Class 9 Science Chapter 15
Improvement in Food Resources
Introduction
We all know that we need food for
growth, development and repair of the body. It also protects us from diseases
and provides us energy for carrying various activities. We also know that only
green plants are autotrophs and rest are heterotrophs. Man is a heterotroph,
that is why he is involved in the activities of farming and rearing animals to
meet his food requirements.
Sustainable agriculture
As you all know that resources are
limited and we need to conserve them and also need to maintain ecological balance
and also, we have to cope up with demand of humans. So, we need to adopt
certain techniques in order to maximize agriculture yield.
It is the adoption of various farming and production management techniques to
maximize the yield. Implementing them would help in the following ways-
1. Conserving natural resources.
2. Maintaining environmental balance.
3. Coping with the changing human needs.
Due to
these reasons, it is necessary to adopt practices like the following-
1. Mixed cropping
2. Crop rotation
3. Intercropping
4. Integrated farming
Integrated agriculture – It implies
to a combination of agriculture with other forms of culture such as
pisciculture, aquaculture, apiculture, sericulture, poultry farming, livestock
production (animal husbandry), etc.
Advantages of sustainable agriculture are as follows-
1. Achieves integration of natural
biological cycles and controls.
2. Protects and renews soil fertility.
3. Optimizes the management and use of
farm resources.
4. Reduces the use of non renewable
resources.
5. Provides income.
Organic farming – It is the practice of raising crops which have been polluted by the
use of manures, bio-fertilizers and bio-pesticides.
This farming insures the following-
1. No pests, no weeds.
2. Proper supply of nutrients.
3. No toxicity means no pollution.
4. Organic waste can be recycled.
5. It maintains soil health.
There are many vegetables, fruits,
etc. which we get in a particular season like watermelon, mangoes, etc. These
are not available throughout the year. They are seasonal. Likewise, there are
many vegetables that are seasonal. This is because they require particular
conditions for their growth.
There are different types of crops that are sown and they are classified
depending upon the seasons when they are grown.
The types of crops are:
- Kharif crops
- Rabi crops
- Zaid crops
Kharif crops – These crops are sown in the beginning of monsoon that is between June and
July. They are harvested in September or October. They require a lot of water.
For example: rice, maize, groundnut, etc.
Rabi
crops – These crops are sown in winter season
that is between November and December. They require cold conditions therefore,
called as winter crops.
For example: wheat, barley, gram, mustard, etc.
Zaid crops – They are harvested by March or April. These crops are grown in the
summer season.
For example: water melon, cucumber, etc.
Crop Production Management
It refers to controlling the various
aspects of crop production to obtain the best and maximum yield.
Crop management includes the following-
1. Nutrient management
2. Irrigation
3. Cropping patterns
Nutrient management
As we have already studied that
different crops require different nutrients for their growth. So, let us study
about the nutrients that are essential and required by plants.
It involves selection, timing and the right amount of nutrient supply to crops.
Like us, they also need inorganic elements for building their structure and
maintaining their metabolic processes. These inorganic substances are called
nutrients.
Nutrients are supplied to plants by the following-
1. Air, water and soil.
2. Plants require a lot of nutrients but
some in large and others in small amounts.
Macronutrients and Micronutrients
Plants need nutrients in different
amounts. For example, some plants need nitrogen and some do not need nitrogen
or some need it in comparitively lesser quantity. This shows that the nutrient
requirement is different for different crops. So, accordingly, nutrients are
classified as given below.
1. Macronutrients
2. Macronutrients
Macronutrients: they are required in large amount and are essential for the plant. They
mainly take part in building the plant body and protoplasmic structures.
Out of 13 essential nutrients, 6 are macronutrients. They are as follows-
Nitrogen, Phosphorous, Potassium, Calcium, Magnesium and Sulphur.
Micronutrients: They are those nutrients that are required in small amounts. They are
involved in enzyme activity and electron transportation.
Out of 13 essential nutrients, 7 are
micronutrient that is Iron, Manganese, Boron, Zinc, Copper, Molybdenum and
Chlorine.
Manures And Fertilizers
Soil is the source of many nutrients
and humus. These nutrients are taken up by plants from the soil. You must have
seen that every kind of soil is not able to produce crops. The reason behind it
is that the soil lacks the nutrient part or it may not be suitable for holding
plants or may not have aeration tendency. The factor responsible can be
anything. The necessary condition for soil to produce crops is that it should
be fertile. For that you must have seen that cow dung cakes, etc. are added to
the soil. Let us study how soil can be made fertile.
Manures: They are added to maintain the fertility of soil. These are organic
substances obtained by the decomposition of animal and plant waste.
Types of manures
Depending upon the kind of waste used for making manure, manures are of
different kinds as mentioned below:
1. Farmyard manure
2. Compost
3. Green manure
Farm yard: It consists of cattle dung and urine, etc.
Compost: It is formed by decomposition of plants and animal wastes, etc. It
is a biological process in which both aerobic and anaerobic respiration takes
place in microorganisms and they decompose organic matter.
When compost is formed by use of
earthworms, the composting is called vermicomposting.
Green manure: It consists of decomposed leguminous plants like sun hemp, etc. A green
manure supplies nitrogen, phosphorous, organic matter and also prevents soil
erosion.
Advantages of manure
1. Add nutrients to soil
2. Add humus to soil
3. Improve the quality of soil
Fertilizers
To increase the fertility of the soil, chemicals are also used. They are of
great importance but farmers face problems in disposing of these chemicals as
they are not eco-friendly. But still, they are of great importance. Let us
study about them.
They are inorganic compounds which
supply specific nutrients. For example: NPK, Ammonium Sulphate,
Ammonium Phosphate, etc.
They are classified into four groups:
1. Nitrogenous: like urea, ammonium
sulphate, etc.
2. Phosphatic: like single
superphosphate, triple super phosphate, etc.
3. Potassic like potassium sulphate.
4. Complex fertilizers: which supply
more than one nutrient like NPK, urea, ammonium phosphate, etc.
There are lots of differences between
manure and fertilizers. Let us list them up.
|
Fertilizer |
|
|
Organic Substance |
Inorganic Substance |
|
Contain all essential nutrients |
Supply specific nutrients |
|
Slow in action |
Fast in action |
|
Add humus to soil |
Do not add humus to soil |
|
They are required in large number |
Required in less number |
|
Take long time to show result |
Show fast results |
|
Difficult to store and transport |
Easy to store and transport |
Biofertilizer – It is a type of fertilizer in which organisms enrich the soil with
nutrients. It is renewable and pollutant free.
For example: Blue green algae and Rhizobium etc.
Irrigation
We all know that plants need water
for growth, for photosynthesis and for transportation of nutrients, food and
water. Water is taken by plants from the soil. There are different types of
water like surface water, capillary water, run – way water, etc. that soil
possesses. But out of all, only capillary water is actually available to
plants.
Irrigation: It is supplying water to plants.
Modern techniques of irrigation:
1. Sprinkler system and drip
irrigation for better supply of water.
Sprinkler system
The perpendicular pipes having
rotating nozzles on top. They 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 and gets
sprinkled on crops like rain.
Drip irrigation
In this, water falls drop by drop
just at the position of the roots through the pipes that run along the field.
It is the best technique as it helps
in the following-
1. Provides water directly to roots drop
by drop.
2. saves water.
Role
of water in plants is as follows-
1. Helps in translocation of food.
2. Protects crops from frost and hot
climate.
3. Seeds can not respire.
4. Roots do not grow well.
Crop protection
There are a lot of factors that can
damage crops or reduce the yield like pests, weeds, rodents, etc.They have to
be controlled so as to ensure a healthy crop yield.
Weeds: These are unwanted plants that grow along with the main crop.
Disadvantage of Weeds are as follows-
1. They compete with the main crop for
nutrients, space, sunlight, water, etc.
2. They lower the quality of the main
crop.
3. They lead to several diseases.
Process of removing weeds is as
follows-
1. Manual weeding: Removing weeds by
hands.
2. Chemical method: Use of weedicides:
By using chemicals like 2-4D etc.
3. Biological method: In this method,
some insect or organism is put in the field that eats weeds and not the main
crop.
Pests: They are the organisms that
damage crops by destroying them or by spreading diseases in the crops. For
example: insects, bacteria, etc.
They affect the crops in different
ways which are mentioned below-
1. They lower the quality of the crops.
2. They reduce yield.
3. They bore inside the crops.
We can control them by different methods
which are as follows-
They can be killed by pesticides
which include the following-
1. insecticides.
2. weedicides.
3. fungicides.
For example; DDT, BHC, Malathion,
metasystox, lindane, etc.
Insects affect crops in different
ways as follows-
1. There are chewing insects: that cut
root, stem, leaf, etc. like caterpillars, etc.
2. There are sucking insects: that suck
the cell sap of plants like leaf hoppers, etc.
3. There are internal feeders that bore
into plant parts like: weevils, etc.
4. Root cutting insects are destroyed
by: chloropyriphos.
5. Stem and leaf cutting insects are
destroyed by: Malathion, Lindane and Thiodan.
6. All sap sucking insects are destroyed
by: Dimethoate and Metasystox.
Diseases in crop plants
The commonly occurring diseases are:
- Seed borne diseases. For example: leaf spot of rice.
- Soil borne diseases. For example: smut of bajra.
- Air borne diseases. For example: blast of rice.
- Water borne diseases. For example: bacterial blight in
rice.
Storage
We all know that farmers put their
money, effort and hopes in producing crops. Storage is very important as it is
a crucial step. So, a lot of precautions have to be taken.
Methods Employed
1.
1. Drying- By drying, moisture gets
removed and it prevents the growth of microorganisms.
1.
1. Maintaining storage containers: Gunny
bags, earthen pots, etc. used should be new, without cracks etc.
1. Chemical treatment- Godowns, etc.
should be sprayed with fumigants, there should be no seepage, etc. so that
crops can be stored properly.
2. Use of improved storage structures-
Structures that are airtight, rat proof, can maintain steady temperature, etc.
are used like silos.
Proper storage: it prevents food from
spoiling, helps in availability of fruits & vegetables throughout the year
and also helps in maintaining an emergency stock.
Improvement of Soil fertility
The fertility of soil can be
mentioned by natural methods which are as follows-
1. Crop rotation
2. Multiple cropping
Let us discuss them in detail-
Crop rotation – It is the method of
growing crops alternately on the same land.
For example, let’s say that if we
have grown rosette family plant for one season then in the next season, we will
have to grow plants of the leguminous family. By doing this, the fertility of
soil can be maintained. The rosette family plants take nitrogen nutrient from
the soil for their growth. So, in this way the nitrogen gets deficient in soil.
In order to replenish the soil, nitrogen fixing plants (leguminous) plants are
grown.
Like the Legumes which include peas, beans, grams and pulses are grown in first
season and wheat in the next season. The legume crops (have nitrogen fixing
bacteria), they use up different nutrients from the soil but fix the
atmospheric nitrogen and make the soil richer in nitrogen and so, the fertility
of soil is maintained.
Advantages of crop rotation are as
follows-
1. The land gets utilized in a better
way
2. Soil Fertility is maintained
3. Farmer has a variety of crops for
selling
Mixed cropping- It is a method of
growing two or more types of crops in the same field.
Criteria of selecting crops- Crops
with different maturation period are chosen.
Although this practice helps in
replenishing the soil nutrients, but it leads to some difficulties also like in
harvesting, difficulty in supplying fertilizers, it can spread pests, it can
lower the quality of crops. So, to overcome these disadvantages, mixed cropping
is converted to intercropping.
Intercropping: it is the growing
different crops in definite pattern. All limitations of multiple cropping is
overcomed by intercropping.
Crop variety improvement
We need two important desirable
qualities in food plants that is- high yield and natural resistance to
diseases. These traits can be acquired with the help of natural mutation but
the rate of mutation is very slow. Therefore, they have to take the help of
artificial procedures like hybridization.
Hybridization – It is the technique of crossing plants of different varieties
with desired characters in order to produce new variety that possesses the
desired characters.
Procedure – It includes the introduction, selection and crossing of varieities.
Introduction- It is the process of introduction of crop plants from the place
where they are grown to the place where they are not grown. This is plant
introduction.
Selection- In this, the plants with desired characters are chosen.
Crossing- In this step, the desired varieties are crossed and as a result, they
produce an offspring that possesses the desired characters.
Animal husbandry
Introduction
We know that
like crops, animals are also important for us as they play different roles. So,
raising them and caring for them is very important. They give us many products
and also act as a means of transportation, for ploughing fields and lots more.
Let us learn about them.
Animals are equally important to us. So, proper planning is needed for domestic
animals shelter- breeding, health, disease control, etc. There is a branch of
science that deals with it, called animal husbandry.
Animal
husbandry is that branch of agriculture that deals with feeding, caring and
breeding of domestic animals. The domestic animals are also called livestock
(used for farm purposes) and include cattle, buffalo, yak, horse, goat, sheep,
etc. It includes the following-
- Cattle farming
- Poultry
- Fish production
- Bee keeping
Cattle
farming
It is done
to fulfill the specific needs of dairy, drought or dual purpose. Like, they
provide us with milk, meat, leather, etc. They play an important role in a
farmer’s life.
The scientific name for:
Cow- Bos indicus and for Buffalo– Bubalus bubalis
Breeds of cow are of 2 types –
1.
Milch
2.
draught
Let us
discuss them in detail-
Milch
breeds- They are those breeds that give us milk as they have a large digestive
system and a spacious udder because all of their food is converted into milk.
They include the following breeds-
1.
Gir–
found in Gujarat and Rajasthan.
2.
Sahiwal-
found in Punjab, Haryana, Uttar Pradesh.
3.
Red
Sindhi – found in Andhra Pradesh.
Draught
breeds- They are those breeds that are working animals and they give a little
milk. They are used as beasts of burden in various agricultural practices. They
include the following breeds-
1.
Nageri
– found in Punjab, Haryana and U.P.
2.
Hallikar
– found in Karnataka.
3.
Malvi-
found in Rajasthan and M.P.
Dual purpose
breeds- They are those breeds that serve both functions- that is, provide dairy
products as well as work for us. In India, dual purpose breeds are preffered
because cows provide good milk yield and bullocks act as good workers. They
include the following breeds-
1.
Tharparkar-
found in Gujarat and Andhra Pradesh
2.
Kankrej-
found in Gujarat
Breeds of
buffalo
1.
Murrah-
It is found in Haryana and Punjab. It has short and curved horns. The Weight of
female is 430-500 kg and of male is 530-575 kg. Their Average milk production
is about 1800-2500 litres.
2.
Mehsana-
It is found in Gujarat. It is usually black or grey in colour. The milk
production is 1200-2500 litres.
3.
Surti-
it is found in Gujarat. They are black or brown. Their horns are sickle-
shaped. It gives about 1600-1800 litres of milk.
Breeding
methods
Realizing the importance of livestock for all, the different techniques are
adopted as an effort to improve the yield by developing new varieties.
There are two main breeding methods as follows-
1.
Natural
method
2.
Artificial
method
Natural
method- It is the cross breeding of the desi breed and the bull of high
yielding exotic breed by natural mating process during its heat period.
Artificial
method or Artificial insemination
This is the artificial method adopted to get desired characters in a breed. But
various precautions have to be taken. Let us learn about them.
In it, the
semen obtained from the desired male is injected into the female reproductive
tract during its heat period.
Technique used- The semen of a healthy male is collected and preserved by
freezing it. Then it is injected into the genital tract of the female during
its heat period. It is a reliable method of breeding.
Advantages of artificial insemination
1.
The
breeds formed are more adaptable.
2.
They
give more milk.
3.
The
desired characters are introduced.
4.
Most
reliable and hygienic method.
5.
It
gives a high rate of successful fertilization.
Cattle feed
– The feed provided to cattle is important because it influences their growth
and development. Their diet consists of roughage and concentrates which is as
follows-
1.
Roughage
– It has fibers such as green fodder, silage, hay, legumes, etc.
2.
Concentrates
–they are a mixture of substances rich in one or more nutrients. They are low
in fibers and contain more nutrients. For example- cotton seeds, bajra, gram,
etc.
Cattle
disease – Cattle may suffer from any of the following diseases-
1.
Cow
pox – fever and small nodules.
2.
Rinderpest
– constipation, Diarrhea, loss of appetite, etc.
3.
Anthrax
–fever with swelling of body, milk secretion is reduced.
4.
Ringworm
– small, circular raised patches.
Poultry
farming
Poultry care
is equally important because the poultry products like eggs and meat help in
providing a balanced diet to population. Let us study how we can care about
them.
It means
taking care of poultry birds for the increased production of eggs and meat. For
this, proper management is required that includes hatching, rearing, prevention
from diseases and sanitation and proper marketing management.
Poultry
breeds
Desi breeds:
They are Aseel, Chittagong, Ghagus and Busra.
Exotic
breeds: the two exotic breeds that are very important are White leghorn (small
body size-2.7kg cock and 2kg hen) and Rhode Island red (good egg layer and also
meat yield is enough). Other exotic breeds are Black minorcha, Plymouth.
Cross
breeds: They are obtained by crossing desi and exotic breeds so as to improve
the characters that is HH-260, IBI-80 and B-77.
Stages in poultry- They are layers and broilers.
Layers: It
is an egg laying poultry. They require enough space and light. They are fed
with calculated feed.
Broilers: It
is poultry reared for obtaining meat. Their food requirement is rich in
proteins and Vitamin A and D. They grow fast.
Poultry
care
We have to take good care of poultry birds to get good poultry product. The
care or need of poultry birds depends upon their stages as accordingly the
requirements differ.
There are two distinct life phases:
1.
Growing
period
2.
Laying
period
Growing
period: during this period the chicks grow and called as growers. For this,
they need enough space and feed provided is also restricted and calculated.
Laying
period: it is the period from sexual maturity till the end of laying period.
They are called layers. They need enough space and proper lighting. A feed rich
in nutrients influences the hatching process.
Poultry
disease
Poultry
birds suffer from various diseases that are caused by viruses, bacteria and
other microorganisms. Some common diseases are listed below-
1.Dermitis:
irritation, blisters on skin surface.
2.Fowl pox –
lesions in mouth, discharge from eyes and nose, etc.
3.Fowl cholera
– loose motions and dehydration.
Pisciculture
Fish is an
important aquatic food which is rich in proteins. It is highly nutritious and
easily digestible. Fish products like fish liver oil is rich in vitamin A and
vitamin D. Let us study more about fish production.
It is the
proper rearing and caring of fishes. Fisheries are set up and they deal with
the capturing, preservation, exploitation and utilization of fishes.
Depending upon the mode of obtaining fishes, we have two types of fisheries as
follows-
1.
Capture
fisheries
2.
Culture
fisheries
Capture fisheries: The fish is caught from natural waters and
modern technology is used in the whole process.
Culture fishery: It is the cultivating, rearing and harvesting of fish. It is
also called as Pisciculture.
Composite fish culture – Fish production by culturing single species in a pond
using old traditional methods gives low yield but if several species are
cultured together in a pond, the production increases and so do the monetary
gains.
For culturing different species, we need to select them according to the
feeding habits so that they should be compatible with each other and there
should be no competition between them. Like, we can culture silver carp with
rohu, mrigal as silver carp is surface feeder, rohu is column feeder, mrigal is
a bottom feeder. So, their requirements are different and they also feed on
different levels.
Apiculture
It is
rearing, care and management of bees for obtaining honey, wax and other
substances.
Honey bee
varieties
Indian varieties: Apis
dorsata
Apis florae
Exotic varieties: Apis melifera
Apis adamsoni
The most commonly domesticated bee is Apis mellifera due to the following
reasons-
1.
Its
gentle nature
2.
Good
production of honey
3.
Ability
to protect from diseases
Casts of Bees
are as follows-
- Queen
- Drone
- Worker
Queen: She is the mother of the colony as
its egg laying capacity is maximum (2000 eggs per day). It lays both fertilized
and unfertilized eggs. They are larger in size. They feed on protenious food.
Drone: It is a haploid fertile male. They
are larger in size and are quite noisy. They are stingless and their role is to
mate with the queen.
Worker: It is diploid, sterile female. It
is the smallest of all. They fulfill almost all the responsibilities of the
colony. They live only for 3-12 months.
Pasturage:
The quality and taste of honey depends upon the flora available for nectar and
pollen collection.
Improvement
in food resources Question and Answers
Q1. Explain
any one method of crop production which ensures high yield.
Ans.
Manuring and use of fertilizers can ensure high yields.
Q2. Why are
manures and fertilizers used in fields?
Ans. Manure
and fertilizers are added to the side soil of crop field to increase the
fertility of soil and productivity of crop. They overcome the deficiency of
nutrients in the soil of the field.
Q3. What are
the advantages of inter-cropping and crop-rotation?
Ans. The
advantages of crop rotation and intercropping are as follows-
1.
The
land gets utilized in a better way
2.
Soil
Fertility is maintained
3.
Farmers
have a variety of crops for selling
4.
It
improves crop variety and yield
5.
It
saves nitrogenous fertilizers.
Q4. What is
genetic manipulation? How is it useful in agriculture practices?
Ans. Genetic
Manipulation is the introduction of desired characters such as high yield,
short maturity time, biotic and abiotic resistance, etc. in the genetic set up
of an organism. Hybridization is one of the techniques used for it. It involves
crossing two dissimilar plants in order to get the desired characters in an
organism.
Q5. How do
storage grain losses occur?
Ans. Biotic
and abiotic factors cause losses during storage. These factors can lower the
quality of crops by causing poor power of germination, reducing weight of
grain, discoloration, etc. These types of destroyed grains are unable to fetch
money in the market.
Q6. How do
good animal husbandry practices benefit farmers?
Ans. Animal
Husbandry is the scientific management of farm animals. These farming practices
are undertaken by farmers along with agriculture as mixed farming.
Q7.What are
the benefits of cattle farming?
Ans. The
benefits of cattle farming are as follows-
- It provides milk and milk
products.
- Bullock labour is used for
agricultural practices.
Q8. For
increasing production. What is common in poultry, fisheries and bee-keeping?
Ans. Variety
improvement, housing, rearing, sanitation, disease control and marketing.
Q9. How do
you differentiate between capture fishing, mariculture and aquaculture ?
Ans. In the
following table a comparison has been made between capture fishing, mariculture
and aquaculture.
|
Capture
fishing |
Mariculture |
Aquaculture |
|
In capture
fishing, the fish catching is done from various natural resources, lakes,
rivers, seas,etc. |
In
Mariculture, culture of marine fishes is done in the coastal water. The
desired marine fishes and other animals are cultivated and obtained. |
In
aquaculture, culturing of fish is done using any water body which may contain
salt water or fresh water. Mariculture is a type of aquaculture. |
Q10. What do
we get from cereals, pulses, fruits and vegetables?
Ans :
1.
Cereals
provides carbohydrates for energy requirements.
2.
Pulses
provide us proteins.
3.
Fruits
and vegetables provide us with vitamins, minerals and a small amount of
proteins as well.
Q11.How do
biotic and abiotic factors affect crop production?
Ans : Crop
production goes down due to biotic factors like diseases, insects and nematodes
.It is known that different crops require different climatic conditions ,
temperature and sunlight for their growth and completion of their lifecycle .
Q12. What
are the desired agronomic characters for crop improvement?
Ans : The
desired agronomic characters for crop improvement are as follows-
1.
Tallness
and profuse branching for fodder crops.
2.
Dwarfness
in case of cereals as less nutrients are consumed.
3.
Higher
yield
4.
Improved
quality
5.
Disease
resistance
6.
Biotic
and abiotic resistance
Q13. What
are macro-nutrients and why are they called so?
Ans :
Macronutrients are those nutrients that are required in more quantity and they
are called so because they are very important and required in a large amount.
Q14.How do
plants get nutrients?
Ans : Plants
obtain nutrients from soil, air and water. Carbon and oxygen are obtained from
air and hydrogen from water and other minerals from soil.
Q15. Compare
the use of manure and fertilizers in maintaining soil fertility.
Ans :
|
Manure |
Fertilizer |
|
Organic
Substance |
Inorganic
Substance |
|
Contain
all essential nutrients |
Supply
specific nutrients |
|
Slow in
action |
Fast in
action |
|
Add humus
to soil |
Do not add
humus to soil |
|
They are
required in large number |
Required
in less number |
|
Take long
time to show result |
Show fast
results |
|
Difficult
to store and transport |
Easy to
store and transport |
Q16. Which
of the following condition will give more benefits :
a) Farmers use quality seed but not adopt irrigation and use fertilizer
b) Farmers use ordinary seeds and adopt irrigation, use fertilizer
c) Farmers use quality seeds and adopt irrigation and use fertilizer and use
crop protection measures.
Ans : (c)
Farmers use quality seeds and adopt irrigation and use fertilizer and use crop
protection measures.
Q17. Why
should preventive measures and biological control methods be preferred for
protecting crops?
Ans : These
methods do not cause pollution like fertilizers and can lead to biological
magnification and eutrophication.
Q18. What
factors may be responsible for losses of grains during storage?
Ans : Biotic
and Abiotic factors may be responsible for losses of grains during storage.
Q19. Which
method is commonly used for improving cattle breeds and why?
Ans :
Artificial insemination is preferred for improving cattle breeds because with
this method, we can fertilize 3000 cows from the semen collected from one bull.
Q20. Discuss
the implications of the following statement : “It is interesting to note that
poultry is India’s most efficient converter of low fibre food stuff into
nutritious animal protein food.”
Ans :
Poultry farming is undertaken basically to raise domestic fowl for egg
production and chicken meat. The food consumed by poultry birds is fibrous,
cheap and formulated using agricultural byproduct .Hence, the product that is
not used by the human population is converted into chicken, meat and eggs.
Q21: What
management practices are common in dairy and poultry farming?
Ans : Feeding,
Breeding and disease control are common in dairy and poultry farming.
Q22. What
are the difference between broilers, layers and their management ?
Ans :
Layers: It is an egg laying poultry. They require enough space and light .They
are fed with calculated feed.
Broilers: poultry reared for obtaining meat. Their food requirement is rich in
proteins and Vitamin A and D. They grow fast.
Q23. How are
fish obtained?
Ans : Fish
are obtained by catching from natural resources or by cultivating using cultural
system.
Q24. What
are the advantages of composite fish culture?
Ans. Fish
production by culturing single species in a pond using old traditional methods
gives low yield but if several species are cultured together in a pond, the
production increases and so do the monetary gains. For culturing different
species, we need to select them according to the feeding habits so that they
are compatible with each other and there should be no competition between them.
Like, we can culture silver carp with rohu, mrigal as silver carp is surface
feeder, rohu is column feeder, mrigal is a bottom feeder. So, their
requirements are different and they also feed on different levels.
Q25. What
are the desirable characters of bee varieties suitable for honey production?
Ans. The
desirable characters of bee varieties suitable for honey production are-
1.
Its
gentle nature
2.
Good
production of honey
3.
Ability
to protect from diseases
Q26. What is
Pasturage and how it is related to honey production?
Ans :
Pasturage is concerned with nectar and pollen collection by honey bees. The
quality of honey depends upon flora or pasturage available for nectar
collection.
Extra
questions
Q1. Fill in the blanks
(a)……………. are rich in vitamis.
(b) The crops which are grown in the rainy season are called…………crops.
(c) ………………Crop grows in winter season.
(d) Pigeon peas are a good source of ……………..
(e) Berseem is an important………..crop.
Ans. (a)
Vegetables
(b) Kharif
(c) Rabi
(d) Protein
(e) Fodder.
Q2. Match
the items of column A with those of column B.
|
Column A |
Column B |
|
(a) Fish
farming |
1. Bottom
feeder |
Ans. (a)-2
(b)-3
(c)-4
(d)-1
Q3. What is
GM Crop? Name any one crop which is grown in India?
Ans. GM or
genetically modified crop is the one which has been developed through the
introduction of some specific genes from other sources for example- insect
resistant Bt cotton (being grown in India), vitamin A rich Golden rice.
Q4. List out
some useful traits in improved crop.
Ans. (1)
Higher yield
(2) Improved quality
(3) Resistance to biotic and abiotic stresses
(4) Change in maturity
(5) Wider adaptability
(6) Desirable agronomic trait.
Q5. Why is
organic matter important for crop production?
Ans. Organic
matter forms humus. It is essential for crop production because it makes the
soil fertile. Organic matter has the following advantages-
1. It improves soil structure by forming soil crumbs.
2. It increases water holding capacity of sandy soils.
3. It improves aeration of clayey soils.
4. During its decomposition, it liberates minerals (inorganic molecules)
which enrich the soil.
5. Biochemical’s present in decaying organic matter improve growth of crop
plants.
Q6. Why is
the use of excess fertilizers detrimental for the environment?
Ans. Use of
excess fertilizers tends to cause the following-
1. Mineral loading of underground water.
2. Excess minerals in the crop plants.
3. Salinization of soil.
4. Runoff from fertilizer rich soil, will causes eutrophication of water
bodies.
Q7. Give one
word for the following
1. Farming without the use of chemicals are fertilizers, herbicides and
pesticides is known as ………..
2. Growing of wheat and groundnut on the same field in called…………….
3. Planting of soya bean and maize in alternate rows in the same field is
called………………..
4. Growing different crops on a place on a piece of land in pre planned
succession is known is…………………….
5. Xanthium and Parthenium are commonly known as………….
6. Causal organism of any disease is called as …………….
Ans: 1.
Organic Farming
2. Mixed cropping
3. Inter-cropping
4. Crop rotation
5. Weeds
6. Pathogen
Q8. Match column A and B
|
Column A |
Column B |
|
A. Milch |
1. Milk
producing female |
Ans.
- A – 1
- B – 4
- C – 3
- D – 5
- E – 2
Q9. If there
is low rainfall in a village throughout the year, what measures will you suggest
to the farmers for better cropping?
Ans. 1.
Reduce tilling
2. Enrich soil with humus which increases its water holding capacity
3. Use of drought resistant and early maturing varieties of crop.
Q10. Group
the following and tabulate them are energy yielding, protein yielding, oil
yielding and fodder crop- Wheat ,Rice ,Berseem, Maize, Gram, Oat, Pigeon gram,
Sudan grass, Lentil, Soyabean, Groundnut, Castor and Mustard.
Ans. 1.
Energy yielding crop – Wheat, Rice, Maize, Oat.
2. Protein yielding Crop – Gram, Pigeon gram, Lentil, Sudan grass.
3. Oil yielding crop – Groundnut, Castor, Mustard, Soyabean.
4 . Fodder crop – Berseem, Oat, Sudan grass.
Q11. Define
the terms hybridization and photoperiod.
Ans.
Hybridization – It is crossing of two (or more) types of individuals with
different useful traits in order to bring them together in the progeny.
Photoperiod – It is duration of day light that influences plants and other
organisms
in their growth, reproduction and maturation.
Q12. Fill in
the blanks.
1. Photoperiod affect the………………..
2. Kharif crops are cultivated from………..to……………..
3. Rabi crops are cultivated from…………………….to……………
4. Paddy, Maize, Green Gram and Black gram are……………crops.
5. Wheat, Gram, Pea and Mustard are ………………crops.
Ans. 1.
Flowering (of plants)
2. June, October
3. November, April
4. Kharif
5. Rabi
Q13.Cultivation
practices and crop yield are related to environment conditions. Explain.
Ans. All
crops do not grow under similar conditions. Some require high temperature ,
some low temperature, longer duration of sunlight, shorter duration of
sunlight, more humidity, low humidity, moderate humidity, loam soil, sandy
soil, etc. Apple cannot be grown in the plains because it require several days
of low temperature. In the plains, there are two major seasons of crop plants-
Kharif (rainy season) and rabi (witner season).
Q14. Fill in
the blanks
1. A total of …………………nutrients are essential to plants.
2. ………….and …………..are supplied by air to plants.
3 ………is supplied by water to plants.
4. Soil supplies …………..nutrients to plants.
5. …………… nutrients are required in large quantity and called is …………….
6. ………nutrients are needed in small quantity for plants are called…………
Ans. 1.16
2.Carbon, oxygen
3. Hydrogen
4. 13
5. Six, macronutrients
6. Seven, micronutrients.
Q15.Differentiate
between compost and vermicompost.
Ans.
|
Compost |
Vermicompost |
|
1. It is
prepared from all types of organic remains-garbage, sewage, sludge, animal
refuse, farm waste, straw, uprooted weeds, etc. |
3. It takes
3 to 6 months to prepare.
1. It is
prepared from domestic waste, vegetable waste, uprooted weeds and farm refuse.
2. Organic
remains are fed by earthworms and in pulverized state.
3. It takes
1 to 12 months to prepare.
Q16. Arrange
these statements in the correct sequence of preparation of green manure.
(a) Green plants are decomposed in soil.
(b) Green plants are cultivated for preparing manure or crop plants are used.
(c) Plants are ploughed and mixed in soil.
(d) After decomposition, it becomes green manure.
Ans. (b) →
(c) → (a) → (d)
Q17. In
agriculture practices, higher input gives higher yield. Discuss how.
Ans. In
agriculture, higher yield can be obtained only by applying yielding varieties,
improved farming practices, modern technology, latest agricultural machines and
implements, nutrient supply, etc. All these require high cost and knowledge of
new techniques and improvements. Therefore, a farmer’s purchasing capacity for inputs
determines the cropping system and production exercises.
Q18.
Differentiate between the following
Beekeeping and poultry farming.
Ans.
Differences between Beekeeping and Poultry farming.
|
Beekeeping |
Poultry
farming |
|
1. it is
the practice of rearing, care and management of honey bees. |
1.It is
the practice of raising domestic fowl. 2. It
provides egg and meat. 3. Poultry
birds are provided feed by their rearers. |
Q19. Give
merits and demerits of fish culture.
Ans. Merits-
1. Economically important desired fish are made available.
2. A large number of fish are raised in a small area.
3. Fishes are made to breed in different seasons.
4. There is a little mortality in the younger stages of the fish.
5. Through selective hybridization, yield and quality of fish are improved.
Demerits-
1. Only some selected high yielding and economically important breeds are
reared.
2. Fish culture is a threat to biodiversity, since other forms of aquatic
organisms
are being ignored. Even natural waters are being seeded with economically
important fish, this too is affecting the natural biodiversity of the water
bodies.
Q20. Discuss
why pesticides are used in very accurate concentration and at a very
appropriate time.
Ans.
Pesticides are very toxic substances, they should not be used indiscriminately.
Only very accurate dose should be applied at appropriate time. Even slight
excess of the pesticides is extremely harmful.
1. Pesticides are harmful to soil biota. Therefore, they reduce soil fertility.
2. They pass into ground water and make it toxic.
3. They enter the crop plants and make their products (leaves, stem, flowers,
fruits, seeds) toxic.
4. Pesticides pass into surface water through runoff from sprayed fields and
harm the aquatic biota.
Q21. What
would happen if poultry birds are larger in size and have no summer adaptation
capacity? In order to get small sized poultry birds having summer adaptability,
what methods will be employed?
Ans. Larger
sized birds require more feed. Summer adaptation is connected with egg laying,
Little summer adaptation reduces egg laying. In order to get small sized
poultry birds having summer adaptability, it is desirable to adopt the
following-
1. Either introduce the required exotic birds from outside and
2. Cross breed the local birds with exotic birds from outside.
Small sized poultry birds are preferred for
(a) Lower requirement of feed
(b) Higher egg laying capacity
(c) Lower requirements for space.
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