NCERT Grade 9-Improvement in Food Resources-Answers – MySchoolPage

NCERT Grade 9-Improvement in Food Resources-Answers

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1.    To ensure high yield various cropping patterns can be very useful. The cropping patterns to be mentioned here are :

(i) mixed cropping

(ii) inter cropping

(iii) crop rotation

Mixed cropping is growing two or more crops simultaneously on the same piece of land, for example, wheat + gram, or wheat +mustard, or groundnut + sunflower. This reduces risk and gives some insurance against failure of one of the crops.

Inter-cropping is growing two or more crops simultaneously on the same field in a definite pattern (as shown below). The crops are selected such that their nutrient    requirements are different. This ensures maximum utilisation of the nutrients supplied, and also prevents pests and diseases from spreading to all the plants belonging to one crop in a field for example, soyabean + maize, or finger millet (bajra) + cowpea (lobia).

Crop rotation is growing of different crops on a piece of land in a pre-planned succession. Depending upon the duration, crop rotation is done for different crop combinations. The availability of moisture and irrigation facilities decide the choice of the crop to be cultivated after one harvest. If crop rotation is done properly then two or three crops can be grown in a year with good harvests.

2.    Manure helps in enriching soil with nutrients and organic matter and increasing soil fertility. The bulk of organic matter in manure helps in improving the soil structure. Fertilizers are used to ensure good vegetative growth (leaves, branches and flowers), giving rise to healthy plants by providing specific nutrients like nitrogen, phosphorus and potassium.

3.   Advantages of inter cropping: Inter cropping ensures maximum utilisation of the nutrients supplied, and also prevents pests and diseases from spreading to all the plants belonging to one crop in a field. This way, both crops can give better returns.

Advantages of crop rotation: Crop rotation if well planned allows replenishment of soil nutrients without using even fertilisers like growing leguminous plants after a non leguminous crop in the same field will ensure nitrogen enrichment of that soil. Hence it prevents any decrease in the soil fertility.

4.    Plant breeding or hybridisation method that involves crossing two different plant varieties to obtain a new and better variety is called genetic manipulation. In agricultural practices to reduce the application of insecticides and fungicides or even fertilizers such varieties are being prepared that are:

(a) high yielding

(b) pest resistant

(c) resistant to environmental stress

(d) don’t need fertilizers for good growth

All these features help not only to improve quality and quantity of products but also reduces chances of environmental pollution.

5.   There are various biotic and abiotic factors responsible for the storage grain losses:

(a) biotic factors: Insects, rodents, bacteria, fungi etc that feed on grains.

(b) abiotic factors: Unfavourable conditions of humidity and temperature.

6.   Animal husbandry is the scientific management of animal livestock. It includes various aspects such as feeding, breeding and disease control.

As the population increases and as living standards increase, the demand for milk,
eggs and meat is also going up. Also, the growing awareness of the need for proper
treatment of livestock has brought in new limitations in livestock farming. Thus, livestock production also needs to be improved. This improvement can be brought about by good animal husbandry practices like providing good food and preventing diseases in the cattles that will benefit farmers to obtain better quality and quantity products.

7.    Cattle farming has dual benefits:

(i) Draught animals for farm labour (males)i.e. for agricultural work such as tilling, irrigation and carting.

(ii) Milch animals (dairy animals) those are milk producing females.

8.    For increasing production, steps that are common in poultry, fisheries and bee-keeping are as follows :

(a) good varieties/breeds are used.

(b) good nutritious food is provided.

(c) hygienic conditions/cleanliness is taken care of

9.    Capture fishing: It is the method of catching fishes from natural resources.

Mariculture: These are culture fisheries that are maintained in the marine water bodies only to rear and breed marine animals like fish and prawns hence also called marine culture.

Aquaculture: These culture fisheries are maintained in fresh water or marine bodies and allows rearing and production larger number of aquatic animals.

10.  We get carbohydrates from cereals, proteins from pulses, vitamins and minerals from fruits and vegetables.

11.  The biotic factors include living organisms like honey bees and earthworms who help in better crop production while pests(insects and rodents) and microbes that produce bad effect on crop production. The abiotic factors are the climatic conditions and non living natural resources like soil, water and air. They also affect crop production since favourable conditions of temperature, humidity and mineral nutrition improve crop production.

12. The desirable agronomic characteristics for crop improvements are as follows:

(i) For cereal crops desirable characteristic is dwarfness since such plants will utilise less amount of nutrients.

(ii) For fodder crops desirable characteristics are tallness and profuse branching so that we can obtain more amount of leaves for feeding our animals.

13.  There are sixteen nutrients which are essential for plants. Amongst these thirteen nutrients, six are required in large quantities and are therefore called macronutrients.

Macronutrients: nitrogen, phosphorus, potassium, calcium, magnesium, sulphur.

14.  Nutrients are supplied to plants by air, water and soil.

Source     Nutrients provided

Air                  Carbon, oxygen

Water             hydrogen, oxygen

Soil                 nitrogen, phosphorus, potassium, calcium, magnesium, sulphur, iron, manganese, boron, zinc, copper, molybdenum, chlorine

15.   Manure: Manure is prepared by the decomposition of animal excreta and plant waste so contains large quantities of organic matter and also supplies small quantities of nutrients to the soil that improves soil fertility.

Fertilizer: Fertilizers are commercially produced in factories to supply nitrogen, phosphorus and potassium that ensures soil fertility in terms of proper dose, time, and observing pre and post-application precautions.

16.  (c) Farmers use quality seeds, adopt irrigation, use fertilizer and use crop protection measures.

17.  Prevention is better than cure so is true for plants also. Such preventions involve spraying of herbicides, weedicides, insecticides, pesticides, fungicides etc in the crop field. Since their excessive use can harm the crop plants and cause pollution so proper seed bed preparation, timely sowing of crops, intercropping and crop rotation are additionally applicable. Other than these biological control methods like use of resistant varieties is highly useful.

18.  Factors that may be responsible for losses of grains during storage are:

(a) abiotic factors: Unfavourable conditions of humidity and temperature.

(b) biotic factors: Insects, rodents, bacteria, fungi etc that feed on grains.

19.  The method of cross breeding is commonly used for improving cattle breeds for example in milch animals Exotic or foreign breeds (for example, Jersey,Brown Swiss) are selected for long lactation periods, while local breeds (for example, Red Sindhi, Sahiwal) show excellent resistance to diseases. The two can be cross-bred to get animals with both the desired qualities.

20.  Under poultry the birds kept are fed on agricultural waste material and broken grains etc which are not useful for humans but those birds consuming such waste provide us with eggs and meat. It is highly nutritious animal protein food hence the statement made is quite appropriate.

21.  The management practices that are common in dairy and poultry farming are:

(a) Food requirements

(b) Proper cleaning and shelter facilities

(c) Protection from unfavorable climatic conditions and diseases.

(d) Protection from pests.

22.  Broilers: Used for meat purpose. Broiler chickens are fed with vitamin-rich supplementary feed for good growth rate and better feed efficiency and care is taken to avoid mortality and to maintain feathering an carcass quality.

Layers: Used for egg production. Layers don’t need any specific diet as prescribed for broilers their requirements are simpler.

Other than above differences housing, nutritional and environmental requirements of broilers are somewhat different from those of egg layers.

23.  There are two ways of obtaining fish. They can be obtained by:

(a) capture fishing : It is the way of obtaining fish from their natural resources(rivers, lakes, oceans).

(b) culture fishery : It is also known as fish farming where selected fishes are
reared and bred.

24.  Composite fish culture has following advantages :

(a) Both local and imported fish species can be used in such systems.

(b) Due to non-competitive nature of selected fishes food available in all the parts of the water reservoir is used.

(c) Increases the fish yield from the water reservoir (intensive fish farming).

25.  The desirable characters of bee varieties suitable for honey production are :

(a) high honey collection capacity.

(b) they must sting less.

(c) They should stay in a given beehive for long periods, and breed very well.

26.  Pasturage refers to the flowers available to the bees for nectar and pollen collection. The value or quality of honey depends upon the pasturage. Along with this the kind of flowers available will determine the taste of the honey.

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