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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    Data and R code: Bioconversion efficiencies, greenhouse gas and ammonia emissions during black soldier fly rearing – a mass balance approach
    Parodi, Alejandro ; Boer, Imke de; Gerrits, Walter ; Loon, Joop van; Heetkamp, Marcel ; Schelt, Jeroen van; Bolhuis, Liesbeth ; Zanten, Hannah van - \ 2020
    Wageningen University & Research
    ammonia - bioconversion - emissions - GHG - Hermetia illucens - nitrogen
    Contains data and R code for analysis and visualizations of the study Bioconversion efficiencies, greenhouse gas and ammonia emissions during black soldier fly rearing.
    Lesmateriaal over “Duurzame melkveehouderij” voor MBO
    Plomp, M. ; Doornewaard, G.J. ; Zijlstra, J. - \ 2018
    Wageningen : Wageningen Livestock Research - 19 p.
    animal welfare - teaching materials - animal production - intermediate vocational training - sustainability - greenhouse gases - ammonia - biodiversity - minerals - cycling
    Deze bundel is gemaakt binnen het project ‘Ondersteuning CIV Melkveehouderij – 2018’ onder verantwoordelijkheid van Wageningen Research. De productie ervan is mede mogelijk gemaakt door de financiering van het project vanuit de WURKS-regeling.
    Effects of Stigeoclonium nanum, a freshwater periphytic microalga on water quality in a small-scale recirculating aquaculture system
    Mohamed Ramli, Norulhuda ; Yusoff, Fatimah M. ; Giatsis, Christos ; Tan, Geok Yuan A. ; Verreth, Johan A.J. ; Verdegem, Marc C.J. - \ 2018
    Aquaculture Research 49 (2018)11. - ISSN 1355-557X - p. 3529 - 3540.
    ammonia - bacterial community - microalgae - nitrate - recirculating aquaculture system - Stigeoclonium nanum - water quality

    Recirculating aquaculture systems (RAS) are becoming important for aquaculture due to land and water supply limitations and due to their low environmental impact. Bacteria are important in RAS as their role in nutrient recycling has been the main mechanism for waste removal in these systems. Besides bacteria, the presence of microalgae can benefit the water quality through the absorption of inorganic nitrogen (ammonium and nitrate) and phosphorus from the water. However, reports on the inclusion of microalgae in RAS are very scarce. The objective of this study was to determine the effect of microalgae on water quality (total ammonia nitrogen, nitrite, nitrate and phosphate) and bacterial composition in a freshwater small-scale RAS. A periphytic microalga, Stigeoclonium nanum, was used in this study. A rapid fingerprint analysis, denaturing gradient gel electrophoresis (DGGE), was used to determine the bacterial community composition in the water. The results showed that ammonia concentrations were not significantly different (p > 0.05) between RAS with microalgae (RAS+A) and RAS without microalgae (RAS-A). However, nitrite, nitrate and phosphate were significantly lower in the RAS+A than the RAS-A (p < 0.05). Pielou's evenness and Shannon diversity index of bacterial community between the treatments were not different (p > 0.05); however, the bacterial composition between the treatments was significantly different (p < 0.05).

    Emissies naar lucht uit de landbouw in 2014 : berekeningen met het model NEMA
    Bruggen, C. van; Bannink, A. ; Groenestein, C.M. ; Huijsmans, J.F.M. ; Luesink, H.H. ; Oude Voshaar, S.V. ; Sluis, S.M. van der; Velthof, G.L. ; Vonk, J. - \ 2017
    Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 90) - 96
    ammoniak - landbouw - emissie - mest - distikstofmonoxide - dierhouderij - modellen - nederland - ammonia - agriculture - emission - manures - nitrous oxide - animal husbandry - models - netherlands
    Landbouwkundige activiteiten zijn in Nederland een belangrijke bron van ammoniak (NH3), stikstofoxide (NO), lachgas (N2O),methaan (CH4) en fijnstof (PM10 en PM2,5). De emissies in 2014 zijn berekend met het National Emission Model for Agriculture(NEMA). Tegelijk zijn enkele cijfers in de reeks 1990-2013 aangepast op basis van nieuwe inzichten. De rekenmethodiek gaatbij de berekening van de ammoniakemissie uit dierlijke mest uit van de hoeveelheid totaal ammoniakaal stikstof (TAN) in demest. De ammoniakemissie uit dierlijke mest, kunstmest en overige bronnen in 2014 bedroeg 121 miljoen kg NH3, bijna4 miljoen kg meer dan in 2013. De stijging komt voornamelijk door uitbreiding van de melkveestapel en een hogerstikstofgehalte van het ruwvoer. De N2O-emissie nam toe van 19,1 miljoen kg in 2013 naar 19,4 miljoen kg in 2014. De NOemissienam toe van 16,9 naar 17,2 miljoen kg. De methaanemissie nam iets toe van 499 tot 503 miljoen kg. De emissie vanfijnstof nam licht toe van 6,3 miljoen kg PM10 tot 6,4 miljoen kg, door een toename van het aantal stuks pluimvee. De emissievan PM2,5 bedroeg in beide jaren 0,6 miljoen kg. Sinds 1990 is de ammoniakemissie uit dierlijke mest en kunstmest mettweederde gedaald, vooral door een lagere stikstofuitscheiding door landbouwhuisdieren en emissiearme mesttoediening.Emissies van lachgas en stikstofoxide daalden in dezelfde periode eveneens, maar minder sterk (ca. 40%) omdat doorondergronds toedienen van mest de emissies hoger zijn geworden en door de omschakeling van stalsystemen met dunne naarvaste mest bij pluimvee. Tussen 1990 en 2014 daalde de emissie van methaan met 16% door een afname in de dieraantallenen een hogere voeropname en productiviteit van melkvee---Agricultural activities are in the Netherlands a major source of ammonia (NH3), nitrogen oxide (NO), nitrous oxide (N2O),methane (CH4) and particulate matter (PM10 and PM2.5). The emissions in 2014 were calculated using the National EmissionModel for Agriculture (NEMA). At the same time some figures in the time series 1990-2013 were revised. The method calculatesthe ammonia emission from livestock manure on the basis of the total ammonia nitrogen (TAN) content in manure. Ammoniaemissions from livestock manure, fertilizers and other sources in 2014 were 121 million kg, which was almost 4 million kghigher than in 2013, mainly due to expansion of the dairy herd and a higher N-content of roughage. N2O emissions increasedfrom 19.1 million kg in 2013 to 19.4 million kg in 2014. NO emission increased slightly from 16.9 to 17.2 million kg. Methaneemissions increased from 499 to 503 million kg. Emissions of particulate matter increased slightly from 6.3 to 6.4 million kgPM10 as a result of higher poultry numbers. Emission of PM2.5 in both years was 0.6 million kg. Ammonia emissions fromlivestock manure in the Netherlands dropped by almost two thirds since 1990, mainly as a result of lower nitrogen excretionrates by livestock and low-emission manure application. Nitrous oxide and nitrogen oxide also fell over the same period, butless steeply (by about 40%), due to higher emissions from manure injection into the soil and to the shift from poultry housingsystems based on liquid manure to solid manure systems. Methane emissions fell by 16% between 1990 and 2014 caused by adrop in livestock numbers and increased feed uptake and productivity of dairy cattle
    Modelling of ammonia volatilisation in fertilised and flooded rice systems
    Khairudin, Nurulhuda - \ 2017
    Wageningen University. Promotor(en): Nurul Khairudin, co-promotor(en): Karel Keesman; Mohamad Pauzi Zakaria. - Wageningen : Wageningen University - ISBN 9789462576698 - 209
    oryza - flooded rice - ammonia - volatilization - modeling - dynamic modeling - flooded land - nitrogen - oryza - natte rijst - ammoniak - vervluchtiging - modelleren - dynamisch modelleren - overstroomde gronden - stikstof

    In flooded rice systems that are broadcast with urea, significant amounts of nitrogen (N) may be lost to the atmosphere in the form of ammonia (NH3). Many models with different complexities with regards to describing the process of NH3 volatilisation and the overall N dynamics in the systems are available. However, given the differences in local conditions, both too simple and too complex models may not be able to predict NH3 volatilisation correctly or may lead to large prediction uncertainties. Therefore, the main objective of this thesis is to provide a framework to determine an appropriate process-based model with corresponding uncertainty characteristics for estimating NH3 volatilisation in fertilised and flooded rice systems.

    As a first step in the selection of a model for a specific application, an overview on the modelling concepts and the performance of 14 models developed to simulate N dynamics in flooded soil systems is given. Next, in order to understand differences in modelling concepts for a specific process, co-validation was conducted at single process level: urea hydrolysis, NH3 volatilisation, and floodwater pH. Then, a new process-based model for estimating NH3 volatilisation in fertilised and flooded rice systems, which is of a complexity appropriate for scarce soil N data, is presented and evaluated with field observations. For the flooded rice systems in the Philippines, conceptualisation of the two-step urea hydrolysis, partitioning between ammonium and NH3, and a time-varying rate coefficient of NH3 volatilisation in the proposed model improved the prediction of the net NH3 loss. Subsequently, a set-membership parameter estimation approach with soft-error-bounds was used to characterise the uncertainty in the parameter estimates in the proposed model. The set-membership approach is appropriate for poor quality data sets as it allows simultaneous consideration of the different sources of uncertainty affecting the model prediction, such as uncertainty in the model structure, parameters, and observations. Findings of this study can be used as criteria for stakeholders to make an informed selection of models, to modify the existing models for a specific purpose, and to interpret model-output responses critically.

    Het effect van een verhoogde ammoniak concentratie in het water op fysiologie, groei en voeropname van Europese paling (Anguilla anguilla)
    Abbink, W. ; Blom, E. ; Pelgrim, Thamar ; Vries, P. de; Vis, J.W. van de; Schram, E. - \ 2015
    Yerseke : IMARES (Rapport / IMARES C187/15) - 18
    european eels - ammoniak - dierfysiologie - groei - voeropname - visteelt - aquacultuur - dierenwelzijn - dierlijke productie - kweekvis - palingen - huisvesting, dieren - diergezondheid - european eels - ammonia - animal physiology - growth - feed intake - fish culture - aquaculture - animal welfare - animal production - farmed fish - eels - animal housing - animal health
    Effecten van landschapselementen op de ammoniakdepositie in Natura 2000- gebieden
    Kros, J. ; Gies, T.J.A. ; Voogd, J.C.H. ; Vries, Wilco de; Aben, Jan ; Pul, Addo - \ 2015
    Alterra, Wageningen-UR (Alterra-rapport 2689) - 37
    landschapselementen - landschap - ammoniak - depositie - overijssel - landscape elements - landscape - ammonia - deposition - overijssel
    Om het mogelijke effect van het aanbrengen van landschapselementen op de NHx (NH3 + NH4 +) depositie op Natura 2000-gebieden in te schatten, is door Alterra een aantal indicatieve berekeningen uitgevoerd voor de gehele provincie Overijssel. De berekeningen zijn uitgevoerd met het OPS-model van het RIVM. Het aanbrengen van een landschapselement van 50m breed rondom bedrijven, lijkt van de doorgerekende scenario’s het meestbelovend.
    Economische gevolgen ammoniakemissie reducerende maatregelen: scenariostudie van praktijkbedrijven in Overijssel
    Evers, A.G. ; Haan, M.H.A. de; Vermeij, I. ; Schooten, H.A. van - \ 2015
    Wageningen : Wageningen UR Livestock Research (Rapport 918) - 51
    veehouderij - ammoniak - ammoniakemissie - emissiereductie - economie - overijssel - livestock farming - ammonia - ammonia emission - emission reduction - economics - overijssel
    Voor een aantal veehouders in het project “Proeftuin Natura 2000 in Overijssel” is in beeld gebracht welke economische gevolgen ammoniakemissie reducerende maatregelen hebben. De effecten van deze maatregelen zijn vergeleken met de ontwikkeling waarbij de bedrijven hun stal moeten aanpassen om ammoniakuitstoot te verminderen. De berekeningen laten zien dat bij alle bedrijven (een combinatie van) managementmaatregelen een beter inkomen tot gevolg heeft dan het aanpassen van de stal, bij een gelijkblijvende of grotere emissiereductie.
    Haalbaarheid van BEX-BEA voor varkens- en pluimveebedrijven : verkenning van een verantwoordingsinstrument voor bedrijfsspecifieke milieuprestaties
    Holster, H.C. ; Migchels, G. ; Aarnink, A.J.A. ; Harn, J. van - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 914) - 32
    varkenshouderij - pluimveehouderij - milieubescherming - milieubeheer - emissiereductie - ammoniak - overijssel - pig farming - poultry farming - environmental protection - environmental management - emission reduction - ammonia - overijssel
    Proeftuin Natura 2000 Overijssel (‘de Proeftuin’) richt zich op de realisatie van Natura 2000- doelstellingen in de provincie Overijssel met behoud van agrarisch ontwikkelingsperspectief. Het project combineert het ontwikkelen en toepassen van ammoniak reducerende maatregelen in de praktijk, met de kennisuitwisseling tussen veehouders, adviseurs en andere betrokkenen. Voor de melkveehouderij is de KringloopWijzer een bekend instrument voor het verantwoorden van de milieuprestaties. De BEX (Bedrijfsspecifieke Excretie) en BEA (Bedrijfsspecifieke Excretie Ammoniak) maken hier onderdeel van uit. De gedachte dat aantoonbaar goed milieugedrag door de ondernemer mag leiden tot een vorm van beloning is niet alleen voorbehouden aan de melkveehouderij. Ook de intensieve veehouderij zoekt naar ruimte om te ondernemen. De melkveehouderij zit complex in elkaar met bijvoorbeeld ruwvoeropbrengsten en rantsoenen (gras en mais) die kunnen variëren. Bij de intensieve veehouderij is de voersamenstelling nauwkeurig bekend. De aanname bij de start van deze verkenning was dan ook dat een BEX-BEA intensief eenvoudig is op te zetten.
    N-verlies en bemestende waarde van een riet/veenbaggerbedding uit een vrijloopstal bij drie verschillende opslagmethoden
    Boer, H.C. de - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 887) - 21
    stikstof - phragmites - turf - uitloop - bodemkwaliteit - ammoniak - dierenwelzijn - organische meststoffen - opslag - dierhouderij - nitrogen - phragmites - peat - outdoor run - soil quality - ammonia - animal welfare - organic fertilizers - storage - animal husbandry
    Een toenemend aantal melkveehouders heeft interesse in de bouw van een vrijloopstal met een organische bedding, om daarmee o.a. het welzijn van de koeien te verhogen. Om de bedding voldoende droog te houden moet er regelmatig nieuw strooisel worden aangevoerd om het met mest uitgescheiden vocht te absorberen of door compostering te verdampen. Voor vochtabsorptie of verdamping kunnen verschillende organische materialen gebruikt worden. In het westelijk veenweidegebied is gedroogde veenbagger in combinatie met riet mogelijk een interessante optie voor vochtabsorptie. Riet en veenbagger zijn gebiedseigen materialen, waardoor hun gebruik bijdraagt aan het sluiten van de kringloop op het bedrijf en in de regio. Een bijkomend voordeel is dat door een relatief lage zuurgraad van veenbagger de emissie van ammoniak uit de bedding geremd kan worden. Riet is in de combinatie nodig om de bodem voldoende draagkracht te geven. Door riet en veenbagger in afwisselende lagen te stapelen ontstaat een zogenoemde ‘lasagne’ bedding.
    Metingen aan een biofilter voor de behandeling van ventilatielucht van een vleesvarkensstal - locatie 2 = Measurements on a biofilter for treatment of exhaust air from a fattening pig house in the Netherlands
    Melse, R.W. ; Hol, J.M.G. ; Ploegaert, J.P.M. ; Nijeboer, G.M. ; Hattum, T.G. van - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research report 896) - 35
    ventilatie - biologische filtratie - varkensstallen - slachtdieren - luchtfilters - emissiereductie - luchtkwaliteit - ammoniak - stankemissie - fijn stof - broeikasgassen - ventilation - biological filtration - pig housing - meat animals - air filters - emission reduction - air quality - ammonia - odour emission - particulate matter - greenhouse gases
    In this study the emission reduction of ammonia (NH3), odour, fine dust (PM10, PM2.5), and greenhouse gases (CO2, N2O, CH4) was determined for a biofilter (440 m2) treating exhaust air from a pig house (total ventilation capacity: 290.000 m3.uur-1). The average removal for ammonia, odour and fine dust (PM10) was 38%, 43%, and > 93%, respectively. For CO2, N2O, and CH4, no significant difference between inlet and outlet concentration was found for the biofilter.
    Effect van snijmaissilage als strooiselmateriaal in vleeskuikenstallen op de emissies van ammoniak, geur en fijnstof
    Harn, J. van; Nijeboer, G.M. ; Ogink, N.W.M. - \ 2015
    Wageningen : Wageningen UR Livestock Research (Livestock Research rapport 845) - 49
    emissie - ammoniak - stankemissie - fijn stof - methaan - distikstofmonoxide - vleeskuikens - huisvesting van kippen - pluimveehouderij - maïskuilvoer - emissiereductie - luchtkwaliteit - duurzame veehouderij - emission - ammonia - odour emission - particulate matter - methane - nitrous oxide - broilers - chicken housing - poultry farming - maize silage - emission reduction - air quality - sustainable animal husbandry
    This report describes the results of emission measurements of ammonia, odour, PM10, methane and nitrous oxide from broiler houses bedded with white wood shavings (=control), fresh silage maize or pre-dried silage maize.
    Optimizing the performance of a reactor by reducing the retention time and addition of glycerin for anaerobically digesting manure
    Timmerman, M. ; Schuman, E. ; Eekert, M. ; Riel, J.W. van - \ 2015
    Environmental Technology 36 (2015)10. - ISSN 0959-3330 - p. 1223 - 1236.
    co-digestion - methane production - crude glycerin - cattle manure - biogas - waste - biogasification - inhibition - ammonia
    Anaerobic digestion of manure is a widely accepted technology for energy production. However, only a minimal portion of the manure production in the EU is anaerobically digested and occurs predominantly in codigestion plants. There is substantial potential for biogas plants that primarily operate on manure (>90%); however, the methane yields of manure are less compared to coproducts, which is one of the reasons for manure-based biogas plants often being economically non-viable. Therefore, it is essential to begin increasing the efficiency of these biogas plants. This study investigated the effect of decreasing retention time and introducing a moderate amount of glycerin on the biogas production as methods to improve efficiency. An experiment has been conducted with two different manure types in four biogas reactors. The results of the study demonstrated that, first, it was possible to decrease the retention time to 10–15 days; however, the effect on biogas production varied per manure type. Secondly, the biogas production almost triples at a retention time of 15.6 days with an addition of 4% glycerin. The relative production-enhancing effect of glycerin did not vary significantly with both manure types. However, the absolute production-enhancing effect of glycerin differed per manure type since the biogas production per gram VS differed per manure type. Thirdly, the positive effect of the glycerin input declines with shorter retention times. Therefore, the effect of glycerin addition depends on the manure type and retention time.
    Equivalence testing of filter-based, beta-attenuation, TEOM, and light-scattering devices for measurement of PM10 concentration in animal houses
    Winkel, A. ; Llorens Rubio, J. ; Huis in 'T Veld, J.W.H. ; Vonk, J.A. ; Ogink, N.W.M. - \ 2015
    Journal of Aerosol Science 80 (2015). - ISSN 0021-8502 - p. 11 - 26.
    particulate matter concentrations - pig fattening facilities - emission rates - indoor concentrations - gaseous pollutant - greenhouse gases - broiler houses - air-pollution - layer house - ammonia
    Emissions of particulate matter (PM) from poultry and pig houses may contribute significantly to ambient concentrations. Yet, our knowledge on the accuracy and comparability of samplers available for measuring the high PM10 concentrations (>100 µg m–3) in the inside air directly upstream of the ventilation exhausts of these buildings is very limited. The aim of this study was to provide insight into this matter for five candidate samplers: a filter-based cyclone sampler (CYS), the Thermo Scientific FH 62 I-R beta-attenuation sampler (BAS), the Thermo Scientific Tapered Element Oscillating Microbalance, model 1400ab (TEOM), the TSI DustTrak model 8520 (DT), and the GRIMM Portable Aerosol Spectrometer model 1.109 (PAS). Equivalence tests were carried out following European Standard EN 12341 using two devices for each candidate sampler (CAS) and four filter-based low-volume reference samplers (RES). Measurements were performed inside three major animal housings (a fattening pig house, a laying hen house, and a broiler house) and inside an office room. Our key results and conclusions are: (1) neither one of the five CASs, nor the RES itself, met the EN 12341 requirement for comparability between devices of the same sampler type. Using a less strict boundary for this aspect – in concert with performing duplicate sampling – may be appropriate. (2) The CYS met the EN 12341 accuracy requirements in pigs and layers, but overestimated the RES concentration in broilers. The BAS, TEOM, and DT underestimated, and the PAS overestimated, RES concentrations in a systematic manner. The use of correction factors seems to be a promising method to calibrate measured values to RES concentrations. (3) The BAS, TEOM, DT, and PAS started to show scattered regression after 432–500 h of sampling, which stresses the need for shortened time intervals between full services. In conclusion, some of the samplers tested could be regarded acceptable when appropriate measures (such as duplicate sampling, correction factors, and more frequent servicing) are applied.
    Optimization of blue mussel (Mytilus edulis) seed culture using recirculation aquaculture systems
    Blanco Garcia, A. ; Kamermans, P. - \ 2015
    Aquaculture Research 46 (2015)4. - ISSN 1355-557X - p. 977 - 986.
    toxicity - ammonia - nitrite - nitrate - growth - flow
    By introducing recirculation aquaculture systems (RAS) in the nursery phase of the blue mussel (Mytilus edulis) (17–18 mm), we aimed at a similar growth and survival and a similar water quality compared to the commonly used flow-through systems (FTS). To calculate water flow and size of the biofilter, a series of experiments were done to determine clearance rate (9.26 mL min-1), pseudo faeces threshold (60 000 cells Pavlova lutheri mL-1), nitrogen production (0.00065 mg TAN h-1 ind-1 and 1.6 × 10-5 mg NO2–N h-1 ind-1) and oxygen consumption (0.03 ± 0.01 mg O2 h-1 ind-1). RAS showed no significant differences in water quality (0.06 mg TAN L-1; 7.7 mg O2 L-1) and growth performance of mussel seed specific growth rate (SGR = 5% day-1) after the experimental period of 4 weeks compared with FTS. The low water refreshment, 10% per day, as well as the constant chlorophyll concentrations (9.76 ± 1.06 µg L-1), suggests the potential of RAS as culture system for mussel seed.
    Regionale bodembelasting door stikstof en fosfaat, en ammoniakemissie 2013
    Koeijer, T.J. de; Luesink, H.H. ; Kuhlman, J.W. ; Puister-Jansen, L.F. ; Hoogeveen, M.W. - \ 2014
    Den Haag : LEI Wageningen UR (Factsheet / LEI Wageningen UR 14-118b1) - 4
    stikstof - fosfaat - emissie - ammoniak - gronddruk - belasting (loads) - mest - landbouwschuren - broeikasgassen - ammoniakemissie - nitrogen - phosphate - emission - ammonia - ground pressure - loads - manures - barns - greenhouse gases - ammonia emission
    In de Emissieregistratie (ER) monitort het RIVM jaarlijks de emissies van diverse stoffen en emissiebronnen van verschillende bedrijven en sectoren. LEI Wageningen UR levert gegevens aan de ER over de regionale ammoniakemissies uit de landbouw en de bodembelasting met stikstof en fosfaat van landbouwbodems. Deze gegevens worden berekend met behulp van het Mest- en Ammoniakmodel voor Beleidsondersteuning (MAMBO) van het LEI.
    Schram, Edward - \ 2014
    fisheries - aquaculture - water quality - feed intake - pike perch - silurus glanis - eels - fishes - diversity - nitrate - ammonia
    Nitrate leaching and apparent recovery of urine-N in grassland on sandy soils in the Netherlands
    Corré, W.J. ; Beek, C.L. van; Groenigen, J.W. van - \ 2014
    NJAS Wageningen Journal of Life Sciences 70-71 (2014). - ISSN 1573-5214 - p. 25 - 32.
    nitrogen - groundwater - lysimeter - dynamics - ammonia - losses - system - input
    Urine patches are an important nitrogen input source in managed pasture systems. The objective of this study was to quantify the effect of artificial urine application at different dates on nitrate leaching in a well drained sandy soil. In three subsequent years, we measured nitrate leaching and apparent urine-nitrogen recovery (ANR) in a field experiment and in two lysimeter experiments over a period of 1 year post urine application. Artificial urine patches with 400 kg ha-1of urine-N were applied at different times of the grazing seasons. For the field experiment, we compared nitrate leaching measurements with NURP model calculations. In the field experiment, greatest ANR was measured for spring and summer applications (averaging 31% of applied urine-N), and significantly declined to 0% for October applications. Nitrate leaching increased under urine patches, with a significant effect of application date. This effect was not, however, consistent over the three years. Total recovery of N in grass and of mineral N in leachate and soil was generally less than the amount of urine-N applied, with a balance deficit of 60-80% (field) or 10-70% (lysimeters). For the field experiment, the total increase in nitrate leaching corresponded reasonably well with NURP model calculations. However, the effect of application date on nitrate leaching was much smaller in the field experiment. Our results suggest that restrictions to grazing in autumn probably will be effective in decreasing the annual amount of nitrate leached, although this decrease remains hard toquantify.
    Evaluation of free water and water activity measurements as functional alternatives to total moisture content in broiler excreta and litter samples
    Hoeven-Hangoor, E. van der; Rademaker, C. ; Paton, N.D. ; Verstegen, M.W.A. ; Hendriks, W.H. - \ 2014
    Poultry Science 93 (2014)7. - ISSN 0032-5791 - p. 1782 - 1792.
    sugar-beet pulp - gastrointestinal-tract - oat hulls - nonstarch polysaccharides - growth-performance - poultry houses - low-viscosity - chickens - ammonia - diets
    Litter moisture contents vary greatly between and within practical poultry barns. The current experiment was designed to measure the effects of 8 different dietary characteristics on litter and excreta moisture content. Additionally, free water content and water activity of the excreta and litter were evaluated as additional quality measures. The dietary treatments consisted of nonstarch polysaccharide content (NSP; corn vs. wheat), particle size of insoluble fiber (coarse vs. finely ground oat hulls), viscosity of a nonfermentable fiber (low- and high-viscosity carboxymethyl cellulose), inclusion of a clay mineral (sepiolite), and inclusion of a laxative electrolyte (MgSO4). The 8 treatments were randomly assigned to cages within blocks, resulting in 12 replicates per treatment with 6 birds per replicate. Limited effects of the dietary treatments were noted on excreta and litter water activity, and indications were observed that this measurement is limited in high-moisture samples. Increasing dietary NSP content by feeding a corn-based diet (low NSP) compared with a wheat-based diet (high NSP) increased water intake, excreta moisture and free water, and litter moisture content. Adding insoluble fibers to the wheat-based diet reduced excreta and litter moisture content, as well as litter water activity. Fine grinding of the oat hulls diminished the effect on litter moisture and water activity. However, excreta moisture and free water content were similar when fed finely or coarsely ground oat hulls. The effects of changing viscosity and adding a clay mineral or laxative deviated from results observed in previous studies. Findings of the current experiment indicate a potential for excreta free water measurement as an additional parameter to assess excreta quality besides total moisture. The exact implication of this parameter warrants further investigation.
    Decision document on the revision of the VERA protocol on air cleaning technologies March
    Mosquera Losada, J. ; Edouard, N. ; Guiziou, F. ; Melse, R.W. ; Riis, A.L. ; Sommer, S. ; Brusselman, E. - \ 2014
    Wageningen : Wageningen UR Livestock Research (Report / Wageningen UR Livestock Research 767) - 51
    luchtreinigers - technologie - landbouwproductie - ammoniak - ammoniakemissie - emissiereductie - intensieve veehouderij - huisvesting, dieren - landbouw en milieu - duurzame landbouw - air cleaners - technology - agricultural production - ammonia - ammonia emission - emission reduction - intensive livestock farming - animal housing - agriculture and environment - sustainable agriculture
    In the project “ICT-AGRI: Development of harmonized sampling and measurement methods for odour, ammonia and dust emissions” different subgroups have been formed focusing on either ammonia, odour or dust. In this report, the conclusions of the ammonia subgroup regarding harmonization of measurement methods for the estimation of the ammonia removal from air cleaning technologies are summarized.
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