Improvement in Food Resources — Class 9 (CBSE)
India produces ~ 320 million tonnes of food grains a year, feeding 1.4 billion people. That's roughly 700 g of grain per person per day — and it comes from agricultural land that's been shrinking for decades. This chapter is about how Indian agriculture meets the challenge: better crop varieties, smarter farming techniques, dairy and poultry industries that now supply 25% of India's gross agricultural output.
1. The story — Green Revolution to Sustainable Agriculture
In 1960, India imported much of its wheat. Famine was an annual threat. By 1980, India was self-sufficient. By 2024, India is the world's largest exporter of rice and second-largest of wheat.
This transformation — the Green Revolution — was led by Indian agricultural scientists (M.S. Swaminathan, B.P. Pal) and Norman Borlaug. Key levers:
- High-yield variety (HYV) seeds.
- Fertilisers and pesticides at scale.
- Irrigation expansion.
- Mechanisation.
But the Green Revolution also created problems: soil degradation, groundwater depletion, pesticide pollution. Today's challenge is the Evergreen Revolution: produce more food with less land, water, and chemicals — sustainably.
This chapter is your introduction to the science behind both eras.
2. Crop variety improvement
Modern agriculture starts with the SEED. A good crop variety has:
- High yield — more grain/fruit/vegetable per hectare.
- Improved quality — better protein, oil, vitamin content.
- Biotic resistance — to pests (insects, nematodes) and diseases (bacteria, fungi, viruses).
- Abiotic resistance — to drought, salinity, waterlogging, heat, cold.
- Wider adaptability — performs across regions and seasons.
- Desirable agronomic traits — short stature (less wind damage), early maturity (more crops per year), responsiveness to fertiliser.
Methods to improve a crop variety
(a) Hybridisation — cross two genetically different parents to combine desirable traits.
- Intervarietal: cross two varieties.
- Interspecific: cross two species (e.g., wheat × rye → triticale).
- Intergeneric: cross two genera.
(b) Genetic modification (GM) — directly introduce desirable genes from any organism. Example: Bt cotton (carries a Bacillus thuringiensis gene for pest resistance).
(c) Selection — repeatedly pick the best individuals over generations.
(d) Mutation breeding — induce mutations (chemical, radiation) and select beneficial ones.
Examples of HYV varieties
- Wheat: Sonalika, Kalyan Sona (Green Revolution mainstays).
- Rice: Pusa Basmati 1, IR-8 (the "miracle rice").
- Pulses: PDM-54 (mung bean), KWR-30 (lentil).
3. Cropping patterns — getting more from the same land
How a farmer arranges crops in time and space affects yield, soil health, pest pressure.
(a) Mixed cropping
Two or more crops grown SIMULTANEOUSLY on the same land. Reduces risk: if one crop fails, the other survives. Example: wheat + mustard, soybean + maize.
(b) Intercropping
Two or more crops in DEFINITE ROW PATTERNS. Better than mixed cropping for harvesting and fertiliser management. Example: maize + soybean rows alternating; turmeric + maize.
(c) Crop rotation
Different crops grown in succession on the same land across seasons. Key benefits:
- Different crops use different soil nutrients — prevents single-nutrient depletion.
- Legumes (pulses) fix atmospheric nitrogen via root bacteria — restore soil N for the next crop.
- Breaks pest cycles.
Example rotation: rice → wheat → mungbean → rice (over 2 years).
(d) Seasonal cropping in India
- Kharif crops: sown in June (monsoon), harvested in October. Examples: rice, maize, soybean, cotton, groundnut.
- Rabi crops: sown in November, harvested in March-April. Examples: wheat, gram, peas, mustard.
4. Nutrient management — manure vs fertilisers
Plants need 16 nutrients. Macronutrients (large amounts): N, P, K, Ca, Mg, S. Micronutrients (small amounts): Fe, Cu, Zn, Mn, Mo, B, Cl. Carbon, Hydrogen, Oxygen come from air and water.
Manure
- Decomposed plant + animal waste.
- Rich in organic matter; provides N, P, K + micronutrients (in small amounts).
- Improves soil texture, aeration, water retention.
- Releases nutrients SLOWLY (over months).
- Made on the farm — cheap, sustainable, environmentally friendly.
Types: compost, vermicompost (using earthworms), green manure (plough a young leguminous crop back into the soil).
Fertilisers
- Manufactured (chemical) — concentrated single or multiple nutrients.
- Three main types:
- Nitrogen fertilisers: urea, ammonium sulphate. ~46% N in urea.
- Phosphorus fertilisers: superphosphate, DAP.
- Potassium fertilisers: muriate of potash (KCl).
- Released quickly → fast plant growth.
- Used in HYV cropping where soil natural fertility cannot keep up with high-yield demand.
Why combine both?
| Property | Manure | Fertiliser |
|---|---|---|
| Nutrient content | Low % (~1-2%) | Very high (~46%) |
| Soil structure | Improves | Doesn't (may degrade with overuse) |
| Release | Slow | Fast |
| Cost | Cheap | Expensive |
| Environmental load | Low | High (runoff causes eutrophication) |
Best practice: integrated nutrient management — manure to build long-term soil quality, fertiliser to give the boost a high-yielding crop needs.
5. Irrigation — water management
India is monsoon-dependent: ~70% of annual rainfall in 4 months. Without irrigation, only one crop per year is possible in most regions.
Sources of irrigation
- Wells (open and tube wells) — ~ 60% of irrigated land in India.
- Canals — from dams (Bhakra Nangal, Indira Gandhi Canal).
- Tanks and ponds — traditional South Indian system.
- River lift schemes — pump river water onto fields.
Modern irrigation techniques
- Drip irrigation: water drips at the root zone via narrow tubes. Uses 30-70% less water than flooding. Best for water-scarce regions.
- Sprinkler irrigation: water sprayed like rainfall. Used for level land with sandy soil.
- Furrow irrigation: water flows in narrow channels between rows. Common but wastes water.
Watershed management
Treating water as a community resource — building check dams, rainwater harvesting structures, contour ploughing — to recharge groundwater and prevent floods.
6. Crop protection — pests and weeds
Three classes of threats:
Weeds
Unwanted plants competing for sunlight, water, nutrients.
- Examples: Xanthium, Parthenium ("congress grass"), Cyperus.
- Control: manual weeding, mechanical (hoe), chemical (herbicides), preventive (clean seeds).
Insect pests
Insects that damage roots, stems, leaves, fruits.
- Examples: locust, aphids, stem borer in rice.
- Control: biopesticides (Neem oil, Bt spray), chemical insecticides, integrated pest management (IPM).
Diseases
Caused by bacteria, fungi, viruses.
- Examples: rust in wheat, blight in potato, mosaic virus in tobacco.
- Control: resistant varieties, fungicides, crop rotation.
Storage losses
After harvest, food is lost to:
- Rodents (rats, mice).
- Insects (weevils in grain).
- Fungi (mould).
- Moisture (rotting, sprouting).
Modern grain silos with controlled humidity and temperature reduce storage losses from ~ 25% (traditional) to ~ 5%.
7. Animal husbandry — cattle, poultry, fish
Half of Indian food comes from animals (dairy, meat, eggs, fish).
Cattle farming
India has the world's largest cattle population. Two categories:
- Milch animals (dairy): cows (Sahiwal, Red Sindhi, Jersey crosses), buffaloes (Murrah).
- Draught animals (work): bullocks for ploughing.
Care includes:
- Shelter — well-ventilated, well-drained, clean.
- Feed — roughage (fibre: straw, hay) + concentrate (grains for energy).
- Disease control — vaccinations against foot-and-mouth disease, anthrax, blackleg.
- Breed improvement — crossbreeding indigenous + exotic breeds to combine resilience + high yield.
Poultry farming
Eggs and meat (broilers).
- Layers = chickens kept for eggs (Rhode Island Red, Leghorn).
- Broilers = chickens for meat.
- Need temperature-controlled coops, balanced feed (protein 20-25%), vaccination.
Fish farming (aquaculture)
Two types:
- Capture fisheries — catching wild fish from sea/rivers.
- Culture fisheries — farming fish in ponds.
Composite fish culture: 5-6 species in one pond, each occupying a different ecological niche (surface feeders, mid-water, bottom). Maximises pond productivity.
Bee keeping (apiculture)
Bees produce honey + wax. Pollination of crops is the bigger economic benefit.
- Indian bee (Apis cerana indica) — gentle but lower yield.
- Italian bee (Apis mellifera) — high yield, used commercially.
8. Sustainable agriculture — the future
Modern challenges:
- Soil degradation from over-fertilisation.
- Groundwater depletion (Punjab, Haryana water tables falling 1 m/year).
- Pesticide pollution.
- Climate change affecting rainfall patterns.
Solutions being adopted:
- Organic farming: no synthetic fertilisers/pesticides, certified by Indian organic agencies.
- Precision agriculture: GPS-guided sowing, satellite monitoring, drone spraying — minimise waste.
- Vertical farming: stacked indoor farms with LED lighting, hydroponics. Land-efficient but energy-intensive.
- Climate-resilient crops: heat-tolerant wheat, salt-tolerant rice (developed by CRRI Cuttack).
- Watershed-based agriculture: holistic management of land, water, vegetation.
9. Closing thought
Agriculture is the only industry on Earth that captures solar energy at scale and converts it into food. India's farmers, working an area smaller than the average American farm's 200+ acres (most Indian farms < 2 hectares), still feed 1.4 billion people.
The science you've learned in this chapter — crop genetics, soil nutrients, water management, animal husbandry — is what makes that possible. The next generation's job is to do it sustainably: producing more from less, while protecting the soil and water for future generations.
The Green Revolution fed India for 50 years. The next 50 years will require an Evergreen Revolution — and you'll be part of designing it.
