1. CLASS-VIII
CHAPTER-1
MADE BY- MOHSINA KHAN(TGT SCIENCE)

2.  CROP- plants of the same kind grown at
one place on a large scale is called a crop.

3.  Kharif crop
 Crops sown in rainy
season.
 Sown in june/july
harvested in
september/october
 E.g.-
rice,maize,soyabean
etc.
 Rabi crop
 Crops sown in winter
season.
 Sown in oct./nov.
harvested in
march/april.
 E.g.-
wheat,gram,pea,must
ard etc.

5.  Preparation of soil a)ploughing b)levelling
 Selection and sowing of seeds
 Replenishment of nutrients in soil (manuring)
 Irrigation
 Crop protection
 Harvesting
 Storage

6. Manual ploughing and
ploughing by machine
levelling
 Ploughing-process of
loosening and turning
the soil.
 Levelling-to level the
field after ploughing.

7.  Ploughing
 More air spaces for roots
to breathe
 Holds more water
 Roots penetrate deeper
 Easily mixes manure and
fertilizer
 Removes weeds
 Promotes microbial
growth
 Nutrient rich soil comes
up.
 Levelling
 Soil crumbs are
crushed
 Prevents soil erosion
 Helps in uniform
distribuition of water
and manure.

8.  Selection means to
select healthy seeds
 Precautions while
selecting:-
 1)clean,healthy,and
disease free seeds.
 2)seeds should be
treated with
fungicides.
 Sowing means
placing seeds in the
soil
 Seeds have to be
sown-:
 1) at the right
depth
 2) at right intervals

9.  Broadcasting
 Traditional tool
 Seed drill
 transplantation

10.  Natural methods to restore soil fertility
 Fallowing
 Crop rotation
 Mixed cropping

11.  Manure
 Natural organic
 Man-Made in fields
 Provides humus
 Less nutrients
 Cheap
 E.g.- urea,potash etc.
Fertiliser
 Inorganic salt
 Prepared in factories
 Does not add humus
 Rich in nutrients
 Costly
 E.g.- cowdung,sesbania
etc.

12.  Time and frequency of irrigation depends
upon –:
 Nature of crop plants (crop-based irrigation)
 Nature of soil (soil-based irrigation)
 Season when the crop grows (season-based
irrigation)

13.  Traditional methods
 Moat,chain
pump,dhekli,rahat
 Modern methods
 Drip system
 Sprinkler system

15.  Drip system  Sprinkler system

16.  Protecion from weeds
 Weeds- the unwanted
plants that grow along
with a cultivated crop
in a field.
 E.g.
 1) amaranthus (chaulai)
 2) chenopodium
(bathua)

17.  Protection from pests
 Pests- are organisms
that attack and
damage crops.
 E.g. 1) rodents (rats)
 2) insects (locusts,
weevils & termites

18.  The process of cutting and gathering of crop
after its maturation is called HARVESTING.
 Methods-
 1) manually by sickle
 2) by machine (harvester)

19.  Separation of grain
from chaff.
 Methods-
 1) Manually
 2) by machine
Thresher and
combine (large
farms)

20.  Separation of grain from the husk with the
help of wind.
 Methods –
 1) manually
 2) winnowing machine

21.  SMALL SCALE
 Jute bags or
metallic bins
 LARGE OR
COMMERCIAL SCALE
 Gunny bags in
granaries or silos

22. technique used for
developing new
varieties of crops
by cross breeding
two different
varieties.

23.  Science that deals
with breeding
feeding and caring
of domestic
animals.