Land degradation

Topic: Environment and Sustainable Development · NCERT: Class 11, Ch 7 "Environment and Sustainable Development"

Meaning

Land degradation is a fall in the quality of land. The land becomes less fertile, loses its topsoil, turns salty or waterlogged, or turns into desert.

It matters because India carries a very heavy load on very little land. It has ~17% of the world's population and ~20% of its livestock on only 2.4% of the world's land (NCERT rounds this to 2.5%). NCERT lists land degradation first among India's five priority environmental issues.

Pressure ratio = share of world population ÷ share of world land = 17 ÷ 2.4 ≈ 7

Explanation

Forms of land degradation

• Loss of fertility: the soil loses nutrients, so crops yield less.
• Soil erosion: rain washes away the topsoil, or wind blows it away.
• Salinity and waterlogging: salt builds up in the soil, or water stands in the field. Both usually come from badly planned irrigation.
• Desertification: land turns into desert.

NCERT's 12 causes

Remember the causes in three groups.

• Forest-related 1. Deforestation (clearing forests for farms, fuelwood, mining and industry). It also releases the carbon stored in trees. 2. Taking more fuelwood and fodder than forests can regrow. 3. Shifting cultivation (clear a forest patch, farm it for a few years, then move on). When the gap before farmers return gets shorter, the soil cannot recover. 4. Encroachment (illegal occupation) of forest land. 5. Forest fires and overgrazing (too many animals grazing the same land).

• Farming practices 6. No soil conservation measures. 7. Poor crop rotation. Growing the same crop again and again drains the same nutrients. 8. Heavy use of agro-chemicals (chemical fertilisers and pesticides). 9. Poor planning of irrigation, which causes waterlogging and salty soil. 10. Pumping groundwater faster than rain refills it.

• Economic and social 11. Open access resources (resources that anyone can use and nobody owns, such as village commons). 12. Poverty of people who depend on farming.

Why open access and poverty make it worse

• Tragedy of the commons (cause 11)
• A user of a village common gets the full gain from using it more.
• The damage is shared by everyone.

• So everyone overuses it, and the common land is destroyed.

• Poverty-induced degradation (cause 12)

• Poor families have no other income or fuel, so they overuse land, forests and fuelwood.
• Soil and grazing land get worse, and the land yields less.
• The families become poorer still. Each problem makes the next one worse, so this is a vicious circle.

Worked example: the forest gap

• Forest land per person: 0.06 ha available against 0.47 ha needed.
• 0.06 ÷ 0.47 ≈ 13%. So each person has only about one-eighth of the forest they need.
• The gap is 0.47 − 0.06 = 0.41 ha per person. Overuse fills this gap.
• Result: about 15 million m³ of forest is cut beyond the permissible limit.

In India

• Soil erosion: about 5.3 billion tonnes of topsoil is lost each year. This removes 5.8-8.4 million tonnes of nutrients a year (GoI estimate).

• Watch out: NCERT's figures (N 0.8 + P 1.8 + K 26.3 Mt) add up to 28.9 Mt, which does not match. Use the GoI range in the exam.

• Desertification and Land Degradation Atlas: the Space Applications Centre, ISRO, Ahmedabad published it in 2021, using data for 2018-19.

• It found that 97.85 million ha, or 29.77% of India's geographical area, is affected by land degradation and desertification [3][4].

• Restoration pledge: PM Modi announced it at UNCCD COP14, New Delhi (2019). India will restore 26 million ha of degraded land by 2030 [5].

• The target is linked to Land Degradation Neutrality (LDN). This means any new degradation is balanced by restoration, so net degradation is zero [4].
• Progress: 21.76 million ha is under restoration (Bonn Challenge) [6].

• Worked example: 21.76 ÷ 26 ≈ 84% of the target is covered.

• Forest cover, ISFR 2023 (India State of Forest Report, by the Forest Survey of India):

• Forest and tree cover is 8,27,357 sq km, or 25.17% of geographical area. Forest cover is 21.76% and tree cover is 3.41% [2].
• Forest and tree cover rose by 1,445 sq km over ISFR 2021. Of this, 156 sq km was forest cover and 1,289 sq km was tree cover [2].

• So most of the gain is in tree cover (trees outside recorded forests), not natural forest.

• Global link: SDG 15 (Life on Land) under the SDGs (2015-2030).

Don't confuse with

• Desertification: this is one form of land degradation, where land turns into desert, mainly in dry areas. Land degradation is the wider term. It also covers erosion, salinity, waterlogging and loss of fertility in any climate.
• Deforestation: this is a cause of land degradation (NCERT cause no. 1), not the same thing. One is loss of trees; the other is a fall in land quality.
• Land Degradation Neutrality vs zero degradation: LDN allows new degradation as long as an equal area is restored, so the net change is zero. It does not mean no land ever degrades.
• Forest cover vs tree cover: forest cover (21.76%) and tree cover (3.41%) together make up 25.17% [2]. Most of the recent gain is in tree cover, which does not mean natural forests are recovering.

Prelims Hooks

• ISRO Desertification and Land Degradation Atlas (Space Applications Centre, Ahmedabad; released 2021, data for 2018-19): 97.85 mha, or 29.77% of India's area is degraded [3][4].
• India's pledge: restore 26 mha by 2030, announced at UNCCD COP14, New Delhi, 2019 [5]. So far, 21.76 mha is under restoration [6].
• Trap: "21.76" appears twice. It is 21.76% forest cover (ISFR 2023) and also 21.76 mha of land under restoration [2][6].
• Open access resources → tragedy of the commons is NCERT cause no. 11 of land degradation.
• Soil erosion is about 5.3 billion tonnes a year. For nutrient loss, use the GoI range of 5.8-8.4 Mt, not NCERT's N+P+K total.
• India has ~17% of the world's population and ~20% of its livestock on 2.4% of the world's land (NCERT: 2.5%). The pressure ratio is about 7.

Mains Points

• Poverty and degradation feed each other:
• Poor families overuse fuelwood, fodder and commons, so the land yields less and the families get poorer.
• Fines and bans alone will not work. People need other sources of fuel, fodder and jobs, for example LPG to cut fuelwood use and MGNREGA work on land and water.

• Village commons need community rules so they stop being open to everyone without limit.

• Farm policy drives degradation:

• Heavy use of agro-chemicals, the same crop grown year after year, and poorly planned irrigation cause salty, waterlogged and nutrient-poor soil.
• Soil erosion strips 5.8-8.4 Mt of nutrients a year, which lowers yields and farm incomes.

• Fixes: crop rotation, balanced fertiliser use, soil conservation and better irrigation planning.

• LDN and SDG 15:

• Nearly 30% of India's land is degraded [3], and forest-cover gains are mostly outside natural forests [2].
• India has covered about 84% of its 26 mha restoration target [5][6]. The real test is the quality of restoration (soil, natural forest) and not just the area.

Related concepts

• Poverty-induced degradation and pollution from affluence
• Deforestation
• Soil erosion
• Open access resource
• Biodiversity loss
• Air pollution
• Industrial pollution
• Water pollution
• Groundwater overuse
• Virtual water

Read more

• State of India's environment: the dichotomy and the five priority issues