Class VIII_ Science _Crop Production and Management
Crop: - When plants of the same kind are cultivated at one place on a large
scale,
it is
called a crop.
Cropping patterns:- India is a vast country. The
climatic conditions like
temperature,
humidity and rainfall vary from one region to
another.
Accordingly, there is a rich variety of crops grown in
different
parts of the country. Despite this
diversity, two
broad
cropping patterns can be identified.
These are:
(i) Kharif Crops: The crops which are sown in the
rainy season are called kharif crops.
The rainy season in India is
generally from June to September. Paddy,
maize,
soyabean, groundnut and cotton are kharif crops.
(ii) Rabi Crops: The crops grown in the winter season
(October to March) are called rabi
crops. Examples of rabi crops are wheat, gram, pea, mustard and linseed.
Agricultural practices: - The several activities undertaken by
farmers over a period of time for the cultivation of crops are called
agricultural practices.
List of Agricultural practices: -
(i) Preparation of soil
(ii) Sowing
(iii) Adding manure and fertilizers
(iv) Irrigation
(v) Protecting from weeds
(vi) Harvesting
(vii) Storage
Agricultural Implements: - The tools which are required to carry out agricultural
practices are called Agricultural implements.
Examples: - The plough,
hoe and cultivator.
Agricultural practices: - The several activities undertaken by
farmers over a period of time for the cultivation of crops are called
agricultural practices.
List of Agricultural practices: -
(i) Preparation of soil
(ii) Sowing
(iii) Adding manure and fertilizers
(iv) Irrigation
(v) Protecting from weeds
(vi) Harvesting
(vii) Storage
Preparation
of soil:-The
preparation of soil is the first step before growing a crop. One of the most
important tasks in agriculture is to turn the soil and loosen it. This allows
the roots to penetrate deep into the soil. The loose soil allows the roots to
breathe easily even when they go deep into the soil.
The loosened soil helps in the growth of
earthworms and microbes present in the soil. These organisms are friends of the
farmer since they further turn and loosen the soil and add humus to it.
The soil contains
minerals, water, air and some living organisms. In addition, dead plants and
animals get decomposed by soil organisms. In this way, various nutrients in the
dead organisms are released back into the soil. These nutrients are again
absorbed by plants.
Since only a few
centimeters of the top layer of soil supports plant growth, turning and
loosening of soil brings the nutrient-rich soil to the top so that plants can
use these nutrients. Thus, turning and loosening of soil is very important for
cultivation of crops.
Tilling or Ploughing:- The process of loosening and turning
of the soil is called tilling or ploughing.
Sowing:- Sowing is the process of planting seeds. In sowing,
generally little soil is placed over the
seeds.
Traditional Method of sowing:
The tool used traditionally for sowing
seeds is shaped like a
funnel [Fig. 1.2 (a)].
The seeds are filled into the funnel, passed
down through two or
three pipes having
sharp ends. These ends
pierce into the
soil and place seeds there
Seed Drill: Nowadays the seed drill [Fig. 1.2 (b)]
is used for sowing with the help of
tractors. This sows
the seeds
uniformly at equal distance and depth.
It ensures that seeds
get covered by
the soil after sowing. This protects
seeds from being eaten
by birds.
Sowing by using a seed drill saves time
and labour.
Sowing:- Sowing is the process of planting seeds. In sowing,
generally little soil is placed over the
seeds.
Traditional Method of sowing:
The tool used traditionally for sowing
seeds is shaped like a
funnel [Fig. 1.2 (a)].
The seeds are filled into the funnel, passed
down through two or
three pipes having
sharp ends. These ends
pierce into the
soil and place seeds there
Seed Drill:
Nowadays the seed drill
is used for sowing with the help of
tractors. This sows
the seeds
uniformly at equal distance and depth.
It ensures that seeds
get covered by
the soil after sowing. This protects
seeds from being eaten
by birds.
Sowing by using a seed drill saves time
and labour.
(iii)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 fertilisers.
Advantages of Manure
: The organic manure is
considered better than
fertilisers. This is because
-It enhances the water holding
capacity of the soil.
-It makes the soil porous due to
which exchange of gases becomes easy.
-It increases the number of friendly
microbes.
-It improves the texture of the soil.
(iv) Irrigation:- The supply of water to crops at
regular intervals is called irrigation.
Traditional Methods of Irrigati:-
(i) Moat
(pulley-system) (ii) Chain pump (iii) Dhekli,
and (iv) Rahat (Lever system)
| Modern Methods of Irrigation:- | |||||||
(i)Sprinkler System: This system is more useful on the uneven land where sufficient water is not available. The perpendicular pipes, having rotating nozzles on top, are joined to the main pipeline at regular intervals. When water is allowed to flow through the main pipe under pressure with the help of a pump, it escapes from the rotating nozzles. It gets sprinkled on the crop as if it is raining. Sprinkler is very useful for lawns, coffee plantation and several other crops.
(ii) Drip system: In this system, the water falls drop
by drop directly near the roots. So it is called drip system. It is the best
technique for watering fruit plants, gardens and trees . Water is
not wasted at all. It is a boon in regions where availability of water is poor.
(v) Protection from Weeds:-
Weeds-The undesirable plants may
grow naturally along with the crop are called weeds.
Weedicides-The chemicals used to control the weeds are called weedicides
Examples:- 2,4-D. These are sprayed in the fields to
kill the weeds. They do not damage the crops. The weedicides are diluted with
water to the extent required and sprayed in the fields with a sprayer.
Weeding:- The removal of weeds is
called weeding.
Weeding is necessary since weeds compete with
the crop plants for water, nutrients, space and light. Thus, they affect the
growth of the crop. Some weeds interfere even in harvesting and may be
poisonous for animals and human beings.
Farmers adopt many ways to remove
weeds and control their growth. Tilling before sowing of crops helps in
uprooting and killing of weeds, which may then dry up and get mixed with the
soil. The best time for the removal of weeds is before they produce flowers and
seeds. The manual removal includes physical removal of weeds by uprooting or
cutting them close to the ground, from time to time. This is done with the help
of a khurpi. A seed drill is also used to uproot weeds.
(VI) Harvesting: - The cutting of crop after it is mature
is called harvesting.
In harvesting, crops are pulled out
or cut close to the ground. It usually takes 3 to 4 months for a cereal crop to
mature. Harvesting in our country is either done manually by sickle or by a
machine called harvester.
Threshing:-The process of separation of the
grain seeds from the chaff is called threshing.
Combine:-The machine which help harvesting as
well as threshing is called combine.
Farmers with small holdings of land do the separation of
grain and chaff by winnowing
Storage of produce is an important task. If the harvested
grains are to be kept for longer time, they should be safe from moisture,
insects, rats and microorganisms. Harvested grains have more moisture. If
freshly harvested grains (seeds) are stored without drying, they may get spoilt
or attacked by organisms, making them unfit for use or for germination. Hence,
before storing them, the grains are properly dried in the sun to reduce the
moisture in them. This prevents the attack by insect pests, bacteria and fungi.
Farmers store grains in jute bags or
metallic bins. However, large scale storage of grains is done in silos and
granaries to protect them from pests like rats and insects [Fig. 1.10 (a) and
(b)]. Dried Neem leaves are used for storing food grains at home. For storing
large quantities of grains in big godowns, specific chemical treatments are
required to protect them from pests and microorganisms.
Food from Animals:-
Like plants, animals also provide us with different kinds of
food. Many people living in the coastal areas consume fish as a major part of
their diet.
Animal husbandry is the branch of agriculture concerned with animals
that are raised for meat, fibre, milk, eggs, or other products.
Animals reared at home or in farms, have to be provided with
proper food, shelter and care. When this is done on a large scale, it is called
animal husbandry.
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