Soil And Water Conservation Techniques Research Articles

Soil Erosion Mapping and Severity Analysis Based on RUSLE Model on Welmel Catchments of Ganale-Dewa River Basin Bale Lowland South Eastern Ethiopia

Soil erosion is a kind of environmental deterioration through decreased agricultural output, increased floods, and habitat loss, soil degradation has an impact on many people's livelihoods, either directly or indirectly. In many developing tropical nations throughout the world where soil and water conservation (SWC) planning and management initiatives are either ineffective or nonexistent, soil erosion is on the rise. Because there isn't precise scientific research that gives information, identifying locations that are susceptible to soil erosion is also insufficient. The Oromia area of Ethiopia, where the majority of livelihoods mainly rely upon agriculture, is home to the little-recognized watershed of Welmel. A thorough understanding of the spatial variability across various climatic zones, land uses, and soil erosion is crucial for the planning of successful SWC management approaches. Through the use of a geographic information system (GIS), remote sensing (RS), and numerous characteristics such as land uses, and climate, this study has attempted to identify prospective places in need of SWC techniques by undertaking a spatial modeling of soil erosion within the Welmel watershed's Genale Dawa basin. The revised universal soil loss equation (RUSLE), which was previously modified for Ethiopian circumstances, was utilized to predict potential soil loss after laboratory study and processing multiple input datasets in ArcGIS to get the requisite six RUSLE model input parameters. It made use of data from a digital elevation model (DEM) on interpolated rainfall erosivity (R), soil erodibility (K), plant cover (C), topography (LS), and conservation practices (P) from satellite pictures. The study demonstrates that the RUSLE using GIS taking into account various climates and land management practices provides a great advantage in that it enables one to spatially analyze multilayer data to identify areas that are susceptible to soil erosion and subsequently develop the be

Assessment of runoff variability under various factors using SWAT model in a Tunisian semi-arid watershed

This research aims to establish a correlation between prolonged shifts in precipitation patterns and runoff and to delineate spatial surface runoff distribution within the Wadi Rmel watershed using the Soil and Water Assessment Tool (SWAT) model. The calibration and validation processes reveal good agreement between measured and simulated flows with a monthly time step. Significantly, the Nash-Sutcliffe Efficiency (NSE) values of 0.61 and 0.83, accompanied by the coefficient of determination (R2) values of 0.66 and 0.85 for calibration and validation, respectively. It clearly indicates a strong agreement between the observed and simulated streamflow data. Subsequently, an exploration of the spatiotemporal variability of runoff underscores the synchronous relationship between runoff and monthly and annual precipitation fluctuations between 2000 and 2020. The values of R2 were 0.7 and 0.79 for monthly and annual studies, respectively, confirming a strong correlation between the two cited variables. Additionally, anthropogenic impacts, particularly Soil and Water Conservation (SWC) measures, were investigated. A high R² coefficients (0.91 for linear relationship) were obtained and showed the high relation between SWC and runoff. In fact, the combination of SWC techniques, vegetation cover, topography and precipitation led to a reduction of 44% of surface runoff, during 2015-2020. Spatially, higher runoff occurred in central and eastern parts due to agriculture and hilly terrain, while forested areas and gentle slopes exhibited lower runoff. In conclusion, this study underscores the model's utility in characterizing arid catchment surface runoff. Its capacity to simulate and assess runoff enriches water resource management comprehension in such contexts.

Soil Erosion in a Changing Environment over 40 Years in the Merguellil Catchment Area of Central Tunisia

Soil degradation and erosion in semi-arid regions can significantly impact agricultural development, environmental sustainability, and hydrological balance. Understanding the impacts of land use changes and soil and water conservation (SWC) technique implementation on soil erosion and sediment yield is critical to planning effective watershed management. This study aims to evaluate the impacts of environmental changes in the Merguellil watershed (Central Tunisia) over the last forty years. To achieve this, remote sensing techniques and a geographic information system (GIS) will be employed to classify Landsat images from 1980 to 2020. Additionally, the Revised Universal Soil Loss Equation model will be utilized to estimate soil erosion rates, while the sediment delivery distributed model will be employed for sediment yield modeling. Spatiotemporal changes in land use and land cover and in areas treated with SWC techniques were analyzed as the main factors influencing changes in erosion and sediment yield. The combined impact of land use change and SWC techniques resulted in a decrease in the annual soil erosion rate from 18 to 16 t/ha/year between 1980 and 2020 and in sediment yield from 9.65 to 8.95 t/ha/year for the same period. According to the model’s predictions, both soil erosion and sediment yield will experience a slight increase with further degradation of natural vegetation and a reduction in the efficiency of SWC works. This emphasizes the importance of continued efforts in adopting and sustaining SWC techniques, as well as preserving natural vegetation cover, to proactively combat soil degradation and its adverse effects on the environment and communities. Continuous dedication to these measures is crucial to preserving our ecosystem, promoting sustainable practices, and protecting the well-being of both the environment and society.

Potential Development of Biochar in Africa as an Adaptation Strategy to Climate Change Impact on Agriculture.

One of the most important obstacles to increasing agricultural production yields worldwide, especially in developing economies such as those in Africa is the continued degradation of soils due to climate change. In response to this threat, one of the strategies advocated is biochar technology, which is one of the emerging sustainable and climate-friendly soil amendments. This article reviews a brief description of biochar, the advantages and disadvantages of its use, and the prospects for developing its potential impact on agricultural productivity in African countries with a case study in Burkina Faso. Biochar is mainly useful for soil carbon sequestration, increasing and maintaining soil fertility, environmental management, and as a renewable energy source. However, it can have secondary effects including negative impacts on human health, pollution, and water quality. Furthermore, the positive results of biochar use in Africa suggest a prospect for ensuring the feasibility of biochar technology in policy decisions as a sustainable alternative to agricultural land management in the combat against climate change. As recommendations, a combination of improved seed varieties, and SWC (Soil and Water Conservation) techniques with the application of Biochar will be a perfect innovation for an intelligent adaptation practice to the destructive action of climate change in agriculture.

The impact of land certification and risk preferences on investment in soil and water conservation: Evidence from southern Ethiopia

This paper evaluates the impact of land certification and risk preferences on the adoption of different soil and water conservation (SWC) technologies using survey data at plot and household level from Ethiopia. Both long-term and short-term investments are considered. Using multivariate probit and correlated random-effect Poisson regression models, we find a heterogeneous impact of land certification on the adoption of SWC techniques among farmers with different risk profiles. We find that certification enhances land investment and that the effect is stronger for more risk-averse farmers. Land certification has a positive effect on the adoption of SWC techniques with a longer payback period such as biological and physical practices, but only for high risk-averse farmers. For short-term investments in SWC techniques like agronomic practices, which are used less to claim the land but with considerable productivity effects, the land certification has a positive effect for both low and high risk-averse farmers, but more strongly for the latter. Hence, our findings suggest that land certification programs could have an important contribution to breaking the risk-induced low technology uptake - agricultural development trap by motivating (particularly risk-averse) farmers to enhance their land investments.

Evaluating soil erosion and factors determining farmers’ adoption and management of physical soil and water conservation measures in Bachire watershed, southwest Ethiopia

Soil degradation due to erosion, which emanates from improper land management, has been one of major challenges affecting agricultural production and food security. To control soil erosion, soil and water conservation (SWC) measures including soil and stone bunds have been developed and adopted. However, little is known on the impacts of SWC techniques in Africa. Objective of this study was to assess soil erosion and analyze effect of physical SWC measures on cropland productivity. Data were collected using focus group discussion, key informant interview and survey of 169 farm households (122 adopters and 47 non-adopters of physical SWC). Farmers were responded on soil erosion (rill and gully) and its impacts, long existed indigenous erosion mitigation measures as well as effects of introduced physical SWC techniques such as soil and stone bunds. Descriptive statistics and binary logistic regression model were used to analyze data. Based on visible erosion features such as rills and gullies, about 92% of respondents indicated that soil erosion is a major problem on cultivated land, where 64% of the farmers abandoned part of their plot due to exhausted soil fertility and gully development. About 97% of the farmers perceived that soil erosion reduces crop production. Traditional drainage ditch, grass strip and contour furrow are common indigenous SWC measures. More than 86% of the respondents believe that the introduced physical SWC measures (e.g., bunds) reduce erosion and improve crop production. Family size, participation in technical training, access to extension service, the perceived land tenure security, slope of the plot, and perceived severity of erosion had significant (p < 0.05) and a positive association with adoption of introduced physical SWC measures, while farm size had significant (p < 0.05) negative relationship. Increasing knowledge and skill of farmers, providing technical and resource supports and implementing appropriate policy could help sustainable land management that ensure environmental quality and food security in the study area as well as in the other areas having related biophysical and socioeconomic settings.

Effectiveness of soil and water conservation structures in increasing community perception and controlling erosion and sedimentation

The increasing frequency of floods and landslides has prompted the Ministry of Environment and Forestry to intensify the construction of soil and water conservation (SWC) structures in various watersheds in Indonesia. However, the evidence on how the high-cost measure can effectively increase community perception and participation while controlling erosion and sedimentation is still limited. For this reason, this preliminary research was conducted in 2019 to observe community perception and assess the effectiveness of the SWC structures in controlling gully erosion and sedimentation. The activities carried out in the Jeneberang and Lisu Sub Watershedsconsisted of two parts: 1) social and economic data collectionand 2) observing the effectiveness of the SWC structures in controlling sedimentation. Based on the socio-economic survey, respondents in the Jeneberang showed a better understanding and higher incomes than respondents in the Lisu Sub Watershed, despite their lowereducation levels.These phenomena relateto the length of time the community has learnedfrom surrounding examples and the applied SWC techniques on their land.In terms of the effectiveness of SWC structures, more than half of the retaining dam and gully plug capacityhad been filled with sediment in just oneyear after construction and is expected to be full at the end of the rainy season.The leadingcause is the high erosion of the tillage area on both sides.As a suggestion, agricultural land in the catchment area needs to be managed by applying SWC techniques according to site conditions through incentives given to landowners.

Erosion and soil and water conservation in South‐Kivu (eastern DR Congo): The farmers' view

AbstractDespite being one of the hotspots for soil erosion in the world, little is known regarding farmer's knowledge of soil erosion in the highlands of South‐Kivu in the Democratic Republic of Congo. A proper understanding of farmers' knowledge regarding soil erosion and conservation measures is a prerequisite for implementing resilient erosion control measures. The objective of this study was therefore to assess farmers' knowledge of soil erosion, to document existing soil and water conservation (SWC) measures and to identify their adoption constraints in the highlands of South‐Kivu. Data were collected using interviews with a semi‐structured questionnaire involving 720 respondents from eight watersheds in four territories. Farmers reported eight main erosion indicators. As opposed to gullies (80% of farmers), rills were perceived as important erosion indicators by only 50% of farmers, despite their common occurrence. Farmers were largely unaware of the potential impact of their crops and cropping practices on erosion. Farmers knew about only a limited range of SWC measures, which were perceived to be little to moderately efficient. Furthermore, the average level of adoption was very low (21%). Adoption constraints varied widely depending on the SWC measure. Thus, future interventions need to place much greater emphasis on awareness regarding soil erosion and SWC measures, to strengthen farmers' capacity for experimentation and adaptation to new technologies and finally to create a policy and institutional environment that stimulates widespread adoption of SWC techniques.

Can Social Capital influence Smallholder Farmers’ Climate-Change Adaptation Decisions? Evidence from Three Semi-Arid Communities in Burkina Faso, West Africa

This study examines the influence of farmers’ social capital on their decisions to deal with climate change and climate variability in Burkina Faso. The study is based on a household survey conducted among 450 households, randomly selected from three communities in Burkina Faso. Two indexes were constructed to capture farmers’ structural and cognitive social capital; and using generalized Poisson regression (GPR) and a multivariate probit model, the study probes the effect of farmers’ social capital on their choice of adaptation alternatives, the number of adaptation practices used, and the extent to which adaptation measures were applied. The results indicated that the effect of social capital depends on the type of indicator used and on the type of adaptation strategies necessary. Farmers’ cognitive social capital was significantly and positively related to their choice of soil and water conservation techniques (SWCT), and techniques such as agroforestry and irrigation. Structural social capital, on the other hand, was positively associated with the adoption of new varieties and conservation tillage strategies and negatively associated with the use of a crop-diversification strategy. The results also highlighted that socio-economic, institutional and agro-ecological variables determine farmers’ decisions to adapt to climate change.

Soil erosion and conservation in Ethiopia

This paper reviews Ethiopia’s experience and research progress in past soil and water conservation (SWC) efforts and suggests possible solutions for improvement. Although indigenous SWC techniques date back to 400 BC, institutionalized SWC activity in Ethiopia became significant only after the 1970s. At least six national SWC-related programs have been initiated since the 1970s and their focus over time has shifted from food relief to land conservation and then to livelihoods. The overall current soil erosion rates are highly variable and large by international standards, and sheet, rill, and gully erosion are the dominant processes. The influence of human activities on the landscape has traditionally been deleterious, but this trend seems to have recently reversed in some parts of the country following the engagement of the communities in land management. The efficiency of SWC measures show mixed results that are influenced by the type of measures and the agro-ecology under which they were implemented; in general, the relative performance of the interventions is better in the drylands as compared with humid areas. Methodological limitations also occur when addressing the economic aspects related to benefits of ecosystem services and other externalities. Although farmers have shown an increased understanding of the soil erosion problem, SWC efforts face a host of barriers related to limited access to capital, limited benefits, land tenure insecurity, limited technology choices and technical support, and poor community participation. In general SWC research in Ethiopia is fragmented and not comprehensive, mainly because of a lack of participatory research, field observations, and adoptable methods to evaluate impacts. A potentially feasible approach to expand and sustain SWC programs is to attract benefits from global carbon markets. Moreover, a dedicated institution responsible for overseeing the research–extension linkage of SWC interventions of the country should be established.

English

At the onset of climate change, the adoption of soil and water conservation (SWC) techniques in Africa sub of the Sahara has become even more crucial. The study aimed at estimating the determinants and effects of SWC adoption. The data was obtained from the Ghana Agriculture Production Survey (GAPS), a national level survey conducted by Ghana’s Ministry of Food and Agriculture with technical and financial support from the International Food Policy Research Institute (IFPRI). A total sample size of 1,530 farm households selected from 20 districts across Ghana was used. The Poisson model was employed to estimate the determinants of adoption of SWC technology while the stochastic frontier model was used to analyze the effects of SWC technology adoption on technical efficiency. The study found that SWC adoption significantly affected technical efficiency in maize production. Significant policy variables that were found to positively influence the adoption of SWC techniques included credit, farm size, group membership and proximity to input sale points. Also, credit, education and extension services significantly influenced farmers’ technical efficiency. There is the need for a holist approach to supporting farmers. In general, access to education, extension services and credit must be stepped up. Farmers must also be supported to form farm groups as a viable source of farm labour. Key words: Adoption, poisson model, technical efficiency, soil and water conservation.

Using soil and water conservation techniques to rehabilitate degraded lands in northwestern Burkina Faso

Agricultural productivity in West Africa is low and cropping systems are hard to sustain. Farmers generally make little use of improved seeds or mechanization, and rely on organic matter to improve the fertility of their soils. Soil and water conservation techniques (SWCTs) can help secure agricultural output in unpredictable climates, and have been promoted in northwestern Burkina Faso for several decades. Rock bunds, filter walls, zaï, half-moons and agroforestry are now widespread. This paper describes the agroecological conditions in Burkina Faso and discusses the agroforestry and SWC technologies most widely applied in the country. SWCTs have contributed to improvements on the ground, helping secure livelihoods and reduce rural poverty and vulnerability to drought and famine.

Stochastic Dominance Analysis of Soil and Water Conservation in Subsistence Crop Production in the Eastern Ethiopian Highlands: The Case of the Hunde-Lafto Area

The aim of this paper is to analyze whether investment in soil and water conservation results in a higher yield and income and/or mitigate variability in yield and income to subsistence farm households in the Hunde-Lafto area. Net returns from crop production with and without soil and water conservation (SWC) are compared based on stochastic dominance (SD) criteria. A non-parametric first order SD and normalized second order are used for data analysis. Analysis is based on the Soil Conservation Research Program (SCRP) database for the Hunde-Lafto research unit. The results of the analysis suggest that adopting a conservation strategy results in higher grain yield and net return than in not adopting. The normalized second order SD analysis results do not support the hypothesis that conservation strategy is unambiguously better than a noconservation strategy in reducing variability in yield and net return to farmers. However, conservation strategy has shown second order dominance at lower levels of yield and income that often correspond to unfavorable rainfall conditions. This makes it a preferred strategy to cope with the most prevalent risk factor of moisture shortage. Therefore, appropriate policies to help and encourage farmers to adopt SWC structures will contribute to improving the welfare of subsistence farm households in the study area and in other similar settings in the country. Designing and implementing SWC techniques that may result in unambiguous second order SD dominance will further improve the desirability and adoption of conservation measures.

Changing land management practices and vegetation on the Central Plateau of Burkina Faso (1968–2002)

In the early 1980s, the situation on the northern part of the Central Plateau of Burkina Faso was characterized by expanding cultivation on lands marginal to agriculture, declining rainfall, low and declining cereal yields, disappearing and impoverishing vegetation, falling ground-water levels and strong outmigration. This crisis situation provoked two reactions. Farmers, as well as technicians working for non-governmental organizations, started to experiment in improving soil and water conservation (SWC) techniques. When these experiments proved successful, donor agencies rapidly designed SWC projects based on simple, effective techniques acceptable to farmers. A study looked at the impact of SWC investments in nine villages and identified a number of major impacts, including: significant increases in millet and sorghum yields since the mid-1980s, cultivated fields treated with SWC techniques have more trees than 10–15 years ago, but the vegetation on most of the non-cultivated areas continues to degrade, greater availability of forage for livestock, increased investment in livestock by men and women and a beginning change in livestock management from extensive to semi-intensive methods, improved soil fertility management by farmers, locally rising ground-water tables, a decrease in outmigration and a significant reduction in rural poverty. Finally, data are presented on the evolution of land use in three villages between 1968 and 2002.

Human impact on the environment in the Ethiopian and Eritrean highlands—a state of the art

This review analyses the environmental evolution of the Ethiopian highlands in the late Quaternary. The late Pleistocene (20,000–12,000 14C years BP) was cold and dry, with (1) low lake levels in the Rift Valley, (2) large debris fans on the flanks of Lake Abhé basin, and (3) the Blue Nile transporting coarse bedload. Then, a period with abundant and less seasonal rains existed between 11,500 and 4800 14C years BP, as suggested by increased arboreal pollen, high river and lake levels, low river turbidities and soil formation. Around 5000–4800 14C years BP, there was a shift to more arid conditions and more soil erosion. Many phenomena that were previously interpreted as climate-driven might, however, well be of anthropic origin. Thick sediment deposits on pediments as well as an increase of secondary forest, scrub and ruderal species in pollen diagrams are witnesses of this human impact. One important aspect of the late Quaternary palaeoenvironment is unclear: changes in Nile flow discharges and Rift Valley lake levels have been linked to changes in precipitation depth. Most authors do not take into account changes in land use in the highlands, nor changes in the seasonality of rain, both of which can lead to a change in runoff coefficients. Tufa and speleothem deposition around 14,000 years ago tend to indicate that at the end of the Last Glacial Maximum (LGM), conditions might have been wetter than generally accepted. The most important present-day geomorphic processes are sheet and rill erosion throughout the country, gullying in the highlands, and wind erosion in the Rift Valley and the peripheral lowlands. Based on existing sediment yield data for catchments draining the central and northern Ethiopian highlands, an equation was developed allowing to assess area-specific sediment yields: SY=2595A −0.29 (n=20; r 2=0.59) where SY=area-specific sediment yield (t km −2 year −1), and A=drainage area (km 2). With respect to recent environmental changes, temporal rain patterns, apart from the catastrophic impact of dry years on the degraded environment, cannot explain the current desertification in the driest parts of the country and the accompanying land degradation elsewhere. Causes are changing land use and land cover, which are expressions of human impact on the environment. Deforestation over the last 2000–3000 years was probably not a linear process in Ethiopia. Studies on land use and land cover change show, however, a tendency over the last decades of increasing removal of remnant vegetation, which is slowed down or reversed in northern Ethiopia by a set-aside policy. Ongoing land degradation requires urgent action at different levels of society. Soil and water conservation (SWC) structures are now widely implemented. Local knowledge and farmer's initiatives are integrated with introduced SWC techniques at various degrees. Impact assessments show clear benefits of the soil conservation measures in controlling runoff and soil erosion. In high rain areas, runoff management requires greater emphasis during the design of soil conservation structures. In such areas, investment in SWC might not be profitable at farm level, although benefits for society are positive. This pleads in favour of public support. The present land degradation in the Ethiopian highlands has a particular origin, which includes poverty and lack of agricultural intensification. Causes of these are to be found in the nature of past and present regional social relations as well as in international unequal development. This review strengthens our belief that, under improved socio-economic conditions, land husbandry can be made sustainable, leading to a reversal of the present desertification and land degradation of the Ethiopian highlands.