Crop Production and Management - NCERT Class 8 Notes (Comprehensive)
Introduction
All living organisms require food for growth and survival.
Food is the combination of organic and inorganic substances that provide energy for metabolic activities.
Food supplies carbohydrates, proteins, fats, vitamins, and minerals.
Major sources of food: plants (agriculture) and animals (animal husbandry).
With a rapidly increasing population, food and shelter demand has risen.
Strategies to increase production:
Bring more land under cultivation.
Increase production efficiency of plants and animals.
Develop and use improved varieties with high yield and better management (pre- and post-harvest).
Goal: increase food production without degrading the environment; adopt sustainable agriculture.
Green Revolution concepts: genetic improvement of crops (second green revolution) and domesticated animals; sustainable practices.
Father of Green Revolution (India): M. S. Swaminathan; Father of Green Revolution (World): Norman Borlaug.
Agriculture is an applied biological science dealing with production of crops (agronomy) and raising livestock (animal husbandry) for human use.
Green Revolution and Agricultural Foundations
The introduction of high-yielding varieties after 1965, along with increased use of fertilizers and irrigation, collectively known as the Green Revolution.
It contributed to making India self-sufficient in food grains.
Early agricultural transition: up to 10{,}000 B.C. people were nomadic; moved in groups seeking food and shelter; later they began cultivating land and producing crops like rice and wheat.
Why we eat food and how to feed a large population: food provides energy for bodily functions; large-scale production requires regularity, proper management, and distribution.
Definition of food: energy and materials for growth and maintenance.
Functions of food:
(i) For energy
(ii) For growth
(iii) For protection
(iv) For repair of injured/damaged body parts
Crop Production and Management: Key Concepts
Crops: plants of the same kind grown and cultivated at one place on a large scale; require different climatic conditions.
Two main crop groups by growing season:
Kharif crops: sown in the rainy season; require warm and wet weather; examples include Paddy, maize, soyabean, groundnut, cotton.
Rabi crops: sown in winter (October–March); examples include Wheat, gram, pea, mustard, linseed.
Horticulture: science and art of growing fruits, flowers, vegetables, and other cultivars.
Why crop production is essential: to feed a growing population with regular production, proper management, and distribution.
Differences Between Kharif and Rabi Crops (Overview)
Cereal crops (rice, wheat, maize, sorghum, barley, millets) are rich in carbohydrates for energy; paddy requires abundant water and is grown in the rainy season.
Pulses are rich in protein (e.g., Gram, moong, pea, lentil, urad, arhar).
Oilseed crops provide oils and fatty acids (e.g., Groundnut, sunflower, soyabean, mustard, sesame).
Vegetable crops provide vitamins/minerals with small amounts of carbohydrate, protein, and oils (e.g., Spinach, Cabbage, Potatoes, Carrot).
Fodder crops provide green fodder for cattle (e.g., Berseem, oat, Sudan grass).
Agricultural Practices: Core Activities
Agriculture practices are the sequence of activities carried out by farmers to ensure good crop yield.
Sowing window and methods include:
Broadcasting (manual)
Seed drill (tractor-assisted; sows seeds uniformly at proper distance/depth)
Traditional seed planting through pipes or funnels
Key steps in crop production cycle:
Soil preparation (ploughing and levelling)
Sowing
Adding manure and fertilizers
Irrigation
Protection from weeds
Harvesting
Storage
Transplantation: sowing seeds in a nursery and shifting healthy seedlings to the main field (e.g., Rice, Onion, Tomato, Brinjal, Chilli).
Soil Preparation
(a) Ploughing or tilling: loosening and turning the soil.
Advantages: mixes manure/fertilizer uniformly; aids germination; improves root penetration and respiration; promotes soil aeration; stimulates soil microbes and worm activity.
Implements:
Plough: has ploughshare (triangular iron strip) and a plough shaft (wood); operated by bullock pair and a person; indigenous ploughs being replaced by iron ploughs.
Hoe: removes weeds; loosens soil; blade-like iron plate at the end; pulled by animals.
Cultivator: tractor-driven; saves labor/time.
(b) Levelling: breaks down soil crumbs and smooths the field for uniform sowing and irrigation; advantages include uniform water/manure distribution and preventing erosion.
(2) Sowing: process of placing seeds in soil.
Seed quality: select healthy seeds; discard weak/insect-eaten seeds (healthy seeds sink, damaged float).
Methods: Broadcasting, traditional seed funnel with pipes, seed drill.
Transplantation and Seedlings
Transplantation: sown seeds are raised in nursery and transplanted to main field; helps select healthier seedlings. Examples: Rice, Onion, Tomato, Brinjal, Chilli.
Seed Spacing and Manuring
Question: Why sow seeds at correct distance? To avoid overcrowding and ensure adequate water, sunlight, nutrients; avoid waste of field space; go along with manure/fertilizer application.
Manure and Fertilizers:
Manure: organic substances from decomposition of plant/animal wastes; added to replenish soil nutrients; can be added before tilling; green manure refers to green plants ploughed into soil to turn into manure; examples of green manures include guar and sun hemp.
Vermicompost: manure produced by degradation of organic wastes via earthworms.
Compost: manure produced from plant/animal wastes via microbes.
Advantages of manure: increases friendly microbes, improves soil texture & humus, increases fertility and water-holding capacity, reduces erosion, cheap.
Disadvantages of manure: less nutrient-specific; bulky; hard to store/transport.
Earthworms: called farmer’s friend because their burrowing loosens soil and adds humus, improving soil structure.
Fertilizers: chemical nutrients, often nutrient-specific; types include nitrogenous, phosphatic, potassium, mixed (NPK, CAN, ammonium sulfate).
Advantages of fertilizers: nutrient-specific, water-soluble and readily absorbed, easy to store/transport.
Disadvantages of fertilizers: can alter soil microbe populations; overuse reduces long-term soil fertility; eutrophication can occur in water bodies due to runoff.
Common fertilizer examples:
Nitrogenous: urea, sodium nitrate
Phosphatic: ammonium phosphate, super phosphate
Potassium: potassium sulfate
Mixed: NPK, CAN (calcium ammonium nitrate)
Compost and vermicompost are considered organic fertilizers/manures.
Experiment: Effect of Manures and Fertilizers on Plant Growth
Aim: study effects on growth using seedlings such as moong or gram.
Method: three glasses A, B, C with similar soil seeds; A = soil + cow dung manure; B = soil + urea; C = soil only.
Observation: Seedlings with urea (B) show faster growth than A and C; A shows better growth than C.
Conclusion: fertilizers enhance growth; excessive use should be avoided to maintain soil fertility.
Maintaining Soil Fertility Without Fertilizers
Field fallow: leaving field uncultivated for a season.
Crop rotation: growing different crops in succession to replenish soil nutrients (e.g., legumes + wheat) and replenish nitrogen.
Biofertilizers: organisms that enrich soil nutrients through biological activity (e.g., Rhizobium bacteria; Nostoc and Anabaena blue-green algae).
Nitrogen fixation in legumes: roots have nodules hosting Rhizobium; nitrogen fixed by bacteria is used by host plant; plant provides shelter/food to bacteria.
Differences: Manures vs Fertilizers (summary): organic vs inorganic; nutrient quantity and specificity; solubility and mobility in water; environmental impact; storage/transport differences; field preparation differences.
Irrigation
Definition: artificial supplying of water to crops at intervals; varies by crop, soil, season.
Sources: wells, tube wells, ponds, lakes, rivers, canals, dams.
Traditional methods: moat (pulley system), chain pump, dhekli, rahat (lever system); cheaper but labor-intensive and less efficient; powered by diesel, biogas, solar, or electricity.
Modern methods:
Sprinkler system: rotating nozzles on upright pipes; distributes water uniformly; good for sandy soil and uneven land; efficient in canal-irrigated areas.
Drip (trickle) system: emitters release water drop by drop at roots; minimal waste; best for fruit crops, gardens, trees; often used with fertigation (fertilizer application through drip).
Drip is highly water-efficient and valuable in water-scarce regions.
Fertigation: applying fertilizers via drip irrigation.
Water-logging: standing water in fields due to excessive irrigation; roots suffocate; salinization can occur.
Advantages of irrigation: plants are ~90% water; supports germination, essential nutrient transport, frost and heat protection, and overall growth.
Other Indian irrigation systems: canals with distributaries, tanks, wells (digs and tube wells), river valley systems, river lift systems.
Soil type effects: clay soils retain water (less irrigation needed) vs sandy soils require more irrigation.
Organic Farming
Organic farming emphasizes avoiding harmful chemicals.
Relies on organic manures, biofertilizers, and biopesticides.
Protection from Weeds and Pests
Weeds: undesirable plants that compete for light, water, space, and nutrients; some can be poisonous to animals/humans.
Weeding methods:
Mechanical control: ploughing, burning before sowing, cutting weeds; khurpi (trowel) and seed drill used for uprooting.
Chemical control: applying weedicides or herbicides (e.g., 2,4-D, 2,4,5-T, MCPA, Butachlor, Atrazine).
Biological control: using living organisms to destroy weeds (e.g., Cassia plant against Parthenium; fish that feed on hydrilla).
Pesticides/biocides: chemicals to kill or control pests.
Types: Insecticides (for insects), Fungicides (for fungi).
Examples: DDT, Aldrin, Malathion (insecticides); Bordeaux/Burgundy mixtures, HgCl2 (fungicides).
Advantages: quick pest kill, increased production, ease of storage.
Disadvantages: soil and water pollution, residues on crops, non-target effects on beneficial organisms, potential long-term soil fertility reduction; excessive use causes environmental harm.
Preventive measures to avoid pesticide overuse:
Crop rotation, multiple cropping, field fallow
Sowing healthy seeds and summer ploughing
Pest/disease-resistant varieties
Physical protection from grazing animals (fences, walls)
Scarecrows and noise to deter birds
Health considerations for pesticide use: spraying requires protective masking to minimize inhalation exposure.
Harvesting, Threshing, and Storage
Harvesting: cutting/gathering crops when mature; can be manual (sickle) or mechanical (harvester).
Festivals often associated with harvest season (e.g., Baisakhi, Bihu, Onam, Pongal, Holi, Nabanya).
Harvesting machinery: cotton strippers, corn huskers, etc.
Threshing: separating grain seeds from chaff; can be done by threshers.
Combine harvester: harvests and threshes in one operation.
Winnowing: separating grain from chaff by wind/air action.
Chaff: seed coverings and small stems/leaves.
Storage basics:
Grains should be moisture-free and protected from insects, rats, and microorganisms.
Dry grains in the sun to reduce moisture.
Store in jute bags or metallic bins; silos or granaries with chemical treatment offer pest protection.
Neem leaves can be used for home grain storage.
Buffer stock: surplus grain preserved for emergencies (droughts/floods) by agencies like FCI and state warehousing.
Factors affecting stored food: biotic (insects, microorganisms, mites, birds, rodents) and abiotic (moisture, humidity, temperature).
Animal Husbandry: Branch Overview
Livestock: domesticated useful animals; major categories include cattle, poultry, pisciculture (fish farming), and apiculture (beekeeping).
Cattle farming: milk production and draught labor (tilling, irrigation).
Cattle feed components:
Roughage: high-fiber fodder and legumes.
Concentrate: cereals (maize, oats, barley, jowar, gram), rice polish, cotton seeds, gram bran; molasses; oilseed cake; soaked in water; protein-rich and digestible.
Poultry farming: rearing birds for eggs and meat.
Egg layers (egg production): layers; meat production birds: broilers.
Pisciculture (Fisheries): rearing fish on a large scale; fish are good sources of protein and oils; vitamin A and D.
Freshwater fishes: Catla, Rohu, Mrigal.
Marine fishes: Tuna, Cod, Pomfret, etc.
Hatcheries: fish eggs hatched; fries transferred to culture ponds.
Apiculture: beekeeping for honey and bee wax; apiaries are used for commercial honey production. Bee colony roles:
Queen bee: fertile female lays eggs.
Drone bee: male; fertilizes the queen.
Worker bee: infertile female; cares for young, collects nectar/pollen, makes honey.
Common livestock diseases and agents:
Foot-and-mouth disease: virus; affects cattle.
Anthrax: bacteria; affects cattle and humans.
Ranikhet (Newcastle) disease: virus; affects poultry.
Fowl cholera and fowl typhoid: bacteria; affects poultry.
Quick Review and Practice Prompts
Levelling a field after ploughing is often done to ensure uniform sowing and irrigation.
Healthy seeds can be separated from damaged seeds via floatation test (weak seeds float; healthy seeds sink in water).
A single agricultural implement that can be used for both harvesting and threshing is the combined harvester-thresher (often referred to as a combine).
Chapter At a Glance: Core Topics
Agricultural practices: soil preparation (ploughing/tilling, levelling), sowing (broadcast, seed drill), transplantation; manure and fertilizers (compost, vermicompost, farmyard manure, green manure; ammonium phosphate; potassium sulfate; NPK; urea; CAN).
Irrigation: traditional vs modern methods (sprinklers, drip, canal systems, tanks, wells, river valley systems, river lift systems).
Weeding: mechanical, chemical, biological controls; common weedicides and pests; pest/disease management strategies.
Harvesting, storage, and protection: harvesting methods and storage strategies (silos, granaries, buffer stock).
Animal husbandry: overview of cattle farming, poultry, pisciculture, apiculture; disease management.
Organic farming: emphasis on organic manures and biofertilizers; avoidance of harmful chemicals.
Basic terms: broadcasting, nomadic, germinate, seedling, cultivar, manual, decomposition, replenish, overcrowding, silos, granaries, organic, precaution, porous.
SOME BASIC TERMS (Glossary Highlights)
Broadcasting: sowing seeds manually.
Nomadic: involving a lot of moving from place to place.
Germinate: to start growing.
Seedling: young plant.
Cultivar: a plant variety cultivated by humans.
Manually: done by hand, not automatically.
Decomposition: breaking down into smaller parts.
Replenish: to replace what has been used.
Overcrowding: more plants/objects in a space than is safe or comfortable.
Silos: large cylindrical structures for storing grains.
Granaries: large buildings for storing grains.
Organic: derived from natural materials.
Precaution: measures to avoid problems.
Porous: allowing liquids or air to pass through.
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