1. Introduction
More than two-thirds of the world's population today belongs to the developing countries where agricultural production has not been able to keep pace with rapid population increase. This global increasing trend in the human population has put enormous pressure upon a widening range of land and soils to maintain a balance between the ecosystem and increasing demands due to increased population growth. According to Baumhardt & Blanco-Canqui (2014), global food demands of population growth can be addressed through agricultural production if we can keep a simultaneous balance between the use and conservation of lands (soils) that are considered cultivable.
Soil is considered both sink and source of greenhouse gases and has an important role in maintaining environmental quality. It is much more than just a thin layer of dirt covering the surface of the earth. Soil is an important natural resource serving as a habitat for a diversity of species and is equally responsible as any other fundamental factor for the survival of the existence of plants, animals, and human populations providing numerous ecosystem services. Despite been familiar with the soil productiveness and role of soil in human existence, anthropogenic activities have led to the rapid degradation of productive soils throughout the world. Such activities have caused declination in soil quality and quantity, water quality, and quantity along with degradation of biological diversity which further resulted in the loss of agriculturally productive lands. Soil erosion along with sedimentation, salinization, acidification, chemical pollutions, and many others are responsible for such land degradation issues, worldwide (Guerra et al., 2017).
According to the United Nations report 2019 on soil activity, every year around 24 billion tons of fertile cultivable land is being lost worldwide. Such losses via different forms are found to hamper agricultural sustainability of developing countries like Nepal, through the significant reduction in National domestic products almost up to eight percent (UN, 2019). According to Gautam (1993), it is estimated that soil erosion results in the loss of 1.7 mm of topsoil each year, but 1cm of soil formation requires almost a century. Kaini (2019) reported that every year about 87 tonnes of topsoil per hectare are found as eroded on sloping terraces of Nepal. Land degradation and soil erosion in Nepal are due to Geographical and social diversity, population growth, lack of a governmental plan, intense cultivation, etc. are the major causes behind the severity of land degradation and soil erosion problems of Nepal (Gardner & Gerrad, 2003).
According to a soil bulletin FAO (1976), soil erosion and land degradation are not confined to land under arable use. They may be associated with road constructions, miming, grazing lands, forestry, or any other kinds of land use. Therefore, soil conservation is not only related to mechanical protection measures of land use. Instead, it deals with all aspects of land use including planning, development, and management which contribute to the maintenance and improvement of soil resources leading to soil conservation. As soil is the basic source for the present and future, its conservation value cannot be summed up in terms of monetary gain or loss.
Thus, the concept and implementation of soil conservation including its approaches and practices have been the major source of concern among soil conservationists globally, as its damages are considered almost irreversible. Also, to maintain control of the problems of soil erosion and degradation and maintain food security, the adoption of soil conservation practices at individual, community, and national level has become the necessity for managing the prospective impacts of soil erosion like hazards on agricultural and ecological sectors
2. Objective
The objective of this article is to briefly summarize the status and major challenges of soil conservation in Nepal along with practices and approaches followed against soil degradation to limit its impact to an acceptable level, through the critical analysis of related pieces of literature.
3. Methodology
This article is the outcome of secondary sources of data gleaned through various literature including reports, journals, articles, books, different websites, newspapers, and knowledge-based on B.Sc.Ag Soil Science curriculum of Agriculture and Forestry University, Rampur Chitwan. Information related to soil conservation emphasizing present status was collected from the available literature including challenges for its conservation. Related kinds of literature were analyzed thoroughly to reveal the present status regarding soil conservation and challenges for its preservation in Nepal. Thus, obtained relevant information was arranged systematically and major findings including the challenges are summarized in the article.
4. Status of Soil Conservation In Nepal
Soil science in Nepal was established in 1957 under the Department of Agriculture (DOA) and currently, it is running in its 65th year of studying soil science (Ojha & Chalise, 2016). After almost 17 years of establishment of soil science unit, in 1974 a new and separate department; the Department of Soil Conservation and Watershed Management was established under the Ministry of Forest and soil conservation which provided the basis for soil conservation from the national level (MoFSC, 2015). Since then, various policies have been made and brought into action under the Government of Nepal emphasizing the need for Soil Conservation.
4.1. Policies, Periodic Plans and their strategies for soil conservation
Several initiatives have been taken to cope up with the problem of land degradation including soil erosion at different institutional and national levels in Nepal. Such initiatives include
formulation and enactment of national acts and policies, implementation of different projects and missions in restoring the fertility of degraded land, and so on. Some sectoral policies and five-year national periodical plans have contributed to some extent in addressing the land degradation and soil erosion issues of Nepal (MOEST, 2008).
Forest Policy of Nepal endorsed in 2015 had emphasized soil conservation and watershed management as prime sectors to be dealt with. One of the strategies of the policy was to implement a soil conservation program integrating agriculture and forest system to contribute to food production and food security. The Soil and Watershed Conservation Act promulgated in 1982, followed by the Soil and Watershed Conservation Regulation in 1985 gave authority to the government to implement various conservation measures in prone areas.
Chalise et al. (2019) reported that the foremost attempt to conserve soil in the Nepalese context was included in the Eighth Five Year Plan through forest preserve in the forest of Chure and Bhawar regions of Nepal. Later, the Ninth Five Year Plan (1997 to 2002) aimed to reduce the adverse effects of increased landslides, the institutionalization of land use planning. Similarly, the Tenth Five Year Plan emphasized achieving sustainable development through effective use of natural resources including the major issues of land degradtion. Forest and soil conservation were given priority in the Thirteenth three-year plan (2013 to 2016) to preserve the environment and biodiversity. National Land use Policy 2006 was taken into account for soil conservation approaches in the Fourteenth Three Year Plan for the scientific classification of lands and to enforce laws on land use (Chalise et al., 2019). The ongoing Fifteenth Three Year Plan is aimed to work on the shortcomings of the past periodic plans.
Despite the national level soil conservation targets set in periodic plans by the Government of Nepal, the status of soil conservation has not improved noticeably. The majority of the targets set were unsuccessful due to the hindrances like soil erosion, forest encroachment, uncontrolled grazing, forest fires along with a lack of coordination between community forest users’ groups and government bodies (Chalise et al., 2019). Therefore, for achieving the status of soil conservation as per the expectations by addressing the current soil erosion and degradation problems, there is still a need for clear-cut directives and a separate Land degradation management policy.
4.2. Programs and Practices for Status Improvement of Soil Conservation in Nepal
Land degradation, soil erosion, and other factors responsible for loss of soil quality and other elemental properties have different causes. In the context of Nepal, anthropogenic causes along with geological instability among different physiographic regions are considered as the major cause of soil degradation. According to Gardner and Gerrard (2003), the land-use practices and management options have less significant local impacts on nutrient losses, runoff, and soil erosion from sloping uplands. ‘‘Theory of Himalayan Environmental Degradation’’ (THED) given by Ives and Messerli in 1989, has asserted that soil degradation and fertility decline in the Hills of Nepal is due to deforestation and encroachment in marginal land by mountain farmers as cited in (Tiwari et al., 2008). According to Schreier and Shah (2000), topsoil erosion and nutrient losses are high during pre-monsoon rain in hill slope Bari land of Nepal.
Acharya (2002) reports an increase in forest covers in the hills of Nepal since the 1980s when Community forestry was introduced for the first time. However, the high intensity of monsoon rain during the summer season and mass wasting continued to degrade the lands in the hills (Gardner and Gerrard 2003). Based on these research data, Paudel and Thapa (2004) concluded that land degradation and soil erosions are the combined outcomes of anthropogenic and geological factors which are further deteriorated by inappropriate development programs and policy. To cope up with these sorts of land degradation problems and to improve the status of soil conservation, different conservational practices are being carried out in Nepal. According to Baumhardt & Blanco-Canqui (2014), soil conservation practices are described as farming operations and management strategies conducted with the goal to control soil erosion. Such practices control soil erosion by preventing or limiting soil particle detachment and transport through water or air. In most of the conservation practices, land resources are togetherly considered with water resource management as they are inter-linked. New terms and approaches have arisen in the conservation of soil and ultimately the environment. The motive of recent approaches of conservation is to control erosion along with fertility maintenance. Some of the major soil conservation practices in Nepal reported by various authors are given in the table below:
Table 1. Major Practices against soil erosion for improving the status of Soil Conservation in Nepal as reported by various author
Conservation Practices | Study Area and Methods | Status Improvement (Key findings) | References |
Cover Cropping | Planting Napier grass on devastated gully catchment of the Pipaltar, Nuwakot district | Restored soil fertility and recovered the catchment to a noticeable extent (1995 to 2003) | (Higaki, et al., 2005) |
Mulching | Maize planting with reduced-tillage and rice straw mulching in Kathmandu University | Mulching reduced soil runoff by 18% | (Atreya, et al., 2008) |
Reduced Tillage | Maize, cowpea, finger millet, and capsicum planting with reduced and conventional tillage practices in the Pokhara Khola watershed | In comparison with conventional tillage, reduced tillage decreased soil erosion and sediment runoff by 23% and 9%, respectively | (Tiwari, et al., 2008) |
Strip Planting | Strip planting with maize and legumes in the Palpa district | Strip crop technologies effective in reducing soil erosion through the sieve-barrier effect | Acharya, et al., 2008 |
Hedgerows | Planting hedgerows in the contours in Godavari, Kathmandu | Reduction of soil loss by 80–99% | (Ya & Nakarmi, 2004) |
Check Dams | Planting Dalbergia sissoo, Eucalyptus camaldulensis, and bamboo along with small check dams in the degraded stream of the Sarlahi district | Stabilized the streams, reduced landslides, and soil erosion over a period of four years (2006 to 2010) | (Dhital, et al., 2013) |
5. Challenges for Soil Conservation in Nepal
Ojha and Chalise (2016) reported that the annual soil loss in Nepal ranges from 2 to 105 t per ha with geological erosion contributing the most with 60%, followed by water erosion about 30% and 3% wind erosion. The study also reported other forms of land degradation like flooding and waterlogging which were responsible for around 10% of soil degradation. The problems of soil erosion and land degradation are of major concern for the Government too, but still, due to some major challenges, the status of soil conservation has not been as planned in the context of Nepal.
Uneven land topography among different physiographic regions which causes soil erosion, and other anthropogenic activities like forest encroachment, uncontrolled grazing, forest fires along with lack of coordination between community forest users’ groups and government bodies for carrying out effective works regarding soil conservation are the major challenges which need to be addressed to keep the pace up with ongoing population growth and their demands (Chalise et al., 2019). According to Abubakar and Attanda (2013), among developing countries, one of the challenges for soil conservation circulates around the abilities of agricultural engineers to develop new technologies that not only increase yield but also contribute to the ecological balance in the environment.
Physiographic regions of Nepal, vary in types of land degradation and soil erosion occurring there. Due to the presence of different unstable slope problems, the mechanism of soil loss is different among physiographic reasons which are illustrated in the table below:
Table 2. Types of land degradation in the physiographic regions of Nepal
Physiographic Regions | Elevation (m) | Land degradation types |
High Himalayas | 4000-8848 | Rock slides, an outburst of glacial lakes |
High Mountains | 2000-4000 | Mass wasting, bank cutting, rill, and inter-rill erosion |
Middle Mountains | 1500-2700 | Mass wasting, rill erosion, inter-rill erosion, and bank cutting |
Siwalik Hills | 700-1500 | Rill, inter-rill, and gully erosion |
Terai Plains | 600-700 | Flooding, waterlogging, sheet erosion, and shifting of river courses leading to streambank erosion |
The challenges due to the physiographic variations in the country have impacted the process of soil conservation. The plans and policies implemented by the concerned Ministry under the Government of Nepal been able to carry out its preplanned strategies throughout the country. The issues of soil loss through different means have not been properly addressed equally for all geographic reasons which have ultimately slowed down the conservation process.
Besides these, many anthropogenic activities have influenced the process of conservation negatively. Overgrazing in erosion-prone areas has subsequently increased the chances of soil degradation. Conservative agricultural practices in the arable lands are limited in many parts of Nepal. Human-led forest fires with the hope of a new flush during monsoon have destroyed many forests of Nepal which has increased the problems like soil erosions landslide throughout the country. Apart from these challenges, the other important are less adoption ratio among the farmers and villagers regarding the implemented conservation practices due to a lack of sufficient technical knowledge. Many reports in Nepal have concluded a major challenge as insufficient extension and participatory programs among farmers related to soil conservation.
Above all, there is no special coordinated and stabilized program implemented from the national level that can address the problem of soil erosion throughout the country. Failure in achieving the objectives of past implemented programs and policies due to political instability has slowed down the process of soil conservation in Nepal, which has led to the poor status of soil conservation. These challenges should to be given more emphasis and further policies should be implemented as soon as possible in order to improve the status of soil conservation in Nepal.
6. Conclusion
This article reviewed the status of soil conservation in Nepal along with its challenges in the Nepalese context. Soil conservation is a farming method or practice that helps to obtain the maximum sustainable level of production along with a reduction in soil degradation by maintaining soil loss below a threshold level. High population growth leading to a shortage of basic natural resources and intense rainfall events have been leading to soil erosion floods, landslides in Nepal for a long time ago. To address these sorts of problems, a lot of policies were implemented, conservation practices in arable land were prioritized. Despite all these actions and efforts, the status of soil conservation has not been able to achieve the heights as it was supposed to do. But, they have controlled the soil loss to some extent and failed in many instances. The land degradation issues including floods, soil erosion, and landslides have been listed in almost every three- and five-year periodic plan but were not much successful in decreasing the soil loss problem. Therefore, in order to overcome the challenges in soil conservation, more realistic and applicable periodic plans have to be implemented in the days to come which might improve the status of soil conservation in Nepal as per the expectations.
Thank you Krishna Raj Pandey for this lovely writing.
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