FST -1

21st Part 

Q.  How the application of scientific knowledge has made agriculture possible in arid zones, drylands, and hills?

A.  The advancements in our scientific knowledge have now enabled us to practice agriculture in arid zones, drylands, and hills.

 Arid Zones  - The chief arid areas of our country are confined to Rajasthan, Gujarat, Haryana, Karnataka, and Ladakh. They cover an area of about 400,000 square kilometers. Of this, Ladakh has a cold desert spread over 70,000 square kilometers.

           Here, aridity and low temperature limit the agricultural season to about five months in a year. Therefore, crops that require a short period to mature and can withstand severe cold are grown. These are some cereals, oil seeds and fodder crops. In the hot desert regions, of Rajasthan, Gujarat, and Haryana, there is an abundance of sunshine which causes high rate of evaporation. Many of these areas have adequate reserves of ground-water which is scientifically tapped for irrigation. In the arid zone fruit trees like ber and pomegranate and fuel-wood yielding trees like Acacia (Kikar), Prosopis (Mosquite) and Eucalyptus (Safeda) are grown. In such areas, large scale planting of shelter-belts minimizes soil erosion caused by wind. It also helps in the establishment of pastures and grazing lands. Later on, this land is used for growing pearlmillet and mungbean.

Dry Lands - Drylands constitute about 74% of our cultivated lands and produce about 42% of our food. These are entirely rain-dependent and crop fortunes are closely linked to the vagaries of the monsoon. Sometimes rains may set in very early or very late or may come on time but withdraw too soon. There may also be large breaks between showers. When evaporation and loss of water by seeping in the soil exceeds rainfall, these lands are plagued by drought, scarcity of drinking water and thus crop failure. Rain water is collected in ponds to support agriculture. In Dry lands with red soil, deep ploughing helps in conserving water while In black soils, sowing two crops at a time is possible with surface drainage and good water management. Leaves and crop residues, when mixed with soil improve its texture, and water holding capacity. Crops like pigeonpea and castor that have deep roots, are cultivated in these regions which improves the physical condition of the soil further, as the roots of these crops add organic matter. Varieties of sorghum, millets, sunflower, safflower, mustard, groundnut, various pulses and cotton are available which grow within a shorter time withstanding scarcity of water and also diversifying crops in dry lands. A variety of crops and cropping patterns allow the farmer to make a proper choice of what to grow in different climates and soil types.

Hills - Based on a study of the slope and depth of the soil, and availability of water, scientists have devised an interesting agricultural system that requires low inputs and puts the land to most productive use without disturbing the ecosystem. Under this system, the upper reaches of the hills are devoted to forestry. The next zone is developed for growing fruit trees, perennial fodder grass and legumes. The roots of legumes fix nitrogen and improve the soil. In the third zone, a mix of crops are raised on terraces constructed with low-cost implements. Earthen dams are constructed with locally available material. These collect enough water to be utilized for irrigation.

Q.  Make a table showing the protein and energy contents of 10 common food. 

A.   Energy and Protein Contents of Some Common Foods

Foodstuffs                 Energy (Cal/100g)                       Proteins (g)

Cereals                              340                                         10-13

Pulses and Legumes         345                                         20-25

Soyabean                          430                                           43

Milk-Buffalo                    120                                           4.3

Cow                                  70                                            3.2

Paneer                              264                                          18.3

Egg                                  170                                           13.3

Potatoes                            95                                            1.6

Meat                                200                                           18.5

Fish                                 100                                           14.9

Q.  Deliberate upon the recent technological developments in the energy sector giving appropriate examples.

A.  The energy sources available in India are fossil fuels (like lignite, coal, and petroleum) the sun, wind, geothermal energy (for example, hot springs) water (hydro-electric power). The demand for energy doubles every 14 years and is taken as one of the indicators of development of a country. Many technological developments are shaping the energy sector in a new way by using technology to harness the energy of resources available which was not earlier possible. Some of these sources of energy are- 

Solar Energy - With the help of photocells, solar energy is harnessed. Solar energy is used directly to give us hot water during winter or run a refrigerator. It is also used for heating rooms in colder regions. Photocells are used to produce electricity for driving vehicles and illumination of streets. In a desert like Rajasthan, the earth's surface receives solar energy at the rate of 200 watts per square meter per hour. Since this feature of using solar energy is that it can be generated where needed. Solar cookers are being used in many homes to cook food now. 

Wind Energy - Like solar energy, wind flow can also be harnessed to obtain mechanical energy for fetching water from the wells or from rivers. Once the windmill is turning due to the force of the wind, it may as well run a generator to get electrical energy. In the coastal and hilly regions, where the wind blows at high speed, a windmill can be used for the supply of electricity to a small town.

Wave and tidal energy -  Waves and tides are other sources of energy which is perpetual and can be converted into electric energy, particularly where seawater can move into a narrow cut, such as is provided naturally where rivers flow into the sea. The energy carried is used in India's hilly regions when a wheel with pedals can be made to turn when it is put in a fast-flowing stream. Flour mills of small size built on this principle were used in Kashmir. Here a natural or artificial water fall is made to turn turbine blades which when rotates generates electricity. Large hydroelectric power stations work on the same principle for generating electricity.

Geothermal Energy -

Hot water and super heated steam of hot springs are a natural phenomenon and is used to generate electricity. In our country, there arc 46 hydrothermal areas where the temperature of the spring water exceeds 150°C. These hot springs can be used to generate electricity for heating homes, or glass-houses to prow vegetables.

Atomic energy -

In view of the fast depletion of our non-renewable resources like coal and petroleum, and because of pollution which power stations burning coal causes efforts are underway to construct Atomic reactors to produce electricity. With the energy of the atom controlled in nuclear fission reaction, the energy and heat produced during the bombardment of atoms of U235 is channelized for electricity generation. The device used for this purpose is called an atomic reactor. Nuclear reactors produce heat, which is commonly used to raise steam, which rotates turbines and thus generates electric power. It is estimated that 1 kg of natural uranium generates energy equal to that produced by 35,000 kg of coal. Thus the production of energy from nuclear fuel like uranium is efficient, and since great loads of coal or diesel are not consumed daily this energy is convenient. 

Biogas -

Cattle dung for the production of biogas which is used for cooking. Water weeds like water hyacinth, water lettuce, Salvinia, hydrilla, duckweeds, and algae are found to be a useful supplement to cattle dung. Biogas can be used not only as cooking gas, it can also be used to raise steam, which can be used for running engines or machines in the factories or for running turbines to generate electricity. It has been found that large biogas plants can supply the needs of a number of families or even small villages. What is left over after generating the gas, can be used as manure. Hence this is also an economical way of getting more energy. Great efforts are being made to install tens of thousands of biogas plants in rural areas as it is one of the efficient ways of generating electricity.

Q.  ‘Science and technology do not exist independent of the society, its culture and value system. They are part of the socio-economic and political framework of a given society’. Analyze this statement by giving suitable examples. 

A.   As science and technology provide all the necessities as well as many of the ideas that hold our society together, society itself provides the environment and the atmosphere for science and technology to either grow fast or stagnate or even decay. Science and technology do not exist independent of the society, its culture and the value system. They are a part of the socio-economic and political framework of a given society. Motivation for the practical application of science and, hence, its growth and use comes from the economic needs of the society. The economic planning and policy of a society determine its social programmes and the purposes and goals of society's production activity, which in turn provides the incentive for scientific growth. However, answers to questions like what kind of economic policy will be pursued, whether the social programmes will be implemented, and to what extent, depends on the political and social organization of a society. Thus, science and technology can be more directly influenced by the general policies and social structure of a society. For example, when economic growth is purely determined by market demands, artificial demands for goods are created by advertising, even though there is no pressing need for them.
            Ideas of people are sought to be moulded by propaganda carried on by radio or television or even by education. The competition to produce more goods, increase profits or the desire to provide fancy goods to an influential section of population results in one kind of development of science and technology. On the other hand, if society desires and plans to improve rural life or give priority to public health or provide a certain level of nutrition to all citizens, the tasks and consequent development of science and technology should follow a different path. Still another example is the question of spending money on weapon of offense or defense that naturally affects science and technology.
             It is known that the world today is annually spending Rs. 15 lakh crores on weapons and their development. This not only takes away money needed to feed, clothe or provide health and shelter to people, but it also prevents the development of science and technology for constructive purposes. We can conclude that science and technology are part and parcel of a larger social system, whose other components are industry, agriculture, trade, distribution of goods, communication, education, government, and administration, etc. 
            Science and technology cannot be advanced by viewing them in isolation. The whole social, economic and political system will have to work in unison so that all round advancement can take place. In the end, we can say that science influences the entire social edifice, the material as well as ideological, and in turn science itself is influenced by society and its objectives. Before any project is taken up, its positive, as well as negative aspects, the effect it will have on human beings and the environment, must be properly evaluated. "Social good" must have primacy in the overall planning and the use to which science and technology is put.