Insights Static Quiz -325, 2019–Environment

Solution: b)

• Desertification is the degradation of land in arid, semi-arid and dry sub-humid areas. It is caused primarily by human activities and climatic variations. Desertification does not refer to the expansion of existing deserts.
• It occurs because dryland ecosystems, which cover over one third of the world‘s land area, are extremely vulnerable to overexploitation and inappropriate land use.

Established in 1994, the United Nations Convention to Combat Desertification (UNCCD) is the sole legally binding international agreement linking environment and development to sustainable land management. The Convention addresses specifically the arid, semi-arid and dry sub-humid areas, known as the drylands, where some of the most vulnerable ecosystems and peoples can be found.

Source

Solution: c)

• India has witnessed increase in the level of desertification in 26 of 29 states between 2003-05 and 2011-13, according to the State of India’s Environment (SoE) 2019 in Figures.

• More than 80 per cent of the country’s degraded land lies in just nine states: Rajasthan, Maharashtra, Gujarat, Jammu and Kashmir, Karnataka, Jharkhand, Odisha, Madhya Pradesh and Telangana.
• Top three districts with highest area under desertification or land degradation are Jaisalmer, Rajasthan (92.96 per cent during 2011-13 and 98.13 per cent during 2003-05), Lahaul and Spiti, Himachal Pradesh (80.54 per cent during 2011-13 and 80.57 per cent during 2003-05) and Kargil, Jammu and Kashmir (78.23 per cent during 2011-13 and 78.22 per cent during 2003-05).

Source

Solution: c)

Main reasons that cause desertification in India are:

• Water erosion (10.98 per cent)
• Wind erosion (5.55 per cent)
• Human-made/settlements (0.69 per cent)
• Vegetation degradation (8.91 per cent)
• Salinity (1.12 per cent)
• Others (2.07 per cent)

Source

Solution: b)

Eutrophication is when a body of water becomes overly enriched with minerals and nutrients which induce excessive growth of algae. This process may result in oxygen depletion of the water body. One example is an “algal bloom” or great increase of phytoplankton in a water body as a response to increased levels of nutrients.

Eutrophication is often induced by the discharge of nitrate or phosphate-containing detergents, fertilizers, or sewage into an aquatic system.

Solution: d)

A biofertilizer is a substance which contains living microorganisms which, when applied, colonize the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant.

There are five biofertilizers viz. Rhizobium, Azotobacter, Azospirillum, Phosphate Solubilizing Bacteria and mycorrhiza, which have been incorporated in India’s  Fertilizer Control Order (FCO), 1985.

Rhizobium, Azotobacter, Azospirillum and blue green algae (BGA) have been traditionally used as Biofertilizers. Blue green algae such as Nostoc, Anabaena, Tolypothrix and Aulosira fix atmospheric nitrogen.