Agricultural Soil Erosion Research Articles

Organochlorine pesticide residues in sediments of a tropical mangrove estuary, India: implications for monitoring

The paper examines the concentrations of isomers of hexachlorocyclohexane (HCHs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), α-endosulfan and endosulfan sulfate in surface sediment samples collected from the mouth of Hugli estuary in the vicinity of Sundarban mangrove environment, eastern part of India. An overall pattern of accumulation of these pesticides was in the order of: ΣHCH>endosulfan sulfate>ΣDDT>α-endosulfan. The concentration of these compounds was quite low. An elevated level of ΣHCH, ΣDDT and endosulfan sulfate were marked during premonsoon months, a period characterized by high salinity and pH values. Among the isomers and metabolites of HCH and DDT, β-HCH, pp′-DDT and pp′-DDE were found to be dominant. The sources of contamination are closely related to human activities, such as domestic and industrial discharges, agricultural chemical applications and soil erosion due to deforestation. The study is compared to other estuarine environment in India and abroad. The present data will serve as a baseline against which future anthropogenic effects may be assessed.

Quantitative assessment of agricultural runoff and soil erosion using mathematical modeling: applications in the Mediterranean region.

Three mathematical models, the runoff curve number equation, the universal soil loss equation, and the mass response functions, were evaluated for predicting nonpoint source nutrient loading from agricultural watersheds of the Mediterranean region. These methodologies were applied to a catchment, the gulf of Gera Basin, that is a typical terrestrial ecosystem of the islands of the Aegean archipelago. The calibration of the model parameters was based on data from experimental plots from which edge-of-field losses of sediment, water runoff, and nutrients were measured. Special emphasis was given to the transport of dissolved and solid-phase nutrients from their sources in the farmers' fields to the outlet of the watershed in order to estimate respective attenuation rates. It was found that nonpoint nutrient loading due to surface losses was high during winter, the contribution being between 50% and 80% of the total annual nutrient losses from the terrestrial ecosystem. The good fit between simulated and experimental data supports the view that these modeling procedures should be considered as reliable and effective methodological tools in Mediterranean areas for evaluating potential control measures, such as management practices for soil and water conservation and changes in land uses, aimed at diminishing soil loss and nutrient delivery to surface waters. Furthermore, the modifications of the general mathematical formulations and the experimental values of the model parameters provided by the study can be used in further application of these methodologies in watersheds with similar characteristics.

History and necessity: the evolution of soil conservation technology in a Jamaican farming system

The soil conservation campaigns that have been a prominent feature of Jamaican agricultural policy since the 1950s are frequently presented as having failed to ameliorate the problem of soil erosion in hillside agriculture. A case study of a small farming community in the Blue Mountains explores the development of the soil conservation practices currently employed by farmers. The use of trash barriers in carrot farming is described and the origins of this technology and its subsequent adaptation are considered. The study concludes that extension interventions and government policy have influenced the development of current soil conservation practices; practices which have their roots in indigenous techniques. Other factors such as the adaptation of trash barriers to suit local conditions and their importance in soil fertility management also play a role in their widespread use in the study area. The study demonstrates that to understand the process of technical change in farming communities, it is necessary to consider a range of factors, external and internal, technical and social, that have over time influenced farmers’ decision making.

Chemical contamination of the East River (Dongjiang) and its implication on sustainable development in the Pearl River Delta

A recent survey reveals that water quality and river sediments of Dongjiang (the East River) have been mildly contaminated by heavy metals and organic chemicals, such as copper, lead, PCBs, PAHs and HCHs. According to photogrammetic surveys, the sources of contamination are closely related to human activities, such as domestic and industrial discharges, agricultural chemical applications and soil erosion due to deforestation. The level of water and sediment contamination is most serious at the mid-river section near the urban of Weizhou. Due to natural dilution and diffusion, the levels of contamination are slightly decreased at the medium low section of the River near Qiaotou and Matan. Nevertheless, the levels of contamination increase again in the lower river section near Shenzhen, which is a highly developed economic zone. Since Dongjiang is the major source of potable water supply for Hong Kong (nearly 80% of potable water of Hong Kong is abstracted from Dongjiang) and the other parts of the Pearl River Delta (PRD), such organic and inorganic pollution merit concern. Ironically, most of the industrial and commercial activities in the watershed of Dongjiang are business investments of Hong Kong citizens. Cross-border environmental efforts should be enhanced with collaboration of different jurisdictions to achieve targets of regional sustainability.

An expert system/neural network model (ImpelERO) for evaluating agricultural soil erosion in Andalucia region, southern Spain

Soil erosion by water is one of today’s most important environmental problems, in great part due to changes in agricultural land use and management. This paper illustrates the formulation, calibration, sensitivity and validation analysis of a hybrid model of expert decision trees and artificial neural networks (named ImpelERO) to evaluate the soil erosion process A total of 237 field units were selected, which represent 34 major land resource areas (MLRAs)for five traditional crops in the Andalusian region, southern Spain. The field units observed cover the whole range of erosion events, from what was considered very small to extreme erosion. Seventy-six per cent of the fields suffered small, moderate or large erosion problems. However, only 14% of the fields suffered very small, and 10% of the fields suffered very large or extreme erosion problems. Because of the complexity of the soil erosion process, and the interrelationships of the parameters, ImpelERO was developed as an Universal Soil Loss Equation (USLE) type model following traditional land evaluation analysis and advanced empirical modelling techniques. Using expert-decision trees, soil survey information and expert knowledge of the soil erosion process were combined through land and management qualities. An artificial neural network approach was then applied to capture the interactions between the land and management qualities and one output: vulnerability index ( V i) to soil erosion. The neural network was trained using the Correlation-cascade algorithm. The trained network estimated the output with a high degree of accuracy (maximum deviation 14%), and also had a good generalisation capacity. By means of correlation analysis, observed erosion vulnerability data were compared with predicted data using a previously developed model and using the ImpelERO model. The latter model gave more accurate results ( r = 0.91) than the previous approach ( r = 0.66). Along with the prediction of soil loss by water erosion, ImpelERO could be used as a optimisation tool for selecting the land use and management practices which satisfy the optimum environmental protection including reduction of soil erosion.

Economically efficient watershed management with environmental impact and income distribution goals

This paper presents a methodology for incorporating environmental impacts and income distribution goals in economic analysis of watershed management policies. Empirical results on a small Illinois, USA, watershed indicate that farm costs are increased notably by restricting agricultural pollution and soil erosion. The income distribution constraint also reduces economic efficiency, but the efficiency loss due to implementing this constraint is less than 10% of the costs resulting from environmental regulations. An ex post comparison of these results with the actual payments offered to farmers under the incentive program currently in place in the watershed reveals that these payments are approximately equal to the losses estimated by the analysis when the burden of environmental control is shared equally among the farmers.

Contemporary erosion of the Canadian landscape

Studies of contemporary patterns of erosion in the glaciated and largely undisturbed Canadian landscape reveal spatial patterns that do not conform to the conventional concepts of drainage basin sediment delivery. In particular stream and valley side sediment sources dominate over erosion of the land surface, and specific (unit) sediment yield is often positively, rather than inversely, related to drainage area. Much of this is a legacy of glaciation that left large quantities of sediment in the landscape and disrupted regional drainage patterns. The absence of an integrated drainage network affects sediment delivery in many areas. To some extent unusual patterns of specific yield are to be expected in large drainage basins where environmental and geologic conditions may vary considerably within the basin. Only in the agricultural areas of the Great Lakes basin and St. Lawrence valley do more conventional patterns of erosion occur. Applied studies related to agricultural soil erosion and pollution have helped to illuminate the pathways and sources of sediment in particular cases and show the effects of landscape disturbance.

Principles of soil conservation for cultivated land

Summary Soil erosion by water from cultivated land is the most threatening degradation process for sustainable soil productivity. Both in mechanized as well as in subsistence agricultural systems soil erosion is a long-term threat, although industrialized agriculture has hidden somewhat the damage of this degradation through increased fertilizer and other inputs. Soil conservation is a problem of implementation in both systems. One has to differentiate between on-farm and off-farm influenced measures. On-farm measures are again subdivided into biological and mechanical measures. For the detection of soil erosion as a problem in the field, seven rules of thumb are given to detect and validate past degradation as well as actual processes. Potential soil erosion can also be estimated with the help of some formula and experience rules. In mechanized cultivation systems, soil conservation measures must be off-farm influenced measures and subject to and beneficeries of policies, tax regulations or subsidies. On-farm biological conservation is implemented through minimum tillage, cropping patterns and landuse changes. Mechanical structures such as bunds or terraces may be developed, but need spacing to fit the slope steepness and a good design. An upper limit for cropping is given at about 15% slope gradient for mechanized cultivation systems. In subsistence cultivation systems, on the other hand, off-farm influenced measures are mainly social or service incentives, where motivation and agitation play a more important role. On the farms, mechanical measures become more important, since biologically, subsistence farmers have cultivation practices which are highly optimized for their survival strategy, well adapted to the natural, social, political and economic prerequisites. Bunds, i.e. earth walls across the slope, or terraces, i.e. systems of bunds with a levelling of the surface area between them, or other earthmoving activities, however, must be well planned according to agro-ecology, soils, and the populations concerned.

Une méthode cartographique d'évaluation de processus physiogéographiques appliquée à l'érosion hydrique des sols

A cartographie approach for evaluating physico-geographical processes. — The approach is to map separately the controls of the process and the spatial distribution of the process itself, then to compare both by data processing techniques. This yields interesting complementary results to the usual experimental plot approach of physico-geographical processes : it produces a better spatial representativeness of the results; it gives a better knowledge of threshold values in the factor interaction system; it is relatively cheap. Two examples of the method are given : agricultural soil erosion in the Alsace vineyards (France) and in two sectors near Oran (Algeria).

Comparative measures of effectiveness in farm‐level soil conservation

Abstract. Agricultural soil erosion is serious in developed and developing countries alike. Soil runoff can diminish long‐term land productivity and accompanying sedimentation of waterways contributes to flooding and substantially reduces both water quality and the useful life of reservoirs and irrigation works. To design effective erosion control policies, planners need to be able to evaluate conservation efforts by fanners. The research reported here develops comparative measures of conservation effectiveness using the management factors of the Universal Soil Loss Equation. These factors measure the effectiveness of farmers' existing conservation practices and can help policymakers identify the regions and types of farms which are not using effective erosion control measures, enabling them to direct scarce personnel and funds to areas where they are most needed.

Agricultural Land Markets and Soil Erosion: Policy Relevance and Conceptual Issues

American Journal of Agricultural EconomicsVolume 67, Issue 5 p. 938-942 Invited Papers Session Agricultural Land Markets and Soil Erosion: Policy Relevance and Conceptual Issues David E. Ervin, David E. Ervin associate professor Department of Agricultural Economics, University of MissouriSearch for more papers by this authorJohn W. Mill, John W. Mill budget analyst Division of Budget and Planning, Missouri Office of Administration, Jefferson CitySearch for more papers by this author David E. Ervin, David E. Ervin associate professor Department of Agricultural Economics, University of MissouriSearch for more papers by this authorJohn W. Mill, John W. Mill budget analyst Division of Budget and Planning, Missouri Office of Administration, Jefferson CitySearch for more papers by this author First published: 01 December 1985 https://doi.org/10.2307/1241350Citations: 24AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume67, Issue5December 1985Pages 938-942 RelatedInformation

Soil Erosion Measurement and Soil Conservation Research in Cultivated Areas of the UK

Agricultural soil erosion by both water and wind is a local scale problem in the UK, particularly on the sandy and sandy loam soils under continuous cereal production or market gardening in the midland and eastern counties of England. Mean annual rates of soil erosion by water on these soils in fields on hillslopes up to 11? can exceed 2 kg/m2 when rilling occurs, compared with a rate for top soil renewal of only about 0.1 kg/m2. Rates as high as 1.9 kg/m2 have been recorded in individual storms and storm rates greater than 0.2 kg/m2 can occur as frequently as in four years out of seven. Storm losses by wind erosion are of similar magnitude but those for gully erosion are much higher with rates reaching 15 to 19 kg/m2 in single storms. Research into soil conservation has been carried out on Experimental Husbandry Farms and by farmers and commercial organizations with a direct interest in the problem. It has been largely limited to the use of shelterbelts, guard crops, soil stabilizers and land imprinting or pressing to control wind erosion with virtually no work having been undertaken on water erosion control. There is a need for more fundamental research which will allow the mechanics of the control measures to be

Management of Watersheds and Water Resources Planning

ABSTRACT Siltation of reservoirs is a consequence of poor management of watersheds. Four case studies have been highlighted in this study to indicate the reasons for increased siltation, such as population growth, deforestation, extensive agricultural operations, cattle grazing and soil erosion. Nizamsagar and Sriramsagar are reservoirs heavily silted due to lack of proper management practices in the watershed. Machkund and Tungabhadra are reservoirs in which siltation has been contained through systematic management of the watersheds. Procedures needed for managing watersheds in water resources projects have been derived based on the four case studies