L'état de fertilité des terres agricoles et forestières en région wallonne (adapté du chapitre 4 - sol 1 de

Fertility state of agricultural and forest soils in Walloon region. Feeding on plants and animals, the human societies are broadly dependent on soils because these, beyond their role as support of plant production, produce, contain, and collect the most part of the nutriments necessary to life. The sustainable management of the agricultural and forest soils implicates an uninterrupted assessment of their state by the measure of fertility indicators. This last is perceptible as the soil suitability to assume the plant biomass production. The soil suitability results from environmental physical, chemical and biological factors such as parental material, climate, etc. The human activities, particularly the agricultural and forest practices, also play a major role in the soil suitability. To avoid losses towards aquatic environment, these practices have to aim at satisfying the vegetables needs, while watching not to exceed the capacity of soil to keep the nutriments. Several tools exist in Walloon region to estimate the fertility state of soils, mainly at (physico-)chemical levels. This article introduces an outline of the agricultural, and forest soils state in various mineral and organic elements, and specify as well as possible involvements in other environmental problems

Estimation of soil weathering stage and acid neutralizing capacity in a toposequence Luvisol-Cambisol on löss under deciduous forest in Belgium

Soils derived from loess are extensive in Europe and are well suited for forestry. They are suspected to be poor acid buffers, however. We have estimated the weathering stage and acid neutralizing capacity of acid soils under forest in a toposequence on loess in the Belgian silt belt. The soils vary distinctly in morphology and physico-chemical properties according to their topographic position. Dystric Cambisols have developed in colluvial deposits in the dry valley floors, whereas Dystric Luvisols have formed on the slopes in a rejuvenated material. The Cambisols are more acid and less saturated in bases than are Luvisols. They are strongly depleted of clay and contain less weatherable minerals. Easily weatherable minerals are concentrated mainly in the clay fraction of both soil types. Clay minerals of size < 2 μm therefore act as major sinks for protons in these soils. A simplified expression taking into account the total reserve in bases, total aluminium and iron occluded in silicates is used to estimate acid neutralizing capacity. Our estimates confirm that these acid loessic soils are indeed poor acid buffers. They show that the Dystric Cambisols depleted of clay are sensitive to potential acidification, whether natural or man-made.status: publishe

Projet WalRB : traduction de la légende de la Carte des Sols de la Belgique dans le système World Reference Base for Soil Resources (WRB)

WalRB project: translation of the legend of the soil map of Belgium into World Reference Base for Soil Resources (WRB). Soil maps are among the most important reference maps in environmental and agriculture fields. Determination of land, agricultural potential, erosion thread, land management or soil pollution are some topics that need spatial soil data. Attention to cross-border environmental matters, such as soil protection, has become an international concern that requires harmonized soil information. This is why the World Reference Base for Soil Resources has been selected by European Union as official soil classification system (IUSS Working Group WRB, 2007). Belgium is one of the first nations to have achieved the whole country soil survey at large scale (1:20,000). The legend of the soil map of Belgium is based on three or four main soil specifications, texture, drainage class, profile development and stoniness nature (for stony soil), each one represented by a letter. Those three or four letters all together form the main soil series. Prefix and suffix may be added to further detail it. The WRB system based on soil morphology is formed of two levels, 32 Reference Soil Groups (RSGs), and various qualifiers (prefix, suffix or both). A common methodology between Flanders, Luxembourg and Wallonia (that use the same soil map legend) is requested to carry out the translation. Data from different databases, digital soil maps, soil profile descriptions, soil analytical data, Digital Elevation Model, other thematic maps (e.g. flooding hazard areas) are collected and organized under a common PostgreSQL database [Belgian Soil Profile Database (BSP)], with PostGIS geographical extension, hosted under a dedicated server. Data validation is proposed to be done under the auspices of National Soil Committee of Royal Academy for Sciences and Arts of Belgium. Algorithms are implemented in Perl and R languages

A LARGE MAGNETIC SPECTROMETER SYSTEM FOR HIGH-ENERGY MUON PHYSICS

The European Muon Collaboration has built a large magnetic spectrometer system for deep inelastic muon scattering experiments at the CERN SPS muon beam. The general characteristics of the apparatus - composed of a target of either liquid hydrogen or deuterium, or iron plus scintillator, followed by a large magnet with wire chambers before and after it for precise angle and momentum measurement, a muon identifier, large trigger hodoscopes, and hadron identifiers - are explained and each part is described in some detail. The main features of the data-acquisition and apparatus-monitoring systems and of the off-line event reconstruction are given. © 1981