Soils of Nepal a General Treatise

Lying inconspicuously beneath our feet, often unnoticed by the vast majority of people, soils are an essential component of terrestrial ecosystems and sustain the myriad of life forms on land including human beings. At first glance, to the untrained eye, soil may appear lifeless and may be mistaken as an abiotic component of the physical environment. On the contrary, soils are home to innumerable organisms of a wide diversity of species ranging from microscopic bacteria, protozoa and actinomycetes, to insects, earthworms and small rodents, as well as, the vast webs of the roots of higher plants. In fact, so intricately are soils associated with life and organic matter derived from living creatures, that they themselves can be considered living entities.

Soils, along with the land upon which they are formed, serve many vital functions. Not only are they the primary medium for crop production to sustain human societies, but they comprise habitats for a vast array of plants and animals, allow for the storage and movement of water, function as a receptor of wastes, and together with vegetation, they contribute to the regulation of climate. Soils can be both sinks and sources of greenhouse gases, such as, carbon dioxide, methane and oxides of nitrogen. The accelerated global warming or climate change phenomenon, attributed to human activities like the clearing of vast areas of forests and the burning of fossil fuels as an energy source, could potentially be mitigated through the sequestration of atmospheric carbon in soils. This is because soils contain about 75 percent of the terrestrial carbon pool, or approximately 1500 Petagrams (1015g), which represents more than the total amount of carbon contained in the atmosphere and living plants and animals combined (FAO, 2001; Lal, 1994). Therefore, it is crucial to ensure the restorative management and conservation of soils, while enhancing their productivity so as to ensure the nurturing of an ever-growing global population, as well as, to maintain a climatic balance.

This book provides a general overview of soil formation processes and dominant soil types in the various physiographic regions of Nepal. In addition, it gives a brief description of key soil genesis principles and soil formation factors operational in different agro-climatic zones of the country. Finally, it also highlights the importance of productive soils and the need for sustainable use and sound management of land and soils. A detailed discussion of soil classification principles and the classification of soil types found across Nepal are beyond the scope of this book. It is intended, rather, as a general reference for scholars and researchers interested in the predominant processes involved in the development of soils and the common soil types found in various regions of the country.