Which one is not the major technique of soil conservation?

The correct answer is D, Shelter belts. A shelter belt is a row or a block of trees and shrubs planted across the direction of the prevailing wind. It breaks the force of the wind before it reaches the field, and because wind erosion is the dominant form of soil loss in dry regions such as western Rajasthan and along open coasts, shelter belts are the measure chosen there; they also check the advance of sand dunes. A is wrong because contour ploughing runs furrows along the contour of a slope to hold back running water, so it answers water erosion on sloping land, not wind. B is wrong because terrace farming cuts a hill slope into level steps and is used in hilly and mountainous country such as the Himalayas and the Nilgiris, not in flat coastal or arid plains. C is wrong because mulching covers bare soil with straw or crop residue to reduce evaporation and splash erosion; it is a useful supporting practice but it is not the method specifically associated with coastal and dry regions.

The correct answer is B, 1994. The United Nations Convention to Combat Desertification was adopted at Paris on 17 June 1994 and it entered into force in December 1996. It is the only legally binding international agreement that links environment and development to sustainable land management, and it is counted as the third of the three Rio Conventions. A is wrong because 1992 is the year of the Earth Summit at Rio de Janeiro, where the UNFCCC and the Convention on Biological Diversity were opened for signature and where governments only agreed to negotiate a desertification treaty. C is wrong because 1996 is the year the Convention entered into force and the year India ratified it, not the year of adoption; candidates are regularly trapped by this pair. D is wrong because 2001 is the year of India's National Action Programme to Combat Desertification, a national plan made under the Convention.

The correct answer is B, 17 June. The day marks the anniversary of the adoption of the United Nations Convention to Combat Desertification at Paris on 17 June 1994, and the United Nations General Assembly declared it in the same year so that governments would review progress on land restoration annually. A is wrong because 5 June is World Environment Day, instituted after the Stockholm Conference of 1972 and first observed in 1973. C is wrong because 22 April is International Mother Earth Day, which grew out of the first Earth Day held in the United States in 1970 and is not a United Nations convention anniversary. D is wrong because 16 September is the International Day for the Preservation of the Ozone Layer, which marks the signing of the Montreal Protocol in 1987. Keeping these four June and April dates apart is a frequent one-mark question in SSC and railway papers.

The correct answer is C, Cadmium. Itai-itai, which means ouch-ouch in Japanese, was first recorded in the Jinzu river basin of Japan, where mine waste put cadmium into irrigation water and then into rice grown in the contaminated soil. Cadmium weakens the bones and damages the kidneys, so the softened bones fracture easily and cause the severe pain that gave the disease its name. Phosphatic fertiliser carries cadmium as a natural impurity, which is why overuse of fertiliser is a soil pollution concern. A is wrong because lead poisoning, or plumbism, causes anaemia and damage to the nervous system, especially in children. B is wrong because mercury causes Minamata disease, also named after a place in Japan, which affects the nervous system and was traced to industrial effluent in a bay. D is wrong because arsenic causes skin lesions, hyperkeratosis and black-foot disease.

The correct answer is B, New Delhi Declaration. India hosted the fourteenth Conference of the Parties to the UNCCD at Greater Noida near New Delhi in 2019, and the meeting closed with the New Delhi Declaration, in which the parties committed themselves to restoring degraded land and to working towards Land Degradation Neutrality. India used the same platform to announce that it would restore 26 million hectares of degraded land by 2030. A is wrong because the Rio Declaration on Environment and Development came out of the Earth Summit of 1992 and set out twenty-seven principles including the precautionary principle. C is wrong because the Nagoya Protocol of 2010 belongs to the Convention on Biological Diversity and deals with access to genetic resources and benefit sharing. D is wrong because the Bonn Challenge is a voluntary global forest landscape restoration target launched in 2011, not a declaration adopted at this conference.