Staff Publications

Staff Publications

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    'Staff publications' is the digital repository of Wageningen University & Research

    'Staff publications' contains references to publications authored by Wageningen University staff from 1976 onward.

    Publications authored by the staff of the Research Institutes are available from 1995 onwards.

    Full text documents are added when available. The database is updated daily and currently holds about 240,000 items, of which 72,000 in open access.

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    Waterretentie- en doorlatendheidskarakteristieken van boven- en ondergronden in Nederland: de Staringreeks; vernieuwde uitgave 2001
    Wösten, J.H.M. ; Veerman, G.J. ; Groot, W.J.M. de; Stolte, J. - \ 2001
    Wageningen : Alterra (Alterra-rapport 153) - 86
    bodemwaterbeweging - hydraulisch geleidingsvermogen - beschikbaar bodemwater - hysterese - pf-curve - soil water movement - hydraulic conductivity - available water - hysteresis - pf-curve
    Het bij Alterra aanwezige bestand van gemeten bodemfysische karakteristieken is de laatste jaren aanzienlijk uitgebreid. Deze uitbreiding heeft geleid tot een vernieuwing van de in 1994 uitgebrachte Staringreeks. De Staringreeks vermeldt de gemiddeldebodemfysische karakteristieken voor alle onderscheiden 18 boven- en 18 ondergronden. De reeks geeft een complete landelijke dekking van alle op de Bodemkaart van Nederland 1 : 50 000 onderscheiden bodemeenheden. Om het gebruik van de bodemfysische karakteristieken in simulatiemodellen te vereenvoudigen zijn de karakteristieken beschreven met analytische vergelijkingen. Tevens is een programma beschikbaar waarmee de gebruiker aan de hand van de bodemkenmerken textuur, organischestofgehalte, dichtheid, boven- of ondergrond met behulp van continue vertaalfuncties voorspellingen kan maken van de bodemfysische karakteristieken.
    Irrigation practices affecting land degradation in Sicily
    Crescimanno, G. - \ 2001
    Wageningen University. Promotor(en): J. Bouma; H.W.G. Booltink. - S.l. : S.n. - ISBN 9789058084262 - 169
    irrigatie - bodemwaterbeweging - bodemzoutgehalte - bodemdegradatie - scheurvorming - italië - irrigation - soil water movement - soil salinity - soil degradation - cracking - italy

    The available amount of fresh water for agriculture, and specifically for irrigation, is decreasing all over the world. The quality of irrigation water is deteriorating, and saline/sodic waters are increasingly used in many arid and semi-arid regions of the world. Salinization is closely associated with the process of desertification.

    Sustainable land management practices are urgently needed to preserve the production potential of agricultural land while safeguarding environmental quality. In cracking soils sustainable management should take into account the occurrence of bypass flow and the influence that land use may have on soil structure and bypass flow phenomena.

    Measurement of vertical and horizontal shrinkage in confined soil cores was found to be suitable for determining the Soil Shrinkage Characteristic Curve (SSCC) and for incorporating shrinkage in the soil hydraulic parameters/functions determined on confined undisturbed soil samples. An optimization procedure based on multi-step outflow experiments with inverse modelling was developed for determining the soil hydraulic characteristics (HC). The need for accounting for structural porosity and shrinkage processes was recognized on the basis of hydraulic conductivity values determined by the suction crust infiltrometer method and of the SSCC determined on confined soil cores.

    Analysis of the response of clay soils to ESP values up to 15, showed that the concept of critical threshold needs reconsideration, because increasing soil degradation upon increasing ESP appeared to be a continuum. A major hazard of deterioration of structural and hydraulic properties was recognized even at low ESP values (ESP<5) in dilute solutions. In addition, the major influence that reductions in hydraulic conductivity due to salinity and/or sodicity may have in water transport in the soil-crop system was also documented by application of the LEACHM model.

    The relevance of bypass flow on the water balance in a Mediterranean climatic context as that occurring in Sicily, was evaluated by application of the FLOCR model. The results showed that bypass flow corresponded with about 70-74% of cumulative yearly rainfall, and that models not accounting for bypass flow may lead to a significant overprediction of crop evapotranspiration and underestimation of the hazard of land degradation and desertification.

    Results of bypass flow measurements performed in a Mediterranean cracking soil under alternated use of a high salinity solution to distilled water showed that exchange of solutes occurred at the contact surfaces between the macropores/cracks walls and the incoming solution in concomitance with bypass fluxes. These exchanges were effective in determining leaching of solutes and removal of Sodium, and in preventing salinization and sodification in part of the soil volume that is in contact with the roots.

    Combined use of morphometric and physical techniques made it possible to explore the effect of irrigation on soil structure and bypass flow phenomena of a Mediterranean cracking soil under two different irrigation systems, i.e. drip and micro-sprinkler. Different vertical distributions of cracks was found under the two irrigation systems. In agreement with these observations, different flow behaviour was observed in the laboratory in cylindrical soil cores taken from the irrigated micro-sprinkler field. No bypass flow or lower amounts of bypass flow in the micro-sprinkler irrigated field compared to the drip irrigation treatment. Chemical dispersion of clay particles and detachment of these particles from the surface and their movement into the cracks were the mechanisms responsible for the partial or total occlusion of the (macro) pores in the micro-sprinkler irrigated field.

    In conclusion, this study showed that drip irrigation alternatively using high and low salt water was most effective in maintaining the productive capacity of the clay soil being studied, particularly when this water was applied to a cracked soil. Combined use of morphometric and physical methods was necessary to understand the underlined highly dynamic flow behaviour in these complex soils.

    Evaluating drainage design parameters for the Fourth Drainage Project, Pakistan by using SWAP model: Part II - modeling results
    Sarwar, A. ; Feddes, R.A. - \ 2000
    Irrigation and Drainage Systems 14 (2000). - ISSN 0168-6291 - p. 281 - 299.
    drainage - ontwerp - buisdrainage - bodemwaterbeweging - uitspoelen - verzilting - modellen - pakistan - drainage - design - tile drainage - soil water movement - leaching - salinization - models - pakistan
    Evaluating drainage design parameters for the fourth drainage project, Pakistan by using SWAP model: Part I - calibration
    Sarwar, A. ; Bastiaanssen, W.G.M. ; Boers, T.M. ; Dam, J.C. van - \ 2000
    Irrigation and Drainage Systems 14 (2000). - ISSN 0168-6291 - p. 257 - 280.
    drainage - buisdrainage - bodemwaterbeweging - uitspoelen - verzilting - modellen - pakistan - ontwerp - drainage - design - tile drainage - soil water movement - leaching - salinization - models - pakistan
    Spatial variability of solute leaching : experimental validation of a quantitative parameterization
    Rooij, G.H. de; Stagnitti, F. - \ 2000
    Soil Science Society of America Journal 64 (2000)2. - ISSN 0361-5995 - p. 499 - 504.
    bodemoplossing - bodemwaterbeweging - uitspoelen - modellen - ruimtelijke variatie - soil solution - soil water movement - leaching - spatial variation - models
    Soil heterogeneity, soil structure, and fingered flow affect solute leaching from the vadose zone to the ground water. Recently, the spatial variation of cumulative solute fluxes at a given depth was characterized by fitting the two-parameter beta distribution to sorted amounts of solute leaching at different sampling points. We tested this parameterization on data from a chloride tracer experiment performed on a monolith lysimeter, below which drainage was collected from 300 compartments with a combined area of 0.75 m2. The effect of total sampling area, sample size, and the number of samples and their spatial distribution (random locations vs. clustered) on the fitted parameters was examined. Sixteen or more sampling locations of 25 cm2 each (5% of the total area) resulted in adequate representation of parameter values. Increasing the sample size underestimated the degree of heterogeneity. We therefore recommend that the fitted parameter values of the beta distribution be reported together with the sample size. In solute-transport experiments, collecting many small samples will give more accurate results than taking fewer but larger samples. | Soil heterogeneity, soil structure, and fingered flow affect solute leaching from the vadose zone to the ground water. Recently, the spatial variation of cumulative solute fluxes at a given depth was characterized by fitting the two-parameter beta distribution to sorted amounts of solute leaching at different sampling points. We tested this parameterization on data from a chloride tracer experiment performed on a monolith lysimeter, below which drainage was collected from 300 compartments with a combined area of 0.75 m2. The effect of total sampling area, sample size, and the number of samples and their spatial distribution (random locations vs. clustered) on the fitted parameters was examined. Sixteen or more sampling locations of 25 cm2 each (5% of the total area) resulted in adequate representation of parameter values. Increasing the sample size underestimated the degree of heterogeneity. We therefore recommend that the fitted parameter values of the beta distribution be reported together with the sample size. In solute-transport experiments, collecting many small samples will give more accurate results than taking fewer but larger samples.
    Nitraattransport naar de wortels door de neerwaartse waterstroming in de grond bij in kassen geteelde tomaten ; een simulatie
    Ende, J. van den; Kipp, J.A. - \ 1998
    Naaldwijk : Proefstation voor Bloemisterij en Glasgroente, Vestiging Naaldwijk (Rapport / Proefstation voor Bloemisterij en Glasgroente 132) - 45
    nitraten - plantenvoeding - voedingsstoffentransport - bodemwaterbeweging - toevloei naar wortels - simulatiemodellen - nitrates - plant nutrition - nutrient transport - soil water movement - flow to roots - simulation models
    Voor teelten van tomaten in kassen waarbij bij het fertigeren een doorspoelfractie van 0.25 wordt aangehouden, is het potentiële belang van de neerwaartse waterstroming in de grond voor het transport van nitraat naar de wortel nagegaan. Voor dit doel is een simulatie van die stroming uitgevoerd met behulp van het model SWACROP. Uit de hierbij verkregen snelheid van de neerwaartse waterstroming en de nitraatconcentratie van de bodemoplossing is de snelheid van het neerwaartse nitraattransport afgeleid en vergeleken met een schatting van de door de plant benodigde nitraatopnameflux aan het worteloppervlak. De diverse gebruikte basisgegevens worden omschreven en toegelicht. De verkregen resultaten worden vanuit verschillende gezichtspunten bediscussieerd. Zij maken het aannemelijk dat, althans gedurende de produktiefase van het gewas, bij genoemde teelten het vereiste nitraattransport naar de wortel grotendeels voor rekening van de neerwaartse waterstroming kan komen.
    Three-dimensional patterns of moisture, water repellency, bromide and pH in a sandy soil
    Ritsema, C.J. ; Dekker, L.W. - \ 1998
    Journal of Contaminant Hydrology 31 (1998)3/4. - ISSN 0169-7722 - p. 295 - 313.
    bodemwaterbeweging - hydraulisch geleidingsvermogen - bodemwater - infiltratie - zandgronden - tracers - bromide - ph - soil water movement - hydraulic conductivity - soil water - infiltration - sandy soils - tracers - bromide - ph
    Sprinkling of grassland. Fundamentals of soil water flow at the experimenta field
    Boheemen, P.J.M. van; Humbert, H. - \ 1984
    Wageningen : ICW (Nota / Instituut voor Cultuurtechniek en Waterhuishouding 1540) - 50
    beregening - graslanden - bodemwaterbeweging - overhead irrigation - grasslands - soil water movement
    De bepaling van de transporttijd van het grondwater bij stroming in de verzadigde zone
    Ernst, L.F. - \ 1973
    Wageningen : I.C.W. (Nota / Instituut voor Cultuurtechniek en Waterhuishouding 755) - 42
    grondwaterstroming - transportprocessen - snelheid - grondwater - concentratie - verzadigde stroming - bodemwaterbeweging - geohydrologie - groundwater flow - transport processes - velocity - groundwater - concentration - saturated flow - soil water movement - geohydrology
    De stroming van het grondwater wordt zeer dikwijls gezien als een drainageprobleem, waarbij het van belang is iets te weten van de hoeveelheid water, die per tijdseenheid door het beschouwde gebied stroomt, van de bergingsveranderingen in dit gebied en van de corresponderende potentiaalverschillen. Het kan ook van belang zijn iets te weten omtrent het transport van opgeloste stoffen en wel in het bijzonder in die gevallen dat de concentratie van de opgeloste stof niet constant is, maar afhangt van plaats en tijd. Als voorbeelden van dergelijke gevallen kunnen worden genoemd: zoute kwel in kustgebieden; infiltratie van water door middel van diepe putten of open leidingen met hoog peil, waarbij infiltratiewater en oorspronkelijk grondwater in het algemeen enig verschil in samenstelling hebben;uitspoe1ing van verzilte gronden door irrigatie met zout water, transport van meststoffen, insecticiden enz., die door het neerslagoverschot in de grondwaterstroom terecht komen. Bij deze problemen wordt gevraagd naar de snelheid waarmee het grondwater zich beweegt en naar de tijd, die het grondwater nodig heeft om het beschouwde gebied geheel of gedeeltelijk te doorlopen.
    Mull and mor (Mueller - Hesselman) in relation to the soil water regime of a forest
    Minderman, G. - \ 1960
    Arnhem : [s.n.] (Mededeling / Instituut voor toegepast biologisch onderzoek in de natuur. ITBON no. 49) - 27
    klimaat - bosbouw - humus - uitspoelen - strooisel - bodemvorming - bodemwaterbeweging - climate - forestry - humus - leaching - litter (plant) - soil formation - soil water movement
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