NCERT Notes for Class 9 Science Chapter 12: Improvement in Food Resources

NCERT Notes for Class 9 Science Chapter 12: Improvement in Food Resources: The food that we eat gives us protein, fats, carbohydrates, vitamins, and minerals, which we require for body development, growth, and health. Both plants and animals are major sources of food for us and we obtain most of this food from agriculture and animal husbandry. 

Notes on Improvement in Food Resources Chapter 12 of Class 9 discusses the various aspects of agriculture, including crop production, animal husbandry, fisheries, and also the different techniques and methods used to enhance food production to meet the growing demands of a growing population in our country. However, it is important that we should increase food production without degrading our environment and disturbing the balance of maintaining it. Hence, there is a need for sustainable practices in Agriculture and Animal husbandry.

Improvement in Crop Yields

In India, there has been a four times increase in the production of food grains from 1952 to 2010 with only a 25% increase in the cultivable land area. If we think of the practices involved in farming, we can see that we can divide it into three stages. The first is the choice of seeds for planting. The second is the nurturing of the crop plants. The third is the protection of the growing and harvesting crops from loss. Thus, the major groups of activities for improving crop yields can be classified as:

• Crop variety improvement
• Crop production improvement
• Crop protection management.

Crop Variety Improvement

The crop variety improvement approach depends on finding a crop variety that can give a good yield. It can be done in the following two ways:

1. Hybridization: Hybridization refers to crossing between genetically dissimilar plants. This crossing may be intervarietal (between different varieties), interspecific (between two different species of the same genus), or intergeneric (between different genera).
2. Genetic Modification (GM): GM is a technology that involves inserting DNA into the genome of an organism. To produce a GM plant, new DNA is transferred into plant cells. Usually, the cells are then grown in tissue culture where they develop into plants.

Some of the factors for which variety improvement is done are:

1. Higher yield: To increase the productivity of the crop per acre.
2. Improved quality: The quality of crop products varies from crop to crop. e.g., protein quality is important in pulses, oil quality in oilseeds, and preserving quality in fruits and vegetables.
3. Biotic and abiotic resistance: Crop production can go down due to biotic (diseases, insects, and nematodes) and abiotic (drought, salinity, water logging, heat, cold, and frost) stresses under different situations. Varieties resistant to these stresses can improve crop production.
4. Change in maturity duration: Shorter maturity period of a crop reduces the cost of crop production and makes the variety economical. Uniform maturity makes the harvesting process easy and reduces losses during harvesting.
5. Wider adaptability: It allows the crops to be grown under different climatic conditions in different areas.
6. Desirable agronomic characteristics: It increases productivity, for example, tallness and profuse branching are desirable characteristics for fodder crops; while dwarfness is desired in cereals so that less nutrients are consumed by these crops.

Crop Production Management 

Crop production management refers to the growing of crops and providing all the nutrients to the crop plant that are needed and also properly storing them. It includes the following:

• Nutrition Management
• Irrigation
• Cropping Patterns

Nutrition Management

Deficiency of nutrients affects physiological processes in plants including reproduction, growth, and susceptibility to diseases. To increase the yield, the soil can be enriched by supplying these nutrients in the form of manure and fertilizers.

1. Manure: Manure contains large quantities of organic matter and also supplies small quantities of nutrients to the soil. Manure is prepared by the decomposition of animal excreta and plant waste. Manure helps in enriching the soil with nutrients and organic matter and increases soil fertility. Based on the kind of biological material used, manure can be classified as Compost and vermicompost, Green Manure.
2. Fertilizers: Fertilizers are commercially produced plant nutrients. Fertilizers supply nitrogen, phosphorus, and potassium. They are used to ensure good vegetative growth (leaves, branches, and flowers), giving rise to healthy plants. Fertilizers are a factor in the higher yields of high-cost farming.

Irrigation

Poor monsoons cause crop failure. Ensuring that the crops get water at the right stages during their growing season can increase the expected yields of any crop. Therefore, many measures are used to bring more and more agricultural land under irrigation. Under such conditions, several different kinds of irrigation systems are adopted to supply water to agricultural lands. These include wells, canals, rivers, and tanks.

1. Wells: These are of two types namely dug wells and tube wells. In a dug well, water is collected from water-bearing strata. Tube wells can tap water from the deeper strata. From these wells, water is lifted by pumps for irrigation.
2. Canals: Canals receive water from one or more reservoirs or from rivers. The main canal is divided into branch canals having further distributaries to irrigate fields.
3. River lift system: In areas where canal flow is insufficient or irregular due to inadequate reservoir release, the lift system is more rational. Water is directly drawn from the rivers for supplementing irrigation in areas close to rivers.
4. Tanks: These are small storage reservoirs, which intercept and store the run-off of smaller catchment areas.

Cropping Patterns

These include different ways of growing crops so as to get the maximum benefit. These different ways include the following:

1. Mixed cropping: Mixed cropping is growing two or more crops simultaneously on the same piece of land.
2. Inter-cropping: It involves growing two or more crops simultaneously on the same field in a definite proportion or pattern. The crops are selected such that their nutrient requirements are different. This ensures maximum utilization of the nutrients supplied and also prevents pests and diseases from spreading to all the plants belonging to one crop in a field.
3. Crop rotation: The growing of different crops on a piece of land in a preplanned succession is known as crop rotation. If crop rotation is done properly then two or three crops can be grown in a year with a good harvest.

Crop Protection Management

Field crops are infested by a large number of weeds, insect pests, and diseases. If weeds and pests are not controlled at the appropriate time, then they can damage the crops so much that most of the crop is lost. Weeds, insects, and diseases can be controlled by various methods. First is: the use of pesticides. It includes herbicides, insecticides, and fungicides. These chemicals are sprayed on crop plants or used for treating seeds and soil. However, excessive use of these chemicals creates problems, since they can be poisonous to many plant and animal species and cause environmental pollution. Another is mechanical removal.

Storage of Grains

Storage losses in agricultural products can be very high. Preventive and control measures are used before grains are stored for future use. They include strict cleaning of the produce before storage, proper drying of the product first in sunlight and then in shade, and fumigation using chemicals that can kill pests.

Animal Husbandry

Animal husbandry is the scientific management of animal livestock. It includes various aspects such as feeding, breeding, and disease control. Animal-based farming includes cattle, poultry, and fish farming.

Cattle Farming

Cattle husbandry is done for two purposes: milk and draught labor for agricultural work such as tilling, irrigation, and carting.

• Milk production depends on the duration of the lactation period. So, milk production can be increased by increasing the lactation period. Exotic or foreign breeds are selected for long lactation periods, while local breeds show excellent resistance to diseases. The two are cross-bred to get animals with both the desired qualities.
• The food requirements of dairy animals are of two types: 
  • (a) maintenance requirement, which is the food required to support the animal to live a healthy life, 
  • (b) milk-producing requirement, which is the type of food required during the lactation period.
• The animal feed includes (a) roughage, which is largely fiber, and (b) concentrates, which are low in fiber and contain relatively high levels of proteins and other nutrients. 

Poultry Farming

Poultry farming is undertaken to raise domestic fowl for egg production and chicken meat. The cross-breeding programs between Indian and foreign breeds for variety improvement are focused on developing new varieties.

Broiler chickens are fed with vitamin-rich supplementary feed for a good growth rate and better feed efficiency. Care is taken to avoid mortality and to maintain feathering and carcass quality. For good production of poultry birds, good management practices are important. These include maintenance of temperature and hygienic conditions in housing and poultry feed, as well as prevention and control of diseases and pests.

Fish Production

Fish production includes the finned true fish as well as shellfish such as prawns and mollusks. There are two ways of obtaining fish. One is from natural resources, which is called capture fishing. The other way is by fish farming, which is called culture fishery. Fishing can be done both by capturing and culture of fish in marine and freshwater ecosystems.

• Marine fisheries: Popular marine fish varieties include pomphret, mackerel, tuna, sardines, and Bombay duck. Marine fish are caught using many kinds of fishing nets from fishing boats. Yields are increased by locating large schools of fish in the open sea using satellites and echo sounders.
• Inland Fisheries: Freshwater resources include canals, ponds, reservoirs, and rivers. Brackish water resources, where seawater and freshwater mix together, such as estuaries and lagoons are also important fish reservoirs. While capture fishing is also done in such inland water bodies, the yield is not high. Most fish production from these resources is through aquaculture.

Bee-Keeping

Honey is widely used and therefore bee-keeping for making honey has become an agricultural enterprise. Since bee-keeping needs low investments, farmers use it as an additional income-generating activity. In addition to honey, the beehives are a source of wax which is used in various medicinal preparations. The Italian bees have a high honey collection capacity. They sting somewhat less. They stay in a given beehive for long periods and breed very well. For commercial honey production, bee farms or apiaries are established.

FAQs on Improvement in Food Resources

Q1: What is Green Manure?

Answer:

Prior to the sowing of the crop seeds, some plants like sun hemp or guar are grown and then mulched by plowing them into the soil. These green plants thus turn into green manure which helps in enriching the soil in nitrogen and phosphorus.

Q2: What Factors may be Responsible for the Losses of Grains During Storage?

Answer:

Storage losses in agricultural products can be very high. Factors responsible for such losses are biotic: insects, rodents, fungi, mites, and bacteria, and abiotic: inappropriate moisture and temperatures in the place of storage.

Q3: What is the Advantage of Composite Fish Culture?

Answer:

In composite fish culture, a combination of five or six fish species is used in a single fishpond. These species are selected so that they do not compete for food among them have different types of food habits. As a result, the food available in all the parts of the pond is used.