4. Nutrients for plant
plants , like human being and animals
required food for their growth and
development.
The food of plants is compose of certain
chemical elements known as nutrient or
plant food element.
About 35 elements such as
C,H,O,N,P,K,Ca Mg, S,Mn, Mo, Cu, B, Zn,
Fe, Cl, Na, Si, Al, Co, I,V, Ni, As, Br, Ga,
La, b, Zr, Se, Sr,Cr and Rb
Out of these 16 elements have been
consider essential for plant growth and
5. The primary and secondary nutrient
element are collectively known as major
plant nutrient.
The nutrient which are used by the
field crops in very small quantity are
known as micro nutrient. They are also
known as trace elements.
Zn , Fe , Cu , Mn , Cl all are micro
nutrients.
6. Role of various elements in plant
growth
Nitrogen
Nitrogen is the most important nutrient for
plant.
It tends primarily to encourage above
ground vegetative growth.
It imparts dark green colour to the plant.
It increases the tillering of cereal crops.
It increases the protein content of the
food and increases the plumpness of
grain.
7. Potassium
It is act as a traffic police man, root
booster, food former, sugar and starch
transporter, protein builder, water
stretcher and as a disease retarder.
Formation and movement of
carbohydrates in plant is contributed by
potassium.
It increase the plumpness and boldness
of grains and seeds.
It act as a enzyme activator.
potassium deficient plant show a
decreased rate of photosynthesis.
8. Calsium
It act as a acid amendment to correct soil
acidity.
It is help full in translocation of sugar in
plant.
It induce stiffness of straw.
It is closely associated with the growth of
flower.
It is a structural component of
chromosomes.
Deficiency calcium increase the soil
acidity , plant growth is arrested and
leaves become wrinkled.
9. Magnesium
In oil production plant Mg play a key role
in the synthesis of fat and oil.
It play an important role in the production
of carbohydrate and proteins.
It is capable of increase the crop
resistance to drought and disease.
It also regulates the uptake of nitrogen
and phosphorous from the soil.
Deficiency of Mg in cotton they change to
purple red vein.
10. Sulphur
It is involved in the formation of
chlorophyll.
Pungent odour of onion and garlic is
because of the presence of sulphur.
It is an essential for the synthesis of
certain amino acids and oils.
Sulphur may be called as master nutrient
for the oil seed production.
Deficiency of sulphur cause fruit trees
may become light green , mis-shaped ,
thick skinned , less juicy.
11. Iron
It takes part in the synthesis of
chlorophyll and impart dark green color to
the plant.
It is essential for the synthesis of protein
in chloroplast.
Iron act as a catalyst in the activities of
several enzymes.
It regulate photosynthesis and
respiration.
In deficiency of iron , chlorosis of younger
leaves takes place but the vein remain
green.
12. Zinc
It is involved in the synthesis of
chlorophyll.
It is involved in the biosynthesis of plant
growth hormone and in the reproduction
process of certain plants.
It has a role to play in photosynthesis ,
RNA synthesis and rate of growth.
Deficiency of Zn may cause , new leaves
of maize plant emerge white in colour.
13. Copper
It is act as electron carrier in enzyme
systems which bring about oxidation
reduction system in plants.
It is essential for the synthesis of vit.A ,
chlorophyll and various other compounds
in plants.
It is also involved in utilization of Fe.
The food synthesis by the process of
photosynthesis is hampered in presence
of copper deficiency.
15. Natural fertilizer
Natural fertilizers are fertilizers derived
from animal matter , animal excreta ,
human excreta and vegetable matter .
Majority of fertilizers used in commercial
farming are extracted from minerals.
1)Natural organic fertilizer
2)Natural inorganic fertilizer
16. Natural organic fertilizer
plant matter
Oil cakes from cotton seed meal ,
linseed meal and caster cake belonging to
this class and contain 7% , 5.5% and 6%
of nitrogen respectively .
Farm yard manure
A typical farm yard manure consists of
cow dung , sheep dung and humane
excretion .
Animal matter
Powdered dry fish and red dry blood
from the slaughter house are important
nitrogenous fertilizer .
17. Guano
Guano is a classical example of
complete fertilizer and it is a mixture of
bird’s excrement , fish refuge and fish
hones .
Natural inorganic fertilizer
Rock phosphate
Finely divided rock phosphate ,
although insoluble water , weather rapidly
and may be used directly . Bone metal is
another source which supply phosphorous
.
Potassium salts
Natural potassium sources are wood
18. Synthetic fertilizers
Nitrogen fertilizer
All nitrogen fertilizers are soluble in
water . These fertilizers are added to the
soil in order to remove the deficiency of
nitrogen in the soil . These are easily
carried away into the soil during abundant
rain fall or irrigation.
20. Urea
urea is a nitrogen fertilizer . It contain
nearly 45 -47 % of nitrogen .
urea can be manufactured by passing
liquid CO2 and liquid NH3 in a silver lined
special auto clave when ammonium
carbonate is formed .
2 NH3 + CO2 NH2COONH4
Then later is heated at 130 – 135⁰C
under about 35 atm pressure to get urea .
The conversion is about 40 %
NH2COONH4 NH2CONH2 +H2O
21. Action of urea as fertilizer
urea is first hydrolyzed by soil water to
CO2 and NH3 .
NH2CONH2 +H2O 2 NH3 + CO2
Then nitrification of NH3 takes place by
the agency of nitrosomonas and
nitrosococcus bacteria and nitrites are
formed .
2 NH3 + O2 bacteria 2NO2.2H2O + 2H++
Energy
Nitrification of nitrites is brought about by
nitrobactor bacteria to form nitrates
utilized by the plants in the soil .
22. Phosphate fertilizer
Depending on their composition the
various phosphate fertilizer have different
solubility in soil solution . Some
phosphate fertilizers are
rock phosphate
normal super phosphate
triple super phosphate
ammonium phosphate
calcium meta phosphate
thermal phosphate
