nutrition principles principles

1. N P K
Nutrition
Principles

2. Nutrition Principles
Nitrogen
Cycle
Factors
Affecting
Availability
Sources
Forms
Taken up
Role in
Plants
Nitrogen
Key Presentation Points

3. Role in Plants
• Protein
• Nucleic acid
• Chlorophyll
• Carbohydrate
Four nitrogenous bases –
au
de
tin
li
in
ze
at
(i
A
o
)n
, thymine (T), guanine
(G), and cytosine (C) are
components in the DNA double
helix.

4. Forms Plants Uptake
Ammonia
• Plants uptake both forms.
3
• Uptake NO - the most.
-
• NO3 is mobile, NH4 is not.
• NO3- prefers acidic pH.
• NH4
+ prefers neutral pH.
• Combination is better.
Which form is vulnerable to leaching losses?
Nitrate

5. Nitrogen Cycle
• N in soil enters, exits, and changes
forms in many ways.
• Can you name some of the processes
and pools in N cycles?
mineralization, immobilization,
nitrification, denitrification, nitrogen
fixation, nitrogen leaching…

6. Denitrification
N2
Biological
and
Chemical
Fixation
Atmospheric
Nitrogen, 78%
Clay Fixation
and Release
NH3 + H+ = NH4
NO3
N2
N2O
Immobilization
(use by the plant)
Leaching
N states
NO3
NO2
NITROGEN CYCLE
Nitrate ion
Nitrite ion
NO
N20
Nitric oxide
Nitrous oxide
oxide
oxide
N2
Dinitrogen gas
Various states of N

7. NITROGEN
Denitrification
Biological
and
Chemical
Fixation
NH3 + H+ = NH4
Clay Fixation
and Release
NO3
Leaching
N2
N2O
Immobilization
(use by the plant)
N Fixation
Atmospheric
Nitrogen, 78%
NITROGEN
N2
N from air is fixed by
microbes and
lightning.
Nitrogen Fixation

8. Denitrification
N2
Biological
and
Chemical
Fixation
Atmospheric
Nitrogen, 78%
NH3 + H+ = NH4
Clay Fixation
and Release
NO3
Leaching
N2
N2O
Immobilization
(use by the plant)
N from
Organic
Matter
N is released from
organic matter
decomposition.
Mineralization

9. Denitrification
N2
Biological
and
Chemical
Fixation
Atmospheric
Nitrogen, 78%
NH3 + H+ = NH4
Clay Fixation
and Release
N2
N2O
Immobilization
(use by the plant)
NO3
Leaching
N from
NH4
When the process
reverses with plant
and microbial uses
Immobilization

12. Fertilizer Nitrogen
• Nitrogen fertilizer should be
added to the soil when the crop
will use it, adding excess N will
cause losses that may harm the
environment.
• Nitrogen is expensive and using
only what the crop needs for
adequate growth is important -
• THUS it becomes important to
give N - CREDITS for previous
management (legumes, manure or
other organic additions with low
C:N ratios).
Wheat with N response

13. Nitrogen soil testing
• Mobile nutrient
• In drier areas use a
fall or spring nitrate-N
soil test.
• In humid areas, use
spring nitrate-N test
or table value based on
previous crop and
organic matter.

14. Nitrogen soil testing
n
• After arriving at N
recommendation then
credits need to be take
for:
– Previous crop
– Previous manure
applications or sludge
– 2ndyear after alfalfa

15. More on
The story behind residual
n u tri en t cred i ts to growers

16. NH2
Upon decomposition
plant animal residues,
N-containing molecules
are released from
Chlorophyll
DNA and RNA
Protein }
NH2

17. Chlorophyll
DNA and RNA
Protein }
2
NH2
NH2
NH2
When organic matter
decomposes, N-containing
molecules are released fromNH
N molecules from
this amino group
combine with H to
produce NH3 and NH4
H
H
3
NH + H = NH -
4
Ammonium

18. Chlorophyll
DNA and RNA
Protein }
NH2
First they make
this gas, then
NH2
NH2
NH2 NH3
H
H+
H
+ NH4
Ammonium
Ammonia
(gas)
=
The simple steps in the mineralization process are now complete.
The process is also called ammonification.
When organic matter
decomposes, N-containing
molecules are released from

19. Denitrification
N2
Biological
and
Chemical
Fixation
Clay Fixation
and Release
N2
N2O
Immobilization
(use by the plant)
NITROGEN
Nitrobactor
NO3
Nitrification
NH3 + H+ = NH4
Nitrosomonas
NO2
Oxidation of NH4 to NO3 is
nitrification.
Two kinds of bacteria are
involved in two steps.

20. Denitrification
N2
Biological
and
Chemical
Fixation
Clay Fixation
N2
N2O
Immobilization
(use by the plant) NITROGEN
Nitrobactor
NO3
Nitrification
and Release
NH3 + H+ = NH4
Nitrosomonas
NO2
In water-logged soil, NO3
transforms to gaseous N, and
this loss to air is denitrification.
Steps: NO2--NO--N2O and N2

21. Denitrification
N2
Biological
and
Chemical
Fixation
Atmospheric
Nitrogen, 78%
Clay Fixation
NO3
N2
N2O
Immobilization
(use by the plant)
Leaching
and Release
NH3 + H+ = NH4
NITROGEN
Clay Fixation and
Release of NH4

22. Denitrification
N2
Biological
and
Chemical
Fixation
Atmospheric
Nitrogen, 78%
Clay Fixation
and Release
NH3 + H+ = NH4
NO3
N2
N2O
Immobilization
(use by the plant)
Leaching
NITROGEN
Nitrate Leaching

23. Sources of N in Wheat
• Organic – residue breakdown (slow)
• Organic manures (N content varies)
• Commercial
– Urea
– Ammonia
– Monoammonium phosphate (MAP)/diammonium
phosphate (DAP)
– Potassium nitrate
– URAN (urea + ammonium nitrate) solutions
– Ammonium nitrate
More discussion in Sections 4 and 5

25. P Nutrition Principles
How the materials will be presented
P-cycle
Key
Factors
Sources
Forms
uptake
Role in
plant
P

26. P Essentiality
solution is low
• Low solubility
• Low availability
• Low mobility
Nutrient Amount in
Solution (mg/L)
3
• Second most importanNtO -
nutrient
60
--
0.8
14
60
40
26
4
NH +
4 4
• Its concentration in soH
il PO -, HPO 2-
2
K+
Ca2+
Mg2+
SO4
2-
are key characteristics for
better management

27. Role in Plants
• ATP
• DNA/RNA
• Enhance crop maturity
• Root growth
Can you
justify how
P is
important
in these

28. Role in Plants
• ATP
• DNA/RNA
• Enhance crop maturity
• Root growth P is a critical component of
cell’s energy currency, ATP

29. Role in Plants
• ATP
• DNA/RNA
• Enhance crop maturity
• Root growth
P containing sugar
phosphate is the
backbone of DNA

30. Plant Available Forms
Orthophosphate ions: H2PO4 & HPO4
- 2-
Availability is pH dependent
7.2 pH
Both species are even at this pH

31. Phosphorus Cycle
• Not involved in atmospheric exchanges
• Cycles among various pools
– Soil solution
– Organic matter
– Inorganic minerals
• Interaction among pools is complex.
• Knowledge of each pool is necessary.

32. Phosphorus Cycle
Secondary
Minerals
Fe & Al PO4
CaPO4
Nonlabile P
Primary
Minerals
(Nonlabile P)
Solution P
-
H2PO4 HPO42-
Microbial-
P
bacteria
Fungi
nematode
Plant residue
Labile P
Adsorbed
P
Dissolution
Dissolution
Precipitation
Adsorption
Desorption
Immobilization
Mineralization
Fertilizer-P
Soil Organic
Matter
Microbial P
(Nonalabile P)
(Labile P)
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SOIL SOLUTION POOL
INTERACTIONS

33. Phosphorus Cycle
Secondary
Minerals
Fe & Al PO4
CaPO4
Nonlabile P
Primary
Minerals
(Nonlabile P)
Solution P
4
H2PO - HPO4
2-
nematode
Plant residue
Labile P
Adsorbed
P
Dissolution
Dissolution
Precipitation
Adsorption
Desorption
Immobilization
Mineralization
Fertilizer-P
Soil Organic
Matter
Microbial P
(Nonalabile P)
(Labile P)
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ORGANIC POOL
INTERACTIONS
What is good – high or low C/P?
Why?

34. Organic-P, quick facts
• P of organic matter range
between 1% and 3%
• Organic P is ~50% of total
P in soil
• Organic P decreases with
soil depth
• Organic-P increases with
increased organic-C (the
C/P, likewise N and C/N)

35. Phosphorus Cycle
Secondary
Minerals
Fe & Al PO4
CaPO4
Nonlabile P
Primary
Minerals
(Nonlabile P)
Solution P
-
H2PO4 HPO4
2-
Microbial-
P
bacteria
Fungi
nematode
Plant residue
Labile P
Adsorbed
P
Dissolution
Dissolution
Precipitation
Adsorption
Desorption
Immobilization
Mineralization
Fertilizer-P
Soil Organic
Matter
Microbial P
(Nonalabile P)
(Labile P)
INORGANIC POOL
INTERACTIONS
Inorganic P fixed or released by
primary and secondary minerals

36. P
soi
l
• Soil test for P (Bray pH<7.4 of soil)
• 0-5 ppm = very low
• 6-10 ppm = LOW
• 11-15 ppm = med
• 16-20 ppm = high
• > =21 ppm = very high
• No reason to have
test > 21
• environmental problems
when P >16
• ppm x 2 = lbs/acre
P deficient tomato

37. Soil P
• Crops need more P than is
dissolved in the soil solution at any
one time, therefore, this P in the
solution phase must be replenished
many times during the growing
season.
• The ability of a soil to maintain
adequate levels of phosphorus in
the solution phase is the key to
the plant available P status of the
soil. The solid phase P is both
organic and inorganic
Solid P Phase Solution Phase Root Hair
P deficiency reduces root growth

38. Inorganic-P, quick facts
• Low concentration & solubility of P due to slow
release and fixation
• Minerals mainly with Ca, in alkaline soils
• Minerals with Fe, Al, and Mg in acidic soils
•

39. Solubility of P-containing compounds
Compound Formula Compound type
Monocalcium phosphate Ca(H2PO4)2.H2O
CaHPO4.2H2O
Ca8H2(PO4)6.5H2O
Ca3(PO4)2
[3Ca3(PO4)2].CaO
[3Ca3(PO4)2].Ca(OH)2
[3Ca3(PO4)2].CaCO3
3Ca3(PO4)2].CaF2
Calcium
Dicalcium phosphate
Octacalcium phosphate
Tricalcium phosphate
Oxy apatite
Hydroxy apatite
Carbonate apatite
Fluorapatite
Strengite FePO4-2H2O Iron
Variscite AlPO4-2H2O Aluminum
• Ca-phosphate - major contributor in alkaline
soils
• pH determines its availability
• Solubility decreases in order of:
di > tri calcium phosphates
mono >

40. Commercial P Fertilizers

42. K Nutrition Principles
K-Cycle
Key
Factors Sources
Forms
Taken up
Role in
Plants
K

43. P Essentiality Principles
• Plant absorbs larger amount of K next
only to N
• Plant tissue K: ~2.5% to 4.5% leaf dry
wt.
• Soil K: 0.5% to 2.5%
• Most soil K’s are tied up, availability is
often limited

44. Role in Plants
• Enzyme activation
• Water relations
(stomatal control)
• Energy relations
• Translocation (sugar
transport)
• Crop quality
Justify
how K is
important
in these

45. Role in Plants
• Enzyme activation
•
•
K activates at least 60 enzymes in cell
K level determines reactions catalyzed by enzymes

46. Potassium Fertility (Potash)
• Potassium (K+) is a problem
on acid soils, soils with low
CEC and with irrigation or
high rainfall where leaching
can readily occur.
• Potassium can be stored in
the soil from one year to
the next
• K is not a pollutant - even if
leached from soil, K does
not cause environmental
problems.
K deficient corn

47. Role in Plants
• Water relations
– K regulates stomatal
opening
K is critical to stomatal opening and closure in
regulating gas exchanges (CO2 in and H2O out)

48. Role in Plants
• Energy relations
– K is required for production of ATP
• Crop quality
– Increases root growth
– Enhances translocation of sugar
– Increase protein content in plant
– Reduces lodging

49. Forms uptake
K+
S
o
ilKP
o
o
lsa
n
dC
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c
entratio
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M
in
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ral…
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…
..…
50
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N
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…
...…
.50–7
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p
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E
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a
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…
…
…
…
..4
0
0–6
0
0p
p
m
K-Cycle will show
S
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…
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a
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c
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t
–
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o
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n
p
m
among pools

50. K forms - characteristics
1. Mineral – K : Minerals like
Mica, Feldspar, K is mainly
unavailable
2. Non-exchangeable – K : K in
secondary minerals like vermiculite
or colloidal-size mica, K is slowly
available
……more

51. In the non-exchangeable fraction of K
Most K
trapped
K slowly available K is widely
exchangeable

52. K forms - characteristics
3. Exchangeable-K: K on the cation
exchange sites of soil colloids is
readily available

53. K forms - characteristics
4. Soil solution-K: K is readily
available. Range in most cropland
soils ~ 1-10ppm.
~80% K plant uptake by diffusion,
availability depends of many
factors

54. Exchangeable K+
K+
K+
K+
K+ K+
Nonexchangeable K+
Plant &
animal
residues
K+
Plant uptake
Desorption
Adsorption
Weathering
90-98%
0.1-0.2%
Soil solution
1-2%
K+ K+
1-10%
2:1 Clay minerals
Leaching Erosion
Feldspar
Mica
Primary
minerals
K
Mineral-K, mostly
unavailable, accounts
for majority of soil K
K
,
s, slowly
Non-exchangeable-K
in secondary mineral
available, 2:1 clay
K
Exchangeable-K,
readily available, K
in cation exchange
site…

55. Exchangeable K+
K+
K+
K+
K+ K+
Nonexchangeable K+
K+
Plant uptake
Desorption
Adsorption
Plant/
animal
residues
Weathering
90-98%
0.1-0.2%
Soil solution
1-2%
K+ K+
1-10%
Feldspar
Mica
Primary
minerals
K
K K
Residue K recovery is
minor, usually leach out
2:1 Clay minerals
K leaching loss is ofteL
ne
a
sc
h
ui
n
bg
stanE
tr
io
as
li
o
n

56. K Cycle Quick Fact
• K transfer from minerals is slow but
continuous
• Exchangeable and soluble K equilibrate
rapidly
• Fixed K equilibrate very slowly
• Transfer from mineral to other form is
very slow, usually unavailable (in one
crop year)

57. K Fixation – who is involved?
• Reentrapment of K ions between the layers of
2:1 clay (illite) is a major reason
• The 1:1 clay (kaolinite) do not fix potassium
• Major factor affecting K availability
– Clay minerals, CEC, nature of cations
– Soil moisture
– Soil temperature
– Amount of exchangeable K, capacity to fix K

58. Potassium Fertilizers
• Organic sources – K content varies with sources,
range in manure is 4-40 pounds
• Commercial sources – potassium oxide (K2O) is
guaranteed standard for fertilizer K
• Potash and Potassium names are used
interchangeably
• The world’s largest high-grade potash deposit is in
Canada
END OF SECTION 02 INSTRUCTION

59. Tools for detecting nutrient deficiency
• 1) Tissue testing -involves a complete
and detailed laboratory analysis of
nutrient elements in the plant leaves.
This is a very accurate way of assessing
how much nutrient the plant has
actually taken up from the soil.
• Recommendations are made on the
basis of these test results:
– Backed by research
– Dependent on plant growth stage and plant
part.

60. Soil testing
• Collecting a soil
sample to determine
the current nutrient
status of the soil.

61. Calibration
• Process of ascertaining the degree of
limitation to crop growth or the probability
of getting a growth response to applied
nutrient at any soil test level.
• Soil test interpretation develops fertilizer
recommendations.

62. Correlation - process
• Exploratory
fertilization trial
– Greenhouse – a
controlled environment
with soil homogeneity.
• Trials in field with
selected soils.

63. Thank you
A.Swaroopa rani