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Land Used (land + used)

Distribution by Scientific Domains

Earth and Environmental Science	50%

Selected Abstracts

Rainfall variability and hydrological and erosive response of an olive tree microcatchment under no-tillage with a spontaneous grass cover in Spain

EARTH SURFACE PROCESSES AND LANDFORMS, Issue 7 2010
E. V. Taguas
Abstract Most studies on runoff and soil loss from olive orchards were performed on plots, despite the fact that measurements that examine a range of erosive processes on different scales are essential to evaluate the suitability of the use and soil management of this type of land. The main environmental limitations of much of the land used for olive orchards in the Mediterranean are the steep slopes and the shallow soil depth , and this was the case in the study area. Soil erosion and runoff over two hydrological years (2005,2006 and 2006,2007) were monitored in an olive orchard microcatchment of 6·1,ha under no-tillage with spontaneous grass in order to evaluate its hydrological and erosive behaviour. Moreover, soil parameters such as organic matter (%OM), bulk density (BD) and hydraulic saturated conductivity (Ks) were also examined in the microcatchment to describe management effects on hydrological balance and on erosive processes. In the study period, the results showed runoff coefficients of 6·0% in the first year and 0·9% in the second. The differences respond to the impact of two or three yearly maximum events which were decisive in the annual balances. On the event scale, although maximum rainfall intensity values had a big influence on peak flows and runoff, its importance on mean sediment concentrations and sediment discharges was difficult to interpret due to the likely control of grass cover on volume runoff and on soil protection. In the case of annual soil erosion, they were measured as 1·0,Mg,ha,1,yr,1 and 0·3,Mg,ha,1,yr,1. Both are lower than the tolerance values evaluated in Andalusia (Spain). These results support the implementation of no-tillage with spontaneous grass cover for sloping land, although the reduced infiltration conditions determined by Ks in the first horizon suggest grass should be allowed to grow not only in spring but also in autumn. In addition, specific measurements to control gullies, which have formed in the terraced area in the catchment, should be included since it is expected that they could be the main sources of sediments. Copyright © 2010 John Wiley & Sons, Ltd. [source]

Green Energy or Organic Food?: A Life-Cycle Assessment Comparing Two Uses of Set-Aside Land

JOURNAL OF INDUSTRIAL ECOLOGY, Issue 3 2001
Richard van den Broek
Summary Bioenergy has a large worldwide potential in future climate change abatement, although its application may become limited by demands for land for other functions. The aim of this study was to make an environmental assessment of the use of energy crops in the Netherlands in a context that incorporates scarcity of land. A base case system was defined, consisting of conventional winter wheat production, set-aside land (1 hectare, together), and the production of coal-based electricity. Using life-cycle assessment, we compared this system with (1) a green energy system in which willow is cultivated on the set-aside land to replace the coal-based electricity and (2) an organic agriculture system in which the full hectare produces wheat under the Dutch EKO organic agriculture standard. In this way, the functional unit and the amount of land used is the same in each system. The final system comparison was based on normalized scores per environmental theme. The green energy system scored the best with respect to acidification, climate change, and energy carrier depletion. The organic food system scored best on terrestrial eco-toxicity and slightly better on the mutually related themes of seawater and seawater sediment eco-toxicity. The base case system performed slightly better with regard to eutrophication. Preferences, from an environmental point of view, for one of the systems should be determined by environmental policy priorities and the severity of local environmental problems. The case studied here shows that when climate change, energy carrier depletion, and acidification are the main drivers behind environmental policy, one should focus not on the extensification of agriculture, but rather dedicate more land to energy crops. Extensification of agriculture would be the preferred system when toxicity from pesticides is considered the main problem. [source]

Utilization of Metallurgical Slag as Resource Materials in China

ASIA-PACIFIC JOURNAL OF CHEMICAL ENGINEERING, Issue 3-4 2006
Jian-Guo Shen
New developments that utilize metallurgical slag as resource materials are important in order to decrease the land used for disposal of slag, reducing environmental pollution, and also promoting the continuous and highly efficient development of China's metallurgical industry. Current major problems and possible future uses of metallurgical slag are discussed based on assessments of present uses. Improving the use of metallurgical slag as resource materials requires the development of new high-value-added products. [source]

Technical Efficiency, Technological Change and Output Growth of Wheat Farms in Saskatchewan

CANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 2 2001
Konstantinos Giannakas
This paper utilizes recent advances in stochastic decomposition methodology to examine the level and the driving forces of technical efficiency for an unbalanced panel data set of 100 wheat farms in Saskatchewan during the period 1987,95. The contributions of resource use and total factor productivity to the output growth of these farms are also investigated. The analysis indicates moderate levels of technical efficiency and a considerable variation of efficiency ratings among Saskatchewan farms. The ownership status, composition of labor employed, participation in crop insurance and government income transfer programs, participation in Top Management Workshops, degree of specialization, level of intensification and mechanization of production, type of land used, and the farm debts account for differences in efficiency across wheat farms. Even though the productive efficiency of the farms has been increasing over time, the results show that technological progress was the main source of productivity and output growth during the study period. L'analyse que voici fait appel aux plus récentes améliorations apportées à la méthode de décomposition stochastique pour déterminer le degré d'efficacité technique et les motivations d'ungroupe non pondéré de 100 producteurs de blé de la Saskatchewan entre 1987 et 1995. Les auteurs ont aussi déterminé dans quelle mesure l'exploitation des ressources et la productivité totale des facteurs affectent la croissance de la production dans les exploitations concernées. L'analyse révéle un degré moyen d'efficacité technique et une variation considérable du rendement chez les agriculteurs de la Saskatchewan. La variation du rendement s'explique par divers facteurs comme le type de propriété, la composition de la main-d',uvre, l'inscription aux programmes gouvernementaux d'assurance récolte et de transfert du revenu, la participation à des ateliers de gestion, le degré de spécialisation, le niveau d'industrialisation et de mécanisation de la production, le genre de terres cultivées et la dette de l'exploitant. Même si la productivité des fermes a augmenté au fil des ans, les résultats indiquent que le progrés de la technologie demeure la principale source d'une croissance du rendement et de la production durant la période à l'étude. [source]