bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of crop rotation and residue management on properties of cracking clay soils under irrigated cotton‐based farming systems of new south wales
Authors: Hulugalle N. R. , Cooper J. 
Published: February 2007

AbstractThe effects of planting cereal or leguminous crops in rotation with irrigated cotton (Gossypium hirsutum L.) on the properties of cracking clay (swelling) soils in the Macquarie and Namoi Valleys of New South Wales, Australia were evaluated during the summer of 1992–3. The observations were made on commercial farmers' fields. The soil properties evaluated were the particle size distribution, the dispersion index, the plastic limit, the percentage of coarse (particle diameter 212–2000 μm) and fine (particle diameter 53‐212 μm) particulate soil organic matter, soil respiration rate, soil reactivity, soil aggregate density, pH, nitrate‐N and exchangeable Ca, Mg, K and Na. In general, the planting of rotation crops decreased the dispersion index, plastic limit and soil aggregate density, and increased the amount of coarse particulate organic matter. Planting rotation crops also resulted in significantly higher clay and lower silt contents in the Macquarie Valley, and significantly higher soil respiration in the Namoi Valley. Soil pH, nitrate‐N and exchangeable cation concentrations were not significantly affected by planting rotation crops in the Macquarie Valley, whereas exchangeable Na was increased in the Namoi Valley. The retention of crop residues in situ, compared with burning crop residues, decreased the dispersion index, plastic limit and aggregate density, and increased the amount of coarse particulate soil organic matter at all measured depths of the Macquarie Valley. The retention of crop residues in the Namoi Valley decreased the plastic limit and dispersion index only in the 0–50 mm depth range, whereas burning crop residues increased exchangeable K at all depths. In general, planting rotation crops and the retention of crop residues had greater beneficial effects on the soil physical properties in the Macquarie Valley than in the Namoi Valley, and in the topsoil compared with the subsoil. These differences are attributed to a shorter rotation interval in the Namoi Valley, smaller amounts of coarse particulate soil organic matter in the subsoil, and differing soil types in the two valleys. In the Namoi Valley the coarse organic matter produced by leguminous crops appeared to be more effective in promoting structural stability than that from non‐leguminous crops, although no such difference was observed in the Macquarie Valley.
Planning strategies and funding modalities for land rehabilitation
Authors: Kessler J. J. , Laban P. 
Published: February 2007

AbstractA framework for planning development strategies for sustainable land use in developing countries is proposed based on the carrying capacity concept. The rehabilitation of degraded land includes a stabilization and a restoration phase, with corresponding measures to be taken and funding modalities to be explored. Restoration measures focus on the rehabilitation of ecosystem functions, but are effective only when preceded or accompanied by measures stabilizing exploitation levels. Short‐term benefits are required to ensure local participation, but may be counterproductive when long‐term ecological rehabilitation is the major objective. Incentives are important policy instruments to enhance participation by rural communities in rehabilitation activities. Long‐term economic, ecological and social (humanitarian) arguments, at a scale surpassing the local level, should receive more attention in the process of justifying investments for land rehabilitation. Some criteria and conditions to be met both at a macro‐scale and at the local level are discussed.
Land evaluation in an area of severe erosion: The loess plateau of china
Authors: Fu B. , Gulinck H. 
Published: February 2007

AbstractLand evaluation is an important basis for landscape and land use planning. A framework was developed for land evaluation in an area of severe erosion, focusing on integrative, process and ecological analyses. Two classification systems, soil quality and erosion risk, were combined in the land evaluation framework. The Quanjiagou catchment, with typical loess hill and gully topography, in the loess plateau of China was selected as the study area. A geographical information system (GIS) was used for data storage, analysis and display. The soil quality classification was based on the main characteristics of the soils (soil organic matter, effective depth of soil and soil moisture); four soil quality classes were defined in the study area. Slope, micro‐landform type and the type and processes of soil erosion were integrated to classify the erosion risk. The soil qualities and erosion risk for each site were combined using the GIS to evaluate the suitability of the land for farmland, grassland and forest. By comparing these results with the current land use, measures for better land use and conservation are suggested.
A legacy of competing imperatives: Environment and development in australia since 1788
Authors: Powell J. M. 
Published: February 2007

AbstractAustralia's environments have been dramatically transformed by immigrant communities who were impelled by a simple utilitarian dream and obliged by geographical and historical circumstance to contend with accumulating uncertainties, including those connected with the operation of Nature's own independent dynamic. With the exception of a few critical junctures and significant but highly localized settings which are reasonably well supplied with primary material, the historical records are scarcely satisfactory for fine‐textured reconstructions of changing physical landscapes. There is certainly some potential for very broad ‘indicative’ stocktaking, but unavoidable imprecisions and the irritating problem of discontinuities rule out the most ambitious of International Geosphere‐Biosphere Programme (IGBP) style studies. Therefore a major premise of this discussion is the acceptance that we are obviously better placed to offer a range of underpinning social, political and economic analyses than to launch into the production of confident, large‐scale reconstructions of the past ‘faces’ of Australia. The bulk of this paper explores that proposition and is confined to such analyses. On the other hand, it also suggests that the time is ripe for tailoring novel co‐operative research into landscape change in the ‘European’ era, especially by combining physical and documentary evidence in the investigation of carefully selected sites and situations.
Land use choices in a changing world
Authors: Chisholm A. H. 
Published: February 2007

AbstractThe primary factors which are likely to mould future non‐urban land use patterns in Australia are identified. Over the past three decades the rate of increase in land productivity in Australia has been higher than for any other OECD country. Land degradation does not appear to have seriously threatened agricultural output over the last 45 years. However, there is cause for concern that land degradation, attributable to past activities, may only now be exerting a significant impact on productivity in some regions. Many of the services provided by natural resources have been underpriced; consequently, there has been a bias in agricultural research towards technologies that enhance on‐site productivity, but which impose excessive external social costs. Underpricing of native trees from state‐owned and managed forests appears to have caused excessive exploitation of these forests and lowered the establishment of softwood and hardwood plantations. Many important land use and land cover issues remain unresolved in Australia's rangelands, including questions relating to the optimum grazing pressures, the role of fires in the suppression of unpalatable shrubs and appropriate management strategies for controlling numbers of large kangaroos and rabbits and protecting the natural habitat of threatened species of native animals. The riparian zone, which acts as a crucial buffer between rivers and their catchments, has been one of the most neglected environments in Australia, possibly because river banks, floodplains and wetlands do not fit neatly into the category of land or water. It is widely accepted that the aboriginal peoples must be involved in seeking to achieve the sustainable use of our natural resources. How to achieve the appropriate participation and involvement of aboriginal peoples is a problem that is yet to be fully resolved. In many respects, renewable natural resource systems in Australia are unique. Knowledge creation and application will be a most important resource for the future management of our agricultural forestry and natural resource systems. The solutions to many of the major renewable resource problems do not depend on technology alone. Institutional changes and incentive structures are required that recognize and take account of the pervasive and complex interrelationships between human reactions and responses in their production and consumption activities and the environment.
Understanding farmers' attitudes to land degradation: Some methodological considerations
Authors: Reeve I. J. , Black Alan W. 
Published: February 2007

AbstractThe attitudes of farmers in the New England region of Australia are internally consistent in some cases, but in others seem inconsistent. Cluster analysis and discriminant analysis indicate that even internally inconsistent respondents can be divided into definable categories, and differences in response patterns relate significantly to other variables such as business structure, commodities being produced, attitudes to external influences in decision‐making and to conservation generally. The results suggest that for policy‐oriented research on attitudes to complex environmental issues, analysis should take account of data which do not necessarily conform to the requirements for unidimensional scale construction, but which can usefully be interpreted by analysing respondent clusters.
Evaluation of the characteristics of 14 cover crops used in a soil rehabilitation trial
Authors: Barber R. G. , Navarro F. 
Published: February 2007

AbstractMany of the soils in Santa Cruz Department, Bolivia, are degraded by serious weed infestation, subsoil compaction, and low organic matter and nitrogen contents. Fallow periods with cover crops are frequently used to recuperate the fertility of degraded soils, but little information exists on the desired characteristics of cover crops for this purpose. The aim of this study was to describe those characteristics, believed to be most relevant to the rehabilitation of degraded soils in Santa Cruz, of 14 cover crops, which included three grasses, nine legumes, and two winter cover crops sown after summer soybean (Glycine max). The cover crop characteristics, evaluated over two years, were ease of establishment, competitiveness against weeds, tolerance to drought, dry matter production and nutrient contents of the above‐and below‐ground residues, nodulation, rooting density and root diameters. The three grasses Tobiata (Panicum maximum var. Tobiatd), Centenario (Panicum maximum var. Centenario) and Brizantha (Brachiaria brizantha) appeared to be the most promising for increasing soil organic matter contents, and the three grasses and groundnuts (Arachis hypogaea)/pigeon pea (Cajanus cajan) for the recuperation of subsoil structure. Mucuna deeringiana and Lablab (Dolichos lablab) were the most promising for increasing soil N status. All of these cover crops competed successfully with weeds.
Application of spectral mixture modelling to the regional assessment of land degradation: A case study from basilicata, Italy
Authors: Zhou X. , Folving S. 
Published: February 2007

AbstractMapping and monitoring of land degradation processes such as soil erosion has become an important task for both agricultural and environmental planners. The potential of using SPOT‐HRV data for assessing the types of soil erosion and land degradation is obvious. The spectral information and the spatial resolution of the multispectral data allow a high accuracy in local mapping and rapid regional assessment.In Basilicata, southern Italy, spectral mixture modelling (end‐member techniques) has been applied to extract relevant information for assessing soil erosion. This method allows an estimate of the proportion of surface cover types (end‐members) within the pixel. From the data sets average spectral responses were extracted for growing vegetation, non‐green sclerophylous vegetation mixed with dry grasses and bare soil. Using these spectra as end‐members in the model, it was possible to decompose the spectral information of all pixels into the three surface components, giving the percentage cover of the three types within every pixel. Classification of the pixels according to the percentage of surface cover or bare soil allows an assessment of erosion or erosion risk.
Studies of the causes of soil erosion on marl soils in northern Algeria: The role of traditional soil tillage
Authors: Prinz D. , Gomer D. , Belz S. 
Published: February 2007

AbstractIn semiarid regions such as the Maghreb, the pressure on natural resources such as water and soil are increasing. Reservoir sedimentation and soil degradation are basic problems in these areas. The Oued Mina watershed (5000km2) has been chosen by the Algerian Ministry of Agriculture and the Deutsche Gesellschaft für Technische Zusammenarbeit (GTZ) GmbH for a Technical Cooperation Project to quantify soil erosion and to assess various methods of soil and water conservation at the watershed level. The study area (about 1000km2) is essentially a landscape of ancient dissected plateaux, with badlands as a major feature in some places. Both the agricultural areas and the reservoir, located at the basin outlet, are strongly affected by soil degradation. The climate is semiarid Mediterranean (wet winters), with an average annual rainfall of 300–350mm. Investigations using a large rainfall simulator revealed that soil tillage on marls under semiarid conditions could be an excellent tool to diminish runoff and soil erosion.
Agricultural terrace abandonment in the alpujarra, andalucia, spain
Authors: Douglas T. D. , Kirkby S. J. , Critchley R. W. , Park G. J. 
Published: February 2007

AbstractThe environmental impact of recent changes in land use is assessed in a part of Andalucia, southern Spain, where the deintensification and abandonment of low productivity upland areas is taking place. In the uplands of the Alpujarra, the traditional landscape most at risk is that of the irrigated cultivation terraces. These have often been established centuries ago and rely on water abstracted from streams draining the southern slopes of the Sierra Nevada. The causes of this deintensification include labour shortages, with many Alpujarra municipios reporting population decreases of up to 50 per cent since 1950. Landsat Thematic Mapper digital data from May and August 1992 have been used to identify the various land cover components of the Alpujarra. Ground verification undertaken in September 1992 and April 1993 has confirmed that deintensification of terraced areas around the villages of Trevélez (at 1500m, the highest village in Spain) and Pórtugos (1300 m) can be identified as either grassland or matorral. It is recognized that many classes of land cover are mosaics with several elements at a subpixel scale (e.g. terrace risers with fruit trees). However, the output from image processing has allowed areal estimates of the main land covers representing deintensification within the terraced zone. The pattern of deintensification of terraced land is fairly complex. It can be assumed that all terraces were irrigated and cropped at some stage. Land which is no longer cropped is usually grazed and the invasion of matorral species is common, particularly when irrigation ceases. Unirrigated tree crops and vines are sometimes planted on terraces no longer used for cropping. A model of deintensification of farming on terraced land in the Alpujarra is presented.
Mapping environmental carrying capacity using an artificial neural network: A first experiment
Authors: Lein J. K. 
Published: February 2007

AbstractThe economic development activities of an increasing world population threaten the assimilative capacity of our environment and have stimulated interest in the concept of environmental carrying capacity. While the pace of land transformations has encouraged the refinement of information technologies such as satellite remote sensing to provide a synoptic view of earth‐system processes, the volume of information these systems generate and the high level of expertise required to translate these data retard effective and timely land‐management decision making. This paper introduces a methodology that employs an artificial neural network trained to recognize categories of population support capacity from satellite data acquired from the NOAA‐AVHRR. The network, functioning as an ‘intelligent’ mapping tool, achieved a classification accuracy of 77.5 per cent for the study site and points to the potential role a model of this type may play in land degradation monitoring.
The early performance of deciduous trees grown in acidic minespoil ameliorated with pulverized fuel ash
Authors: Perkins P. V. , Vann A. R. 
Published: February 2007

AbstractA field trial investigated the early performance of six tree species planted into an acidic minespoil ameliorated by ploughing or incorporation of 10 per cent by weight of pulverized fuel ash (PFA). Common alder, Italian alder and silver birch produced the greatest total shoot extensions for PFA‐ameliorated minespoil. Rowan, sycamore and aspen were unsatisfactory for both ameliorative treatments. PFA increased the pH of the minespoil for a period of time potentially beneficial for the establishment of the tree species. For the rate of PFA application studied, general salinity effects and cold‐water‐soluble boron both presented problems for successful tree growth.
Effects of livestock farming and recommendations for management and conservation of páramo grasslands (Colombia)
Authors: Hofstede R. G. M. 
Published: February 2007

AbstractAlthough páramos cover extensive areas in the northern Andean countries, this tropical alpine ecosystem, which evolved without large mammals, is almost unique in the world. The ecological processes of the páramos ecosystem on volcanic soils are to a large extent controlled by low temperatures and phosphorous limitation.Páramos are considered an important ecosystem because of the high degree of endemism and because of their regulative function in the hydrology of the northern Andes. Their economic value reflects their function as a drinking water reserve and their role in agriculture. Grazing and burning have a large impact on the structure of the vegetation and soil, but nutrient concentrations remain almost unchanged owing to the large nutrient immobilization capacity. The high aboveground biomass and complete coverage of the soil is of the utmost importance for the ecosystem. The management and conservation of the ecosystem is difficult if the various functions of the páramos are to be respected. If plant diversity and water storage are to be protected, but if the same production of beef and milk is to be achieved, grazing should be concentrated in a few areas only. In these areas, which must be flat and have good ground coverage, production can be sustained by an input of organic and inorganic fertilizers (phosphorus). Many other areas can remain ungrazed and left for recovery of the natural, tall vegetation with its high endemism. In the future, tourism might play an important role in the conservation of some páramos areas.
Soil factors affecting tree growth on former opencast coal land
Authors: Scullion J. , Malinovszky K. M. 
Published: February 2007

AbstractThe growth of three tree species (Alnus glutinosa, Betula spp. and Quercus spp.) was related to soil factors on two restored opencast coal sites in South Wales, UK. The main factors favouring tree growth were greater soil depth and organic content. Factors limiting growth included poor site drainage and high magnesium levels. Whilst all species were related to most of the above factors, soil depth was of particular importance for Alnus glutinosa and Betula spp., whilst site drainage had the greatest influence for Betula spp. Soil‐tree associations tended to be closer on the older of the two sites. Combinations of soil depth, percentage clay and percentage organic content in a multiple regression predicted around 40 per cent of the growth variation in Alnus glutinosa, between 6.9 and 32 per cent of that for Betula spp. and between 14.5 and 32.6 per cent of that for Quercus spp. Growth prediction for Betula spp. improved to 40.9 and 34.8 per cent when a site drainage factor was included in the regression. The development of such predictive relationships might contribute to the planning of site reinstatement for tree planting after opencast mining, and to a better ‘matching’ of tree species to site characteristics.
Laconex: A rule‐based implementation to advise on plot‐level land conservation in Vilathikulam, Southeastern India
Authors: Balachandran C. S. 
Published: February 2007

AbstractKnowledge about land conservation exists along a spatial continuum, represented at the broadest level (with least depth) by international‐level experts who have international‐level expertise, and at the narrowest level (with most depth) by the individual farmer with the most site‐specific knowledge at the plot level. This continuum covers many different aspects of knowledge about land degradation and its amelioration, including technical and cultural knowledge. This paper reports an effort (one in a series of steps) to gather, formalize, codify, and operationalize knowledge about land conservation from two different levels of the continuum. Land conservation knowledge was elicited from farmers and extension agents in Vilathikulam taluk (an area of contiguous villages) in Tamil Nadu, southeastern India, using semi‐structured interviews. The knowledge thus gained was combined with knowledge from the literature on soils and land conservation for the area. This information was organized into factual knowledge and process knowledge, and implemented in the form of general recommendations, constraints, and specific recommendations. The process of arriving at these categories was organized into several steps using a spatial anchor and soil type as keys. These were operationalized in a rule‐based computer program (LAnd CONservation EXpert ‐LACONEX), which offers land conservation advice at the plot level for Vilathikulam taluk, using an expert system development environment.
Collaboration in contingent capacities with information asymmetry
Authors: Chakravarty Amiya K. , Zhang Jun 
Published: February 2007

AbstractWe study the optimal contracting problem between two firms collaborating on capacity investment with information asymmetry. Without a contract, system efficiency is lost due to the profit‐margin differentials among the firms, demand uncertainty, and information asymmetry. With information asymmetry, we demonstrate that the optimal capacity level is characterized by a newsvendor formula with an upward‐adjusted capacity investment cost, and no first‐best solution can be achieved. Our analysis shows that system efficiency can always be improved by the optimal contract and the improvement in system efficience is due to two factors. While the optimal contract may bring the system's capacity level closer to the first‐best capacity level, it prevents the higher‐margin firm from overinvesting and aligns the capacity‐investment decisions of the two firms. Our analysis of a special case demonstrates that, under some circumstances, both firms can benefit from the principal having better information about the agent's costs. © 2007 Wiley Periodicals, Inc. Naval Research Logistics 54:, 2007