Class 9 Science
Question 1: Explain any one method of crop production which ensures high yield.
Answer: When two or more crops are simultaneously grown on the same piece of land, it is called mixed cropping. For example; wheat + gram, or wheat + mustard, or groundnut + sunflower are often grown together; under this practice. Mixed cropping ensures better utilization of resources. It also reduces risk and gives some sort of insurance in case of failure of one of the crops.
Question 2: Why are manure and fertilizers used in fields?
Answer: When crops are grown on a farmland for many seasons, the soil loses its nutrients. Thus, soil fertility reduces in due course of time. Manure and fertilizers are used to replenish nutrients in soil.
Question 3: What are the advantages of inter-cropping and crop rotation?
Answer: Inter-cropping helps in better utilization of soil nutrients. It also helps in preventing the spread of pests and diseases in plants. Crop rotation helps in improving soil fertility, and in harvesting more number of crops in a given year.
Question 4: What is genetic manipulation? How is it useful in agricultural practices?
Answer: When a gene with a desirable character is introduced into a plant or animal, it is called genetic modification or genetic manipulation. Genetic modification helps in producing better varieties of plants and animals. BT cotton is a good example of genetically modified crop. Here, BT stands for Bacillus thuringiensis which is a bacteria that produces various toxins against different types of pests. Introducing the gene from BT equips cotton with an ability to ward off attacks from different types of insect pests. It helps in improving the yield of cotton.
Question 5: How do storage grain losses occur?
Answer: Improper storage may result in damage to grains. The grains’ quality can become poor. The grains may lose their ability to germinate. They may lose weight. It can result due to moisture, fungi, pests, or due to improper temperature in the storage area.
Question 6: How do good animal husbandry practices benefit farmers?
Answer: Good animal husbandry practices help in maintaining a healthy population of cattle. Healthy cattle mean higher production of milk. It also means availability of sturdier animals for farm labour. It helps in improving the income of farmers.
Question 7: What are the benefits of cattle farming?
Answer: Cattle-farming helps in supplementing the income of farmers. A farmer can earn extra money by selling milk or by selling wool. A farmer can also utilize drought animals for farm related work.
Question 8: For increasing production, what is common in poultry, fisheries and bee-keeping?
Answer: Suitable use of particular breed of animals
Question 9: How do you differentiate between capture fishing, mariculture and aquaculture?
Answer: Capture fishing involves catching the fish from natural resources. Mariculture involves breeding fish and other marine food in oceans and seas. Aquaculture encompasses everything, i.e. capture fishing, fish farming and mariculture.
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