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Q. No. 1: How do biotic and abiotic factors affect crop production?
Biotic factors such as pests, insects and diseases reduce the crop production. A pest causes damage to our crops by feeding. Weeds also reduce crop productivity by competing with the main crop for nutrients and light.
Similarly, abiotic factors such as temperature, wind, rain etc. affect the net crop production. For example droughts and floods have a great impact on crops sometimes, destroying the entire crop.
Q. No. 2: What are the desirable agronomic characteristics for crop improvements?
The desirable agronomic characteristics for crop improvements are:
(i) Tallness and profuse branching in any fodder crop.
(ii) Dwarfness in cereals.
These desirable agronomic characteristics help in increasing crop productivity.
Q. No. 1: What are macro-nutrients and why are they called macro-nutrients?
Macro-nutrients are those nutrients which are required in large quantities for growth and development of plants. Since they are required in large quantities, they are known as macro-nutrient. The six macro-nutrients required by plants are nitrogen, phosphorus, potassium, calcium, magnesium, and sulphur.
Q. No. 2: How do plants get nutrients?
Plants get nutrients from air, water, and soil. Soil is the major source of nutrients. Thirteen of these nutrients are available from soil. The remaining three nutrients (carbon, oxygen, and hydrogen) are obtained from air and water.
Q. No. 1: Compare the use of manure and fertilizers in maintaining soil fertility.
Ans: Manures increase soil fertility by enriching the soil with organic matter and nutrients as it is prepared by the decomposition of animal excreta and plant wastes. while fertilizers are inorganic compounds whose excessive use is harmful to the symbiotic micro-organisms living in soil.
So they are preferred only for short period of time.
In text questions of page no 208
Q. No. 1:Which of the following conditions will give the most benefits? Why?(a). Farmers use high-quality seeds, do not adopt irrigation or use fertilizers.
Ans: Option (c) will give the maximum benefits because good quality seeds, proper irrigation and use of fertilisers is very helpful for the plants growth and crop protection measures are essential for the high yielding of the crop.
In text questions of page no 209
Ans: Sometimes crops are very much affected or destroyed by the weeds, insects pests and diseases. For example
(i) Weeds compete for food, space and light. They use the nutrients from the soil and reduce the growth of the crop.
(ii) Insect pests affect the health of the crop and reduce its yield.
(iii) The pathogens like bacteria, viruses and fungi cause the disease in the plants. Therefore they must be controlled by using suitable preventive masures.
Q. No. 2: What factors may be responsible for losses of grains during storage?
Ans: During the storage of grains both biotic and abiotic factors cause losses to the grain. Biotic factors such as insects, rodents, mites, fungi, bacteria, etc. and various abiotic factors such as moisture, temperature, lack of sunlight, etc. are responsible for losses of grains.
In text questions of page no 210
Q. No. 1: Which method is commonly used for improving cattle breeds and why?
Ans: Cross breeding method is commonly used for improving cattle breeds. Cross breeding between two good varieties of cattle will produce a new improved variety. For example, the cross between foreign breeds such as Jersey Brown, Swiss (having long lactation periods) and Indian breeds such as Red Sindhi, Sahiwal (having excellent resistance power against diseases) produces a new variety having qualities of both breeds.
In text questions of page no 211
Q. No. 1: Discuss the implications of the following statement:
â€śIt is interesting to note that poultry is Indiaâ€™s most efficient converter of low fibre food stuff (which is unfit for human consumption) into highly nutritious animal protein food.â€ť
Ans: In poultry farming, domestic fowls are raised to produce eggs and chicken. For this, the fowls are given animal feeds in the form of roughage, which mainly consists of fibres. Thus, by feeding animals a fibre rich diet, the poultry gives highly nutritious food in the form of eggs and chicken. Thus it verifies the above statement.
In text questions of page no 211
Q. No. 2: What are the differences between broilers and layers and in their management?
Ans: Broilers are for meat while layers are for egg production.
A broiler chicken requires vitamin rich supplements especially vitamin A and K. Also, their diet includes protein rich food and enough fat. While egg laying birds utilise more fibrous cheaper diets.
In text questions of page no 213
Q. No. 1: How are fish obtained?
Ans: Fish can be obtained by following two ways:
Q. No. 2: What are the advantages of composite fish culture?
Ans: In a composite fish culture, five or six different species are cultured together in a single fish pond. Fishes with different food habitats are chosen so that they do not compete for food among themselves. Also, this ensures a complete utilization of food resources in the pond. As a result fish yield from the pond increases.
In text questions of page no 213
Q. No. 1: What are the desirable characters of bee varieties suitable for honey production?
Ans: Desirable characters of bee varieties suitable for honey production are:
Q. No. 2: What is pasturage and how is it related to honey production?
Ans: Pasturage means the flowers available to the bees for nectar and pollen grain. It is related to the production of honey as it determines the taste and quantity of honey.
Q. No. 1: Explain any one method of crop production which ensures high yield.
Ans: Inter-cropping is one of the methods of crop production that ensures high yield. It is the method of growing two or more varieties of crops on the same land in a definite pattern. These crops having different nutrient requirements. Inter-cropping helps in preventing pests and diseases to spread throughout the field. It also increases soil fertility, whereas crop rotation prevents soil depletion, increases soil fertility, and reduces soil erosion.
Q. No. 2: Why are manures and fertilizers used in fields?
Ans: Manures and fertilisers are used in fields to supply plant nutrients to the soil. They increase soil fertility.
Q. No. 3: What are the advantages of inter-cropping and crop rotation?
Ans: Inter-cropping and crop rotation are used to obtain maximum benefit. Inter-cropping helps in preventing pests and diseases to spread throughout the field. It also increases soil fertility, whereas crop rotation prevents soil depletion, increases soil fertility, and reduces soil erosion. Both these methods reduce the need for fertilizers. It also helps in controlling weeds and controls the growth of pathogens and pests in crops.
Q. No. 4: What is genetic manipulation? How is it useful in agricultural practices?
Ans: Genetic manipulation is a process in which genes of desirable characters are taken from a plant and transferred to another plant by the technique of hybridisation. Genetic manipulation helps in obtaining desirable agronomic characters liked Dwarfness in cereals and tallness and profuse branching in fodder crops. It is useful in developing varieties with higher yield, good quality, biotic and abiotic resistance, short maturity period, wider adoptability and desirable agronomic characteristics.
Q. No. 5: How do storage grain losses occur?
Ans: During the storage of grains both biotic and abiotic factors cause losses to the grain. Biotic factors such as insects, rodents, mites, fungi, bacteria, etc. and various abiotic factors such as moisture, temperature, lack of sunlight, etc. are responsible for losses of grains. These factors cause loss in weight, degradation in quality and poor germinability.
Q. No. 6: How do good animal husbandry practices benefit farmers?
Ans: Cattle farming is one of the methods of animal husbandry that is most beneficial for farmers. In this method better breeds of animals can be produced. Such animals are engaged in agricultural fields for labour work such as irrigation, tilling, carting, etc.
Q. No. 7: What are the benefits of cattle farming?
Ans: The benefit of cattle farming are production of milk and drought labour for agricultural work such as carting, tilling and irrigation.
Q. No. 8: For increasing production, what is common in poultry, fisheries and bee-keeping?
Ans: For increasing production cross breeding and use of imported species are common in poultry, fisheries and bee-keeping.
Q. No. 9: How do you differentiate between capture fishing, mariculture and aquaculture?
It is method in whichfishes are obtained from the natural resources like river, lake or seas.
It is the culture offishes in sea or marine water.
It is the culture offishes in fresh water.
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