In our country, heavy metal related pollution is increasing day by day adversely affecting soil profile, soil texture, soil structure, soil nutrients are fractured which is inimical for crop production and soil ecological health. Nowadays unstable level of natural temperature, humidity and rainfall has created an apprehension of climate change. Both issues are closely interconnected with soil. Soil is the most noteworthy natural building block in our environment for biological communities. It is very essential natural resource as it cannot be replaced if it is cracked through excessive soil erosion caused by an anthropogenic activities and it is the base for the evolution and development of human civilization. Proper utilisation of soil ensures the food security and helps to acclimatize with climate change.
Healthy status of soil is fundamental for our natural environment. Structured and fertile soil works as a medium of ensuring food security as well as an adaptation and mitigation factor of climate change. Soil is a natural body comprised of minerals, organic matter, liquid and gases that occurs on the land surface, occupies space, and is characterized by one or both of the horizons or layers that are distinguishable from the initial material as a result of losses, transfers, and transformations of energy and matter or the ability to support rooted plants in a natural environment. Soil provides water, nutrients for plants and trees in natural forests and Grasslands, perennial crops and planted grassland. It provides the habitat for decomposer organisms which have an essential role in the cycling of carbon and mineral nutrients. Soil acts as a buffer for temperature change and for the flow of water between the atmosphere and ground water. Soil has ion exchange properties and it acts as a pH buffer, retains nutrient and other elements against loss by leaching and volatilization. The increasing human population, particularly in the third world, presents a new problem. In many parts of the world, the development of higher-yielding crop varieties and more intensive use of fertilizers, pesticides and irrigation have led to the over production of food. In addition, there is a public concern about the quality of food, drinking water and air.
An ecosystem can be defined as a community of interacting organisms and its environment functioning as a reasonably self-sufficient unit. A terrestrial ecosystem consists of primary producers (trees, herbs, grasses) and decomposers (microorganisms, herbivores, carnivores). The primary producers are photoautotrophic, that is, they use some of the energy from the sun to convert atmospheric carbon dioxide into organic compounds, a process that requires water and nutrients which are supplied from the soil. The organic compounds are used by herbivores and carnivores as a source of energy, and carbon compounds are used to build their tissues; some of the energy is lost as heat and some of the carbon is respired as carbon dioxide. The most active group of decomposers is the soil microorganisms. The end product of oxidation of carbon in organic compounds is carbon dioxide, which returns to the atmosphere.
The nutrients taken up from the soil are partly retained in the vegetation and the animals and partly returned to the soil. Although there are additions from outside, especially of water and there are usually leakages, for example in drainage water, the soil, vegetation and associated animals form a unit which is roughly self-contained. Soil is an essential component of the terrestrial ecosystem of Earth.
It supports plant growth and provides a habitat for large numbers of animals and microorganisms that decomposes leaf, litter and plant residues, thereby helping to cycle the nutrients on which plant growth depends. Soil also supports the growth of arable crops, grassland and trees on which man depends for food, fiber, and wood for fuel and as a building material. An increasing world population requires more of these resources. This requirement can be met by bringing more land into cultivation, by more intensive use of land, or by a combination of the two. Soil creates an ecosystem which interacts with each other and with their physical and chemical environment. The inputs are carbon compounds from the primary producers, water, oxygen and nitrogen from the atmosphere, and essential nutrients from mineral weathering. Between these extremes are life zones, in which soils support a particular type of flora and fauna and there is a characteristic climate. Tropical rainforest and boreal forests are examples of life zones.
To understand the significance of carbon in soil in the form of biochar, it characteristics and dynamics should be compared to those of the remaining soil organic matter which accounts for most of the carbon that exists in soil. Peat soils comprise mainly organic matter and contain much more carbon on a per unit area basis. Most organic matter in soil is derived from plant roots, plant debris and microbial re-worked substances. The presence of soil organic matter is important for a range of useful soil properties. The process of microbial energy acquisition from substrate is accompanied by a release of various nutrient elements which may be conserved in the soil in microbial biomass. A portion of certain nutrients may also be released in soluble form and a fraction may be lost from the soil through leaching or run-off; which is essential to crop nutrition. It is a case where external nutrient provision is limited. Overall, a balance slowly develops between the rate of carbon addition and the emission of CO2, which are specific to the land-use and environmental conditions. The amount of organic matter maintained once this balance is reached, depends on its average rate of turnover. Although conversion of soil has been promoted as an approach to enhance soil organic matter as well as to control erosion and conserve water.
Adaptation to climate is the process through which people reduce the adverse effects of climate on their health and well-being, and take advantage of the opportunities that their climatic environment provides. Carbon is only one of the elemental constituents of humus. There are several sources of nutrients for Carbon sequestration, including biological nitrogen fixation, recycling from subsoil, aerial deposition, use of bio solids, and crop residues. One ton of cereal residue contains 12 to 20 kg N, 1 to 4 kg P, 7 to 30 kg K, 4 to 8 kg Ca, and 2 to 4 kg Mg. Crop residues are also a potential source of energy by direct combustion. It can be used either for bio fuel production or to sequester Carbon and improve soil quality. The economics of these two competing uses need to be assessed. The Soil oxygen carbon is preferentially removed by wind- and water-borne sediments through erosion processes. Some of the Soil oxygen carbon-enriched sediments are redistributed over the landscape others are deposited in digressional sites and some are carried into the aquatic ecosystems. Although a part of the Carbon translocated by erosion may be buried and redistributed, the rest is emitted into the atmosphere either as CO2 by mineralization or as CH4 by methanogenesis. Mining Carbon from soil for nutrients through organic-matter decomposition has an effect on the atmosphere similar to that of fossil-fuel combustion. Commoditization of soil Carbon is important for trade. The low current price of Soil Oxygen Carbon may increase with emission cap and regulation. Enhancing Soil Organic Carbon stock increases the soil’s capacity to oxidize CH4, especially under no-till farming but may also exacerbate emission of N2O. Fluxes of CH4 and N2O may change the CO2-mitigation potential of soil management practices and must be considered along with Carbon sequestration. Soil Carbon sequestration is a natural, cost-effective and environment friendly process.
According to the father of classical economist William Petty, soil or land is the mother of all resources. So its management and conservation are urgent for sustainable development. Any type of resource is necessary for future. Such as soil, air, water etc. The concept of sustainable development had its roots in the idea of a sustainable society and in the management of renewable and non-renewable resources. The World Commission on Environment and Development adopted the concept and launched sustainability into political, public and academic discourses.
The concept was defined as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs. Today our farmers use unusual hostile pesticides and fertilizers in land for several crops. But such type of activities has dented the land. It increases our concern for upcoming generation. If emissions of radioactive gases continue largely unchecked it is predicted that the 0.3 degree rise per decade will raise sea levels by about 6 cm per decade, and the atmospheric CO, concentration will have doubled by the second half of the twenty-first century. The effects will be less if emissions of the gases are reduced.
The writers are environmental activists.