Baron Justus von Liebig showed in the mid-19th century that nutrients are essential for plant life. He determined that plants deprived of any essential element would cease to exist and stated plants will only use essential elements in proportion to each other, with the element in shortest supply determining plant growth. Sixteen nutrients are essential for crops, each important yet required in different amounts, leading to their categorization as primary, secondary, or micronutrients.

3. Baron Justus von Liebig, a German scientist in the mid-19th century,
showed that nutrients are essential for plant life. He stated, "We have
determined that a number of elements are absolutely essential to plant life.
They are essential because a plant deprived of any one of these elements
would cease to exist. . . ." He also authored the term "law of the minimum,"
which states that "plants will use essential elements only in proportion to
each other, and the element that is in shortest supply—in proportion to the
rest—will determine how well the plant uses the other nutrient elements."

4. 1. Sixteen plant food nutrients are essential for proper
crop development.
2. Each is equally important to the plant, yet each is
required in vastly different amounts.
3. These differences have led to the grouping of these
essential elements into three categories;
a) Primary(macro) nutrients,
b) Secondary nutrients,
c) Micronutrients.

7.  Carbon
 Hydrogen
 Oxygen

8.  Carbon plays tremendous role in life of all organisms including plants
 In fact every plant cell and animal cell has carbon in it in various
combinations with other molecules .
 This carbon enters the plant body in the form of CARBON DIOXIDE GAS (
CO2 gas ) .
In no other form can it enter .
 From the plants it enters the animal bodies through their food
 Carbohydrates , proteins and fats / oils have carbon in them.
 There is no place for carbon in fertilizers as it cannot be absorbed through
roots .

10.  Protein structure is partially determined by hydrogen
bonding.
 Hydrogen bonds can occur between a hydrogen on an
amine and an electronegative element, such as oxygen on
another residue.
 As a protein folds into place, a series of hydrogen bond
"zips" the molecule together, holding it in a specific three-
dimensional form that gives the protein its particular
function

12.  Oxygen in plants is for absorption of nutrients across the cell walls and roots.
 Oxygen is also used to produce glucose and fructose, which are the main products of
photosynthesis, excess Oxygen is released via transpiration.
 Oxygen therapy is a treatment that provides you with extra oxygen, a gas that your
body needs to work well. Normally, your lungs absorb oxygen from the air.
 Oxygen is needed by plants for energy
through night time hours.

14. 1. Primary (macro) nutrients are nitrogen,
2. phosphorus, and potassium.
3. They are the most frequently required in a
crop fertilization program.
4. They are need in the greatest quantity by
plants as fertilizer.

15. 1. Affects energy reactions in the plant ,in vegetative growth and root
development
2. Aids in production and use of carbohydrates
3. Directly involved in photosynthesis
4. Essential for plant cell division, vital for plant growth
5. Necessary for formation of amino acids, the building blocks of protein
and enzymes
6. Necessary component of several vitamins
7. Nitrogen improves the quality and quantity of dry matter in leafy
vegetables and protein in grain crops.
8. Boost plant protein level
9. It hastens ripening of plants and counteracts the effects of excessive
nitrogen.
10. 10.Essential for nitrogen fixing organism
6CO2 + 12H2 O + 672 Kcal radiant energy = C6 H12O6 + 6H2 O + 6O2

17. 1. Young , spindles and Stunted growth
2. Pale green to light yellow color (chlorosis) appearing first on older leaves, usually
starting at the tips. Depending on the severity of deficiency, the chlorosis could
result in the death and/or dropping of the older leaves. This is caused by the
translocation N from the older to the younger tissues.
3. Reduced N lowers the protein content of seeds and vegetative parts. In severe
cases, flowering is greatly reduced followed by reduced growth .
4. N deficiency causes early maturity in some crops, which results in a significant
reduction in yield and quality
5. Yellowing of plants starting witl old leaves.

19.  The nitrogen molecule (N2) is quite inert. To
break it apart so that its atoms can combine
with other atoms requires the input of
substantial amounts of energy.
 Three processes are responsible for most of
the nitrogen fixation in the biosphere:
 atmospheric fixation by lightning
 biological fixation by certain microbes —
alone or in a symbiotic relationship with some
plants and animals
 industrial fixation

20. 1. Hastens maturity
2. Helps plants survive harsh winter conditions
3. Improves water-use efficiency
4. Improves quality and yield of fruits, vegetables, and grains
5. Involved in photosynthesis, respiration, energy storage and
transfer, cell division, and enlargement
6. Promotes early root formation and growth
7. Promote seed formation and reproduction.
8. Increases disease resistance, enhances the activity of rhizobia and
increases the formation of root nodules in legumes
9. It increases efficiency of the leaf in manufacturing sugars and starch.

21. 1. Because P is needed in large quantities during the early stages of cell
division, the initial overall symptom is slow, weak, and stunted growth.
2. P is relatively mobile in plants and can be transferred to sites of new
growth, causing symptoms of dark to blue-green coloration to appear on
older leaves of some plants. Under severe deficiency, purpling of leaves
and stems may appear.
3. Lack of P can cause delayed maturity and poor seed and fruit
development.

23. 1) Is essential for photosynthesis,
2) Activates enzymes to metabolize carbohydrates for the manufacture of
amino acids and proteins,
3) Fcell division and growth by helping to move starches and sugars
between plant parts,
4) Astalk and stem stiffness,
5) Idisease resistance,
6) Increases drought tolerance,
7) Regulates opening and closing of stomates,
8) Gives plumpness to grain and seed,
9) Improves firmness, texture, size and color of fruit crops
10) Increases the oil content of oil crops.

24. 1. The most common symptom is chlorosis along the edges of leaves (leaf margin
scorching). This occurs first in older leaves, because K is very mobile in the plant.
2. Because K is needed in photosynthesis and the synthesis of proteins, plants lacking
K will have slow and stunted growth.
3. In some crops, stems are weak and lodging is common.
4. The size of seeds and fruits and the quantity of their production is reduce

26. The secondary nutrients
1.Calcium
2. Magnesium
3. Sulphur.
For most crops, these three are needed in lesser amounts
that the primary nutrients. They are growing in importance
in crop fertilization programs due to more stringent clean
air standards and efforts to improve the environment.

27. 1. Aids translocation of photosynthesis from leaves to fruiting organs and
Improves general plant vigor and stiffnes of straw
2. Essential for nut development in peanut.
3. Involved in nitrogen metabolism
4. Increases fruit and seed production
5. Reduces plant respiration
6. Stimulates microbial activity
7. Utilized for Continuous cell division and formation
8. Translocation of sugar

28. 1. Ca is not mobile and is not translocated in the plant, so symptoms first appear on the younger
leaves and leaf tips. The growing tips of roots and leaves turn brown and die.
2. Ca deficiency is not often observed in plants because secondary effects of high acidity resulting from
soil calcium deficiency usually limit growth, precluding expressions of Ca deficiency symptoms.
3. Without adequate Ca, which in the form of calcium pectate is needed to form rigid cell walls, newly
emerging leaves may stick together at the margins, which causes tearing as the leaves expand and
unfurl. This may also cause the stem structure to be weakened.
4. In some crops, younger leaves may be cupped
and crinkled, with the terminal bud deteriorating.
5. Buds and blossoms fall prematurely in
some crop. Blossom end of tomatoes

30. 1. Activator and component of many plant enzymes.
2. Directly related to grass tetany
3. Increases iron utilization in plants
4. Influences earliness and uniformity of maturity
5. Improves utilization and mobility of phosphorus
6. Key element of chlorophyll production

31. A. Because Mg is a mobile element and part of the chlorophyll molecule, the deficiency symptom of
interveinal chlorosis first appears in older leaves.
B. Leaf tissue between the veins may be yellowish, bronze, or reddish, while the leaf veins remain
green.
C. Corn leaves appear yellow-striped with green veins, while crops such as potatoes, tomatoes,
soybeans, and cabbage show orange-yellow color with green veins.
D. In severe cases, symptoms may appear on younger leaves and cause premature leaf drop.
E. Symptoms occur most frequently in acid soils and soils receiving high amounts of K fertilizer or
Ca.

33. 1. Aids in seed production
2. Helps develop enzymes and vitamins
3. Integral part of amino acids
4. Necessary in chlorophyll formation (though it isn’t one of the
constituents)
5. Promotes nodule formation on legumes

34. a. Younger leaves are chlorotic with evenly, lightly colored veins. In some
plants (e.g., citrus) the older leaves may show symptoms first.
b. However, deficiency is not commonly found in most plants.
c. Growth rate is retarded and maturity is delayed.
d. Plant stems are stiff, thin, and woody.
e. Symptoms may be similar to N deficiency and are most often found in
sandy soils that are low in organic matter and receive moderate to heavy
rainfall.

36. Element Ge=neral Deficiency Symptoms Probable Cause of
Deficiency
Method
of
Correctio
n
Nitrogen Yellow leaves, stunted growth,
lower leaves turn brown leaves
abort
low soil N, leaching from
the soil,inadequate N
applied
Apply N
fertilizers
Phosphorus small plants, reddish purple
leaves, slow growth, loss of plant
vigor
Low soil P , cool, wet soil ,
Inadequate P applied
Apply P
Fertilizer
Potassium Small plants, brown margins on
lower leaves , small weak stem ,
lodging of plants , poor yield and
quality
Low K leaching from the
soil, inadequate k applied
Apply K
Fertilizer

37. Element Ge=neral Deficiency Symptoms Probable Cause of
Deficiency
Method
of
Correctio
n
Calcium Small plants , deformed buds .
Distoted leaves, failure to grow
poor fruit development
Low soil pH , leaching
from the Soil , Inadequate
lime applied
Apply
lime
ferytilizer
s
Magnesium Lower leaves , in severe cases
,entire plants , turn yellow with
green intervenial areas.
Low soil Ph , leaching
from the soil ,no Mg
applied in lime fertilizers
Apply
dolomitic
lime or
Mg
fertilizer
Sulphur Yellow plants , slow growth, low
vigour, no response to applied
nitrogen. Low crop yield and
quality
Low soil S , leaching from
the soil , low organic
matter content, no S
fertilizer applied.

38. Element Form in which plant take it
Nitrogen Aminization: Proteins ——> R+ -NH2 + R-OH
Ammonification: R-NH2 + H2O —> NH3 + R-OH
Phosphorus Phosphorus is taken in (H2PO4 - ), but some is also absorbed as secondary
orthophosphate (HPO4 =), this latter form increasing as the soil pH increases.
Potassium Plants absorb potassium in its ionic form, K+
Calcium Calcium absorbed in form of Ca2+
Magnesium Magnesium is absorbed by plant s in Mg2+
Sulphur Sulphur is absorbed in form of SO4
--
Iron Fe2+ (ferrous cation) or Fe3+ (ferric cation).
Boron H3BO3 (boric acid) and H2BO3
- (borate)
Manganese Mn2+ (manganous ion)
Zinc Zn2+ cation is the predominate form taken up by plants.
Copper Cu2+ (cupric ion)
Molbdenum MoO4
2- (molybdate ion).
Chlorine Chlorine is absorbed by plants in (Cl-)

40. 1) Boron
2) Chlorine
3) Copper
4) Iron
5) Manganese
6) Molybdenum
7) Zinc.
These plant food elements are used in very small amounts, but they
are just as important to plant development and profitable crop
production as the major nutrients. Especially, they work "behind
the scene" as activators of many plant functions.

41. 1. Affects nitrogen and carbohydrate
2. Essential of germination of pollon grains and growth of pollen tubes
3. Essential for seed and cell wall formation
4. Necessary for sugar translocation
5. Promotes maturity

42.  Boron deficiency causes stunted growth, first showing symptoms on the growing point and younger leaves.
The leaves tend to be thickened and may curl and become brittle.
 In many crops, the symptoms are well defined and crop-specific, such as:
 Peanuts: hollow hearts
 Celery: crooked and cracked stem
 Beets: black hearts
 Papaya: distorted and lumpy fruit
 Carnation: splitting of calyx
 Chinese cabbage: midribs crack, turn brown
 Cabbage, broccoli, and cauliflower: pith in hollow
stem

43. Boron cycle In soils, B is present in four forms:
(1) soluble B (boric acid or H3BO3), present in the soil solution and directly
plant-available, (2) mineral B, released to the soil by weathering of soil
minerals
(3) B adsorbed onto the surfaces of clay minerals and iron hydroxides,
released to the soil solution upon desorption from these mineral surfaces
(4) B in organic matter, released to the soil solution upon decomposition of
the organic material (microbial mineralization).

44. 1. Enhances maturity of small grains on some soils
2. Interferes with P uptake
3. Not much information about its functions
4. Chloride also functions in photosynthesis, specifically in the water
splitting system.
5. Chloride functions in cation balance and transport within the plant.
6. Chloride diminishes the effects of fungal infections in an as yet
undefined way.
7. Chloride functions in cation balance and transport within the plant.

45.  Chlorosis of younger leaves and wilting of the plant.
 Deficiency seldom occurs because Cl is found in the atmosphere and
rainwater.
 Leaf margins are scorched and abscission is excessive.
 Leaf/leaflet size is reduced and may app
 Overall plant growth is reduced.ear to be thickened.

46.  Natural inputs of chlorine (Cl) to soils come mainly from rainwater, sea
spray, dust and air pollution. In addition, human practices, such as
irrigation and fertilization, contribute significantly to Cl deposition. In the
soil solution, Cl occurs predominantly as the chloride anion (Cl−). The
Cl−anion does not form complexes readily, and shows little affinity (or
specificity) in its adsorption to soil components

47. 1. Catalyzes several plant processes
2. Indirect role in chlorophyll production
3. Increases sugar content
4. Intensifies color
5. Improves flavor of fruits and vegetables
6. Major function in photosynthesis
7. Major function in reproductive stages

48.  Reduced growth, distortion of the younger leaves, and possible necrosis of
the apical meristem.
 In trees, multiple sprouts occur at growing points, resulting in a bushy
appearance. Young leaves becomes bleached, and eventually there is
defoliation and dieback of twigs.
 In forage grasses, young leaf tips and growing points are affected first. The
plant is stunted and chlorotic.

49. Copper (Cu) is one of the micronutrients needed in very
small quantities by plants. The normal range in the
growing medium is 0.05-0.5 ppm, while in most tissue the
normal range is between 3-10 ppm. In comparison, the
ideal range for iron in the tissue is 20 times higher than that
of copper. Although copper deficiency or toxicity rarely
occur, it is best to avoid either extreme as either can have a
negative impact on crop growth and quality.

50. 1. Acts as an oxygen carrier
2. Promotes formation of chlorophyll
3. Reactions involving cell division and growth

51. Deficiencies occur on alkaline or high pH soils due to insolubility of the iron
and on acid soils due to the extreme solubility and resultant leaching of
iron.
Tall, slender plants with few leaves.
Pale green, then yellow, then white between the veins. (Generally new
leaves with light green band along the leaf margins.) Die back in the case
of advanced deficiency.
Short, much branched root system.

52. Aids in oxidation and respiration processes of the plant.
Accelerates seed germination and plant maturity with resultant crop
yield and quality.
Increases the availability of calcium, magnesium, and phosphorus.
Aids in the synthesis of chlorophyll.
Functions in photosynthesis

53. Occurs on new growth first.
Fading between veins changing to medium yellow with dark mid-rib.
Does not affect size of leaf nor texture, only color.
More deficient on soils with a high pH, either due to natural calcareous
content or due to over-liming.

54. 1. Aids in the formation of legume nodules
2. Needed to convert inorganic phosphates to organic forms in the plant
3. Required to form the enzyme "nitrate reductas" which reduces nitrates
to ammonium in plant
4. Aids in nitrogen metabolism
5. It is essential for nitrogen fixing organisms both symbiotic and non-
symbiotic.

55.  Deficiency symptoms resemble those of N because the function of Mo is to
assimilate N in the plant. Older and middle leaves become chlorotic, and
the leaf margins roll inwards.
 In contrast to N deficiency, necrotic spots appear at the leaf margins
because of nitrate accumulation.
 Deficient plants are stunted, and flower formation may be restricted.
 Mo deficiency can be common in nitrogen-fixing legumes.

56.  Plants require a minimum amount of molybdenum to help
nitrogen assimilation. It is also important to potassium absorption.
Molybdenum uses in other plants increase plant health and
growth.
 In legumes, deficiencies are the most prominent. This is because
legumes rely upon a symbiotic bacterium to fix nitrogen, an
essential nutrient for plant growth, to the root nodules. Legumes
find it crucial to fix ambient nitrogen to the plant nodes. Node
growth is retarded in soils with low molybdenum. When sufficient
amounts are present, the plants grow more vigorously and protein
contents of the legumes are enhanced.

57. 1. Aids in seed formation
2. Aids plant growth hormones and enzyme system
3. Necessary for chlorophyll production
4. Necessary for carbohydrate formation
5. Necessary for starch formation
6. Influences protein synthesis rate of maturing of seed, and stalks, height
or length of plants.

58.  Interveinal chlorosis occurs on younger leaves, similar to Fe deficiency.
 Zn deficiency is more defined, appearing as banding at the basal part of
the leaf and finally distorted small and sharp leaves.
 In vegetable crops, color change appears in the younger leaves first. The
new leaves are usually abnormally small, mottled, and chlorotic.
 In citrus, irregular interveinal chlorosis occurs with small, pointed,
mottled leaves. Fruit formation is significantly reduced.
 In legumes, stunted growth with interveinal chlorosis appears on the
older, lower leaves. Dead tissue drops out of the chlorotic spots.
 In cotton white buds form.

59. Zinc (Zn), one of the essential micronutrients, is needed by
plants in small quantities. The normal range for zinc in
plant tissue is 15-60 ppm and in the growing medium
between 0.10-2.0 ppm. Zinc deficiency or toxicity does not
occur often; however, they both negatively impact crop
growth and quality. Any deficiency or toxicity has to be
addressed before crop damage is irreversible.

60. Element Ge=neral Deficiency Symptoms Low soil Mn, high
soil pH lower soil
pH, apply foliar
(Mn
Method of
Correction
Manganese interveinal chlorosis of leaves,
stunted plants, yellow cast over
deficient area , reduce yield and
quality
Low soilMn ,high
soil pH due to over
liming
Lower soilpH ,
apply foliar
spray or add Mn
to soil
Zinc chlorotic leaves, slow growth,
reduced vigour , white steak
parallel to leaf blade
Low Zn in soil ,
high spil Ph , high
soil P
lower soil pH,
apply foliar
spray or add Zn
to soil
Copper reduced growth, leaf-tip dies
back , leaf tip break down ,
leaves ragged
low soil Cu, high
organic
apply foliar
spray or add Cu
to soil

61. Element Ge=neral Deficiency Symptoms Low soil Mn, high
soil pH lower soil
pH, apply foliar
(Mn
Method of
Correction
Boron terminal bud dies, multiple
lateral branches (rosette with
short internodes, older leaves
thick and leathery, petioles short,
twisted, and ruptured), hollow
heart (in vegetables), small
deformed fruit (in grapes), cork
spot (in apples)
Low Soil B , esp on
sandy soils
Apply foliar
spray or add B
to soil
Molybdenum reduced growth; pale green
color;necrotic areas adjacent to
midrib , between veins and along
leaf edges , twisted stems
Low soil Ph , Low
MO content in soil
inoculate seed
with Mo, apply
foliar spray , or
add MO to soil
Chlorine reduced growth; stubby roots;
intervenial chlorosis , non
succulent tissues ( in leafy
vegetables )
Low soil CL , esp in
soils subject
toleaching
Apply Cl
containg
fertilizer

63. # Natural Source N-P-K value
Chicken manure 1.1-0.8-0.5
2 Cow manure 0.6-0.2-0.5
3 Sheep/ goat manure 0.7-0.3-0.9
4 Oil cakes cotton seed 6.4 -2.9-2.2
5 Oil cakes rape seed 5.2-1.8-1.2
6 Blood meal 10.0-2-1.0
7 Fish meal 6.0 -9-1.5
8 Raw bone meal 4.0-25-0
9 Compost 6-4-3

64. # Type Name N P K Formula Sulphur
1 Nitrogenous category
Urea 46 0 0 (NH2-CO-
NH2) /
CO-(NH2)2
0
Calcium Ammonium
Nitrate(CAN)
15.5 0 0
Ammonium Sulphate(AS) 21 0 0 (NH4)2SO4 24
Ammonium Nitrate 34 0 0 (NH4NO3) 0
Anhydrou
s ammonia
82 0 0
Aqua ammonia 20 0 0

65. # Type N P K S
1 Phosphatic
category
DAP 18 46 0
MAP 12 51 0 1.5
Ammonium
Phosphate
10 34 0
TSP 0 46 0
SSP 0 20 0
NP

66. # Type N P K Formul
a
1 Potassic
fertilizers
Potassium
nitrate
13 0 45 KNO3
Potassium
sulphate
0 0 52 K2SO4
Mono Potassium
Phosphate
0 12 60 KH2PO4,
Potassium
chloride
0 0 60 KCL
Potassium
Hydrooxide
0 0 70 KOH
Sulphate of
potash
0 0 40 K2SO4

67. # Type N P K Formul
a
1 NPK 10 20 10
NPK 10 10 10
NPK 24 8 4
NPK 20 20 20
NPK 10 8 10
NPK 20 5 5
NPK 16 16 16
NPK 12 12 12
NPK 16 6 4

68. # Name Formula Form absorbed
1 Copper Sulphate CuSo4.5H2O Cu 24% Cu+2
2 Zinc oxy sulphate
Heptahydrate
ZnSo4.7H2O) 21% Zn0% Zn+2
3 Zinc Sulphate Mono Hydrate (ZnSo4.H2O) 33% Zn Zn+2
4. Ferrus Sulphate FeSo4.H2O Fe 19% Fe+2 (ferrous)
and Fe+3 (ferric)
5 Manganese sulphate MnSo4.H2O Mn30.5% Mn+2
6. Boric Acid H3BO3 (boric acid) and H2BO3
-
(borate)
H3BO3 (boric
acid) and
H2BO3
- (borate)