Soil conservation: methods by terrain

Detail

What soil conservation means

• Soil conservation means looking after soil so that it does not wash or blow away (erosion) or lose its quality (degradation), and stays fertile.
• Why it matters:
• In 2018-19, 97.84 million hectares of India's land was degraded or turning into desert [2][3].
• This is about 29.77% of India's total geographical area [4].
• The figure comes from the Desertification and Land Degradation Atlas of India. The Space Applications Centre (SAC), ISRO, Ahmedabad, published it in June 2021 [2].

• The Atlas gives the degraded area for each state in 2018-19. It also tracks change over 15 years, from 2003-05 to 2018-19 [2].

• Basic idea: every method works on one or more of three causes of erosion.

• It slows running water (contours, terraces, bunds, trenches).
• It breaks the force of wind (strip cropping, shelter belts).
• It keeps a cover of plants or crop waste on the soil (afforestation, cover crops, mulching, residue retention).

NCERT methods (Class 10)

1. Contour ploughing

• Contour line: a line on a slope that joins points of the same height.
• Contour ploughing means ploughing along these lines, across the slope, not up and down it.
• How it works:
• Each furrow (the groove made by a plough) runs across the slope and acts as a small barrier.
• Rainwater cannot rush straight downhill, so it slows down.

• Slower water carries away less topsoil and has more time to soak in.

• Where: gently sloping farmland in hill areas and on the uneven Deccan plateau.

2. Terrace farming (terracing)

• Terrace farming means cutting wide, flat steps into a hillside so that crops can grow on level fields.
• How it works:
• A steep slope is broken into many small flat strips.
• Water stands on each step instead of running down the whole slope.

• This means less erosion and more water soaking into the soil.

• Where in India: well developed in the western and central Himalayas. The Class 7 NCERT photograph shows terraces in Uttarakhand.

• Northeast (Class 11): NCERT says terrace farming should replace jhum to reduce landslides.
• Jhum is shifting cultivation, or slash-and-burn farming. A forest patch is cleared and burnt, farmed for a few years, then left.

• Jhum leaves steep slopes bare. Terraces hold the soil in place.

• Where in the world: the rice terraces of the Philippine Cordilleras (Ifugao), Indonesia, southern China and the Andes in Peru.

3. Strip cropping

• Strip cropping means dividing a large field into strips. Strips of grass are left to grow between the strips of crops.
• How it works: wind blowing across a bare field picks up loose soil. The grass strips break the force of the wind and trap soil that is moving.
• Where: windy, dry farmland, for example in Rajasthan, Gujarat and Haryana.

4. Shelter belts

• Shelter belt: rows of trees planted as a windbreak, a barrier that slows the wind.
• How it works:
• Trees cut the wind speed close to the ground.
• Slower wind cannot lift sand or topsoil.

• Moving sand dunes slowly become fixed.

• Result in India: shelter belts have helped to stabilise sand dunes and the desert in western India (the Thar, in Rajasthan).

• Class 7 link: the NCERT photograph of bananas grown on a bund shows a windbreak that also gives a crop.

Other NCERT measures by land use

• Arid areas:
• Control overgrazing, which removes grass cover.

• Fix dunes by planting thorny bushes.

• General: afforestation (planting trees on bare land) and grazing management.

• Mining and industrial areas:
• Control the area that mining is allowed to damage.
• Treat effluents (liquid industrial waste) and solid wastes before they are released.

Beyond NCERT: watershed and dryland measures

Watershed: the whole area that drains into one stream or river. Treatment begins at the ridge (the highest part) and works down to the drainage line (the stream channel).

5. Contour bunding

• Bund: a low wall of earth.
• Contour bunding means building earthen embankments along the contours of sloping fields.
• How it works: each bund stops the water flowing down the slope. The water stays behind the bund, soaks in, and leaves its silt in the field.
• Where: common in Deccan dryland farming (Maharashtra, Karnataka, Telangana), on black and red soils.

6. Continuous contour trenches (CCT)

• Continuous contour trench: a long ditch dug along a contour on a hill slope. The dug-out soil is piled on the downhill side.
• How it works:
• Rain running down the slope falls into the trench.
• The trench slows the water and holds it.

• The water then soaks into the ground (infiltration) and refills groundwater.

• Model villages: Ralegan Siddhi and Hiware Bazar, both in Ahmednagar (now Ahilyanagar) district, Maharashtra. Both are examples of village-led watershed work.

7. Check dams, gully plugging and ravine reclamation

• Gully: a deep channel cut by running water.
• Ravine: a large network of gullies. The best-known example is the Chambal ravines in Madhya Pradesh, Rajasthan and Uttar Pradesh.
• Gully plugging: small walls of stone or earth are built across a gully. The water slows down, drops its silt, and the gully fills up over time.
• Check dam: a small barrier across a stream. It holds water for a while and recharges the soil and groundwater.
• Ravine reclamation: gullies are levelled and trees and grass are planted on them.

8. Farming practices that protect soil

Practice	What it is	How it protects soil
Crop rotation with legumes	Growing pulses (gram, moong) between cereal crops	Legumes add nitrogen to the soil, so fertility comes back
Cover crops	Crops sown to keep the ground covered between main crops	No bare soil is left for rain or wind to carry away
Mulching	Covering the soil with straw, leaves or plastic	Keeps moisture in and reduces the force of raindrops
Zero tillage with residue retention	The next crop is sown without ploughing, and crop stubble is left on the field	Keeps soil structure and organic matter; an alternative to stubble burning in Punjab and Haryana

Government programmes

• PMKSY-Watershed Development Component (WDC-PMKSY)
• This is the watershed part of the Pradhan Mantri Krishi Sinchayee Yojana (PMKSY).
• It treats rainfed and degraded land. Its work includes soil and moisture conservation, rainwater harvesting and livelihood activities [4].

• Its activities include ridge area treatment, drainage line treatment, nursery raising, pasture development, and livelihoods for people who own no assets [4].

• WDC-PMKSY 2.0

• It started in December 2021, for 2021-26 [4].
• Central allocation: ₹8,134 crore. Target: 4.95 million hectares [4].
• In 2021-22, 1,150 projects were sanctioned. Together they cover about 50 lakh hectares and cost ₹12,303 crore [4].
• About 29 million hectares of the roughly 97 million hectares of degraded land had been covered under watershed projects [4].

• In January 2025, 56 new watershed projects worth about ₹700 crore were approved [5].

• National Mission for Sustainable Agriculture (NMSA): one of the missions under India's National Action Plan on Climate Change (NAPCC). It promotes soil health and dryland farming.

Terrain-wise summary

Terrain	Main problem	Main measures	Indian example
Hills	Water erosion on steep slopes, landslides	Terracing, contour ploughing, continuous contour trenches, afforestation	Uttarakhand, Himachal Pradesh, Northeast (instead of jhum)
Plateaus and drylands	Runoff on bare, gentle slopes	Contour bunding, check dams, mulching	Deccan: Maharashtra, Karnataka
Deserts	Wind erosion, moving dunes	Shelter belts, fixing dunes with thorny bushes, grazing control, strip cropping	Thar, western Rajasthan
Canal command areas (land watered by a canal)	Waterlogging (land stays soaked) and salinity/alkalinity (salt builds up at the surface)	Drainage, canal lining (to stop seepage), gypsum (to treat alkaline soils)	Indira Gandhi Canal area (Rajasthan), Punjab, Haryana
Ravines	Gully erosion	Gully plugging, plantation	Chambal valley (MP, Rajasthan, UP)
Mining areas	Spoil heaps (waste rock and earth) and toxic waste	Mining control, treatment of effluents and wastes	Jharkhand, Odisha, Chhattisgarh mining belts

Prelims Hooks

• Contour ploughing = ploughing across the slope, along lines of equal height. It is not ploughing up and down the slope.
• Terrace farming is well developed in the western and central Himalayas. NCERT recommends it in place of jhum in the Northeast to reduce landslides.
• Strip cropping fights wind erosion: grass strips grow between crop strips. It is not a method against water erosion on slopes.
• Shelter belts stabilised sand dunes in western India (the Thar).
• Contour bunding = earthen embankments along contours. It is typical of Deccan dryland farming.
• Ralegan Siddhi and Hiware Bazar are model watershed villages in Maharashtra (Ahmednagar district).
• Gypsum is used to treat alkaline (usar) soils in canal command areas.
• The Desertification and Land Degradation Atlas of India is published by SAC-ISRO, Ahmedabad. It puts degraded land at 97.84 Mha (2018-19), about 29.7% of India's area [2][3][4].
• WDC-PMKSY 2.0 runs for 2021-26 and targets 4.95 million hectares [4].
• Trap: zero tillage with residue retention is a soil conservation practice. Stubble burning, which it replaces, destroys organic matter.

Mains Points

• Match the method to the terrain.
• Water erosion on slopes needs barriers that slow water (terraces, bunds, trenches).
• Wind erosion in deserts needs barriers that break wind (shelter belts, strip cropping).
• Canal command areas need drainage. Their problem is too much water and salt, not too little.

• A single national formula fails. Treating a whole watershed, from ridge to valley, works best.

• Scale of the problem (GS-III).

• About 97.84 Mha was degraded in 2018-19 [2][3].
• About 29 Mha had been covered under watershed projects [4].

• This makes WDC-PMKSY 2.0 central to India's land-restoration effort.

• Community-led success.

• Ralegan Siddhi and Hiware Bazar used trenches, check dams, a ban on grazing and a ban on cutting trees.
• Groundwater and crop yields recovered.

• Lesson: villagers' participation is as important as engineering.

• Linkages.

• In the Northeast, terracing in place of jhum reduces landslides (disaster management).
• In Punjab and Haryana, zero tillage with residue retention reduces stubble burning and air pollution.
• Shelter belts check the spread of desert in Rajasthan.