for class 8 chapter 1 by -Sarita Chourasia

1. BY - SARITA CHOURASIA

2. Content
A. Definition of crop
B. Types of crop
D.b. Sowing seeds
D.c. Improving soil fertility
C. Types of Crop(basis of the season
of sowing wing)
D. Basic practices of Crop
Production
D.a. Preparation of soil D.g. Storage
D.f. Harvesting
D.e. Crop protection
D.d. Irrigation
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3. SARITA C
A crop is a plant or animal product that can be grown and
harvested extensively for profit or subsistence. Crops may refer
either to the harvested parts or to the harvest in a more refined
state. Most crops are cultivated in agriculture or aquaculture. A
crop may include macroscopic fungus, or alga.
What is crop?

4. Types of crop
Food crop
ex. Rice, wheat, maize,
gram, pulses, millets,
etc
Cash crop
Ex. Cotton, jute, sugar
cane, oil seed,
etc
1 2
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5. Types of crop
Plantation crop
ex. Rubber, coffee, tea
etc
3
Horticulture crop
ex. Fruits, vegetables,
flowers
etc
4
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6. Types of crop - Crops are also classified on the basis of the
season of sowing.
Rabi crops
Crops that are grown in the winter season,
from November to April are called Rabi
Crops. Ex. wheat, barley, peas, gram and
mustard.
Kharif crops
crops that are usually sown at the beginning
of the monsoon season around June and
harvested around October. Ex. Rice, maize,
bajra, ragi, soyabean, groundnut, cotton.
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7. SARITA C
Basic practices of Crop Production
A. Preparation of soil
B. Sowing seeds
C. Improving soil fertility
D. Irrigation
E. Crop protection
F. Harvesting
G. Storage
G. Storage

8. SARITA C
Soil is prepared before sowing the seeds. The soil is loosened to
increase the absorption of water and manures. Loosening of soil
particles adds humus and nutrients in the soil that increases
crop yields. Tilling or loosening the soil is done by ploughs which
are pulled by a pair of bulls. Tractor driven cultivators are also
used to loosen the soil.
a. Ploughing c. Manuring
b. Levelling
A. Preparation of soil

9. SARITA C
B. Sowing seeds
Sowing: After preparation of soil it is ready for sowing of
seeds. The healthy and clean seeds should be selected. The
sowing is done by seed drills or funnel shaped tools. Seed
drills are the modern instruments which sow the seeds at
proper depth and proper distance.
a. Broadcasting c. Transplantation
b. Seed-drill
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10. SARITA C
Methods of improving soil fertility
a. Fallow field
c. Nitrogen fixation
b. Crop rotation
C. Improving soil fertility
d. Adding fertilizers and manure
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11. SARITA C
Fallow is a farming
technique in which arable
land is left without sowing
for one or more vegetative
cycles. The goal of fallowing
is to allow the land to
recover and store organic
matter while retaining
moisture and disrupting the
lifecycles of pathogens by
temporarily removing their
hosts.
C.a. Fallow field

12. SARITA C
C.b. Crop rotation
Crop rotation is the process of
growing different types of crops in
the same area in the growing
seasons. - It decreases depending on
one type of nutrients, pest and weed
pressure, and the probability of
developing resistant pests and weeds.
Some crop rotation patterns are:
Maize-mustard,
Rice-cotton-peas, rice-pulses-jute,
rice-wheat-pulses-mustard etc.
Peas Rice
Cotton
Crop rotation
Broccoli
Winter
wheat
Sweet
corn
Broccoli Sweet corn
Winter
wheat

13. SARITA C
1. Free-living
2. Symbiosis
Nitrogen fixation is the process by which atmospheric nitrogen is
converted by either a natural or an industrial means to a form of
nitrogen such as ammonia. In nature, most nitrogen is harvested
from the atmosphere by microorganisms to form ammonia, nitrites,
and nitrates that can be used by plants.
Nitrogen-fixing organisms are two types
C.c. Nitrogen fixation
Some organisms live together and share shelter and
nutrients. This is called symbiotic relationship. For
example, certain fungi live in the roots of trees. The
tree provides nutrients to the fungus and, in
return, receives help from it to take up water and
nutrients from the soil. e.g. Lichens.
Some symbiotic bacteria, blue-green algae are able
to fix Nitrogen as organic nitrogen.
Symbiotic bacteria : Rhizobium
Symbiotic blue-green algae

14. Nitrogen fixation
Nitrogen fixation
is the process by which
atmospheric nitrogen
is converted by either
a natural or an
industrial means to a
form of nitrogen such
as ammonia. In
nature, most nitrogen
is harvested from the
atmosphere by
microorganisms to
form ammonia,
nitrites, and nitrates
that can be used by
plants.
N
N
N
N N
Nitrogen in air
N
Carbohydrates
N
N
Microbes “fix” Nitrogen in
nodules on the roots of
the pulse crop.
N
N
N
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Nitrogen Cycle
Eaten
Nitrogen of
Air
Nitrates
In soil

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D. Adding manure and fertilizers
The substances which are added to the soil in the form of
nutrients for the healthy growth of plants are called
manure and fertilizers.

17. Organic
manure
Animal
dung
compost
Green
manure
Manure
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18. SARITA C
Biofertilizers
Several microorganisms are commonly used
as biofertilizers including nitrogen-fixing
soil bacteria (Azotobacter, Rhizobium),
nitrogen-fixing cyanobacteria (Anabaena),
phosphate-solubilizing bacteria (Pseudomonas
sp.), and AM fungi.
Biofertilizers add nutrients through the
natural processes of nitrogen fixation,
solubilizing phosphorus, and stimulating plant
growth through the synthesis of growth-
promoting substances. The microorganisms
in biofertilizers restore the soil's natural
nutrient cycle and build soil organic matter.
Biofertilizers
Supply
mixture
of
nutrients
Improve
soil health
Enhanced
crop
production
Suppress soil
born
Pathogenic
diseases in
crops
Maintain
Microbial
Consortia in
soil
Maintenance
of symbiotic
relationships

19. Chemical fertilizers
Man-made plant nutrients produced in factories are called chemical
fertilizers.
1.Nitrogenous fertilizers
2.Phosphatic fertilizers
3.Potassic fertilizers
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There are three types of fertilizers

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Fertilizers vs Manure
Fertilizer Manure
1. Easy to store, transport and use
because they are compact
2. Provide specific nutrients not
present in manure
3. Readily absorbed by plants
because they are water soluble
Advantage
Disadvantage
1. They don’t provide humus- they
change the soil structure and make it
prone to erosion
2. Overuse can harm soil fertility by
making it too acidic or alkaline
3. Accumulation of fertilizers in water
bodies causes eutrophication
1. Add humus, and improve soil fertility,
making it hold water and aerating it
2. Not expensive-can be prepared from
wastes in the form
3. Doesn’t cause pollution because it’s derived
from the decomposition of natural
substance
1. Doesn’t provide certain specific nutrients
needed by crops
2. Not easy to store, transport and handle
because it is bulky
3. Not soluble in water

21. Eutrophication, the gradual increase in the
concentration of phosphorus, nitrogen, and
other plant nutrients in an aging aquatic
ecosystem such as a lake. ... This material
enters the ecosystem primarily by runoff
from land that carries debris and products of
the reproduction and death of terrestrial
organisms.
Eutrophication
Fertilizer leaches
into water
Blocked
sunlight
Algae bloom
Algae die
Fish suffocate

22. SARITA C
Surface irrigation
Furrow irrigation
Sprinkler
irrigation
Drip irrigation
Traditional
irrigation Modern
irrigation
D. Irrigation
The process of providing water to crops is
known as irrigation. Natural supply of water
to crop(rainfall, soil and water storage)
Methods of irrigation

23. Protect crop from diseases, pests
and weeds
E. Crop protection
Unwanted plants
which grow along with
crops are called weeds.
Weedicides destroy the
weeds but not the crop
plants.
Controlling pests and diseases
1. Weedicides- weeds
2. Pesticides-
• Insecticides- insects, their eggs
and larvae
• Rodenticides- rodents
• Fungicides
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24. F. Harvesting
ickle
The process of cutting and gathering a
crop is called harvesting.
Traditional
Combine harvester
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25. F.a. Threshing and Winnowing
Threshing- After harvesting
crop, the grain is separated by a
process called threshing.
Winnowing –separating the
outer cover, or chaff, from the
grain. It can be done manually, by
dropping grain and chaff from
height and by machine.
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26. G. Storage
Grain storage system
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27. BY - SARITA CHOURASIA