UPSC Prelims 2012 · Question 98 of 98

UPSC Prelims 2012 question on Carbon Sequestration Farming Practices

Consider the following agricultural practices:

1. Contour bunding

2. Relay cropping

3. Zero tillage

In the context of global climate change, which of the above helps/help in carbon sequestration/storage in the soil?

  1. 1 and 2 only
  2. 3 only
  3. 1, 2 and 3
  4. None of them
Show answer

Answer: C. 1, 2 and 3

Verdict

Correct Answer: 1, 2 and 3

Analysis

Carbon sequestration means capturing and storing carbon, especially in soil and vegetation.

Agricultural practices that reduce soil disturbance, prevent erosion and increase biomass help store more carbon in the soil.

Statement by statement

1. Contour bunding — Correct

Contour bunding involves making bunds along the contour lines of a slope.

It reduces soil erosion and prevents loss of topsoil, which is rich in soil organic carbon.

It also improves water infiltration and supports vegetation growth, helping carbon storage.

2. Relay cropping — Correct

Relay cropping means sowing a second crop before the first crop is harvested.

It keeps the soil covered for a longer period and reduces soil degradation.

It also increases total biomass, root residues and organic matter addition to the soil.

3. Zero tillage — Correct

Zero tillage means growing crops without ploughing or with minimum soil disturbance.

Ploughing exposes soil organic matter to oxygen, increasing carbon loss as carbon dioxide.

Zero tillage keeps carbon stored in the soil and allows crop residues to decompose slowly.

Extra UPSC info

* Soil Organic Carbon is the carbon component of soil organic matter and is important for soil fertility.

* Soil and forests act as carbon sinks when they absorb more carbon than they release.

* Zero tillage is a key practice under conservation agriculture.

* Conservation agriculture is based on minimum soil disturbance, permanent soil cover and crop rotation.

* Climate-smart agriculture aims at productivity, resilience and emission reduction.

* Do not confuse carbon sequestration only with forests; agricultural soils can also store significant carbon.

How to crack it

All three practices help carbon sequestration by reducing soil erosion, maintaining soil cover, increasing biomass and preventing carbon loss from soil.

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