Tag: sustainability of natural resources

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.

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.

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. 

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. 

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.

Biogas typically refers to a mixture of different gases produced by the breakdown of organic matter in the absence of oxygen. Biogas can be produced from raw materials such as agricultural waste, manure, municipal waste, plant material, sewage, green waste or food waste. It is a renewable energy source.
Biogas can be produced by anaerobic digestion with anaerobic bacteria, which digest material inside a closed system, or fermentation of biodegradable materials.

Anaerobic digestion is a natural process in which bacteria convert organic materials into biogas. It occurs in marshes and wetlands and in the digestive tract of ruminants. The bacteria are also active in landfills, where they are the principal process degrading landfilled food wastes and other 
biomass. Biogas can be collected and used as a potential energy resource. The process occurs in an anaerobic (oxygen-free) environment through the activities of acid- and methane-forming (methanogenic) bacteria that break down the organic material and produce methane and carbon dioxide in a gaseous form, known as biogas. 

Fossil fuels are nonrenewable conventional energy resources found inside the earth's crust where they have been formed through heat and compression on forests and other organic matter buried underneath due to earthquakes, landslides, lava etc. Fossil fuels can be solid, e.g., coal; liquid, e.g., petroleum; or gaseous, e.g., natural gas.