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During the last few years the agriculture sector is facing danger in many ways. Conversion of agricultural land in non-agricultural uses is one of the main reasons to follow. Why the land is decreasing, how it is converted to non-agricultural purposes is the important matter of concern at present. The study is going to answer why the land is decreasing, how it is converted to non-agricultural uses and what might be the consequences for improper uses of agricultural land. In Bangladesh most of the people live in rural areas and makes Bangladesh predominantly rural. The development in rural seems development of agriculture. But the agricultural land is decreasing day by day. Poverty, rapid population growth, improper uses of land, lack of interest in agriculture, conventional system of irrigation, Real Estate companies etc are playing a critical role for decreasing agricultural land. Besides this, a nature itself is also responsible for land degradation. Flood, drought and salinity due to climate change are very common in Bangladesh thus the result is land degradation. As a result, soil fertility, crop productivity, and food security might be seriously in danger. But it is important to keep full of life this sector for land-scarce country like Bangladesh or else the consequences might be terrible. Food insecurity, unsustainable environment, economic downturn, agricultural productivity decrease and social decay etc are the important matters to consider.   Key words: Land degradation, Agriculture, Land Zoning

The work presented in this thesis was performed firstly to highlight the changes wrought in restored soil systems following the disruptive activities of opencast coal mining, and thereafter to identify, simulate and assess the effects of some typical perturbations associated with these activities. The microbial community was used as a focus for these investigations and the methods of soil adenosine 5'- triphosphate content analysis, dehydrogenase activity analysis and ergosterol content analysis were utilised alongside several other physical and chemical determinations. A field study of restored sites of various ages after cessation of opencast coal mining was undertaken which reinforced the utility of the microbial measurements. Experimentation was performed to investigate the effects of soil storage (at two depths), physical disturbance, compaction and the effects of the different combinations of these perturbations. Novel findings were obtained largely due to the paucity of research addressing the controlled manipulation and careful interpretation of these individual perturbations, and their effects when combined. The storage of soil was found to be the dominant factor influencing the status of the microbial communities upon restoration, and also influencing the development of these communities and the emergent plant biomass, post-restoration. This study found that soil, reinstated after opencast coal mining, becomes quickly dominated by fungi and, under grassland management, this domination then subsides over many years to a more bacterialcharacterised system. Differences were identified between the action of physical disturbance and compaction on stored and unstored soils. The deleterious effect of physical disturbance on unstored soil and the apparent ameliorative effect on soil affected by opencast operations can be interpreted through the change in soil architecture engendered by this treatment. The severe disturbances associated with opencast coal mining were found to affect the soil biota, primarily in terms of enduring environmental change. Thus the study of soil ecology was used as a sensitive indicator of recovery of disturbed land, and the changing energy flow through detrital food-webs was used as a model to follow this recovery process.

Thesis (Ph. D.)--West Virginia University, 2005. / Title from document title page. Document formatted into pages; contains vi, 181 p. : col. maps. Includes abstract. Includes bibliographical references (p. 100-106).

Thesis (MSc)--University of Stellenbosch, 2005. / Bibliography. Also available via the Internet.

Thesis (doctoral)--Stockholm School of Economics, 1991. / Includes bibliographical references.

This research seeks to explore the complexity of human-land relations in the Aspre, with respect to land degradation. It is argued that in human modified environments, such as this Mediterranean-Pyrenean borderland, nature and culture cannot be meaningfully studied apart. Consequently issues of land degradation must be situated within the broader context of socio-natural interaction. Such a study cannot be approached solely from a natural or social science perspective; what is required, and what has been developed in this research, is a transdisciplinary methodology whereby natural phenomena are situated within their historical and socio-cultural context. Central to that context is the need to position the system within a long term evolutionary dynamic, thus allowing us to view the system in process, rather than as a synchronic present day snapshot. Within this 'longue duree' temporal and spatial scales are seen to be critical. It is argued that land degradation is at root a perceptual issue, thus perception and cognition are seen as critically important in this study. The core field work acts to expose both the physical and social identities of the Aspre, and the multiple perceptions of land degradation held by its inhabitants. The research identifies a series of 'perceptual filters' through which the environment of the Aspre is experienced, and by means of which meaning is negotiated. The recognition of the multiple environmental perceptions and plural rationalities is of crucial importance when contemplating the possible future pathways open to the Aspre, with respect to sustainable futures. What emerges from this research is a redefinition of land degradation in the Aspre, from that of a purely physical issue, to the realization that what we are dealing with are changing social identities within changing landscapes.

Thesis (Ph. D.)--University of Texas at Austin, 2003. / Vita. Includes bibliographical references. Available also from UMI Company.

published_or_final_version / Architecture / Master / Master of Landscape Architecture

Thesis (Ph.D.(Environmental Economics)) -- University of Pretoria, 2007. / Includes bibliographical references.