These comprehensive RBSE Class 9 Science Notes Chapter 15 Improvement in Food Resource will give a brief overview of all the concepts.
RBSE Class 9 Science Chapter 15 Notes Improvement in Food Resource
→ All living organisms need food for health and growth. Food provides important nutritents for body like fats, carbohydrates, proteins, vitamins and minerals. Both plants and animals are major sources of food.
→ India is an agriculture oriented country but still lack of food due to growing population. It is important that we should increase food production without degrading our environment and disturbing the balances maintaining it.
→ Different crops require different climate conditions, photoperiods and temperature for their growth and completion of their life cycle.
→ Green revolution is a programme introduced in many poor countries to increase food production by use of modern technology, proper irrigation, improved seeds, etc.
→ White revolution was introduced in India to increase the production of milk.
→ Similarly blue revolution was introduced to enhance fish production and yellow revolution to increase oil production.
Improvement in Crop Yields :
Yield increases when production increases from same amount of land in same period of time.
For improving crop yields, major activities can be classified as :
- Crop variety improvement
- Crop production improvement
- Crop protection management
→ Crop Variety Improvement : The factors by which variety of crops can be improved are as follows:
(i) Hybridisation : The process of cross-breeding two different varieties of crops to produce a new variety of good properties of both the crops is known as hybridisation.
(ii) Genetic Manipulation : In this process, genes of a crop are modified so that undesired properties can be supported and desired properties can be retained.
→ Factors for which crop variety improvement is done are higher yield, improved quality, biotic and abiotic resistance, change in maturity duration, desirable agronomic traits and wider adaptability.
→ Crop Production Improvement : It includes use of different farming practice and agricultural technologies. Depending on the purchasing capacity, farmers adopt three different cropping systems and production practices :
- “No cost” production practices
- “Low Cost” production practices
- “High cost” production practices
→ Crop production improvement includes :
- Nutrient management
- Cropping patterns
→ Nutrient Management : Plants require inorganic elements for their growth and metabolism, called nutrients. There are 16 essential nutrients. These can be categorised further in two types –
- Macronutrients : Required by plants in large quantities, e.g. C, O2, H2, N2, P, K, Co, Mg, S, etc.
- Micronutrients : Required by plants in small quantities, e.g. Fe, Mn, B, Zn, Cu, Mo, Cl, etc.
→ Manure : It is partially decomposed organic matter derived from plants and animals waste. It is added to soil to restore its fertility and mineral contents. Compost, vermi compost and green manure make the soil fertilised.
→ Fertilisers : These are synthetic chemical substances which are added to the soil to restore its mineral nutrients. They supply Nitrogen, Phosphorus and Potassium. They are required in small quantities, so the excessive use of fertilisers can cause water pollution. Excessive use of fertilisers for long period can damage soil fertility, which can harm the microorganism and insects in soil.
→ Organic farming is cultivation of crops without using chemical fertilisers, herbicides and pesticides. The crops are raised using biofertilisers, biopesticides, organic manures and adopting cropping systems.
→ Irrigation : We cannot depend on rain for water as it is not fully reliable. Irrigation is timely supply of water to the crops through human efforts from sources other than rain. Different sources of water in India are rivers, canals, ponds, lakes, tanks, dams, ground water, etc. Irrigation systems are adopted to supply water to agricultural lands depending on the kinds of water resources available.
→ Cropping Patterns : Different cropping patterns are used to maximise the production from crop field.
(i) Mixed cropping : Growing two or more different crops together at the same time in the same field as a mixture without any proportion or pattern.
Example – Wheat and gram, wheat and mustard etc.
(ii) Intercropping : Two or more crops are grown simultaneously in the same field . in alternate rows.
Example – Soyabean and maize, finger millet and cowpea, etc.
(iii) Crop rotation : It may be defined as the practice of growing different crops on the same piece of land in a pre-planned succession.
→ Crop Protection Management : Field crops are infested by large number of weeds, insects pests, diseases and storage of grain. Insect pests attack the plants in three ways :
- They cut the root, stem and leaf.
- They suck the cell sap from various parts of the plant.
- They bore into stem and fruits. Diseases in the plants are caused by pathogens such as fungi, bacteria and viruses. Various types of pesticides are spread on plants to kill different pests. These are toxic chemicals.
→ Storage of Grains : Most crops like rice, wheat, maize, etc. are harvested only once : a year. Proper storage is necessary to get food grain throughout the years.
→ Factors responsible for loss of stored food grains are : (i) Biotic factors (insects, birds, enzymatic action) (ii) Abiotic factors (moisture, humidity, high temperature, etc.) Prevention and control measures should be used before storage of grains. Animals Husbandry : It is a branch of agriculture that deals with the farming and management of domestic animals for their economic utilisation. Such animals are called livestock. The various aspects of animal husbandry include proper :
- Feeding to livestock
- Shelter for livestock
- Health care of livestock
- Breeding of livestock and proper utilisation of their products.
→ Need for Animal Husbandry: To fulfil the increasing need of fast increasing human population for milk, eggs, milk products and meat. It includes, cattle farming for milk production, poultry farming for meat and eggs, fish farming for inland and marine fishes as food, bee-farming for honey and bee wax and pig farming for meat production.
→ Cattle Farming : Raising of cattle has two motives –
(i) milk, meat and skin production
(ii) agricultural practices. It includes rearing of cows, buffaloes, bullocks, camels and goats. These are broadly placed in following categories :
(a) Milch Breeds or Dairy Animals – are kept for milk.
(b) Draught Breeds – For ploughing fields and transport goods.
→ Poultry Farming : Poultry farming is the rearing of domesticated foul, ducks, geese, Turkey for meat and eggs. Both provide protein to our diet. The specialised meat producing poultry birds are called broilers while egg laying poultry birds are called layers. Most of the broilers and layers are cross-breed. In management practices these include maintenance of temperature and hygenic conditions in housing and poultry feed, as well as prevention and control of diseases and pests. The level of vitamins A and K is kept high in poultry farms.
→ Fish Farming : Fish is an important aquatic food. It is a cheap source of animal protein. It is highly nutritive and is easily digestible. Fishing can thus be done by capture and culture of fish in marine and freshwater ecosystems.
→ Composite Fish Culture : Intensive fish farming can be done in composite fish culture system. Both indigenous and exotic fish species are used in such system. In this system, five or six fish species are reared together in a single fish pond. The species selected have different food habit, so they do not compete for food among themselves. For example – Three exotic varieties : Silver Carp, Grass Carp (aquatic weed feeder) and Common Carp (bottom feeder) along with three indigenous varieties : Catla (surface feeder), Rohu (middle zone feeder) and Mrigal (bottom feeder) are commonly used in composite fish culture system.
→ Bee-keeping : It is an important agricultural enterprise. The practice of keeping or rearing, caring and management of honeybees on a large scale for obtaining honey, beewax and royal jelly is called apiculture. The place where the bees are raised is called apiary. Some common Indian varieties of bees include Apis carana indica (Indian bee), Apis dorsata (rock bee), Apis florae (little bee), etc. Italian variety Apis .. mellifera is used in India for commercial large production because they have high honey collection capacity, reproduce fast, sting less and stay in beehive for long.