Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
Soil grid data were gathered from 110 points and three depths in the Vagia plain, Greece. A total of 48 soil parameters for each point were studied and reduced using multivariate analysis techniques, based on a common variance criterion, and Principal Component Analysis, without loosing less than 8% of the topological information. They were finally reduced to twelve properties which were the most...
Africa, with a total land mass of about 30.7 million km 2 and a population exceeding 746 million persons, has generally lagged behind in agricultural development. Sub-Saharan Africa (excluding South Africa) is the poorest developing region, with 29 out of 34 countries being some of the poorest in the world. The purpose of this study is to develop a Soil Taxonomy map, based on the FAO Soil...
A practical problem in land management in southern France is the classification of cultivated fields according to their hydrological properties as a function of soil and topography. Lack of spatial contiguity and overlap in data space render conventional numerical methods for soil and landscape classification unreliable. Fuzzy k-means with extragrades have been used to create a spatially coherent...
Intensive irrigated rice production technologies have changed the input-output balance of many soil nutrients in tropical Asia, but their impact on soil fertility has not been studied adequately at regional scales. To assess the current soil fertility status in irrigated riceland of Nueva Ecija, Philippines, soil samples were collected from 384 farmers' fields in a 19,176 ha area. Block-kriged maps...
In recent years, methods of fuzzy reasoning were developed for situations akin to those found in land evaluation, in which a decision about land suitability must often be based upon imprecise information. The accuracy of such land evaluations depends on the quality of weighing land qualities with respect to their effect on crop production. The advantage of the fuzzy set approach is that class boundaries...
Numerical classification methods may provide an alternative to manual landform delineation using aerial photographs, a subjective process that requires much knowledge of the landscape in question. Continuous classification (fuzzy set) methods and unsupervised (ISODATA) classification techniques were used to classify the landscape of a study area in southwestern Wisconsin, USA. Each pixel of a 10-m...
Fuzzy systems, including fuzzy set theory and fuzzy logic, provide a rich and meaningful improvement, or extension of conventional logic. The mathematics generated by this theory is consistent, and fuzzy set theory may be seen as a generalisation of classic set theory. Applications in soil science, which may be generated from, or adapted to fuzzy set theory and fuzzy logic, are wide-ranging: numerical...
High concentration of heavy metals caused by soil pollution processes vary in a three-dimensional space. This study focuses on a strip of land which was sampled at three different depths. Fuzzy classification by fuzzy k-means was used to analyze the spatial variability for each separate layer. The concentrations of heavy metals showed abrupt changes in geographical space and the coefficients of variation...
This paper deals with the sensitivity of classification, i.e. the extent to which the modification of soil properties influences the degree of membership in a fuzzy or continuous soil classification system. The sensitivity around the centroids of four Australian Great Soil Groups (GSG), black earth, red-brown earth, krasnozem and euchrozem was determined for the 21 attributes that define the classes...
A fuzzy logic based model (called a similarity model) was developed to represent soil spatial information so that soil landscape is perceived as a continuum in both the parameter space and the geographic space. The similarity model consists of two components: the similarity representation component and a raster representation scheme. The similarity representation component uses a set of prescribed...
Soil maps as multi-purpose models of spatial soil distribution have a much higher level of aggregation (map units) than the models of soil processes and land-use effects that need input from soil maps. This mismatch between aggregation levels is particularly detrimental in the context of precision agriculture. It is argued that, in order to bridge the gap, soil distribution modelling should be based...
This article traces the development of conceptual paradigms of soil classification and mapping from the pre-1960's model of crisp classes in attribute space linked to crisply delineated mapping units in geographical space, to modern approaches using fuzzy classification and geostatistical interpolation for simultaneously handling continuous variation in both attributes and location. Continuous classification...
Fuzzy set logic is used to express the risk in soil interpretation ratings. Uncertainty inherent in the definition of estimated sets of properties used to characterize a given map unit is described with the help of fuzzy sets. Threshold levels of soil properties (where no adverse consequences can be expected) are used to formulate a continuum for assessment. Different types of adverse consequences...
Fuzzy set theory is a useful tool for dealing with uncertainty in the interpretation of quantitative information on soil properties, particularly when this is automated in an expert system or geographical information system (GIS). A fuzzy set of soil conditions suitable for some purpose may be defined on the universe of possible values of a soil property. A particular value of the property corresponds...
The ability to predict long-term plant-availability of soil P provides an additional management tool for sustainable agriculture. Our objective is to present a methodology using P fractionation data for predicting long-term plant-availability of soil P. Soil samples were collected (0-30 cm) in 1975, 1985, and 1992 from two continually cropped field trials. Soils were a Norfolk loamy sand and a Davidson...
Grain sizes of eight profiles from a soil catena (640-3160 m) on andesitic ash in perhumid atlantic Costa Rica were investigated by laser diffraction grain-sizing. The samples were (1) shaken with water, (2) treated with peroxide, and (3) treated with peroxide-oxalate. Allophane is absent above 2000 m; it appears around 2000 m and increases downwards. Peroxide treatment and oxalate extraction indicate...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.