Soil conservation is the process of prevention of soil erosion and to prevent the soil from becoming infertile.  In mulching, a protective layer is placed over the soil such as straw, grasses etc., which helps in retaining soil moisture and also regulates soil temperature. Strip cropping is a process in which field is divided into strips and different crops are grown in alternate strips to preserve soil fertility. Crop rotation means growing of different types of crops on the same field in succession which prevents the depletion of nutrients from the soil. Overgrazing or intense grazing will erode the soil.

If the same crop is grown year after year, fertility of soil is lost due to utilization of same minerals again and again, thus, disturbing the soil structure, which facilitates soil erosion. Legumes are useful in rotation of crops because of having nodulated roots which harbour nitrogen fixing Rhizobium bacteria and it leaves more nitrates in the soil when the roots are left over in fields and only aerial parts of legume crops are harvested.

Vermicomposting is a method in which earthworms are used to convert the organic wastes into compost, which is a good fertilizer for plants. It increases the soil fertility. Manure is the organic matter mainly animal feces and straw. It adds nutrients (nitrogen) in the soil, which increases the soil fertility. So, the correct option is D.

Soil erosion is removal of top soil by agency of water (water erosion) and wind (wind erosion). One of the methods for soil conservation against soil erosion is terracing. In terracing, slope is divided into a number of flat fields for slowing down the flow of water. Terracing is very effective in hilly areas for control of soil erosion.

Anthropogenic soil erosion is caused by removal of plant cover through over grazing, litter collection, tree felling, leaving the soil unprotected during agricultural operations. Anthropogenic factors remove green cover and expose the soil to natural agents of soil erosion i.e., water and wind. When rains fall, most of the top layer of soil is washed away, if the soil is not covered by vegetation. 

Soil pollution is caused by removal or addition of substances which decrease its productivity. It is caused by agrochemicals, industrial wastes, municipal wastes etc. It adversely affects the fertility of the soil. Pesticides, weedicides, and fertilizers are added to soil in agriculture practices to remove unwanted plants and increase the fertility of the soil. These chemicals penetrate into soil and damages the soil.

• The contamination of soil with solid waste, acid rain excess of fertilizers, Insecticides, and herbicides is called soil pollution.
• Soil pollution can lead to water pollution if toxic chemicals leach(drain away from the soil) into groundwater, or if contaminated runoff reaches streams, lakes, or oceans.
  
• Hence Soil pollution can lead to water pollution is a true statement.
• So, the correct answer is 'True'.

Mulching refers to the covering of harvested field with plant litter or polythene of low density, in order to decrease run off, prevent the growth of weeds and retention of water. It protects the roots from seasonal variations.During initial stages of growth, mulching helps to maintain a stable temperature for proliferation of seedling.

When trees are cut on a large scale land becomes barren. This results in the loss of upper soil layer due to heavy wind or flowing water leading to soil erosion. Roots of plants hold the soil particles and prevent their loss. Hence afforestation i.e. growing plants to form a soil cover prevents soil erosion. Thus the correct answer is option B.

Soil erosion is removal of top soil by agency of water (water erosion) and wind (wind erosion). Soil erosion is of two types- natural and anthropogenic. 

Terracing is a process of making sloped plane into series of succesively receding flat surfaces or platforms resembling stairs, this is how erosion is minimised.

Soil erosion is the phenomenon in which the top most layer of soil gets lost, since plants have the capability of holding the soil particles together and prevent them from being eroded away

Soil pollution greatly due to use of  large amount of herbicides, pesticides. There also some more reason of soil pollution like industrial wastes are dumped into fertile soil which get polluted and also not having proper satiation. But soil erosion is not responsible for soil pollution, soil erosion is mainly due to deforestation. So B option is right. 

Soil conservation is the prevention of soil from erosion or reduced fertility, caused by overuse, acidification, salinization or other chemical soil contamination. Techniques for improved soil conservation include crop rotation, cover crops, conservation tillage and planted windbreaks, that affect both erosion and fertility. 

Afforestation is the act of planting trees in a barren land or converting a farmland to a forest in order to use the trees for commercial purposes. Many programs are organised by the government as well as non-government associations to plant trees and thus improving biodiversity.

There is no alluvial basin in the world, which can compare with the Ganga Basin in terms of size, fertility, acreage and topography. It is the most densely populated river basin in the world and is often characterized as a granary or the bread basket of India. 

Afforestation is the process of establishing a forest on land, that has not been a forest for a long time by planting trees or their seeds. Soil erosion is when the soil is blown away by the wind or washed away by the rain. Roots of trees or plants hold the soil. Thus, when more trees are planted their roots do not allow the soil to be blown or washed away and prevent soil erosion.

Soil conservation is the prevention of soil from erosion or reduced fertility caused by overuse, acidification, salinization or other chemical soil contamination. Techniques for improved soil conservation include crop rotation, cover crops, conservation tillage and planted windbreaks, that affect both erosion and fertility. 

Afforestation is the establishment of a forest or trees in an area where there was no forest. As the roots of trees spread deep into the layers of soil, they hold it tightly, thus preventing soil erosion. 

Tree hugging movement also known by the name of chipko movement is forest conservation movement of India which came forward when the forest cover started deteriorating at an alarming rate then soon villagers, especially women, began to organize themselves under several smaller groups and resorted to hugging the trees to stop them from being felled.

As a result of various activities of mankind, our environment is getting increasingly polluted. pollutants are of 2 types: Biodegradable and non-bio degradable

Forests conserve and enhance the soils ability to sustain diverse ecosystems. They conserve the productive capacity of the land by reducing soil and nutrient loss. Forests also restrict soil and nutrient loss by reducing the volume of rain falling to the ground. The forest canopy absorbs much of the kinetic energy of rain, reducing its ability to loosen and displace soil particles and cause surface runoff. 

Cutting of forests also called as deforestation that can provide additional area for cultivation. However, this is an incorrect plan because it leads to decrease in the number of trees. This will in turn lower rainfall and hence decrease the agricultural production. Thus the correct answer is option D.

The prevention of soil erosion is called as soil conservation and the ways can be as follows:
Terrace farming is one way to do so and involves cutting terraces along a slope. These terraces reduce the speed of water flowing down the slope and help in soil conservation.
Contour ploughing is also beneficial in reducing the flow of water down the slope and involves ploughing at right angles to the natural slope of land.
Effective farming techniques further help in soil erosion. In plain areas, strip cropping can be used for soil conservation where strips of grass are allowed to stand between crops in large fields. These strips of grass reduce the force of wind and thus prevent soil erosion.

Planting rows of trees along farmland also help break the force of wind and help in soil conservation. Shelter belts of trees, when planted along sand dunes, help stabilise them and prevent the desert from extending into land available for cultivation.

Effective farming techniques further help in soil erosion. In plain areas, strip cropping can be used for soil conservation where strips of grass are allowed to stand between crops in large fields. These strips of grass reduce the force of wind and thus, prevent soil erosion.

Terrace farming is one way of soil conservation and involves cutting terraces along a slope. These terraces reduce the speed of water flowing down the slope and help in soil conservation.

Contour ploughing is also beneficial in reducing the flow of water down the slope and involves ploughing at right angles to the natural slope of land.

Deforestation is the destruction of forest resources. The major effect of deforestation is the loss of precious wildlife, rare species of flora and fauna. Directly or indirectly, deforestation causes soil erosion and drought. Soil erosion can be prevented by afforestation and reforestation. Afforestation is the planting of the new forests. Plants hold soil with their roots and thus prevent erosion. Eutrophication is the process of enriching water bodies with nutrients.  It supports the abnormal growth of algae.

The harmful change in the colour, texture, and quality of soil due to addition and removal of any material is called soil pollution. Soil pollution reduces the productivity of the soil. There are several pollutants that cause soil pollution. For example, agricultural wastes, radioactive wastes and discarded materials of hospitals etc. Weeds are the unwanted crops that compete with the main crop. Weedicides are the chemicals used to kill the weeds so that plants can grow properly. Cropping techniques should be improved to prevent the growth of weeds to minimise soil pollution. Other chemicals like pesticides, insecticides, fertilizers etc. are also used to promote the growth of crops. These are the chemicals that get consumed with the food by the living beings and are also involved in changing the pH of the soil. These are harmful to living beings and the ecosystem. For example, repeated use of fertilizers makes the soil acidic which in turn decreases the productivity of the soil. So, use of pesticide and fertilizers should be minimised, fertilizers should be replaced by manures and composts. Therefore, the correct option is D.

Earthworms are traditionally called as friends of farmers because they increase aeration and make available nitrogen and potassium to plants in easily usable form. The dead and decaying materials contain certain complex molecules which are churned and broken down into simpler one and forms compost. The process is known as vermicomposting.

The trash is mainly composed of the papers and the cardboard. These components contain the cellulose and can be degraded by the activity of the microorganisms. These products do not cause soil pollution. 

Saalumarada Thimmakka is an Indian environmentalist from the state of Karnataka, noted for her work in planting and tending to 384 banyan trees along a four-kilometre stretch of highway. Her work has been honoured with the National Citizen's Award of India.

The industrial wastes include the chemicals which act as pollutants. These pollutants reduce the fertility of the soil and the soil becomes less productive. This disturbs the soil profile and nutrient content of the soil. The number of beneficial microbes in the soil gets reduced. The domestic and biodegradable wastes can be degraded by the microbial activity and converted to nutrient forms. So, there is no effect of these wastes in the contamination of the soil.

• Afforestation is the process of planting trees, or sowing seeds, in a barren land devoid of any trees to create a forest. The term should not be confused with reforestation, which is the process of specifically planting native trees into a forest that has decreasing numbers of trees.
• Indigenous species refers to species originating or occurring naturally in a particular place(native).
• Hence Afforestation should be with Indigenous species because they are easily available and have a high growth rate.
• So, the correct answer is  'Indigenous species'.

• Mulching is a process of covering (as of straw, compost, or plastic sheeting) the soil and make more favorable conditions for plant growth and development.
• Mulch is a layer of material applied to the surface of the soil. Reasons for applying mulch include conservation of soil moisture, improving fertility and health of the soil, reducing weed growth and enhancing the visual appeal of the area.
  
• Hence Mulching is helpful in Increasing soil fertility, Prevent soil erosion and Control weeds.
• So, the correct answer is 'All the above'.

Agrostologic method of soil conservation means in which grasses are grown to check the soil erosion. In dry farming, crop production, animal husbandry and grazing fields are used to prevent soil erosion. It is carried out in low and moderate rainfall areas. 

Pyrolysis is a thermochemical decomposition of organic material at high temperatures in the absence of oxygen. It involves the change of chemical composition as well as physical state. It is an irreversible process. The process is used heavily in the chemical industry to produce charcoal, activated carbon, to convert biomass into biochar, to turn waste into safely disposable substances.

• In agriculture, a terrace is a piece of sloped plane that has been cut into a series of successively receding flat surfaces or platforms, which resemble steps, for the purposes of more effective farming. This type of landscaping is therefore called terracing.
• Terracing reduces both the amount and velocity of water moving across the soil surface in hilly areas, which greatly reduces soil erosion.
  
• Hence Terracing helps in soil conservation in hilly areas.
• So, the correct answer is 'Hilly areas'.

Reforestation means replanting of forest trees in areas, which were once having dense forests but the forests were later on destroyed by cutting of trees in large numbers. Afforestation is different from reforestation. Afforestation is planting of trees in new areas, which were not previously under forest cover. Typically, waste lands or land other wise not previously having forest cover is selected. Indigenous species are more suited for this purpose because they are well adapted to local climatic and soil conditions. These species are already acclimatized to local conditions.

Agroforestry or agro-sylviculture is a land use management system in which trees or shrubs are grown around or among crops or pastureland.

• Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem.
• Soil pollution causes digestive problems such as diarrhea, abdominal pain, etc. Soil pollution can also cause a neuromuscular blockage as well as depression of the central nervous system, headaches, nausea, fatigue, eye irritation, and skin rash.
  
• Hence Soil pollution can cause digestive problems is a true statement.
• So, the correct answer is 'True'.

• Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem.
• The effects of soil pollution are:
• Sewage sludge is contaminated with pathogenic bacteria, viruses, and worms.
  
• Loss of fertility of soil.
• Results in Various diseases related to the digestive system.
• So, the correct answer is 'All the above'.

Afforestation refers to the conversion of wasteland into a woodland or forest. It is essentially the transformation of land which has not been forested for a period of more than 40 year to woodland through seeding and planting. Afforestation is the best technique used to minimize the greenhouse effect. Planting of trees in semi-arid areas attracts rainfall. This way, agricultural practices such as irrigation are carried out efficiently. In addition, afforestation acts as a catchment for water and soil conservation. With an increase in demand for forest and timber products, afforestation is very valuable due to the explosion of livestock and human population. Disadvantages of high human population density are global warming, pollution, rapid use of natural resources, more exploitation of other living forms and non living systems like rivers, faster destruction of natural systems, deforestation, habitat destruction, pollution, extinctions etc. Hence population density should be reduced. 

• Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem.
• Due to the soil pollution the harmful chemicals present in the soil increase toxicity so soil fertility decreases and yield of soil is also decreased. Hence soil pollution affects the productivity of the soil.
• Hence Soil pollution does not affect the productivity of the soil is a wrong statement.
• So, the correct answer is 'Option B'.

Negative soil pollution occurs because of overuse of soil & its erosion thereby decreasing soil productivity. For example soil salinity due to over irrigation.

Forests are an important natural resource. They provide a variety of products, are a center of biodiversity, conserve water and soil. Forests are very important for maintenance of water cycle and ecological balance. Forests provide habitat to a large variety of organisms and tribal humans are directly dependent on forests for food and habitat.

Terracing is the practice of creating nearly level areas in a hillside area. The terraces form a series of steps, each at a higher level than the previous. Terraces are protected from erosion of soil. 

Soil conservation is a technique aimed at preserving the soil. There are various methods for soil conservation such as afforestation, manuring and crop rotation, step farming, windbreaks, strip cropping, mulching. Strip cropping is the method of farming in which the field is partitioned into long, narrow strips which are alternated in a crop rotation system. Crop rotation is the method of farming in which different types of crops are grown in the same area in different seasons. Mulching is the process of applying a layer of material on the soil in order to conserve soil moisture, improve fertility.

The importance of soil for plant growth is
1. Anchoring the plant.
2. Source of water and minerals.
3. Availability of oxygen for respiration of root cells.
4. Symbiotic association with microbes.

Open dumping or open landfilling is throwing of waste on uncovered low lying area. The waste is piled as high as the equipment can easily do. The waste is periodically burnt or compressed at intervals to reduce its bulk. In sanitary dumping or sanitary landfilling the waste is pulverised, compacted and covered over by a layer of dirt.

Crop rotation is the practice of growing a series of different types of crops in the same area in sequential seasons. Crop rotation gives various nutrients to the soil. Growing the same crop in the same place for many years in a row disproportionately depletes the soil of certain nutrients. With rotation, a crop that leaches the soil of one kind of nutrient is followed during the next growing season by a dissimilar crop that returns, that nutrient to the soil or draws a different ratio of nutrients: for example, rice followed by cotton. 

• Soil conservation is the protection of soil from erosion and other types of deterioration, so as to maintain soil fertility and productivity.
• Dryland Farming is the cultivation of crops without irrigation in regions of limited moisture, typically less than 20 inches (50 centimeters) of precipitation annually. It helps in soil conservation.
  
• Hence an agrostologic method of soil conservation is Dry Farming.
  
• So, the correct answer is 'Dairy farming'.

Fumigant kills the insects with poisonous fumes. Examples are calcium cyanide, ethylene dibromide, etc.

Malathion is an organophosphate. It is an insecticide (pesticide) with relatively low human toxicity. It is being widely used in agricultural application. 

Lead battery manufacturing factory have acid electrolyte, so it will cause for lowering tin pH of river water.

Tillage is the method of mechanical agitation of various types like as digging, stirring, and overturning to improve the crop yield. Crop rotation helps in increase in soil fertility. It is the process of growing a series of different crops in the same area in sequenced seasons. Terrace farming is a type of farming that consists of various steps or terraces. In contour farming, several grasses are left out in soil after the crop is harvested. In contour farming, crops are placed perpendicular to slopes to follow the contours of a slope of a field. This helps in breaking down the flow of water and prevent soil erosion.

Mulch is a protective layer of a material, that is spread on top of the soil. Mulches can either be organic - such as grass clippings, straw, bark chips, or inorganic - such as stones, brick chips, and plastic. Materials used as mulches are used to retain soil moisture, regulate soil temperature, suppress weed growth, and for aesthetics. They are applied to the soil surface, around trees, paths, flower beds, to prevent soil erosion on slopes, and in production areas for flower and vegetable crops. Mulch layers are normally two inches or more deep when applied.