These DAV Class 8 Science Notes and DAV Class 8 Science Chapter 9 Notes – Crop Production and Its Management act as excellent revision resources, particularly in preparation for board exams.
Crop Production and Its Management Class 8 DAV Notes
→ Agriculture: The practice of cultivating land for growing crops is called agriculture. It also includes growing plants for other requirements like fibre, medicines, flowers and ornamental plants.
→ Crop Production: Cultivation of one type of plants on a large scale is called crop production.
→ Different agricultural practices are as follows:
→ Preparation of soil: Preparation of soil involves loosening and turning it. The process is called ploughing or tilling. Tilling is done by wooden or iron plough. The plough is pulled either by oxen or by a tractor. Ploughing gives following advantages:
- Improves air circulation and facilitates respiration by roots.
- Roots can penetrate deeper into the soil and thus can hold the plant firmly.
- It enhances the water retaining capacity of soil.
- It uproots weeds and aids in the growth of the microorganisms.
→ Sowing: Planting of seeds in the soil is known as sowing. Sowing is done after ploughing. Different ways of sowing seeds are as follows:
- Seeds can be manually scattered by hands. This is called broadcasting.
- Seed drill can be used for sowing. The seed drill is composed of a funnel which opens into a long pipe. Seed drill is attached at the back of the plough. Seeds are kept in the funnel and they get implanted in the furrows made by the moving plough.
→ For some crops, seeds are sown on a small plot called nursery, e.g. paddy, tomato and chilly. When saplings come out, they are transplanted onto a bigger plot. This ensures that plants are planted at proper gap so that adequate amount of sunlight, water and air is available to each plant.
→ Manuring: Replenishing of nutrients in soil is done by many methods. Some of them are given below:
(a) Field fallow: The field is left uncultivated for one or more seasons. Dead animals and plant remains accumulate on the field which are decomposed by microorganisms. This helps in replenishment of soil nutrients.
(b) Crop rotation: Some crops like wheat and rice use lot of nitrogen from the soil. This leads to loss of nitrogenous nutrients from the soil. The lost nitrogen can be replenished by growing a leguminous crop in between two cereal crops.
(c) Manures: Plant and animal waste make good manure on decomposition. Farmers dump animal dung, vegetables and crop waste at open places and allow them to decompose. After decomposition, manure becomes ready. The manure is mixed up with soil before sowing. Addition of manure also helps in improving the water retention capacity of the soil.
(d) Fertilisers: Fertilisers are produced in factories. These are rich in specific nutrients like nitrogen, phosphorus and potassium. Overuse of fertilisers can be harmful for the soil.
→ Irrigation: The supply of water to the plants in the field is called irrigation, Irrigation is done with water from various sources like rains, canals, waterways, wells and pumps. Some crops need more water, while some others need less water.
→ Crop Protection: Crop needs to be protected from weeds and pests.
(a) Protection from weeds: Weeds are unwanted plants which grow along with the crop. The removal of weeds is called weeding. Weeding can be done manually by hands using sickles. Weeding is also done before sowing by tilling the weeds along with soil. Weedicides are also used for removing weeds.
(b) Protection from pests: Birds and insects often damage the crops. Animals and birds are scared away by using scarecrow or by creating noise. Pests are killed by using pesticides.
→ Harvesting: Cutting and gathering of crops after maturation is called harvesting. Crops like wheat and paddy are harvested by sickles. Fruits and vegetables are plucked with hands. After harvesting, grains need to be separated from the harvested crop. This is done by the process of threshing. Threshing can be done manually or by using animals or by threshing machines. For large scale farming, combine harvester is used. This is a machine which does harvesting and threshing at one go. After threshing, grains are separated from chaff. This is known as winnowing.
→ Storage: Harvested grains are sun dried to remove moisture. After that they are stored in silos and gunny sacks. Pesticides and insecticides are also added along with grains to prevent attack from pests.
→ Nitrogen Fixation in Soil: Leguminous plants harbor rhizobium bacteria in their root nodules. The rhizobium bacteria help these plants in nitrogen fixation in soil.
→ Crop Improvement: Crop yield and quality can be improved by using modern farming methods and high yield seed varieties. Green Revolution was started in India with an aim of crop improvement. Scientists have developed many high yield varieties of seeds. The Green Revolution has helped India in becoming a food sufficient country.
→ Crop : A single type of plant grown on a large scale is called crop.
→ Agriculture : The practice of cultivating land for growing crops is called agriculture.
→ Plough : A tool for tilling the land.
→ Irrigation : Supplying water to crops ¡s called irrigation.
→ Weeds : Any unwanted plant growing along with crops ¡s called weed.
→ Pest : Birds, animals and insects which may damage the crop are called pests.
→ Nitrogen fixation : The process of converting atmospheric nitrogen into a form which plants can easily absorb from soil.
→ Agricultural Practices: In order to maintain a steady supply of food, farmers undertake several systematic activities, spread over a period of time for growing crops. These activities are called agricultural practices.
|Season||Time period||Examples||Season||Time period||Examples|
|Rainy season||June to October||Paddy, maize, soyabean, groundnut||Winter season||November to April||Wheat, mustard, linseed|