybean) Azotobacter (non-symbiotic bacteria) b) Soil Nitrification - Decomposition of organic matter into ammonium and nitrate - Mediated by ammonifying and nitrifying bacteria Ammonifying bacteria Nitrifying bacteria (Actinomycetes) (Nitrosomonas) (Nitrobacter) Plant residue NH + 4 NO 2 NO - 3 (Protein, aa, etc) Ammonium Nitrite Nitrate

28 SCHEMATIC DIAGRAM OF NITROGENASE COMPLEX Electrons from Reduced ferredoxin Dinitrogenase Reductase (Fe-Protein) Dinitrogenase Reductase ( MO -Fe-Protein) ATP ADP NH + 4 N 2 Reduction

29 Figure The reaction catalyzed by nitrogenase N 2 + 8e - + 8H ATP 2 NH 3 + H ADP + 16Pi 29

30 NITRIFICATION N 2 N 2 O NH 4 NO 2 R-NH 2 NO NO 2 NO 3

31 NITRIFICATION Two step reactions that occur together : 1 rst step catalyzed by Nitrosomonas 2 NH O 2 2 NO H 2 O+ 4 H + 2 nd step catalyzed by Nitrobacter 2 NO O 2 2 NO 3 -

32 Optimal ph is between If ph < 6.0 rate is slowed If ph < 4.5 reaction is inhibited

33 DENITRIFICATION N 2 N 2 O NH 4 NO 2 R-NH 2 NO NO 2 NO 3

34 DENITRIFICATION Removes a limiting nutrient from the environment 4NO C 6 H 12 O 6 2N H 2 0 Inhibited by O 2 Not inhibited by ammonia Microbial reaction Nitrate is the terminal electron acceptor

35 Stages in Root Nodule Formation 1 Recognition and attachment of bacterium to root hair 2 Invasion of root hair, by formation of an infection thread. 3 Travel to main root 4 Formation deformed cells, bacteroids to get to N fixing state 5 Formation of Nodule

Visit For All NCERT solutions, CBSE sample papers, Question papers, Notes for Class 6 to 12. Chapter-12 MINERAL NUTRITION

Visit For All NCERT solutions, CBSE sample papers, Question papers, Notes for Class 6 to 12. Chapter-12 MINERAL NUTRITION Chapter-12 MINERAL NUTRITION POINTS TO REMEMBER Autotroph : An organism that synthesize its required nutrients from simple and inorganic substances. Heterotroph : An organism that cannot synthesise its