NCERT solutions for class 9 science

Chapter 15-Improvements in Food Resources-Exercise Solutions

NCERT Textbook Questions Page Number 214-215
Q.1. Explain any one method of crop production which ensures high yield.
Answer. Inter-cropping is growing two or more crops simultaneously on the same field in a definite pattern. A few rows of one crop alternate with a few rows of a second crop, for example, soyabean + maize, or finger millet (bajra) + cow pea (lobia). 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. This way, both crops can give better returns.
Q.2. Why are manure and fertilizers used in fields?
Answer. They are used to ensure good vegetative growth (leaves, branches and flowers), giving rise to healthy plants, that results in high crop production.
Q.3. What are the advantages of inter cropping and crop rotation?
Answer. Advantages of Inter Cropping:
(i) Crops selected for this differ in their nutrient requirement and ensuring maximum utilisation of the nutrients supplied.
(ii) Prevents pests and disease from spreading to all the plants belonging to one crop in field.
Advantages of Crop Rotation:
(i) It makes the soil fertile and increase the yield from a single field.
(ii) Use of nitrogenous fertilisers are not required as leguminous plant that are grown in crop rotation help in biological nitrogen fixation.
(iii) The selected rotation of crops helps in controlling pests.
Q.4. What is genetic manipulation? How is it useful in agricultural practices?
Answer. Genetic manipulation is the incorporation of desirable characters by hybridisation, mutation, DNA recombination, etc.
By genetic manipulation improved varieties of seeds can be obtained having desirable characters like high yield, disease resistance and better adaptability.
Q.5. How do stored grain losses occur?
Answer. Factors responsible for losses during storage of grains.
(i) Biotic factors: Insect, rodents, mites and bacteria.
(ii) Abiotic factors: Temperature and inappropriate moisture in place of storage.
Q.6. How do good animal husbandry practices benefit farmers?
Answer. Animal husbandry involve the scientific management of the farm animals. The benefit to farmers are:
(i) Improvement of the breeds having good desirable characters.
(ii) Better yield in quantity and quality.
(iii) Reduction of input cost.
Q.7. What are the benefits of cattle farming?
Answer. Main benefits of cattle farming are:
(i) We get milk from cattles. Various milk products can only be manufactured with this milk.
(ii) Cattle are also employed for labour work in agricultural fields for tilling, irrigation and carting.
(iii) Good quality of meat, fibre and skin can be obtained.
Q.8. For increasing production, what is common in poultry, fisheries and bee keeping.
Answer. The common features are:
(i) A good and improved variety should be selected.
(ii) Proper shelter facilities should be given.
(iii) Disease control should be done properly.
Q.9. How do you differentiate between capture fishing, mariculture and aquaculture?