The profile distribution of soil organic carbon (SOC) and total nitrogen (TN) are important indicators for predicting and simulating the effects of human activities on soil fertility and quality. However, most studies have focused on these changes in surface soil or the top 100 cm of short-term cultivated farmlands in arid regions.
Résultats de la recherche
Showing items 1 through 9 of 55.-
Library ResourceArticles et Livresdécembre, 2015Chine
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Library ResourceArticles et Livresdécembre, 2015Afrique du Sud, Brésil, Inde, Chine, Afrique australe
Acacia mearnsii De Wild (black wattle) is an important plantation species for tannin production and woodchip exports in South Africa and Brazil. This study provides an updated overview of the black wattle industries in both countries, including planted areas and land ownership, silviculture and management, bark extract production, woodchip exports, as well as key research and development issues. The current total planted area to black wattle is 110 000 ha in South Africa and c. 170 000 ha in Brazil. In both countries black wattle is mainly cultivated by farmers (c.
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Library ResourceArticles et Livresdécembre, 2015Chine
Up to 50% of nitrogen (N) fertilizer can remain in soil after crop harvest in dryland farming. Understanding the fate of this residual fertilizer N in soil is important for evaluating its overall use efficiency and environmental effect. Nitrogen-15 (¹⁵N)-labeled urea (165 kg N ha ⁻¹) was applied to winter wheat (Triticum aestivum L.) growing in three different fertilized soils (no fertilizer, No-F; inorganic nitrogen, phosphorus and potassium fertilization, NPK; and manure plus inorganic NPK fertilization, MNPK) from a long-term trial (19 years) on the south of the Loess Plateau, China.
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Library ResourceArticles et Livresdécembre, 2011Mongolie, Asie orientale
Changing environmental and socio-economic conditions make land degradation, a major concern in Central and East Asia. Globally satellite imagery, particularly Normalized Difference Vegetation Index (NDVI) data, has proved an effective tool for monitoring land cover change. This study examines 33 grassland water points using vegetation field studies and remote sensing techniques to track desertification on the Mongolian plateau.
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Library ResourceArticles et Livresdécembre, 2012Asie, Asie central, Ouzbékistan, Chine, Viet Nam, Arménie, Europe orientale, Moldova, Fédération de Russie
During the past two decades agrarian (‘land and farm’) reforms have been widespread in the transition economies of Eastern Europe, the Caucasus and Central Asia (EECCA), following earlier ones in Asia (China and Vietnam). However, independent family farms did not become the predominant sector in most of Eastern Europe. A new dual (or bi-modal) agrarian structure emerged, consisting of large farm enterprises (with much less social functions than they had before), and very small peasant farms or subsidiary plots.
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Library ResourceArticles et Livresdécembre, 2012Chine
Complexity embedded in coastal management leads to numerous questions as to how inherent spatial and temporal linkages among evapotranspiration (ET), depth to groundwater and land-use/land-cover change (LUCC) could affect the dynamics among these seemingly unrelated events. This article aims to address such unique dynamics in the nexus of physical geography and ecohydrology.
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Library ResourceArticles et Livresdécembre, 2012Japon
Human activities have created high nutrient surpluses in agricultural lands due to the increasing rate of chemical fertilizer application and the increase in livestock production. To analyse the nutrient characteristics and estimate the nutrient load in streams, we conducted extensive field survey and water quality experiments from 2007 to 2008 in Koise River, a major river of the Lake Kasumigaura watershed, Japan. Water quality indicators of total nitrogen (TN), total phosphorus (TP) and total organic carbon (TOC) were investigated.
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Library ResourceArticles et Livresdécembre, 2011Chine
This article applies a nonlinear machine learning method, support vector regression (SVR), to construct empirical models retrieving water quality variables using remote sensing images. Based on in situ measurements and high-resolution multispectral SPOT-5 (Satellite Pour l'Observation de la Terre) data, a fittest nonlinear function between input and output was obtained from this method, and SVR model parameters were selected automatically using a genetic algorithm (GA).
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Library ResourceArticles et Livresdécembre, 2012Chine
This article presents a sufficient comparison of two types of advanced non-parametric classifiers implemented in remote sensing for land cover classification. A SPOT-5 HRG image of Yanqing County, Beijing, China, was used, in which agriculture and forest dominate land use. Artificial neural networks (ANNs), including the adaptive backpropagation (ABP) algorithm, Levenberg–Marquardt (LM) algorithm, Quasi-Newton (QN) algorithm and radial basis function (RBF) were carefully tested.
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Library ResourceArticles et Livresdécembre, 2012République de Corée
The aim of this study is to extract landslide-related factors from remote-sensing data, such as Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) satellite imagery, and to examine their applicability to landslide susceptibility near Boun, Korea, using a geographic information system (GIS). Landslide was mapped from interpretation of aerial photographs and field surveying. Factors that influence landslide occurrence were extracted from ASTER imagery.
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