Notes-NCERT-Class-8-Science-Chapter-1-Crop Production and Management-CBSE

Topics to be learn : Agricultural Practices Basic Practices of Crop Production Preparation of Soil Agricultural Implements Sowing Adding Manure and Fertilisers Irrigation Protection from Weeds  Harvesting Storage

Introduction :

• All living organisms require food for growth and survival.
• Plants prepare food, while animals, including humans, obtain it directly or indirectly. Regular production, proper management, and distribution of food are necessary for a large population. Proper agricultural practices, including cultivating crops and rearing animals, can help achieve this.

Agricultural Practices :

Crops : When plants of same type are grown and cultivated in a field on a large scale, it is called a crop (fasal in Hindi), e.g. wheat crop, paddy crop, etc.

• India's diverse climate and varied conditions result in a rich variety of crops grown across the country.
• However, two broad cropping patterns can be identified based on the specific season in which they grow, highlighting the importance of climatic conditions in crop cultivation. These are as follows

(i) Kharif Crops :

• The crops which are sown in rainy season are called Kharif crops or summer crops,
• Examples : Paddy (rice), maize, soyabean, cotton, groundnut, millets (bajra), etc.
• These crops generally grown from June to September.

(ii) Rabi Crops :

• The crops that are grown in winter season are called Rabi crops or winter crops.
• Examples : Wheat, gram, pea, mustard and linseed.
• These crops are generally grown from October to March.

Basic Practices of Crop Production :

Cultivation of crops involves several activities undertaken by farmers over a period of time. These activities or tasks are referred to as agricultural practices.

The various agricultural practices of crop production involves

• Preparation of soil
• Sowing
• Adding manure and fertilisers
• Irrigation
• Protecting from weeds
• Harvesting
• Storage

Preparation of Soil :

The first step for the crop production is soil preparation.

• Soil is the uppermost layer of the Earth where plants are grown.
• Only a few centimeters of top layer of soil supports plant growth. It provides water, air, minerals, humus, etc. to the plants.
• Soil is prepared for sowing seeds by three major methods which are as follows

Ploughing :

• Ploughing, or tilling, is the process of loosening and turning soil using a plough.
• It benefits plants by allowing plant roots to penetrate deeper into the soil, allowing them to breathe easily, bringing nutrient-rich soil to the top, and promoting the growth of earthworms and microbes.
• These organisms are friendly to farmers as they further turn and loosen the soil, adding humus.
• Overall, ploughing is a beneficial method for agricultural purposes.

Levelling :

• Levelling is a process where a leveller is used to break down large soil crumbs in a ploughed field,
• Levelling helps to break these crumbs with a planks and prevents loss of moisture from the loose soil.
• It also helps in the uniform distribution of water in the fields during irrigation.

Manuring :

• Manuring is a process where farmers add manure to the soil to replenish nutrients deprived by continuous crop growth.
• This helps in proper mixing of manure with the soil, ensuring a balanced and healthy soil.

Sowing :

• It is the process of scattering or planting seeds into the soil, so as to grow a new crop plant.
• Sowing is the most important part of crop production.
• Before sowing, clean, healthy and good quality of seeds are selected to produce healthy plants and high yield of crops.

Methods of Sowing : Sowing is done either manually or by using machines, as described below.

(i) Traditional Tools :

• Traditional tools are used with the help of bulls. It was used by farmers earlier in their fields for sowing seeds.
• It's upper funnel-shaped part is filled by seeds.
• The seeds pass down through two or three pipes having sharp ends.
• These ends pierce into the soil and place seed in that space.

(ii) Seed Drill :

• Seed Drill is a mechanical sowing method using a tractor, ensuring seeds are sown uniformly at equal distance and depth, covering the soil after sowing.
• This method protects seeds from bird damage, saves time and labor, and prevents overcrowding by ensuring each plant receives sufficient sunlight, nutrients, and water from the soil.

Know This : The National Seed Corporation (NSC) in India plays a key role in producing high-quality agricultural seeds and has contributed to the establishment of seed-testing laboratories across various regions in the country.

Adding Manure and Fertilisers :

• Manure and fertilisers are nutrient-rich substances added to soil for plant growth.
• Farmers use manure to replenish soil with nutrients, as insufficient or improper manuring can weaken plants.
• Improper or insufficient manuring can lead to plant weakness.

For replenishing soil with nutrients following methods are used.

Manures :

• These are organic (natural) substances derived from the decomposition of plant and animal wastes, like cow dung, etc.
• Plant and animal wastes are dumped in pits at open places and allowed to decompose by some microorganisms.
• The decomposed matter is used as organic manure.

Fertilisers

• These are the chemicals which contain the necessary plant nutrients like nitrogen, phosphorus, etc.
• Examples- Urea, ammonium sulphate, super phosphate, potash, NPK (Nitrogen, Phosphorus, Potassium).
• Fertilisers are used to increase soil fertility, that helps farmers to get better yield of crops such as wheat, paddy and maize.
• The excessive use of fertiliser is harmful because it makes the soil less fertile and also causes water pollution.

Advantages of Manure Over Fertilisers :

The organic manure is considered better than fertilisers because of the following reasons

• It enhances the water holding capacity of the soil.
• It makes the soil porous due to which exchange of gases becomes easy.
• It increases the number of friendly microbes.
• It improves the texture of the soil.

Crop Rotation :

• Crop rotation is the practice of growing different types of crops, particularly leguminous and non-leguminous crops, in the same field to improve soil fertility.
• This is done because certain crops, like cereals and vegetables, deplete nitrogen from the soil. Leguminous crops are grown after these crops to maintain soil nitrogen levels.
• Leguminous plants have nitrogen-fixing bacteria called Rhizobium in their roots, which can convert atmospheric nitrogen into soluble compounds.

Irrigation :

The process of supplying water to crop plants at regular intervals is called irrigation.

Water is important for the proper growth and development of all living organisms including plants. Plant contains nearly 90% of water.

Sources of Irrigation : Water supplied for irrigation can be taken from different sources, e.g. rain, wells, tube-wells, ponds, lakes, rivers, dams and canals.

Traditional Methods of Irrigation :

• The water from different sources such as wells, lakes and canals is lifted up by different methods for taking it to the fields. Cattle or human labour is used in these methods.
• The various traditional ways of irrigation are moat (pulley system), dhekli, chain pump and rahat (lever system).
• Pumps are commonly used for lifting water. They run on diesel, biogas, electricity and solar energy.

Modern Methods of Irrigation : Traditional methods use manpower and animal power and there is a wastage of water also occur during irrigation.

To overcome these problems, modern methods of irrigation are used. The main methods used are as follows

(i) Sprinkler System :

• The sprinkler system is a method of irrigation where a main pipeline with perpendicular pipes with rotating nozzles is used to sprinkle water over crops with the help of pump.
• This system is particularly beneficial for lawns, coffee plantations, and other crops on uneven land where sufficient water is not available, as it allows water to escape from the rotating nozzles.

(ii) Drip System :

• In this system, water flows through the narrow pipes and falls drop by drop just near the roots of plants.
• In this method there is no wastage of water as water falls drop by drop, therefore this system of irrigation is very useful in regions where availability of water is poor.
• It is the best technique for watering fruit plants, gardens and trees.

Protection from Weeds :

The unwanted, wild plants that grow along with the cultivated crops are called weeds. The process of removal of weeds is called weeding. It is necessary to remove weeds time to time because

• These unwanted plants are harmful because they competes with the crop plant for the nutrient, fertiliser, space, light and water. Thus, they reduce crop yield.
• Some weeds interfere even in harvesting and may be poisonous for animals and humans.

Harvesting :

• Harvesting is the process of cutting and gathering mature crops, which usually turn yellow, golden, or brown.
• It involves pulling or cutting crops close to the ground, and can be done manually or using a harvester machine.

To obtain seed grains from harvested crops, following two methods are used

Threshing :

• The process by which the grain seeds are separated from the chaff is called threshing.
• This is carried out with the help of a machine called combine which is a combination of a harvester and thresher.

Winnowing :

• After threshing, the grains are separated from chaff by a process called winnowing. In this process, the mixture of grain, hay and chaff is dropped from a height into blowing wind.
• The heavier seed, fall straight to the ground, whereas the chaff and hay are much lighter and are carried away by the wind.
• The grains form a separate heap and can be collected and packed in gunny bags.

Know This : Harvest Festivals : Harvest Festivals, celebrated after three to four months of hard work, bring joy and happiness to farmers. The sight of golden fields filled with grain fills their hearts, and special festivals like Pongal, Baisakhi, Holi, Diwali, Nabanya, and Bihu are associated with this period of celebration.

Storage :

• The harvested grains are dried to evaporate moisture and stored to protect them from moisture, insects, rats, and microorganisms.
• Insecticides, rodenticides are sprayed to protect them from rats and insects.
• Farmers use jute bags or metallic bins for storage, while silos and granaries are used for large-scale storage.
• Neem leaves, a natural insecticide, are used for home storage of food grains, as they are safe from pests.

Food from Animals :

• Besides plants, some animals also provide us with different kinds of food. The food obtained by animals is rich in protein.
• The food derived from animals and the sources are Tabulated below

Animal Husbandry :

• The process of rearing animals, by providing them proper food, shelter and care is called animal husbandry.
• Fishes are an important source of animal food in coastal areas. We get cod liver oil from fish which is rich in vitamin-D.