Staff Publications

Staff Publications

  • external user (warningwarning)
  • Log in as
  • language uk
  • About

    '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.

    We have a manual that explains all the features 

Current refinement(s):

Records 1 - 20 / 21

  • help
  • print

    Print search results

  • export

    Export search results

  • alert
    We will mail you new results for this query: keywords==organic nitrogen
Check title to add to marked list
Topbodem voor topmais
Groten, J.A.M. - \ 2014
Grondig : vakblad voor de cumelasector, specialisten in groen, grond en infra 9 (2014). - ISSN 2210-3260 - p. 52 - 53.
akkerbouw - maïs - zea mays - maïskuilvoer - organische stof - normen - bemesting - groenbemesters - teeltsystemen - wisselbouw - organische stikstof - arable farming - maize - maize silage - organic matter - standards - fertilizer application - green manures - cropping systems - ley farming - organic nitrogen
De organische-stofbalans van een snijmaïsteelt is negatief en de bemestingsnormen liggen inmiddels onder het landbouwkundige advies. Hierdoor neemt de productiviteit van de grond af en daarmee de potentiële maïsopbrengst. Een deel van de oplossing is de teelt van een goed geslaagde groenbemester na de maïsoogst.
An assessment of the variation of manure nitrogen efficiency throughout Europe and an appraisal of means to increase manure-N efficiency
Webb, J. ; Sorensen, P. ; Velthof, G.L. ; Amon, B. ; Pinto, M. ; Rodhe, L. ; Salomon, E. ; Hutchings, N. ; Burczyk, J. ; Reid, J.E. - \ 2013
Advances in Agronomy 119 (2013). - ISSN 0065-2113 - p. 371 - 442.
fertilizer replacement value - reducing ammonia emissions - greenhouse-gas emissions - treated cattle slurry - pig slurry - organic nitrogen - animal manures - short-term - mineral fertilizer - plant utilization
Using the nitrogen (N) in organic manures more effectively reduces losses to the environment. A requirement to take allowance of the N conserved by reduced ammonia (NH3)-emission techniques would increase manure-N efficiency by up to 15%. Covering manure stores and land application of slurry by injection beneath the soil surface and by rapid incorporation of both slurries and solid manures into uncropped soil reduce NH3 emissions. Injection of cattle slurry also reduces N immobilization compared with application methods, which mix the slurry with soil and increases manure-N efficiency by ca 10–15%. In growing cereals, NH3 emissions can be reduced by band spreading within the canopy. Anaerobic digestion of slurry may also increase manure-N availability in the season of application by 10–20%, compared with undigested slurry. Slurry acidification may increase manure-N efficiency by 35–65% by reducing total NH3 losses by 70% compared with unacidified slurry stored without cover and not incorporated after spreading. To fully utilize the fertilizer value of manure-N, uptake over more than 1 year needs to be accounted for. This is particularly important for solid manures which provide less-available N in the season after application than slurries but release more N to crops in subsequent years. Using manure-N as a sole N source may limit overall manure-N efficiency. Applying manures at reduced rates over a larger crop area, using N fertilizer at times when crop recovery of manure-N may be limited, may give the greatest overall manure-N efficiency.
Predicting soil nitrogen supply : relevance of extractable soil organic matter fractions
Ros, G.H. - \ 2011
University. Promotor(en): Willem van Riemsdijk, co-promotor(en): Erwin Temminghoff; Ellis Hoffland. - [S.l.] : S.n. - ISBN 9789085858829 - 243
mineralisatie - organische stikstof - bodem - organisch bodemmateriaal - bodemonderzoek - voorspelling - bodemtestwaarden - beoordeling - oogstresten - mineralization - organic nitrogen - soil - soil organic matter - soil testing - prediction - soil test values - assessment - crop residues

Predicting the potential of soils to supply N is of considerable importance to maximize agricultural N use efficiency and to minimize environmental losses. This research examines and evaluates the current soil testing approach, which uses extractable organic N (EON) fractions to predict soil N supply, using isotopic 15N tracing, multivariate statistics and meta-analytical techniques.
Almost all 20 EON fractions that have been developed during recent decades significantly reflect the potential of soils to supply N, in spite of the strong differences in size and composition of EON due to extraction methodology. The EON fractions have therefore been considered as highly bio-available N pools in soil. However, most of them performed either worse than or similarly to total N as predictor of soil N supply, and the uncertainty of the predicted soil N supply (even under controlled environmental conditions) is still too big for serious improvement of fertilizer management.
A micro-diffusion method is developed to estimate gross EON fluxes in order to investigate the biochemical basis for observed relationships between EON and soil N supply. The fate of EON fractions in N mineralization, in particular those fractions that are obtained with weak hydrolyzing salt solutions, is comparable to that of dissolved organic N (DON). Both DON and EON can be considered as (intermediate) decomposition waste products in an abiotic and biotic controlled equilibrium with total N.
Therefore, their relationship with soil N supply likely reflect that both DON, EON, and soil N supply are mutually dependent on total N.
The dependency of soil N supply on methodological and environmental issues strongly encourages more effort to be put into validation and up-scaling, particularly regarding the quantification of the differences between laboratory and field experiments. A combination of soil testing with simulation modeling is necessary to account for the numerous environmental factors controlling soil N supply. The exact EON fraction that can be used in such an approach is less important and practical considerations may be decisive to select one for routine application in soil analysis.
In conclusion, a holistic approach, which considers spatial and temporal variability of both soil N supply and crop N demand, may provide a successful approach to improving fertilizer management at the farm-scale.

Comparison of indices for the prediction of nitrogen mineralization after destruction of managed grassland
Smit, A. ; Velthof, G.L. - \ 2010
Plant and Soil 331 (2010)1-2. - ISSN 0032-079X - p. 139 - 150.
soil-nitrogen - organic nitrogen - n-mineralization - loam soil - fractions - clover - temperature - extraction - swards - matter
Intensively managed grasslands are occasionally chemically killed with herbicide and ploughed in order to grow an arable crop. After this management, large N mineralization rates with large losses to the environment are commonly observed. However, it remains to be determined to what extent the chemical killing contribute to increased N mineralization. In this study the potential nitrogen (N) mineralization from grasslands, that were killed with herbicides but otherwise undisturbed, was investigated in a laboratory experiment with undisturbed soil columns. Subsequently we assessed the predictive value of several laboratory indices for N mineralization after chemically killing of the grass. Mineralization rates varied from 0.5 to 3.0 g N m-2 wk-1. The contents of total N, total C, dissolved organic carbon (DOC) and hot-KCl extractable NH4 + were best related to N mineralization rates (R2=50, 48, 38 and 47%, respectively). In combination with information on the N content of the roots and stubble and the age of grassland at destruction, up to 62% of the variation in N mineralization rates could be explained. Although previous studies suggested that dissolved organic nitrogen (DON) is a good indicator for mineralization rates, this was not the case after chemically killing grass in the current study.
Estimation of atmospheric nutrient inputs to the Atlantic Ocean from 50°N to 50°S based on large-scale field sampling:Fixed nitrogen and dry deposition of phosphorus
Baker, A.R. ; Lesworth, T. ; Adams, C. ; Jickells, T.D. ; Ganzeveld, L.N. - \ 2010
Global Biogeochemical Cycles 24 (2010). - ISSN 0886-6236 - p. GB3006 - GB3006.
western north-atlantic - organic nitrogen - south atlantic - boundary-layer - world ocean - aerosol - precipitation - chemistry - transport - model
Atmospheric nitrogen inputs to the ocean are estimated to have increased by up to a factor of three as a result of increased anthropogenic emissions over the last 150 years, with further increases expected in the short- to mid-term at least. Such estimates are largely based on emissions and atmospheric transport modeling, because, apart from a few island sites, there is very little observational data available for atmospheric nitrogen concentrations over the remote ocean. Here we use samples of rainwater and aerosol we obtained during 12 long-transect cruises across the Atlantic Ocean between 50°N and 50°S as the basis for a climatological estimate of nitrogen inputs to the basin. The climatology is for the 5 years 2001–2005, during which almost all of the cruises took place, and includes dry and wet deposition of nitrate and ammonium explicitly, together with a more uncertain estimate of soluble organic nitrogen deposition. Our results indicate that nitrogen inputs into the region were ~850–1420 Gmol (12–20 Tg) N yr-1, with ~78–85% of this in the form of wet deposition. Inputs were greater in the Northern Hemisphere and in wet regions, and wet regions had a greater proportion of input via wet deposition. The largest uncertainty in our estimate of dry inputs is associated with variability in deposition velocities, while the largest uncertainty in our wet nitrogen input estimate is due to the limited amount and uneven geographic distribution of observational data. We also estimate a lower limit of dry deposition of phosphate to be ~0.19 Gmol P yr-1, using data from the same cruises. We compare our results to several recent estimates of N and P deposition to the Atlantic and discuss the likely sources of uncertainty, such as the potential seasonal bias introduced by our sampling, on our climatology
Inventory of P-Olsen data in the ISRIC-WISE soil database for use with QUEFTS
Batjes, N.H. - \ 2010
Wageningen : ISRIC - World Soil Information (Report / ISRIC-World Soil Information 2010/06) - 25
bodemchemie - fosfor - bodem ph - organische koolstof - organische stikstof - bodemprofielen - databanken - tropen - soil chemistry - phosphorus - soil ph - organic carbon - organic nitrogen - soil profiles - databases - tropics
Method and timing of grassland renovation affects herbage yield, nitrate leaching, and nitrous oxide emission in intensively managed grasslands
Velthof, G.L. ; Hoving, I.E. ; Dolfing, J. ; Smit, A. ; Kuikman, P.J. ; Oenema, O. - \ 2010
Nutrient Cycling in Agroecosystems 86 (2010)3. - ISSN 1385-1314 - p. 401 - 412.
organic nitrogen - soil - mineralization - netherlands - clover - cultivation - fertilizer - pasture - swards
Managed grasslands are occasionally ploughed up and reseeded in order to maintain or increase the sward productivity. It has been reported that this renovation of grassland is associated with a flush of soil organic nitrogen (N) mineralization and with a temporary increase in soil mineral N contents. Here, we report on the effects of method and time of grassland renovation on herbage yield, nitrate (NO3 -) leaching and nitrous oxide (N2O) emission. Field experiments were carried out at three sites (two sandy soils and a clay soil) in the Netherlands for three years. Renovation of grassland increased the percentage of Perennial ryegrass from 48–70% up to more than 90%. However, averaged over three years, dry matter yields were higher for the reference (not reseeded) swards (on average 13.6 Mg ha-1 for the highest N application rate) than for the renovated grasslands (12.2–13.1 Mg ha-1 dry matter). Grassland renovation in April did not increase N leaching in comparison to the reference. However, renovation in September increased the risk of leaching, because mineral N contents in the 0–90 cm were in November on average 46–77 kg N ha-1 higher than in the reference. Contents of dissolved organic N (DON) in the soil were not affected by renovation. Renovation increased N2O emissions by a factor of 1.8–3.0 relative to the reference grassland. Emissions of N2O were on average higher after renovation in April (8.2 kg N2O-N ha-1) than in September (5.8 kg N2O-N ha-1). Renovation without ploughing (i.e. only chemically destruction of the sward) resulted in a lower percentage of perennial ryegrass (60–84%) than with ploughing (>90%). Moreover, N2O emissions were higher after renovation without ploughing than with ploughing. Clearly, farmers need better recommendations and tools for determining when grassland renovation has beneficial agronomic effects. Losses of N via leaching and N2O emission after renovation can probably not be avoided, but renovation in spring in stead of autumn in combination with ploughing and proper timing of fertilizer application can minimize N losses.
Modelling the long-term soil response to atmospheric deposition at intensively monitored forest plots in Europe
Reinds, G.J. ; Posch, M. ; Vries, W. de - \ 2009
Environmental Pollution 157 (2009)4. - ISSN 0269-7491 - p. 1258 - 1269.
integrated assessment - acidic deposition - organic nitrogen - chemical status - ecosystems - impacts - carbon - acidification - switzerland - simulation
The dynamic soil chemistry model SMART was applied to 121 intensive forest monitoring plots (mainly located in western and northern Europe) for which both element input (deposition) and element concentrations in the soil solution were available. After calibration of poorly known parameters, the model accurately simulated soil solution concentrations for most plots as indicated by goodness-of-fit measures, although some of the intra-annual variation especially in nitrate and aluminium concentrations could not be reproduced. Model evaluations of two emission–deposition scenarios (current legislation and maximum feasible reductions) for the period 1970–2030 show a strong reduction in sulphate concentrations between 1980 and 2000 in the soil due to the high reductions in sulphur emissions. However, current legislation hardly reduces future nitrogen concentrations, whereas maximum feasible reductions reduces them by more than half. Maximum feasible reductions are also more effective in increasing pH and reducing aluminium concentrations, mostly below ‘critical’ values.
Vergelijking van luzerne en gras-klaver, inclusief effect op aanwezige aaltjes en de volgteelt prei
Geel, W.C.A. van; Visser, J.H.M. ; Verstegen, H.A.G. ; Haan, J.J. de - \ 2009
Lelystad : PPO AGV (PPO-AGV / Rapport ) - 32
biologische landbouw - ziektebestrijdende teeltmaatregelen - rotaties - organische stikstof - stikstofkringloop - bodemvruchtbaarheid - weidevlinderbloemigen - luzerne - meloidogyne hapla - trichodoridae - gewasbescherming - akkerbouw - grasklaver - organic farming - cultural control - rotations - organic nitrogen - nitrogen cycle - soil fertility - pasture legumes - lucerne - plant protection - arable farming - grass-clover swards
In het biologisch bedrijfssysteem op proefboerderij Vredepeel (zuidoostelijk zand) is een tweejarige teelt van een vlinderbloemig hoofdgewas in de rotatie opgenomen om extra stikstof in het systeem te brengen. De vlinderbloemige wordt begin augustus gezaaid, na voorvrucht aardappel en fungeert dan tevens als stikstofvanggewas voor de minerale stikstof die na de aardappeloogst in de bodem achterblijft en de stikstof die later in de zomer en herfst nog mineraliseert. De vraag was of luzerne of gras-klaver het meeste geschikt zou zijn als vlinderbloemige in de rotatie, gelet op drogestofproductie, geschiktheid voor latere zaai en vermeerdering van aanwezige probleemaaltjes. Er is voor luzerne gekozen, omdat het een iets slechtere waard is voor enkele specifieke aaltjes. Om beter uitsluitsel te verkrijgen over de geschiktheid van luzerne versus gras-klaver, is tevens een vergelijking tussen beide gewassen aangelegd
Vlinderbloemigen brengen bemesting in evenwicht
Holwerda, J. ; Wel, C. van der; Sukkel, W. - \ 2008
Wageningen : Wageningen UR (BioKennis Bericht : Akkerbouw en vollegrondsgroente ) - 4
biologische landbouw - bodemvruchtbaarheid - organische stikstof - stikstoffixatie - peulgewassen - luzerne - rotaties - groenbemesters - grasklaver - vollegrondsteelt - organic farming - soil fertility - organic nitrogen - nitrogen fixation - legumes - lucerne - rotations - green manures - grass-clover swards - outdoor cropping
Vlinderbloemigen vormen de stikstofbron voor de biologische landbouw. Dit omdat ze in staat zijn stikstof uit de lucht te binden. Voor een duurzame biologische akkerbouw en de groenteteelt zijn ze daarom onontbeerlijk, evenals voor de veehouderij. Uiteindelijk is ook de stikstof uit dierlijke mest in eerste instantie via vlinderbloemigen gebonden.
Demonstratieproeven alternatieven voor bloedmeel in de boomkwekerij
Helm, F.P.M. van der; Reuler, H. van - \ 2008
Lisse : Praktijkonderzoek Plant & Omgeving B.V. (PPO 427) - 34
biologische landbouw - mest - compost - vruchtbomen - organische stikstof - bloedmeel - beendermeel - boomteelt - landbouwplantenteelt - sierteelt - organic farming - manures - composts - fruit trees - organic nitrogen - blood meal - bone meal - arboriculture - crop husbandry - ornamental horticulture
Enkele afnemers van biologische producten stellen als eis dat tijdens het productieproces geen bloed- en beendermeel gebruikt is. Om hieraan tegemoet te kunnen komen zijn in het teeltseizoen 2007 en 2008 proeven gedaan met alternatieven voor bloedmeel. Het niet-gebruiken van beendermeel lijkt gezien de samenstelling van de meeste organische meststoffen geen probleem. De proeven zijn uitgevoerd met de meststoffen Monterra malt 5-1-5 en Monterra ricinus 4,5-1,5-8 en compost in vruchtbomen op klei en Phlox op duinzandgrond
Demonstratieproeven alternatieven voor bloedmeel in de boomkwekerij
Helm, F.P.M. van der; Reuler, H. van - \ 2008
Lisse : Praktijkonderzoek Plant & Omgeving, Bloembollen, Boomkwekerij & Fruit (PPO nr. 3231143017) - 31
biologische landbouw - mest - compost - vruchtbomen - organische stikstof - bloedmeel - beendermeel - boomteelt - bemesting - organic farming - manures - composts - fruit trees - organic nitrogen - blood meal - bone meal - arboriculture - fertilizer application
Enkele afnemers van biologische producten stellen als eis dat tijdens het productieproces geen bloed- en beendermeel gebruikt is. Om hieraan tegemoet te kunnen komen zijn in het teeltseizoen 2007 en 2008 proeven gedaan met alternatieven voor bloedmeel. Het niet-gebruiken van beendermeel lijkt gezien de samenstelling van de meeste organische meststoffen geen probleem. De proeven zijn uitgevoerd met de meststoffen Monterra malt 5-1-5 en Monterra ricinus 4,5-1,5-8 en compost in vruchtbomen op klei en Phlox op duinzandgrond.
Global reactive nitrogen deposition from lightning NOx
Shepon, A. ; Gildor, H. ; Labrador, L.J. ; Butler, T. ; Ganzeveld, L.N. ; Lawrence, M.G. - \ 2007
Journal of Geophysical Research: Atmospheres 112 (2007). - ISSN 2169-897X - p. D06304 - D06304.
general-circulation model - dry deposition - atmospheric chemistry - organic nitrogen - climate-change - trace gases - distributions - parameterization - cycle - emissions
We present results of the deposition of nitrogen compounds formed from lightning (LNO x ) using the global chemical transport Model of Atmospheric Transport and Chemistry¿Max Planck Institute for Chemistry version. The model indicates an approximately equal deposition of LNO x in both terrestrial and oceanic ecosystems, primarily in the tropics and midlatitudes open ocean, despite much higher intensities of lightning flashes above landmasses. The highest values of deposition are due to wet convective deposition, with highest values concentrated in the tropical continents. Nonconvective wet deposition, associated with large-scale weather patterns, occurs over large areas of the ocean amid lower values per square meter, manifesting the long-range transport of NO y , including long-lived species such as HNO3 at high altitudes and PAN. Dry deposition is concentrated primarily above landmasses, yet oceanic deposition over wide areas is still observed. Combined together, the total LNO x deposition exhibits maximal influx values over land, whereas oceanic deposition over wider areas renders the integrated deposition over both ecosystems almost identical. Peaks of terrestrial deposition values (located in Africa, South America, and Asia) show seasonal variability by meridionally penetrating the northern or southern midlatitude following the corresponding summer hemisphere, in accordance with the migration of LNO x production sites. On land, wet and dry deposition rates are more or less equal with a small bias toward wet deposition, whereas above the ocean, wet deposition is markedly higher because of a small water uptake efficiency and relatively small surface roughness. Further work of modeling additional species and obtaining more information on different compounds is required
Bemestingsplanner nuttig hulpmiddel : Bemesting voor een goede grasklaver
Eekeren, N.J.M. van - \ 2007
BioKennis bericht Zuivel & rundvlees 1 (2007). - 4
melkveehouderij - klavers - stikstof - organische stikstof - organische stof - planning - bemesting - mineralenboekhouding - dairy farming - clovers - nitrogen - organic nitrogen - organic matter - fertilizer application - nutrient accounting system
Op veel biologische melkveebedrijven staat het eiwitgehalte in de kuilen onder druk. Lagere klaveraandelen door weersinvloeden zijn slechts gedeeltelijk de oorzaak. Veel problemen met klaver komen door een te lage pH en een slechte kalivoorziening. De bemestingsplanner is hierbij een nuttig hulpmiddel.
Gebruiksnormen van meststoffen in de praktijk, getoetst in 2004 en 2005
Oenema, J. ; Assinck, F.B.T. ; Verloop, J. ; Velthof, G.L. ; Aarts, F. - \ 2007
Lelystad : Animal Sciences Group (Koeien & kansen rapport 38) - 78
stikstofgehalte - nitraatreductie - organische stikstof - stikstofkringloop - mestgiften - agrarische bedrijfsvoering - melkveehouderij - stikstofverliezen - bemesting - nitrogen content - nitrate reduction - organic nitrogen - nitrogen cycle - dressings - farm management - dairy farming - nitrogen losses - fertilizer application
Het doel van dit onderzoek is het toetsen van de voor 2009 geldende gebruiksnormen voor meststoffen (dierlijke mest en kunstmest) in praktijksituaties. De gebruiksnormen voldoen in theorie aan de milieueisen van de EU-nitraatrichtlijn en zijn gebaseerd op veronderstellingen over i) de verdeling van aangevoerde nutriënten over bodem en gewas en ii) het lot van N in de bodem. De toetsing richt zich op deze veronderstellingen. De volgende onderzoeksvragen worden beantwoord: 1. Leidt strikte toepassing van de gebruiksnormen 2009 op perceelsniveau tot in de wet veronderstelde benutting van meststoffen (gewasopbrengsten)?; 2. Hoeveel minerale stikstof blijft in de bodem in het najaar achter? ; 3. Wat is het lot van N in de bodem? Welk deel komt in het grondwater terecht?; 4. Wat is de invloed van waterhuishouding, grondgebruik, bemesting en graslandgebruik op de nitraatconcentraties in het bovenste grondwater? Dit rapport doet verslag van de resultaten van de eerste 2 meetseizoenen. Per onderzoeksvraag worden voorlopige conclusies getrokken. Voor hardere conclusies zijn meer meetjaren nodig. Het onderzoek wordt voortgezet
Increases in nitrogen uptake rather than nitrogen-use efficiency support higher rates of temperate forest productivity under elevated CO2
Finzi, A.C. ; Norby, R.J. ; Calfapietra, C. ; Gallet-Budynek, A. ; Gielen, B. ; Holmes, W.E. ; Hoosbeek, M.R. ; Iversen, C.M. ; Jackson, R.B. ; Kubiske, M.E. ; Ledford, J. ; Liberloo, M. ; Oren, R. ; Polle, A. ; Pritchard, S. ; Zak, D.R. ; Schlesinger, W.H. ; Ceulemans, R. - \ 2007
Proceedings of the National Academy of Sciences of the United States of America 104 (2007)35. - ISSN 0027-8424 - p. 14014 - 14019.
atmospheric carbon-dioxide - rotation poplar plantation - fine-root production - soil-n availability - enrichment face - populus-tremuloides - deciduous forest - organic nitrogen - community composition - ecosystem responses
Forest ecosystems are important sinks for rising concentrations of atmospheric CO2. In previous research, we showed that net primary production (NPP) increased by 23 ± 2% when four experimental forests were grown under atmospheric concentrations of CO2 predicted for the latter half of this century. Because nitrogen (N) availability commonly limits forest productivity, some combination of increased N uptake from the soil and more efficient use of the N already assimilated by trees is necessary to sustain the high rates of forest NPP under free-air CO2 enrichment (FACE). In this study, experimental evidence demonstrates that the uptake of N increased under elevated CO2 at the Rhinelander, Duke, and Oak Ridge National Laboratory FACE sites, yet fertilization studies at the Duke and Oak Ridge National Laboratory FACE sites showed that tree growth and forest NPP were strongly limited by N availability. By contrast, nitrogen-use efficiency increased under elevated CO2 at the POP-EUROFACE site, where fertilization studies showed that N was not limiting to tree growth. Some combination of increasing fine root production, increased rates of soil organic matter decomposition, and increased allocation of carbon (C) to mycorrhizal fungi is likely to account for greater N uptake under elevated CO2. Regardless of the specific mechanism, this analysis shows that the larger quantities of C entering the below-ground system under elevated CO2 result in greater N uptake, even in N-limited ecosystems. Biogeochemical models must be reformulated to allow C transfers below ground that result in additional N uptake under elevated CO2.
Bemesting Buxus in vollegrond kan efficiënter
Aendekerk, T.G.L. - \ 2007
De Boomkwekerij 2007 (2007)20. - ISSN 0923-2443 - p. 16 - 17.
buxus sempervirens - houtachtige planten als sierplanten - overblijvende planten - gewaskwaliteit - organische stikstof - stikstofgehalte - normen - universitair onderzoek - onderzoeksinstituten - vollegrondsteelt - bemesting - ornamental woody plants - perennials - crop quality - organic nitrogen - nitrogen content - standards - university research - research institutes - outdoor cropping - fertilizer application
Binnen de scherpe stikstofnorm blijven, en toch een kwalitatief goede Buxus in de vollegrond telen? Na twee jaar van onderzoek heeft PPO’er Theo Aendekerk aangetoond dat dat in de praktijk mogelijk moet zijn.
Effects of different diets on utilization of nitrogen from cattle slurry applied to grassland on a sandy soil in the Netherlands
Reijs, J.W. ; Sonneveld, M.P.W. ; Sorensen, P. ; Schils, R.L.M. ; Groot, J.C.J. ; Lantinga, E.A. - \ 2007
Agriculture, Ecosystems and Environment 118 (2007)1-4. - ISSN 0167-8809 - p. 65 - 79.
dairy farming systems - ammonia volatilization - pig slurry - manure applications - organic nitrogen - plant uptake - mineralization - carbon - term - management
Dietary adjustments have been suggested as a means to reduce N losses from dairy systems. Differences in fertilizing value of dairy slurry as a result of dietary adjustments were evaluated in a 1-year grassland experiment and by long-term modelling. Slurry composition of non-lactating dairy cows was manipulated by feeding diets with extreme high and low levels of dietary protein and energy. C:Ntotal ratio of the produced slurries ranged from 5.1 to 11.4. To evaluate their short-term fertilizer N value, the experimental slurries (n = 8) and slurries from commercial farms with variable composition (n = 4), were slit-injected in two grassland fields on the same sandy soil series in the north of The Netherlands (53°10¿N, 6°04¿E), with differences in sward age and ground water level. The recently established grassland field (NEW) was characterized by lower soil OM, N and moisture contents, less herbs and more modern grass varieties compared to the older grassland field (OLD). Slurry was applied in spring (100 kg N ha¿1) and after the first cut (80 kg N ha¿1) while in total four cuts were harvested. Artificial fertilizer N treatments were included in the experiment to calculate the mineral fertilizer equivalent (MFE) of slurry N. The OLD field showed a higher total N uptake whereas DM yields were similar for the two fields. Average MFE of the slurries on the OLD field (47%) was lower than on the NEW field (56%), probably as a result of denitrification of slurry N during wet conditions in spring. Slurries from high crude protein diets showed a significantly higher MFE (P <0.05) compared to low crude protein diets. No significant differences in MFE were observed between slurries from high and low energy diets. On both fields, MFE appeared to be positively related to the ammonium content (P <0.001) and negatively to the C:Ntotal ratio of the slurry DM (P = 0.001). Simulation of the effect of long-term annual application of 180 kg N ha¿1 with highest and lowest C:Ntotal ratio suggested that both slurries would lead to an increase in annual soil N mineralization. Both soil N mineralization and SOC appeared to be substantially higher in equilibrium state for the slurry with the highest C:Ntotal ratio. It is concluded that in a situation with slit-injection, the reduced first-year N availability of slurry with a high C:Ntotal ratio as observed in the grassland experiment will only be compensated for by soil N mineralization on the very long term.
Uit de mest- en mineralenprogramma's : Het lot van urinestikstof bij najaarsbeweiding
Groenigen, J.W. van; Corré, W.J. ; Beek, C.L. - \ 2006
Wageningen : Alterra (Informatieblad / Alterra 398.106) - 2
rundvee - lysimeters - graslanden - organische stikstof - stikstofgehalte - urine - isotopenlabelling - mineralenboekhouding - ammoniakemissie - cattle - grasslands - organic nitrogen - nitrogen content - isotope labeling - nutrient accounting system - ammonia emission
Urineplekken in beweid grasland zijn een grote bron van makkelijk beschikbaar N. Lokaal kunnen concentraties oplopen tot hoger dan 1000 kg N ha-1. Toch zijn er, in tegenstelling tot bij het uitrijden van mest, geen restricties aan het beweiden gedurende herfst en winter. Deze studie heeft tot doel om het lot van urine-N bij najaarsbeweiding te kwantificeren, om zodoende mogelijk negatieve gevolgen voor het milieu in kaart te brengen. In eerdere studies werd een groot gat in het budget van urine-N gevonden, dat grotendeels werd toegeschreven aan vastlegging in organische N in de bodem. Om deze post te kwantificeren is deze keer gekozen voor een lysimeterproef met urine gelabeld met de stabiele isotoop 15N. Daarnaast is een literatuurstudie naar het lot van urine-N als gevolg van toedieningstijdstip uitgevoerd
Nitrogen Fractions in Arable Soils in Relation to Nitrogen Mineralization and Plant Uptake
Bregliani, M. ; Temminghoff, E.J.M. ; Riemsdijk, W.H. van; Hagg, E.S. - \ 2006
Communications in Soil Science and Plant Analysis 37 (2006)11-12. - ISSN 0010-3624 - p. 1571 - 1587.
0.01 m cacl2 - organic nitrogen - n mineralization - extraction procedure - calcium-chloride - biomass
Nitrogen (N) as a major constituent of all plants is one of the most important nutrients. Minimizing input of mineral nitrogen fertilizer is needed to avoid harm to the environment. Optimal input of mineral nitrogen should take the nitrogen supply of the soil into account. Many different soil tests have been proposed for determining soil nitrogen availability. In this article we present a new approach that is based on the measurement of nitrate, ammonium, and dissolved organic nitrogen (DON) in a 0.01 M CaCl2 soil extract. Eighteen agricultural soils, differing widely in the availability of nitrogen were used, fertilized and unfertilized. It is shown that the nitrogen uptake by maize plants (Zea Mays L.) in both ¿N-fertilized¿ and ¿N-unfertilized¿ soils as measured in a pot experiment can be described with a simple model using the measured nitrogen fractions in the extract. The main source of nitrogen uptake by the plants is the mineralized organic nitrogen during the growing period. It is shown that the initial measured DON fraction is a good indicator of the nitrogen mineralized during plant growth
Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

Please log in to use this service. Login as Wageningen University & Research user or guest user in upper right hand corner of this page.