Tag: protecting our environment

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.