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Soil Conservation (soil + conservation)

Distribution by Scientific Domains

Earth and Environmental Science	88%

Terms modified by Soil Conservation

soil conservation measure

Selected Abstracts

Assessment of soil erosion hazard and prioritization for treatment at the watershed level: Case study in the Chemoga watershed, Blue Nile basin, Ethiopia

LAND DEGRADATION AND DEVELOPMENT, Issue 6 2009
W. Bewket
Abstract Soil erosion by water is the most pressing environmental problem in Ethiopia, particularly in the Highlands where the topography is highly rugged, population pressure is high, steeplands are cultivated and rainfall is erosive. Soil conservation is critically required in these areas. The objective of this study was to assess soil erosion hazard in a typical highland watershed (the Chemoga watershed) and demonstrate that a simple erosion assessment model, the universal soil loss equation (USLE), integrated with satellite remote sensing and geographical information systems can provide useful tools for conservation decision-making. Monthly precipitation, soil map, a 30-m digital elevation model derived from topographic map, land-cover map produced from supervised classification of a Land Sat image, and land use types and slope steepness were used to determine the USLE factor values. The results show that a larger part of the watershed (>58 per cent of total) suffers from a severe or very severe erosion risk (>80,t,ha,1,y,1), mainly in the midstream and upstream parts where steeplands are cultivated or overgrazed. In about 25 per cent of the watershed, soil erosion was estimated to exceed 125,t,ha,1,y,1. Based on the predicted soil erosion rates, the watershed was divided into six priority categories for conservation intervention and 18 micro-watersheds were identified that may be used as planning units. Finally, the method used has yielded a fairly reliable estimation of soil loss rates and delineation of erosion-prone areas. Hence, a similar method can be used in other watersheds to prepare conservation master plans and enable efficient use of limited resources. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Land under pressure: soil conservation concerns and opportunities for Ethiopia

LAND DEGRADATION AND DEVELOPMENT, Issue 1 2003
B. G. J. S. Sonneveld
Abstract This paper evaluates the future impact of soil degradation on national food security and land occupation in Ethiopia. It applies a spatial optimization model that maximizes national agricultural revenues under alternative scenarios of soil conservation, land accessibility and technology. The constraints in the model determine whether people remain on their original site, migrate within their ethnically defined areas or are allowed a transregional migration. Key to this model is the combination of a water erosion model with a spatial yield function that gives an estimate of the agricultural yield in its geographical dependence of natural resources and population distribution. A comparison of simulated land productivity values with historical patterns shows that results are interpretable and yield more accurate outcomes than postulating straightforward reductions in yield or land area for each geographic entity. The results of the optimization model show that in absence of soil erosion control, the future agricultural production stagnates and results in distressing food shortages, while rural incomes drop dramatically below the poverty line. Soil conservation and migration support a slow growth, but do not suffice to meet the expected food demand. In a transregional migration scenario, the highly degraded areas are exchanged for less affected sites, whereas cultivation on already substantially degraded soils largely continues when resettlement is confined to the original ethnic,administrative entity. A shift to modern technology offers better prospects and moderates the migration, but soil conservation remains indispensable, especially in the long term. Finally, an accelerated growth of non-agricultural sectors further alleviates poverty in the countryside, contributing to higher income levels of the total population and, simultaneously, relieving the pressure on the land through rural,urban migration. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Soil conservation in Polylepis mountain forests of Central Argentina: Is livestock reducing our natural capital?

AUSTRAL ECOLOGY, Issue 4 2010
DANIEL RENISON
Abstract Mountain forests and their soils provide ecological services such as maintenance of biodiversity, provision of clean water, carbon capture and forage for livestock rearing, which is one of the principal economic activities in mountain areas. However, surprisingly little is known about livestock impact in South American mountain forest soils. With the aim of understanding how livestock and topography influence patterns of forest cover, soil compaction, soil loss and soil chemical properties, we analysed these parameters in 100 Polylepis australis woodland plots situated in the humid subtropical mountains of Central Argentina. We used distance from the nearest ranch as an objective index of historical livestock impact and measured standard topographic variables. Our main results reveal that distance from ranch in all cases partly explains tree canopy cover, soil loss, soil compaction and soil chemical properties; suggesting a strong negative effect of livestock. Intermediate altitudes had more tree canopy cover, while landscape roughness , a measure of the variability in slope inclination and aspect , was negatively associated to soil impedance and acidity, and positively associated to soil organic matter content. Finally, flatter areas were more acid. We conclude that livestock has had a substantial influence on forest soil degradation in the Mountains of Central Argentina and possibly other similar South American mountains. Soil degradation should be incorporated into decision making when considering long-term forest sustainability, or when taking into account retaining livestock for biodiversity conservation reasons. Where soil loss and degradation are ongoing, we recommend drastic reductions in livestock density. [source]

Evaluation of a dynamic multi-class sediment transport model in a catchment under soil-conservation agriculture

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 11 2008
Peter Fiener
Abstract Soil erosion models are essential tools for the successful implementation of effective and adapted soil conservation measures on agricultural land. Therefore, models are needed that predict sediment delivery and quality, give a good spatial representation of erosion and deposition and allow us to account for various soil conservation measures. Here, we evaluate how well a modified version of the spatially distributed multi-class sediment transport model (MCST) simulates the effectiveness of control measures for different event sizes. We use 8 year runoff and sediment delivery data from two small agricultural watersheds (0·7 and 3·7 ha) under optimized soil conservation. The modified MCST model successfully simulates surface runoff and sediment delivery from both watersheds; one of which was dominated by sheet and the other was partly affected by rill erosion. Moreover, first results of modelling enrichment of clay in sediment delivery are promising, showing the potential of MCST to model sediment enrichment and nutrient transport. In general, our results and those of an earlier modelling exercise in the Belgian Loess Belt indicate the potential of the MCST model to evaluate soil erosion and deposition under different agricultural land uses. As the model explicitly takes into account the dominant effects of soil-conservation agriculture, it should be successfully applicable for soil-conservation planning/evaluation in other environments. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Use of terrain variables for mapping gully erosion susceptibility in Lebanon

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 12 2007
Rania Bou Kheir
Abstract This paper predicts the geographic distribution and size of gullies across central Lebanon using a geographic information system (GIS) and terrain analysis. Eleven primary (elevation; upslope contributing area; aspect; slope; plan, profile and tangential curvature; flow direction; flow width; flow path length; rate of change of specific catchment area along the direction of flow) and three secondary (steady-state; quasi-dynamic topographic wetness; sediment transport capacity) topographic variables were generated and used along with digital data collected from other sources (soil, geology) to statistically explain gully erosion field measurements. Three tree-based regression models were developed using (1) all variables, (2) primary topographic variables only and (3) different pairs of variables. The best regression tree model combined the steady-state topographic wetness and sediment transport capacity indices and explained 80% of the variability in field gully measurements. This model proved to be simple, quick, realistic and practical, and it can be applied to other areas of the Mediterranean region with similar environmental conditions, thereby providing a tool to help with the implementation of plans for soil conservation and sustainable management. Copyright © 2007 John Wiley & Sons, Ltd. [source]

Hybridization between perennial ryegrass and Italian ryegrass in naturalized Japanese populations

GRASSLAND SCIENCE, Issue 2 2008
Hiroyuki Tobina
Abstract Introduced Lolium species, including perennial ryegrass (Lolium perenne) and Italian ryegrass (Lolium multiflorum), have been widely utilized in Japan for forage, turf and soil conservation. These ryegrasses have escaped from cultivated areas and become naturalized, and this has become a serious issue in recent years. Interspecific hybrids between perennial ryegrass and Italian ryegrass have often been found in naturalized populations. It has also been suggested that hybridization between plant species might serve as a stimulus for the evolution of invasiveness. We surveyed the genetic structure of naturalized ryegrass populations in Japan using genetic markers that distinguished perennial ryegrass and Italian ryegrass. Of the 55 naturalized populations surveyed, 41 exhibited morphological traits of Italian ryegrass. DNA analysis using simple sequence repeat and chloroplast DNA markers characterized 20 of these 41 populations as Italian ryegrass, with the remaining populations as interspecific hybrid derivatives. Approximately half of the naturalized ryegrasses populations in Japan were inferred to include interspecific hybrids. [source]

Using GIS and a digital elevation model to assess the effectiveness of variable grade flow diversion terraces in reducing soil erosion in northwestern New Brunswick, Canada

HYDROLOGICAL PROCESSES, Issue 23 2009
Qi Yang
Abstract Flow diversion terraces (FDT) are commonly used beneficial management practice (BMP) for soil conservation on sloped terrain susceptible to water erosion. A simple GIS-based soil erosion model was designed to assess the effectiveness of the FDT system under different climatic, topographic, and soil conditions at a sub-basin level. The model was used to estimate the soil conservation support practice factor (P -factor), which inherently considered two major outcomes with its implementation, namely (1) reduced slope length, and (2) sediment deposition in terraced channels. A benchmark site, the agriculture-dominated watershed in northwestern New Brunswick (NB), was selected to test the performance of the model and estimated P -factors. The estimated P -factors ranged from 0·38,1·0 for soil conservation planning objectives and ranged from 0·001 to 0·45 in sediment yield calculations for water-quality assessment. The model estimated that the average annual sediment yield was 773 kg ha,1 yr ,1 compared with a measured value of 641 kg ha,1 yr,1. The P -factors estimated in this study were comparable with predicted values obtained with the revised universal soil loss equation (RUSLE2). The P -factors from this study have the potential to be directly used as input in hydrological models, such as the soil and water assessment tool (SWAT), or in soil conservation planning where only conventional digital elevation models (DEMs) are available. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Studying the effects of Mahonia aquifolium populations on small-scale mountain agro-ecosystems in Hungary with the view to minimise land degradation

LAND DEGRADATION AND DEVELOPMENT, Issue 3 2009
C. Hudek
Abstract After the political changeover in Hungary in 1989, many farm owners faced problems typical of a small sized farm (<1,ha) as well as a lack of various resources. This led to many farms with great horticultural backgrounds being abandoned, especially in mountainous areas where erosion control is essential for soil conservation. Severe changes can occur on soil through property abandonment. The local socio-economic aspects must be taken into consideration as well as the problem of soil degradation as this will be a motivating factor in preservation initiatives. Under horticultural management, Mahonia aquifolium was tested to determine its efficiency in water erosion control in mountainous conditions in Hungary. Soil loss and water runoff were measured after every rainfall event at six different plots: four cultivated M. aquifolium populations with different ages (4, 12, 20 and 25 years old) and two control plots. A bare soil field and a grass field represented the control plots. The results show that as the age of the M. aquifolium populations increase, the cumulative runoff and sediment values decrease. It also showed that 2 years after setting up a new M. aquifolium plantation, the cumulative runoff decreased by 69 per cent and the cumulative soil loss decreased by 74 per cent. This indicates that a M. aquifolium population could play a significant role in erosion control within a short period of time. Copyright © 2009 John Wiley & Sons, Ltd. [source]

Immediate effects of prescribed burning, chopping and clearing on runoff, infiltration and erosion in a shrubland area in Galicia (NW Spain)

LAND DEGRADATION AND DEVELOPMENT, Issue 5 2008
C. Fernández
Abstract The immediate effects of three different fuel management treatments on runoff, infiltration and erosion were evaluated in a mixed heathland in Galicia (NW Spain). The treatments compared were: prescribed burning, shrub chopping and shrub clearing. Rainfall simulations were conducted immediately before and after fuel reduction treatments. A rainfall rate of 67,mm,h,1 was applied for 30,min to each runoff plot. Application of treatments significantly affected runoff and infiltration, but the parameter most affected by treatment was soil erosion, especially after prescribed burning. However, sediment yields measured immediately after treatments were low in all the cases, varying from 32,kg,ha,1 after shrub clearing to 248,kg,ha,1 after prescribed burning. In the rainfall simulation plots subjected to prescribed burning, the maximum temperatures reached at mineral soil surface during burns significantly affected soil losses. The organic layer remaining after treatments and soil moisture contents appeared to be critical variables in controlling runoff and erosion during the first rainfall event following fuel reduction treatments. When the remaining organic layer was removed just after treatments and a new rainfall simulation was carried out, mean infiltration rate trended to decrease and cumulative runoff and sediment yield tended to increase. The above information could be useful for determining whether fuel management prescriptions are compatible with fire hazard reduction and soil conservation. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Land use and soil erosion in the upper reaches of the Yangtze River: some socio-economic considerations on China's Grain-for-Green Programme

LAND DEGRADATION AND DEVELOPMENT, Issue 6 2006
H. L. Long
Abstract Soil erosion in the upper reaches of the Yangtze River in China is a major concern and the Central Government has initiated the Grain-for-Green Programme to convert farmland to forests and grassland to improve the environment. This paper analyses the relationship between land use and soil erosion in Zhongjiang, a typical agricultural county of Sichuan Province located in areas with severe soil erosion in the upper reaches of the Yangtze River. In our analysis, we use the ArcGIS spatial analysis module with detailed land-use data as well as data on slope conditions and soil erosion. Our research shows that the most serious soil erosion is occurring on agricultural land with a slope of 10,25 degrees. Both farmland and permanent crops are affected by soil erosion, with almost the same percentage of soil erosion for corresponding slope conditions. Farmland with soil erosion accounts for 86·2,per,cent of the total eroded agricultural land. In the farmland with soil erosion, 22·5,per,cent have a slope of,<,5 degrees, 20·3,per,cent have a slope of 5,10 degrees, and 57·1,per,cent have a slope of,>,10 degrees. On gentle slopes with less than 5 degrees inclination, some 6,per,cent of the farmland had strong (5000,8000,t,km,2,y,1) or very strong (8000,15000,t,km,2,y,1) erosion. However, on steep slopes of more than 25 degrees, strong or very strong erosion was reported for more than 42,per,cent of the farmland. These numbers explain why the task of soil and water conservation should be focused on the prevention of soil erosion on farmland with steep or very steep slopes. A Feasibility Index is developed and integrated socio-economic assessment on the feasibility of improving sloping farmland in 56 townships and towns is carried out. Finally, to ensure the success of the Grain-for-Green Programme, countermeasures to improve sloping farmland and control soil erosion are proposed according to the values of the Feasibility Index in the townships and towns. These include: (1) to terrace sloping farmland on a large scale and to convert farmland with a slope of over 25 degrees to forests or grassland; (2) to develop ecological agriculture combined with improving the sloping farmland and constructing prime farmland and to pay more attention to improving the technology for irrigation and cultivation techniques; and (3) to carry out soil conservation on steep-sloping farmland using suggested techniques. In addition, improving ecosystems and the inhabited environment through yard and garden construction for households is also an effective way to prevent soil erosion. Copyright © 2006 John Wiley & Sons, Ltd. [source]

The role of social capital in the promotion of conservation farming: the case of ,landcare' in the Southern Philippines

LAND DEGRADATION AND DEVELOPMENT, Issue 1 2006
R. A. Cramb
Abstract ,Social capital' refers to the relationships of trust, communication, and cooperation that facilitate collective action in a community. It is particularly relevant to soil conservation in developing countries, which requires collective efforts to raise awareness of soil degradation, provide effective training in soil conservation practices, and implement soil conservation measures on individual farms. The Landcare Program in the Southern Philippines promotes simple conservation practices in upland environments through establishing and supporting community landcare groups and municipal landcare associations, thus augmenting the social capital of farmers in these locations. An evaluation of the Landcare Program in Barangay Ned, South Cotabato, based on a survey of 313 farm households and case studies of nine landcare groups, shows that, despite extreme isolation and difficult working conditions, farmers responded by rapidly forming landcare groups and a landcare association, and adopting contour barriers on their maize farms. They utilized the bonding social capital inhering in their local communities to build stocks of bridging social capital, linking them to information, training and resources from outside their immediate locality. A logistic regression model of the factors affecting adoption of contour barriers shows that farmers who had undergone the practical, farmer-based training provided by the Landcare Program, and who were members of a landcare group, were significantly more likely to adopt conservation measures. These results confirm the value of investing in social capital to promote soil conservation. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Farmers' perceptions of soil erosion and its consequences in India's semiarid tropics

LAND DEGRADATION AND DEVELOPMENT, Issue 3 2005
J. Kerr
Abstract This paper investigates farmers' perceptions of soil erosion and how it affects crop yields, land values, and private conservation investments in India's semiarid tropics. It is based on three types of data: (1) a survey of farmers in three study villages; (2) a plot survey by a professional soil surveyor in the same villages; and (3) experimental and simulated data from nearby research stations with similar conditions. Farmers' perceptions of erosion are compared to the surveyor's using kappa, a statistical measure of interrater agreement. Perceived erosion,yield relationships are estimated econometrically and compared to experimental and simulated data. Effects on land values and conservation investments are estimated econometrically. Findings suggest that farmers are keenly aware of rill erosion but less aware of sheet erosion; kappa values ranging from 0 to 0·28 suggest low agreement with the soil surveyor. They anticipate annual yield losses of 5·8,11,per,cent due to rill erosion; these figures are reasonably consistent with those from nearby research stations. They anticipate yield increases of 3·8,14·5,per,cent due to installation of soil conservation bunds, largely because they can harvest soil from up the slope and capture organic matter. Perceived erosion has some effect on land values and soil conservation investments, but other factors such as irrigation and soil type have a much greater effect. These findings suggest that promoting soil conservation requires capitalizing on farmers' interest in short-term gains, such as from water and nutrient management. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Approaches to landcare,a century of soil conservation in Iceland

LAND DEGRADATION AND DEVELOPMENT, Issue 2 2005
A. Arnalds
Abstract Organized soil conservation in Iceland began in 1907, as a response to severe land degradation and desertification that was threatening the existence of several communities. During the first 75 years, many of the most threatening areas of accelerated soil erosion were fenced and seeded with sand stabilizers. These projects had a high success rate, halting the advancement of sand dunes and other forms of highly accelerated erosion. However, they were limited in scope, and often concentrated on the symptoms of the problems rather than the underlying causes, such as improper grazing management. On a national scale, not enough was being achieved in mitigating the extensive ecosystem degradation. This period of soil conservation in Iceland was characterized by single-issue, top-down approaches, a lack of appropriate incentives for soil conservation and weak laws for protection of the rangelands. During the last two decades there has been a gradual shift to more participatory strategies, community involvement, and ecosystem management for multiple benefits. These changes have greatly increased community involvement in projects, stimulated conservation awareness and improved land use. The ties between agricultural policy and soil-conservation issues are also being strengthened, especially by linking part of governmental subsidies for sheep production to land-use factors. Copyright © 2005 John Wiley & Sons, Ltd. [source]

Land under pressure: soil conservation concerns and opportunities for Ethiopia

Better land husbandry in Honduras: towards the new paradigm in conserving soil, water and productivity

LAND DEGRADATION AND DEVELOPMENT, Issue 3 2002
J. Hellin
Abstract Land shortages are forcing more smallholder farmers to cultivate tropical steeplands. Resulting accelerated soil erosion is being countered by the promotion of soil conservation (SC) technologies, such as cross-slope barriers, which aim to reduce soil loss and preserve land productivity. However, farmer adoption rates tend to be low. This is often attributed to the farmers' conservatism or lack of education. Research in Honduras's steeplands demonstrates that farmers value SC, provided that it promotes agricultural production. Field research from 1995,98, involving farmed test plots on slopes greater than 35 per cent (19 degrees), demonstrates that at least one typical SC technology,live barriers of Vetiveria zizanioides (vetiver grass),has little or no impact on maize yield. This means that farmers see little benefit from their investment in the SC method. They find that erratic rainfall, pests and diseases and a lack of economic resources are far greater threats to their livelihoods than soil erosion. Consequently, SC has a low priority. Keeping soil in place avoids major off-farm disbenefits. However, the SC technique tested here made no discernible difference to slope foot sediment yields during the life of this study. In sum, a new approach is needed. Promoting ,Better Land Husbandry' strategies, which seek to combine farmers' concerns about productivity with conservationists' concerns about reducing soil erosion,often via cover-management,seem to be the best way forward. Copyright © 2002 John Wiley & Sons, Ltd. [source]

Fast Track Land Reform Programme, tenure security and investments in soil conservation: Micro-evidence from Mazowe District in Zimbabwe

NATURAL RESOURCES FORUM, Issue 2 2010
Precious ZikhaliArticle first published online: 21 MAY 2010
Abstract The government of Zimbabwe launched the Fast Track Land Reform Programme (FTLRP) in 2000 as part of its ongoing land reform and resettlement programme which aims to address a racially skewed land distribution. Its goal has been to accelerate both land acquisition and redistribution, targeting at least five million hectares of land for resettlement. This paper investigates the impact of the FTLRP on its beneficiaries' perceptions of land tenure security, and how these subsequently impacted soil conservation investments. Evidence suggests that the programme created some tenure insecurity, which adversely affected soil conservation investments among its beneficiaries. We find support for the contention that households make land-related investments to enhance security of tenure. The results underscore the need for the government of Zimbabwe to clarify and formalize land tenure arrangements within the programme. [source]