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Contour strip farming: Forming by planting several crops, such as corn, wheat, and clover, in alternating strips across a slope or across the path of the prevailing wind.

Dyke Management: Dykes or barriers, nearly 30 cm thick of brick – cement or stone cement barriers, extending down to the compact bedrock with mud or clay fillings were built in underground streams to tap groundwater optimally.

Desert Soils: These soils cover 2 lakh sq. km. area in dry areas of Rajasthan, Gujarat, Punjab, Haryana. These coarse soils are suitable for the cultivation of jawar, bajra, cotton, oats, maize, pulses etc. Methods of irrigation are used. These are sandy soils and are infertile. These do not hold water. So these are used for dry crops. In India 4.3% area is covered by desert soils.

Desert soils are found in Rajasthan, Punjab, Haryana and in some parts of Gujarat.

4Rs means – Reduce, Reuse, Recharge or Regenerate and Research. 

1. Reduce: It refers to minimizing the use of resources and their wastage or trying to use less amount of any resource. For example, we can reduce air pollution by reducing the use of our vehicles. 

2. Reuse: Every resource has not only alternative uses but can be used multiple times. For e.g., the water that was used for bathing can be used for gardening. 

3. Recharge and Regenerate: This refers to taking steps to allow and resource to grow through conscious human efforts. E.g., Afforestation recharges tree stock and the bio-diversity. 

4. Research: Researching ways to find renewable alternatives to nonrenewable resources. Solar or wind energy is a renewable alternative to the energy we use.

The main factors of increasing scarcity are : 

1. Overpopulation: The increasing population requires additional land for growing additional food and providing shelter which is met through conversion of forest and into agricultural land and agricultural land into residential, commercial and industrial land. 

2. Growing industrialization : With increased industrialization, extraction of mineral ores, crude oil and water increase resulting in emptying of mines, oil wells and water sources. 

3. Expanding urban areas: Urban areas are those where a huge population lives in a small area. Naturally the demand for resources and generation of wastes is very high contributing to reduction in quantity and quality of resources. 

4. Atmospheric Pollution: With greater burning of fossil fuels like coal, diesel,’ and petrol, more harmful elements like carbon dioxide, hydrogen sulphide, soot and dust get hydrogen sulphide; soot and dust get into the air polluting it. This reduces the availability of clean air. 

5. The open space: they affect the land and water, reducing the quality as well as availability. Water is also polluted by the agricultural and household activities.

Water is found on the Earth’s surface, under the ground and in the atmosphere as water vapour. Maximum amount of water available is marine water which is salty. Most of the fresh water available on the earth is in the form of frozen ice. Water is essential for the survival of plants and animals, as cellular processes take place in a water medium. Substances are transported from one part of the body to the other in a dissolved form. Hence, organisms need to maintain the level of water bodies in order to stay alive. 

The availability of water decides not only the number of individuals of each species that are able to survive in a particular are, but it also decides the diversity of life there.

1. See the water availability – Choose the crop. 

2. Use micro irrigation – Save water for future. 

3. Use less water – Get more productivity. 

4. Need based irrigation – Best production. 

5. Less water availability – Use dry land crops.

6. Drop by Drop – Grow and grow. 

7. Sprinkle water on crop – Crop feels happy. 

8. See the water – Grow the crop.

9. Today’s rain water to tomorrow’s life saver. 

10. No matter your occupation – Water conservation is your obligation.

The Food and Agriculture Organisation (FAO) of the united nations has predicted that by 2025, 1.8 billion people will be living in countries or regions with absolute water scarcity.

“The humans who were developed by using the natural resources, today has become the reason for destroying them” – This statement is absolutely true.

1. Primitive man lived in forests and hills. He used the natural resources for his livelyhood. He worshipped nature and used them wisely for his development. 

2. After his development, he becomes greedy and using the natural resources indiscriminately and held responsible for their destruction. 

3. To meet the needs of growing population, industrialization, urbanization, and huge constructive activities, man utilised natural resources Indiscriminately. At the same time, he did not planned for their revival. 

4. But now he realised the importance of natural resources and taken up steps for their conservation. The concept of “Sustainable development” is being implemented in natural resource management.

5. He focussed on development of alternatives for fossil fuels, conservation of water and soil at community level and farmer based interventions. 

6. Now he is so keen on conserving forests, wild life and biodiversity. 

7. He is so cautious in minimising the utilization of natural resources by following 4’R principle in the day to day life [R – Reduce, R – Reuse, R – Recycle, R – Recover] 

8. Now, he is adopting micro-irrigation methods like sprinklers and drip Irrigation to minimise the water usage in low water available areas. 

9. He is very interested in following ecofriendly techniques, natural farming methods, using biofertilizers, vermicompost and natural pest control methods in place of toxic chemical pesticides.

If resources are used wisely and efficiently they will last much longer. Through conservation people can reduce waste and manage natural resources wisely.

There are many factors which lead to the degradation of land. Both nature and human factors can lead to degradation of land.

1. Growing population and their ever growing demand is the main reason of land degradation today.
2. Deforestation is the another main reason of land degradation.

• Living things that are bom on land, grow, live and die on the land itself.
• Land is used for construction as well as trade.

1. The various components of air help and support the growth of living organisms. 

2. Nitrogen is used to make proteins, oxygen is used for respiration and carbon dioxide is used to make food by plants. 

3. Similarly, land supports growth of terrestrial plants and animals. It provides important minerals to plants and also to human beings.? 

4. It is the shelter for worms, insects and rodents and supports their growth. Plants also cannot survive without land. 

5. Water is necessary for carrying out all life processes in the living organisms and without water there will be no life on earth. 

6. Hence land, air and water are considered valuable natural resources.

Land degradation is the major consequences of direct interference of human activities in the natural phenomenon.

Land degradation means:

1. Loss of natural fertility of soil because of loss of nutrients.

2. Less vegetation cover

3. Changes in the characteristic of soil.

4. Pollution of water resources from the contamination of soil through which water sweeps into ground or runoff to the water bodies.

5. Changes in climatic conditions because of unbalanced created in the environment.

Causes of Land Degradation:

(a) Deforestation: Deforestation is taking place at a faster rate due to increasing demands of timber, fuel and forest products which results into degradation of land resources.

(b) Overgrazing: Overgrazing refers to excessive eating of grasses and other green plants by cattle. It results into reduced growth of vegetation, reduced diversity of plant species, excessive growth of unwanted plant species, soil erosion, and degradation of land due to cattle movement.

(c) Agricultural practises: The modern agricultural practises, excessive use of fertilizers and pesticides has adversely degraded the natural quality and fertility of the cultivation land.

(d) Industrialization: Development of industries for the economic growth of the country leads to excessive deforestation and utilization of land in such as way that it has lost its natural up gradation quality.

(e) Urbanization: Increasing growth of population and demand for more residential areas and commercial sectors is also one of the reasons for land degradation.

Prevention and Control Measures for Land Degradation:

Following are some practises for controlling land degradation:

1. Strip farming: It is & practice in which cultivated crops are sown in alternative strips to prevent water movement.

2. Crop Rotation: It is one of the agricultural practice in which different crops are grown in same area following a rotation system which helps in replenishment of the soil.

3. Ridge and Furrow Formation: Soil erosion is one of the factors responsible for lad degradation. It can be prevented by formation of ridge and furrow during irrigation which lessens run off.

4. Construction of Dams: This usually checks or reduces the velocity of run off so that soil support vegetation.

5. Contour Farming: This type of farming is usually practiced across the hill side and is useful in collecting and diverting the run off to avoid erosion.

Landslides are the downward movement of a slope composed of earth materials such as rock, soil or artificial fills. Landslides are also called rock-slide, debris-slide, slump, earth-flow or soil-creep

During construction of roads and mining activities huge portions of mountainous fragile areas are cut down and thrown into adjacent areas and streams. These land masses weaken the already fragile mountain slopes leading to man-induced landslides.

EFFECTS OF LANDSLIDES:

Landslides increase the turbidity of nearby streams, thereby reducing their productivity

Destruction of communicative links

Loss of habitat and biodiversity

Loss of infrastructure and economic loss

CAUSES OF LANDSLIDES

Removal of vegetation - Deforestation in slopes creates soil erosion leading to landslides

Underground mining activities cause subsidence of the ground

Movement of heavy vehicles in areas with unstable slopes causes landslides.

Addition of weight by construction on slopes causes landslides.

Over exploitation of groundwater also leads to landslides.

Land is a very valuable resource. It provides food, fibre, wood, medicine and other biological materials needed for food. Soil is a mixture of inorganic materials and (rocks and minerals) and organic materials (dead materials and plants). Top soil is classified as a renewable resource as it is continuously regenerated by natural processes at a very slow rate. However, if the rate of erosion is faster than the rate of renewal, the soil becomes a non-renewable resource.

Food is an essential requirement for survival of life. Main components are carbohydrates, fats, proteins, minerals and vitamins

TYPES OF FOOD SUPPLY

1. Crop plants: Grains mostly constitute about 76% of the world’s food. Ex: Rice, Wheat and Maize

2. Range lands: Produces 17% of world’s food from trees and grazing animals. Ex: Fruits, milk and meat

3. Ocean: Fisheries – 7% of world’s food

WORLD FOOD PROBLEM

1. In the earth’s surface, 79% is water out of total area. 21% land (forest, desert, mountain and barren land) . Less % cultivated land, at the same time population explosion is high therefore world food problem arises.

2. Environmental degradation like soil erosion, water logging, water pollution, salinity affects agricultural land.

3. Urbanization affects agricultural land. Hence production of rice, wheat, corn and other vegetable is difficult.

It is a process of eating the forest vegetation without giving a chance to regenerate.

EFFECTS OF OVER GRAZING

1. Land degradation Over grazing removing the cover of vegetation Exposed soil gets compacted Soil moisture reduces. Desertification - OG leads to poor, dry and compacted soil. Land cannot be used for further cultivation.

2. Soil erosion: When the grasses are removed the soil becomes loose and gets eroded by the action of wind and rain fall.

3. Loss of useful species: OG affects the plant population and their regenerating capacity. OG replace the plant of high nutritive value with plant of low nutritive value

ENERGY DISTRIBUTION IN THE WORLD

Developed countries like USA and Canada constitute only 5% of the world’s population but consume 25% of the world’s available energy.

Energy consumed by a person in a developed country for a single day is equal to energy consumed by a single person in a poor country for one year.

TYPES OF ENERGY RESOURCES:

1. Renewable energy resource (or)Non conventional energy resources

2. Non renewable energy resources (or) Conventional energy resources.

RENEWABLE ENERGY SOURCES: Energy which can be regenerated.

Types of renewable energy resources:

1. Solar energy:

Nuclear fusion reaction of sun produces enormous amount of energy. Several techniques are available for collecting, storing and using solar energy.

a. Solar cell (or) Photovoltaic cell (or) PV cell: Solar cell consists of p- type semi conductor (Si doped with B) and n-type semi conductor (Si doped with P). P-type forms top layer and n-type forms bottom layer. Uses: It is used in calculators, electronic watches, street light, water pumps etc.

b. Solar battery: Large number of solar cells connected in series is called solar battery. It is used in remote areas where continuous power supply is a problem. c.

c. Solar water heater: It consists of insulated box painted with black paint with glass lid. Inside the box black painted copper coil is present. Cold water is allowed to flow, it is heated up and flows out into a storage tank from which water is supplied through pipes.

2. Wind energy:

Moving air is called wind. The energy recovered from the force of the wind is called wind energy .It’s speed is high.

a. Wind mills: When a blowing wind strikes the blade of the wind mill, it rotates continuously. And rotational motion of the blade drives number of machines like water pump, flour mills and electric generators.

b. Wind farms: When a large number of mills are installed and joined together in a definite pattern – it forms wind farm. It produces large amount of electricity. Advantages: 1. It does not cause air pollution 2. Very cheap

3. Ocean energy:

Tidal energy (or) Tidal power: Ocean tides are due to gravitational force of sun and moon which produce enormous amount of energy. High tides – rise of water in the ocean. Low tides – fall of water in the ocean. Tidal energy can be used by constructing a tidal barrage. During high tides sea water enters into the reservoirs and rotates the turbine, produce electricity. During low tides water from reservoir enters into the sea rotate the turbine produce electricity.

4. Geo thermal energy: Temperature of the earth increases at a of 20 –750C per/km when we move down the earth. The energy utilised from the high temperature present inside the earth is called geo thermal energy.

5. Bio mass energy: Bio mass: Organic matter produced by plants or animals used as source of energy Bio gas: Mixture of methane, carbondioxide and hydrogen sulphide. Methane is the major constituent.

NON RENEWABLE ENERGY SOURCES:

Energy which cannot be regenerated is called as non-renewable.

1. Coal: It is a solid fossil fuel. Disadvantages: When coal is burnt large amount of CO2 is released which causes global warming. S, N produces toxic gases during burning.

2. Petroleum: Crude oil is a liquid consists of more than hundreds of hydrocarbons and small amount of impurities. The petroleum can be refined by fractional distillation. In the world level 25% of oil reserves are in Saudi Arabia. At present rate of usage, the world crude oil reserves are expected to get exhausted in just 40 years.

3. Natural gas: These are found above oil in oil wells. It is a mixture of methane and other hydrocarbons. Calorific value is high. There are two types. Dry gas and wet gas.

4. Liquefied petroleum gas (LPG): Petroleum gases obtained during FD and cracking can be easily converted into liquid under high pressure as LPG. It is colorless and odorless gas.

5. Nuclear energy: Dr.H.Bhabha is a father of nuclear power development in India. 10 nuclear reactors are present in India. It produces 2% of India’s electricity. Nuclear energy can be produced by two types of reactions. Nuclear fission and nuclear fusion.

Agriculture is an art, science and industry of managing the growth of plants animals for human use. It includes cultivation of the soil, growing and harvesting crops, breeding and raising livestock, dairying and forestry.

TYPES OF AGRICULTURE

1. Traditional agriculture

2. Modern (or) industrialised agriculture

Traditional agriculture

Small plot, simple tools, surface water, organic fertilizer and a mixture of crops constitute traditional agriculture. They produce enough food to feed their family and to sell it for their income.

Modern agriculture

Hybrid seeds of single crop variety, high tech equipments, lot of fertilisers, pesticides and water to produce large amount of single crops.

EFFECTS OF MODERN AGRICULTURE

1. Problems in using fertilizers

a. Excess of fertilizers causes micronutrient imbalance. (e.g) Punjab and Haryana deficiency of nutrient zinc in the soil affect the productivity of the soil.

b. Blue baby syndrome (nitrate pollution): Nitrate present in the fertilizer causes blue baby syndrome, when the amount exceeds the limit leads to death.

c. Eutrophication: Nitrogen and phosphorus in the crop fields washed out by runoff water in the water bodies, which increases the nourishment of the lakes called eutrophication. Hence algal species increases rapidly. Life time of the species is less and they decompose easily and pollute the water which affects the aquatic life.

2. Problems in using pesticides

Death of non target organism.

Producing new pest – super pest

Bio magnification – Most of the pesticides are non bio degradable, keep on concentrating in the food chain and it is harmful to human beings.

Risk of cancer: a. It directly acts as carcinogen b. It indirectly supports immune system.

3.Water logging:

Land where water stand for most of the year. Causes of water logging:

1. Excessive water supply 2. Heavy rain 3. Poor drainage Remedy: 

1. Preventing excessive irrigation 

2. Subsurface drainage technology 

3. Bio drainage like trees like Eucalyptus 

4.SALINITY

Water not absorbed by soil, is evaporated leaving behind a thin layer of dissolved salts in the top soil. This is called salinity of the soil. Saline soils are characterized by accumulation of soluble salts like sodium chloride, calcium chloride, magnesium chloride, sodium sulphate, sodium carbonate and sodium bicarbonates. Saline conditions are exhibited when pH is greater than 8.0

PROBLEMS IN SALINITY

1. Saline soils yield less crop In order to remedy the condition of saline soils the following two techniques may be used:

1. Salt deposit is removed by flushing with good quality water

2. By using a sub-surface drainage system, the salt water is flushed out slowly

The water percentage used in agriculture is 70%.

It is a wetland dominated by shrubs & trees.

(4) All the above

Gobar gas contains mainly methane.

False 

Photosynthesis is the major process by which oxygen is returned to the atmosphere. During the process of respiration, carbon dioxide is being released into the atmosphere.

Earth’s surface gets heated by the energy received from the sun in short waveform, then the earth itself becomes a radiating body and start radiating heat in long waveforms. This energy heats up the atmosphere from below and the phenomenon is called “terrestrial radiation”.

Option : (b) stratosphere

1. The ultra violet (UV) rays coming from the sun are very harmful for living things.

2. The ozone layer present in the lower stratosphere absorb this U.V. rays and prevent them from reaching the earth. As a result life on earth is protected.

3. Therefore, it is said that the ozone layer is a protective shell of the earth.

During the process of photosynthesis, plants lead to the formation of complex sugars (food) using water and carbon-di-oxide in the presence of sunlight and release oxygen into the environment. While processes like burning fuels and respiration release carbon-di-oxide into the air.

The importance of forests are as follows: 

1. Forest are renewable natural resources that have innumerable contribution to the environment. 

2. Forests maintain water cycle. 

3. They provide habitat for wild animals. 

4. They maintain Soil quantity by preventing Soil erosion. 

5. They provide timber and many other useful products and services. 

6. They are indicators of the natural wealth of a nation.

Due to water logging and Salinisation are the main causes of another serious problems in which once fertile lands are becoming barren and useless. This condition is called desertification.

Normally ozone breaks into oxygen under the influence of sunlight, and reforms into ozone again. The ozone hole is created when the rate of formation of ozone is slower than the rate of its depletion. Hence, when the CFCs accumulate in a specific region, ozone depletion becomes faster the rate of its formation ultimately leading to the formation of the ozone hole.

The importance of soil as follows : 

1. Soil is a natural resource that provides minerals and water to all land plants. 

2. Soil is a primary nutrient base for agricultural crops. 

3. Soil is the place of living for a wide, variety of organism like earth worms, crabs, insects and micro organisms.

Soil is another important natural resource that supports life. Soil contains soil particles, humus and living organisms. It also contains some amount of water in the form of droplets or air in between the soil particles. The sun, water, wind and living organisms form the soil. Uneven contraction and expansion of rocks, cracks and breaks them into smaller particles of soil. Frozen water logged in the cracks of rocks, cracks and breaks the rocks into soil. Lichens growing on the surface of rocks release chemicals which powder the rocks into soil. Flowing water in rivers breaks hard rocks into soil particles. Strong winds erode rocks and carry sand particles. 

Soil contains bits of decayed living organisms which is called humus. It is a major factor in deciding the soil structure because it causes the soil become more porous and allows water and air to penetrate deep underground. The topmost layer of the soil that contains humus and living organisms in addition to the soil particles is called the topsoil.

Poor farming methods, such as repeatedly planting the same type of crop in the same place cause depletion of nutrients in the soil.

We use between 50,000 to 70,000 plant species for medicines world wide.

Soil is vital to food production and also important to plants that grow in the wild.

Organisms need water because:

(i) Cellular processes need water for their functioning.

(ii) Substances dissolve in water for reactions to take place within the cells.

(iii) Transportation of substances within the body need water.

(iv) Water helps in digestion of food and its absorption in the blood.

(v) It helps to maintain body temperature.

(D) afforestation

(C) 1.75 – 2%

Every living organism has certain metabolic processes occurring inside the cells. Processes like metabolites transportation, cell turgidity, membrane viscosity, etc are some life-supporting processes that are mediated by water. If water will not be there, these processes will not occur and cells will die.

Water present in lakes, swamps and rivers is 0.01%

If we talk about outer space, the temperature conditions are highly variable. At those conditions, any biotic component or an organism cannot survive. The atmosphere of a planet acts as a barrier against these conditions. 

1) It maintains a range of temperatures at which organisms can survive. 

2) It maintains other factors like a steady-state of components like water, a specific percentage of gases, gravity. 

3) Prevents us from the harmful U.V radiation coming from the sun. 

4) Maintains surface components like soil which are essential for survival.

Every living organism’s life is supported by certain environmental factors like air, water, wind, climate temperature, gravity, etc. and in order to maintain these factors, we need an atmosphere.

E.g. – Due to no atmosphere the temperature on the moon varies between -190 to 110 degrees Celsius, this variable cannot be tolerated by any kind of living organism. Hence the atmosphere is essential for survival.

Water is essential for life because of these reasons:

(i) It provides medium to carry out all the cellular processes.

(ii) All the reactions that occur in our body and within cells occur between substances that are dissolved in water

(iii) It is required for the transportation of materials from one part of the body to the other.

(iv) It helps to maintain body temperature.

(v) Water makes up about 70% of body weight of all the living organisms.

Rivers fail to benefit the state to an extent they should have. Because

1. There are no sufficient structures (dams) to store river water. 

2. Over usage of water by the other states. 

3. Geographically our rivers are flowing through the rocky and hill areas in most of the places in our state where it is difficult to make canals. 

4. The government should plan for proper utilization of river water after scientific study with the help of expert engineers.

Some gases called greenhouse gases, e.g., CO₂ prevent the escape of heat from the Earth. When the amount of such gases increases more than their normal levels, the average temperature of the Earth increases. This is called green house effect.

Atmosphere is important for life due to following reasons:

(i) It keeps the average temperature of the Earth steady during the day and even throughout the year.

(ii) It prevents the sudden increases in temperature during the daylight hours.

(iii) The gases it contains are required for sustaining life on Earth. These gases are:

(a) Oxygen which is required for respiration by all living organisms.

(b) Carbon dioxide is used in photosynthesis by plants to synthesize food.

(c) Nitrogen provides inert atmosphere and an important component of proteins.

(iv) A thick layer of ozone (in stratosphere) of atmosphere, filters the harmful UV radiations reaching the Earth. The UV rays produce harmful effects on all living organisms.

The two forms of oxygen found in the atmosphere are: 

(i) Elemental oxygen is normally found in the form of diatomic molecule (O₂) in the lower part of atmosphere. It is about 21% in the air and non-poisonous. 

(ii) Ozone is found in the stratosphere part of atmosphere. It contains three atoms of oxygen(O₃). It is the poisonous form of oxygen. 

(iii) Some other forms of oxygen are also found in the combined state. In Earth’s crust, it is found as the oxides of most metals and silicon and also as carbonate, sulphate, nitrate and other minerals. In other forms, it is the part of biological molecules like carbohydrates, proteins, fats and nucleic acids, etc.