JAC Board Class 9th Science Chapter 15 Notes Improvement in Food Resources
→ All living organisms essentially require food to stay alive.
→ Food provides energy to perform various life activities and is required for growth, development and body repair.
→ Sources of Food
a. Food from agriculture: Cereals, pulses, vegetables, fruits, nuts, oilseeds, condiments and spices.
b. Food from animal husbandry: Dairy products like milk, curd, butter, meat, egg, fish and other sea products.
→ Food Revolutions in India
With the increase in population, there is a need for a sufficient increase in food production, so as to meet the food related demands of the growing population. This led to the rise of the following food revolutions in India:
a. Green Revolution: Introduced to increase the food grain production.
b. White Revolution: Introduced to increase the production of milk.
c. Blue Revolution: Introduced to enhance fish production.
d. Yellow Revolution: Introduced to increase oil production.
→ Crop Season: Different crops require different climatic conditions like temperature, moisture and photoperiod, to grow well and complete their life cycle.
Two main crop seasons are:
- Kharif Season: Summer season from the month of June to October, i.e., during rainy season. Crops grown in this season require more water. Examples of Kharif season crops are paddy, soyabean, pigeon pea, maize, black gram, green gram and rice.
- Rabi Season: Winter season from the month of November to April. Crops grown in this season require less water. Examples of Rabi season crops are wheat, gram, peas, mustard and linseed.
→ Improvement in Crop Yield: Main approaches implemented to enhance the crop yield are as follows:
1. Crop Variety Improvement: This involves the introduction of improved varieties to obtain better food qualities. It is mainly done to achieve the following targets:
a. Higher yield of crops by adopting technologies like cross-breeding and hybridisation.
b. Improved quality of products.
c. Biotic resistance against diseases and insects.
d. Aboitic resistance against drought, salinity, heat, cold, etc.
e. Decreased duration to attain maturity as short duration crops require less costing and more rounds of crop can be grown in a season.
f. Wider adaptability so that the crops growing in different environmental conditions can have high production.
g. Desired agronomic traits like height, branching, leaves, etc., will result in an increased production.
2. Crop Production Improvement: It involves different practices carried out by the farmers to achieve higher standards of crop production.
→ Main practices involved here are stated below:
a. Nutrient Management: Like other organisms, plants also require some elements for their growth. These elements are called nutrients. There are sixteen nutrients which are essential for plants. These nutrients are supplied to the plants by air, water and soil.
These nutrients are divided into following two categories:
- Macronutrients: The essential elements which are utilised by plants relatively in large quantities are called macronutrients.
- Micronutrients: The essential elements which are used by plants in small quantities are called micronutrients.
|Air||Carbon and oxygen (macronutrients)|
|Water||Hydrogen and oxygen (macronutrients)|
|Soil||1. Macronutrients present in soil are nitrogen, phosphorus, potassium, calcium, magnesium, sulphur.|
|2. Micronutrients present in the soil are iron, manganese, boron, zinc, copper, molybdenum, chlorine.|
Manure: It is a kind of natural fertiliser formed from the decomposition of animal excreta and plant waste. It mainly contains organic matter and some nutrients in small amount. It helps in improving the soil structure by increasing the water holding capacity of the soil.
→ Types of manures: Based on the kind of biological waste material used, the manures are classified as:
- Farmyard manure (FYM): It is the decomposed mixture of cattle excreta (dung) and urine along with litter and leftover organic matter such as roughage or fodder. The waste materials are collected daily from the cattle shed and stored in a pit for decomposition by the microorganisms (bacteria, fungi, etc.). FYM contains nitrogen, phosphorous and potassium.
- Compost: It is a mixture of decomposed organic matter derived from garbage, sewage, vegetable waste, etc. The mixture is decomposed in pits and the process is known as composting.
- Vermi-compost: The compost which is made by the decomposition of dead parts of plants and animals with the help of redworms is called vermi-compost.
- Green manure: It is prepared by cultivating fast growing green manure crops like sunhemp, horse gram, guar, cow pea, etc., before sowing of seeds. The fast growing crops are then ploughed back into the soil. Green manure enriches the soil with nitrogen, phosphorus as well as organic matter and provides protection against erosion and leaching.
→ Fertilisers: Fertilisers are chemicals manufactured in factories and are highly rich in nutrients like nitrogen, phosphorus and potassium. They provide large amounts of nutrients and thus ensure better growth of plants. Excessive use of fertilisers for a long period of time can damage soil fertility,
b. Irrigation: The process of supplying water to the crop plants through human efforts by means of canals, wells, reservoirs, tube-wells, etc., is known as irrigation. Most agriculture in India is dependent on timely monsoons and sufficient rainfall spread through most of the growing season. However, the extra water required by crops is met through irrigation.
→ Sources of Irrigation: Some most commonly used sources of irrigation are as follows:
- Wells: These are of two types:
Dug wells: Where water is collected from water bearing strata through bullock-operated devices or by pumps. Tube wells: Where water is collected from underground through diesel or electricity run pumps.
- Canal system: Water from the main river or reservoir is carried by canal into the field which is divided into branch canals having further distributaries to irrigate the fields.
- River-lift system: In this system, water is directly drawn from the river for supplementing irrigation. It is used where occurs insufficient flows from canals.
- Rainwater harvesting: Rainwater is collected and recycled into groundwater by digging canals.
- Watershed management: Small check dams are built up in watershed areas to increase percolation of water into the ground and reduce the flow of rainwater to prevent soil erosion.
c. Cropping pattern: It includes different ways of growing crops so as to get the maximum benefit. These different ways include the following types:
- Mixed cropping: It refers to growing of two or more crops simultaneously on the same piece of land.
- Intercropping: It refers to growing of two or more crops simultaneously on the same field in a definite row pattern.
- Crop rotation: The growing of different crops on a piece of land in a pre-planned succession is known as crop rotation.
→ Animal Husbandry: It is the scientific management of animal livestock including feeding, breeding and disease control.
→ The food requirements of dairy animals are of two types:
a. Maintenance requirement, i.e., the food required to support the animals to live a healthy life.
b. Milk producing requirement, i.e., the type of food required during the lactation period.
→ Artificial insemination: It is the process in which semen is collected from the desired bull and is injected into the vagina of cows during the period of heat.
→ Poultry farming: Poultry includes duck, geese, turkeys, pigeons, etc. However, poultry farming is undertaken basically to raise fowl for egg production and chicken for meat.
→ Fish production: It includes finned fishes, i.e., true fishes and shell fishes such as prawns and molluscs.
→ In composite fish culture a combination of five or six species of fishes are put in culture system. These species of fish are such that they do not compete for food among themselves, i.e., have different food habits.
→ Honey has medicinal value specially in disorders related to digestion, dysentery, vomiting, and ailments of stomach and liver.
→ Apis mellifera, Italian bee, has now been domesticated in India to increase the yield of honey.
→ A colony of honeybees includes queen, drones and workers.