Sunday, October 7, 2007

Thesis Proposal of Zaw Wan, Chiang Mai University

Assessment of soil erosion and land degradation in Dry Zone Areas of Central Myanmar


INTRODUCTION
Soil erosion, a natural process, is generally aggravated by human intervention, and exceeds the rate of soil regeneration. Land degradation is a serious problem in most of the upland agricultural areas of Southeast Asia. Because of land degradation, land productivity declines and the land ultimately becomes unproductive (Suwardjo and Neneng, 1994).Therefore, soil and water conservation are the principle measures that need to be undertaken to reduce the increasing pressure on scarce land resources, enhance productivity, generate employment and prevent environmental degradation (Carucci, 2001).
The assessment of soil erosion and land degradation is a wide range of field that needs long-term and multidisciplinary studies. The results of this study are expected to help analyze land-use problems, and plan and develop activities for soil-erosion control in the Dry Zone area of Central Myanmar.

RATIONALE
The tropical monsoon climate, topography, natural vegetation and human activities highly influence the soil status and agriculture of Myanmar. In central Myanmar, where wind and water erosion is very common due to its dry and windy weather condition. The dry zone of Myanmar is characterized by shallow soils, low uneven rainfall distribution, a high degree of soil erosion and annual rainfall which ranges between 500 mm to 1000 mm, and temperature rises to over 40 o C is in summer months. And due to deforestation, soil degradation is now taking place particularly in the central dry zone of the country. Productivity of agricultural land declines as a result of soil degradation (NCEA, 1997).
Such climatic conditions, together with occasional outbreaks of forest fire also enhance the desertification process of the central dry zone and now becoming a state of seriousness (Carucci, 2001). In connection with these, soil erosion and degradation in dry zone area are noted as soil problem in Myanmar. In the areas affected by these problems, the soils have low fertility and crop yields. The proper conservation and improvement of these problem soils needs an immediate action (NCEA, 1997)

LITERATURE REVIEW

Concept and definitions
Soil erosion is the most widely recognized and most common form of land degradation and, therefore, a major cause of falling productivity (Stocking and Murnaghan, 2001). It is the decline of the capacity of soils to produce goods of value to humans (Miller et al., 1988) reported that in Iowa, USA, it takes approximately 30 years or more to develop 1 inch of top soil under ideal conditions where erosion is very low. This would be equal to about 165 tons per acre. Accordingly, tolerable soil losses would range from 2 to 5 tons per acre per year for different soils (Miller et al., 1988). Most agricultural practices, especially in sloping landscapes, increase the erosion potential, which is commonly called accelerated or excessive erosion. When a soil experiences accelerated erosion, removal of renewed soil properties occurs faster than renewal rates. If the soil is removed faster than soil formation, the quality of soil declines, production costs rises and at a certain stage economic crop production will no longer be feasible (Foster, 1977).
Land degradation is a process which implies a reduction of potential productivity of the land (Hill et al., 1995). Barrow (1994) pointed out that land degradation is a reduction in rank or status of the land. Blaikie and Brookfield (1987) affirmed that land is degraded when it suffers from the loss of its intrinsic qualities and capabilities. Biswas and Biswas (1974) reported that about 10% of the world’s arable land has been spoiled by human activities. The global Assessment of Soil Degradation (GLASOD) figures indicate that almost 40% of the agricultural land has been affected by human-induced soil degradation, and that more than 6% is degraded to such a degree that restoration to its original productivity is only possible through major capital investments (Oldman, 1994). Rehabilitation of the highly degrade soils to their original productivity is not possible; it is only possible on the lightly and moderately affected soils. The soil and land resources are finite. Therefore, these negative changes need to be accurately monitored and their long-term effects and ecological risks should be estimated. Through degradation is a key issue in sustainable land management, increased agricultural productivity still remains a key issue in a world with increasing population (Zoebisch and De Pauw, 2002). Therefore, increasing productivity should go together with sustainability of the land resources.

Factors affecting soil erosion
Four main factors control soil erosion, i.e., climate, soil, vegetation and topography (Schwab et al., 1993). Soil erosion is a physical process, but its underlying causes are firmly rooted in the socio-economic, political and cultural environmental in which land users operate. Therefore, the degree of soil erosion in a particular climatic zone with particular soils, land-use and socioeconomic conditions, will always results from a combination of the above factors (De Graff, 1993).

Soil erosion in Myanmar
The entire area of Myanmar Dry Zone is considered affected by various levels of soil erosion. In several townships, i.e., Kyaukpadaung, Magway, Chaung U, Thaung Tha, Nga Htoe Gyi and Ma Hlaing, land degradation and erosion rates are severe, leading to chronic food insecurity and various degrees of poverty (Carucci, 2001).
Ways are needed to address the increasing occurrence of drought as a consequence of this process, for the benefit of the inhabitants of the area as well as for the country at large. Rehabilitation and reclaiming land in the Dry Zone should be viewed as a priority by all stakeholders involved in rural development (Carucci, 2001).

OBJECTIVES
1. To characterize the local farming systems in terms of productivity and conservation effectiveness.
2. To determine major socio-economic factors that limit soil erosion.
3. To conduct an assessment of soil erosion and land degradation.

USEFULNESS OF THE STUDY
Some concrete findings about soil erosion would be able to apply as an input for developing a concept for land conservation and management in Dry Zone area of the country. The findings of the study will be useful for project planning, implementation and evaluation at local and at country level. The result will be discussed among the extension staffs and farmers.

RESEARCH METHODS

Study site
Field survey will be conducted in Dry Zone area of Central Myanmar with average annual rainfall of 500 mm, including three townships; Magwe, Kyaukpadaung and Chaung U. In these three townships, biophysical and socio-economic characteristics are typical and representative for the whole area of Dry Zone.

Field survey
The field survey will be carried out to gain understanding about land management systems, land use practices and patterns, current farmers’ cultural practices in the systems, access to variation of crop yield and limiting factors of crop yield and socio-economic constraints for agricultural production in the study area.
The information on agricultural land use, cropping system and cultural practice, soil and water management, yields and constraints for production will be collected during the survey.
The formal survey with questionnaires and will be conducted to determine erosion intensity survey.

Sampling techniques
Three villages will be selected for field survey; selection will be based on biophysical factors, land-use practices and socio-economic factors. Twenty households in each village will be randomly chosen for the formal survey with questionnaires.

Data analysis
Primary data will be collected on soil analysis, household surveys, group discussion and field observations. It will be analyzed by using descriptive statistics. The secondary data on climatic conditions such as rainfall and temperature will be collected from reliable authorities and from the nearest meteorological center.


REFERENCES
Blaikie, P.M., and H. Brookfield. 1987. Land degradation and society. Methuen, London: pp. 296.
Biswas, A.K. and M.R. Biswas. 1974. Environmental Considerations for Increasing World Food Production, Nairobi: UNEP.
Barrow, C.J. 1994. Land Degradation: development and breakdown of terrestrial environments. Cambridge University Press, UK, pp. 295.
Carucci, V.F.P. 2001. Guidelines on Soil and Water Conservation for the Myanmar Dry Zone. UNDP/ FAO, Yangon: Myanmar.
De Graaf, Jan. 1993. Soil conservation and Sustainable Land Use. An Economic Approach. Royal Tropical Institute, The Netherlands.
Foster, G. R. 1977. Assessing soil degradation, FAO Soils Bulletin 34, Rome: FAO.
Hill, J., S. Sommer, W. Mehl, and J. Megier. 1995. Use of earth observation satellite data for land degradation mapping and monitoring in Mediterranean ecosystems: towards a satellite observatory. Environmental monitoring and assessment, 37 (1-3): 143-158.
Miller, F.P. 1988. Soil-Land Degradation: Intervention for Sustainable Civilization. In: R. Lal ( Eds.). Soil quality and agricultural sustainability. Ann Arbor Press, Chelsea, Michigan: USA, pp.13-32.
NCEA (National Commission for Environmental Affairs). 1997. Myanmar agenda 21. Ministry of Foreign Affairs, Yangon, Myanmar.
Oldman, L. R. 1994.The Global Extent of Soil Degradation. In: Greenland, D.J. and I. Szabolcs (Eds.). Soil Resilience and Sustainable Land use, CAB International, Wallingford, UK. pp. 99-118.
Suwardjo and L. N. Neneng (Eds.). 1994. The collection and analysis of land degradation data. Report of the expert consultation of the Asia network on problem soils. 25 - 29 October, 1993. Bangkok, Thailand.
Stocking, M. and N. Murnaghan. 2001. Hand book for the Field Assessment of Land Degradation. London: Earthscan Publication, UK.
Schwab, G.O., D.D. Fangmeier, W.J. Elliot, and R.K. Frevert. 1993. Soil and Water Conservation Engineering. United States: John Willey & Sons, Inc.
Zoebisch, M. and E. De Pauw. 2002. Soil degradation and food security on a global scale. Encyclopedia of Soil Science, Marcel Dekker, New York: pp. 281-286.