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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It depends: : effects of soil organic matter in aboveground-belowground interactions in agro-ecosystems
Gils, Stijn Herman van - \ 2017
University. Promotor(en): Wim van der Putten; David Kleijn. - Wageningen : Wageningen University - ISBN 9789463436526 - 176
soil organic matter - agroecosystems - aphidoidea - fertilizers - wheat - rape - crop yield - ecosystem services - nutrient availability - pest control - organic farming - organisch bodemmateriaal - agro-ecosystemen - kunstmeststoffen - tarwe - koolzaad - gewasopbrengst - ecosysteemdiensten - voedingsstoffenbeschikbaarheid - plagenbestrijding - biologische landbouw

Over the last decades agricultural production increased drastically due to the use of external inputs. However, the use of external inputs has high environmental costs and may negatively influence ecosystem processes such as pollination and pest control that underpin agricultural production. Soil organic matter has been proposed as a potential alternative to external inputs as it relates to multiple yield promoting ecosystem processes. The aim of my thesis is to assess whether and how soil organic matter content alters the effect of some ecosystem processes and external inputs on crop yield. I examined whether soil organic matter alters biomass of wheat and oilseed rape under fertilizer supply. Other biotic and abiotic factors that operate at different spatial and temporal scales are also included in some of these experiments. I found that under controlled conditions soil organic matter may reduce the positive effect of mineral fertilizer supply on crop biomass. The reduction changed with the presence or absence of a pathogenic root fungus, but not with drought stress. Moreover, soil organic matter enhances performance of aphids under controlled greenhouse conditions, but the enhancement was less than fertilizer supply. None of these controlled experiments, however, showed that soil organic matter can be an alternative to mineral fertilizer supply. Under field conditions soil organic matter did not strongly affect plant nutrient availability or performances of aphid and its natural enemies. The relation between soil organic matter and plant biomass in a greenhouse experiment did not change with organic management or the duration of it, neither did it change with pollinator visitation rate, an ecosystem process that is managed on the landscape scale. These results suggest that soil organic matter may relate to ecosystem services that influence crop yield, whereas these relations might not be significant under field conditions. Collectively, all these results suggest that the relation between soil organic matter content and ecosystem processes that benefit crop yield is highly context dependent. I propose future research may focus on (1) the quality of soil organic matter rather than the content per se and (2) the relation between soil organic matter content and crop yield under realistic conditions in a longer term.

Above- and below-ground responses of four tundra plant functional types to deep soil heating and surface soil fertilization
Wang, Peng ; Limpens, Juul ; Mommer, Liesje ; Ruijven, Jasper van; Nauta, Ake L. ; Berendse, Frank ; Schaepman-Strub, Gabriela ; Blok, Daan ; Maximov, Trofim C. ; Heijmans, Monique M.P.D. - \ 2017
Journal of Ecology 105 (2017)4. - ISSN 0022-0477 - p. 947 - 957.
accelerated thawing - active layer thickness - Arctic tundra - climate warming - competition - nutrient availability - plant functional types - root biomass - vegetation composition - vertical root distribution

Climate warming is faster in the Arctic than the global average. Nutrient availability in the tundra soil is expected to increase by climate warming through (i) accelerated nutrient mobilization in the surface soil layers, and (ii) increased thawing depths during the growing season which increases accessibility of nutrients in the deeper soil layers. Both processes may initiate shifts in tundra vegetation composition. It is important to understand the effects of these two processes on tundra plant functional types. We manipulated soil thawing depth and nutrient availability at a Northeast-Siberian tundra site to investigate their effects on above- and below-ground responses of four plant functional types (grasses, sedges, deciduous shrubs and evergreen shrubs). Seasonal thawing was accelerated with heating cables at c. 15 cm depth without warming the surface soil, whereas nutrient availability was increased in the surface soil by adding slow-release NPK fertilizer at c. 5 cm depth. A combination of these two treatments was also included. This is the first field experiment specifically investigating the effects of accelerated thawing in tundra ecosystems. Deep soil heating increased the above-ground biomass of sedges, the deepest rooted plant functional type in our study, but did not affect biomass of the other plant functional types. In contrast, fertilization increased above-ground biomass of the two dwarf shrub functional types, both of which had very shallow root systems. Grasses showed the strongest response to fertilization, both above- and below-ground. Grasses were deep-rooted, and they showed the highest plasticity in terms of vertical root distribution, as grass root distribution shifted to deep and surface soil in response to deep soil heating and surface soil fertilization respectively. Synthesis. Our results indicate that increased thawing depth can only benefit deep-rooted sedges, while the shallow-rooted dwarf shrubs, as well as flexible-rooted grasses, take advantage of increased nutrient availability in the upper soil layers. Our results suggest that grasses have the highest root plasticity, which enables them to be more competitive in rapidly changing environments. We conclude that root vertical distribution strategies are important for vegetation responses to climate-induced increases in soil nutrient availability in Arctic tundra, and that future shifts in vegetation composition will depend on the balance between changes in thawing depth and nutrient availability in the surface soil.

Technical documentation of the soil model VSD+ : Status A
Mol-Dijkstra, J.P. ; Reinds, G.J. - \ 2017
Wageningen : Statutory Research Tasks Unit for Nature & the Environment (WOt-technical report 88) - 88
soil - soil acidity - models - nutrient availability - soil carbon sequestration - climatic change - precipitation - bodem - bodemaciditeit - modellen - voedingsstoffenbeschikbaarheid - koolstofvastlegging in de bodem - klimaatverandering - neerslag
VSD+ is een model om de gevolgen te berekenen van atmosferische depositie en klimaatverandering voorbodemverzuring, de beschikbaarheid van voedingsstoffen en het vastleggen van koolstof. Het model isontwikkeld ter onderbouwing van strategieën om de uitstoot van zwavel (S) en stikstof (N) in Europa teverminderen. Dit document biedt een samenvatting van de theorie waar het model op gestoeld is, detechnische documentatie hiervan alsmede een beschrijving van het testen, het valideren en de sensitiviteitsanalysevan het model. De processen zoals beschreven in het artikel over VSD+ zijn met goed gevolg getest.De gevoeligheidsanalyse gaf aan dat de constante voor het evenwicht tussen H+ en Al3+ in de bodemoplossingen de Ca-verweringssnelheid de parameters zijn, die voor een groot gedeelte de waarde van degesimuleerde pH bepalen. Voor basenverzadiging zijn de belangrijkste parameters de uitwisselingsconstantetussen H+ en basische kationen en de verwering van Ca. Voor de C/N ratio van bodemorganische stof zijn Cen N in het strooisel en de opname van N zeer bepalende factoren. De nitraatconcentratie hangt sterk samenmet het nerslagoverschot en de netto input van N---VSD+ is a model to calculate effects of atmospheric deposition and climate change on soil acidification,nutrient availability and carbon sequestration. The model has been developed to support emission abatementstrategies of sulphur (S) and nitrogen (N) in Europe. This document contains a summary of the modeltheory, technical documentation and descriptions of testing, validations and the sensitivity analysis of themodel. The processes described in the paper about VSD+ have been tested successfully. The sensitivityanalysis showed that the constant for the equilibrium between H+ and Al3+ in the soil solution and theweathering rate of Ca are the parameters that to a large extent determine the value of the simulated pH. Forbase saturation, most important parameters are the exchange constant between H+ and base cations andthe weathering of Ca. For the C/N ratio of soil organic matter, litterfall of C and N and the uptake of N areimportant influencing factors. The nitrate concentration strongly depends on the leaching flux and the net N input
Arme bossen verdienen beter : OBN Deskundigenteam Droog zandlandschap
Burg, A. Van den; Bijlsma, R.J. ; Bobbink, R. - \ 2015
VBNE, Vereniging van Bos- en Natuurterreineigenaren - 24 p.
bossen - bosbeheer - zandgronden - zure regen - voedingsstoffenbeschikbaarheid - biodiversiteit - verzuring - voedingsstoffenbalans - verstoorde bossen - bosecologie - forests - forest administration - sandy soils - acid rain - nutrient availability - biodiversity - acidification - nutrient balance - disturbed forests - forest ecology
Bossen van het droog zandlandschap van Noordwest- Europa staan bekend als ‘arme bossen’. Het landschap waarin ze voorkomen was tot in de 20ste eeuw overwegend een heidelandschap. Op de voedselarme heide- en stuifzandbodems zijn vanaf 1900 vooral naaldbossen geplant. Inmiddels zijn in deze voormalige plantages volop kenmerken aanwezig van oudere, meer natuurlijke bossen, zoals dikke levende en dode bomen, natuurlijke verjonging van inheemse loofbomen en een gevarieerd lichtklimaat. Veel soorten hebben sterk geprofiteerd van deze natuurlijke ontwikkeling die nog steeds doorzet. In de loop van 20ste eeuw zijn echter eerst zwaveldepositie (‘zure regen’) en later ook stikstofdepositie een grote negatieve invloed gaan uitoefenen op het landschap. Dit raakt niet alleen de biodiversiteit, maar ook de hout- en biomassaproductie en daarmee de duurzaamheid van het bosgebruik. We hebben directe gevolgen vastgesteld voor soorten en nutriëntenvoorraden in de bodem en indirecte effecten op concurrentieverhoudingen en voedselketens. Er zijn echter ook onzekerheden en belangrijke kennisleemten waar het gaat om de precieze mechanismen, het experimenteel vastleggen van oorzaak-gevolg relaties en mogelijke oplossingsrichtingen. De achtergronden van deze problematiek in droge bossen staan centraal in deze brochure.
Ky’osimba Onaanya: understanding productivity of East African Highland banana
Taulya, G. - \ 2015
University. Promotor(en): Ken Giller, co-promotor(en): Peter Leffelaar; P.J.A. van Asten. - Wageningen : Wageningen University - ISBN 9789462575615 - 167
bananen - musa - droogte - voedingsstoffenbeschikbaarheid - kalium - stikstof - kunstmeststoffen - afrika - uganda - gewasgroeimodellen - beslissingsmodellen - drogestofverdeling - groeianalyse - licht - fenotypische variatie - bananas - drought - nutrient availability - potassium - nitrogen - fertilizers - africa - crop growth models - decision models - dry matter distribution - growth analysis - light - phenotypic variation

Over 30 million people in East Africa depend on East African highland bananas for food and income. The bananas are grown with limited additions of nutrients and no irrigation, despite widespread poor soil fertility and regular dry seasons. This thesis describes the effect of increasing rainfall and application of potassium and nitrogen fertilizers on banana growth and yields. In areas that receive less than 1100 mm of rainfall per year, additional rainfall increases yields by 65%. Application of potassium increases yields by 88%, while nitrogen is not required. A framework for computing banana growth and yield in response to the amount of water stored in the soil is described. Where the soil water storage capacity is low, mulching increases yields by 10% but it has no effect in areas where the soil water storage is high. This framework is envisaged to guide improvements in banana management and productivity in East Africa.

Mineral nutrition of cocoa : a review
Vliet, J.A. van; Slingerland, M.A. ; Giller, K.E. - \ 2015
Wageningen : Wageningen UR - ISBN 9789462577053 - 57
cacao - mineralenvoeding - bevruchting - kunstmeststoffen - mestbehoeftebepaling - vruchtbaarheid - voedingsstoffenbehoeften - voedingsstoffenbeschikbaarheid - grondanalyse - voedingsstoffentekorten - kaliummeststoffen - stikstofmeststoffen - fosformeststoffen - agrarische productiesystemen - overzichten - cocoa - mineral nutrition - fertilization - fertilizers - fertilizer requirement determination - fertility - nutrient requirements - nutrient availability - soil analysis - nutrient deficiencies - potassium fertilizers - nitrogen fertilizers - phosphorus fertilizers - agricultural production systems - reviews
This literature review on mineral nutrition of cocoa was commissioned by the Scientific Committee of the Cocoa Fertiliser Initiative to address the following questions: What knowledge is currently available about mineral nutrition of cocoa? What are the current knowledge gaps? What are the key areas for further research?
Testing for disconnection and distance effects on physiological self-recognition within clonal fragments of Potentilla reptans
Chen, B. ; Vermeulen, P.J. ; During, H.J. ; Anten, N.P.R. - \ 2015
Frontiers in Plant Science 6 (2015). - ISSN 1664-462X - 9 p.
herb glechoma-hederacea - fragaria-chiloensis - nutrient availability - kin recognition - rooting volume - pot size - plant - integration - ramets - discrimination
Evidence suggests that belowground self-recognition in clonal plants can be disrupted between sister ramets by the loss of connections or long distances within a genet. However, these results may be confounded by severing connections between ramets in the setups. Using Potentilla reptans, we examined severance effects in a setup that grew ramet pairs with connections either intact or severed. We showed that severance generally reduced new stolon mass but had no effect on root allocation of ramets. However, it did reduce root mass of younger ramets of the pairs. We also explored evidence for physiological self-recognition with another setup that avoided severing connections by manipulating root interactions between closely connected ramets, between remotely connected ramets and between disconnected ramets within one genet. We found that ramets grown with disconnected neighbors had less new stolon mass, similar root mass but higher root allocation as compared to ramets grown with connected neighbors. There was no difference in ramet growth between closely connected- and remotely connected-neighbor treatments. We suggest that severing connections affects ramet interactions by disrupting their physiological integration. Using the second setup, we provide unbiased evidence for physiological self-recognition, while also suggesting that it can persist over long distances.
Nitrogen: The most important nutritional element for the plant : complicated balance between vegetative and generative growth
Heuvelink, E. ; Kierkels, T. - \ 2015
In Greenhouses : the international magazine for greenhouse growers 4 (2015)2. - ISSN 2215-0633 - p. 44 - 45.
glastuinbouw - plantenvoeding - voedingsstoffen - voedingsstoffenbeschikbaarheid - opname (uptake) - plantenfysiologie - nitraten - ammonium - cultuurmethoden - greenhouse horticulture - plant nutrition - nutrients - nutrient availability - uptake - plant physiology - nitrates - cultural methods
Nitrogen is found in almost all parts of the plant. It’s one of the plant’s most essential nutritional element. There’s a tendency in greenhouse horticulture to over-fertilise. In most situations it’s difficult to get around this. However, more precise application offers more possibilities to control production.
Restoration of acidified and eutrophied rich fens: Long-term effects of traditional management and experimental liming
Diggelen, J. van; Bense, I.H.M. ; Brouwer, E. ; Limpens, J. ; Schie, J.M. van; Smolders, A.J.P. ; Lamers, L.P.M. - \ 2015
Ecological Engineering 75 (2015). - ISSN 0925-8574 - p. 208 - 216.
laagveengebieden - eutrofiëring - verzuring - ecologisch herstel - bekalking - fens - eutrophication - acidification - ecological restoration - liming - vegetation development - nutrient availability - nitrogen deposition - surface-water - groundwater - phosphorus - level - limitation - wetlands
Rich fens are known for their high botanical diversity encompassing many endangered species. For decades, several management measures, including mowing and burning, have been applied to maintain a high biodiversity by means of slowing down the natural succession from calcareous rich fens to acidic poor fens or woodland. In this study, we assessed the long-term effects of these traditional management measures, and explored the effectiveness of liming as a measure to restore rich fen vegetation. Effects of summer mowing, and of burning after winter mowing, were assessed by comparing current (2013) and historical (1967) vegetation data. Effects of experimental liming, using different levels of lime addition (0, 1000, 2000, and 4000 kg Dolokal/ha), were monitored in the field during 7.5 years. Summer mowing led to more acidic and nutrient-poor conditions as indicated by a shift from rich to poor fen vegetation, including a well-developed bryophyte cover dominated by Sphagnum with some threatened species. Burning (after winter mowing) counteracted acidification but increased nutrient availability, as indicated by dominance of vascular species characteristic of productive tall-herb grasslands and a sparse bryophyte cover with common species. We conclude that the traditional measures were unable to maintain rich fen composition in the long term. Given the fact that the restoration of hydrological conditions, favouring rich fens, is not always feasible, liming could be an alternative to counteract acidification and improve rich fen conditions in the short term. This measure, however, appeared to be unsustainable as the re-establishment and dominance of Sphagnum spp. seriously complicated the development of rich fen vegetation in the longer term.
Population densities of eastern black rhinoceros : unravelling the controls
Ouma, B.O. - \ 2014
University. Promotor(en): Herbert Prins, co-promotor(en): Ignas Heitkonig; Sip van Wieren. - Wageningen : Wageningen University - ISBN 9789461739599 - 158
rhinoceros - populatiedichtheid - populatie-ecologie - savannen - afgrazen - voedingsstoffenbeschikbaarheid - regen - temperatuur - kenya - population density - population ecology - savannas - browsing - nutrient availability - rain - temperature

Key words: black rhinoceros, browser, corticosterone, diet, density dependence, minerals, moisture, physiological stress, savanna, soil nutrients, woody cover.

Understanding the forces that cause variability in population sizes is a central theme in ecology. The limiting factor in populations of large mammals which are not controlled top‐down by predation is food, i.e., such populations are controlled by bottom‐up processes. However, there is little evidence of density dependence in large‐ to mega-herbivores. Yet, conservationists have managed Critically Endangered mega‐herbivores like rhinoceros as if their population growth were density dependent, i.e., following a logistic growth curve, focusing on large growth at population densities presumed to be at half‐carrying capacity (K/2). This would enable them to translocate animals at presumed half‐carrying capacity to retain local population densities and to create new populations in areas of suitable habitat, where animals are considered safe against poaching. This study focused on one such mega‐herbivore, the eastern black rhinoceros (Diceros bicornis michaeli) to re‐consider the density dependence population regulation in a mega‐herbivore and uses the findings to contribute to possible solutions towards conservation challenges facing this species. The expectations were that increases in population density would result in a decrease in reproductive performance, and that physiological stress levels in animals in populations of high density would be higher than in animals in populations of low densities. Nine populations of black rhinoceros across Kenya were studied, with variation in their respective densities, Plant Available Moisture (‘PAM’ i.e., ‘soil moisture’) and Plant Available Nutrients (‘PAN’ i.e., ‘soil fertility’). Data from available records (1993‐2010) were used to assess reproductive performance. Dietary quality and levels of corticosterone were estimated through faecal analysis from animals sampled in the field and from data on feeding trials of black rhinoceroses in zoos (dietary analysis only). Woody cover estimates were used to assess available browse for black rhinoceros. Two measures of density were used, i.e., absolute density (animals/km2) and relative density, i.e., absolute density as a ratio to the estimated maximum stocking density or ‘carrying capacity’. The effects of PAM and PAN, and subsets of PAM (rainfall and temperature) were incorporated and controlled in testing expectations. No evidence for density dependence was found. Reproductive performances tended to be better where PAM was high, PAN was low and woody cover was sparse. PAM was found to be directly correlated with quality of dietary browse. Black rhinoceros populations appeared controlled more by bottom‐up processes through key resources, even though their densities were perhaps too low to fully support this alternative view. It was apparent that the density dependence concept still requires more investigation. Deliberate efforts should be made to secure high PAM – low PAN – sparse woody cover areas for conservation of black rhinoceros. Conservation managers are advised to consider set percentage translocations, as opposed to the current translocation of black rhinoceros on the basis of an imaginary ‘carrying capacity’ and density dependence.

Understanding causes of tree growth response to gap formation: D13C-values in tree rings reveal a predominant effect of light
Sleen, J.P. van der; Soliz-Gamboa, C.C. ; Helle, G. ; Pons, T.L. ; Anten, N.P.R. ; Zuidema, P.A. - \ 2014
Trees-Structure and Function 28 (2014)2. - ISSN 0931-1890 - p. 439 - 448.
water-use efficiency - carbon-isotope discrimination - tropical rain-forest - nutrient availability - microbial biomass - wood delta-c-13 - canopy gaps - size - photoinhibition - dynamics
Carbon isotope ratios in growth rings of a tropical tree species show that treefall gaps stimulate diameter growth mainly through changes in the availability of light and not water. The formation of treefall gaps in closed canopy forests usually entails considerable increases in light and nutrient availability for remaining trees, as well as altered plant water availability, and is considered to play a key role in tree demography. The effects of gaps on tree growth are highly variable and while usually stimulatory they may also include growth reductions. In most studies, the causes of changes in tree growth rates after gap formation remain unknown. We used changes in carbon isotope 13C discrimination (D13C) in annual growth rings to understand growth responses after gap formation of Peltogyne cf. heterophylla, in a moist forest of Northern Bolivia. We compared growth and D13C of the 7 years before and after gap formation. Forty-two trees of different sizes were studied, half of which grew close (\\10 m) to single treefall gaps (gap trees), the other halfmore than 40 m away from gaps (controls). We found variable responses among gap trees in growth and D13C. Increased growth was mainly associated with decreased D13C, suggesting that the growth response was driven by increased light availability, possibly in combination with improved nutrient availability. Most trees showing zero or negative growth change after gap formation had increased D13C, suggesting that increased water stress did not play a role, but rather that light conditions had not changed much or nutrient availability was insufficient to support increased growth. Combining growth rates withD13Cproved to be a valuable tool to identify the causes of temporal variation in tree growth.
More cells, bigger cells or simply reorganization? Alternative mechanisms leading to changed internode architecture under contrasting stress regimes
Huber, H. ; Brouwer, J.H.F. de; Wettberg, E.J. von; During, H.J. ; Anten, N.P.R. - \ 2014
New Phytologist 201 (2014)1. - ISSN 0028-646X - p. 193 - 204.
shade-avoidance responses - impatiens-capensis balsaminaceae - phenotypic plasticity - population differentiation - arabidopsis-thaliana - nutrient availability - morphogenic responses - adaptive plasticity - stoloniferous herb - trifolium-repens
Shading and mechanical stress (MS) modulate plant architecture by inducing different developmental pathways. Shading results in increased stem elongation, often reducing whole-plant mechanical stability, while MS inhibits elongation, with a concomitant increase in stability. Here, we examined how these organ-level responses are related to patterns and processes at the cellular level by exposing Impatiens capensis to shading and MS. Shading led to the production of narrower cells along the vertical axis. By contrast, MS led to the production of fewer, smaller and broader cells. These responses to treatments were largely in line with genetic differences found among plants from open and closed canopy sites. Shading- and MS-induced plastic responses in cellular characteristics were negatively correlated: genotypes that were more responsive to shading were less responsive to MS and vice versa. This negative correlation, however, did not scale to mechanical and architectural traits. Our data show how environmental conditions elicit distinctly different associations between characteristics at the cellular level, plant morphology and biomechanics. The evolution of optimal response to different environmental cues may be limited by negative correlations of stress-induced responses at the cellular level.
Oosterschelde geschikt als habitat voor bruinvis?
Jansen, O.E. ; Aarts, G.M. ; Reijnders, P.J.H. - \ 2013
Zoogdier 24 (2013)4. - ISSN 0925-1006 - p. 4 - 6.
phocoenidae - oosterschelde - habitats - habitatgeschiktheid - voedingsstoffenbeschikbaarheid - stormvloedkeringen - ecologische risicoschatting - wildbeheer - eastern scheldt - habitat suitability - nutrient availability - storm surge barriers - ecological risk assessment - wildlife management
Sinds tientallen jaren zijn er weer meer bruinvissen waargenomen in de Noordzee rond Nederland. De dieren drongen onlangs ook door in estuaria, zoals de Oosterschelde. Maar is het habitat in de Oosterschelde eigenlijk wel geschikt voor de bruinvis en is er voldoende voedselaanbod en rust? En welke impact heeft de stormvloedkering op deze kleine walvisachtige? Informatie die bijdraagt aan een antwoord op bovenstaande vragen kwam boven water gedurende het onderzoek van Okka Jansen, waarop zij begin 2013 promoveerde.
Eindrapportage organische meststoffen: samenstelling en werking
Haan, J.J. de; Geel, W.C.A. van; Paauw, J.G.M. ; Burgt, G.J.H.M. van der; Hospers-Brands, A.J.T.M. ; Venhuizen, A. ; Oonk, K. - \ 2013
Lelystad : Praktijkonderzoek Plant & Omgeving, Business Unit Akkerbouw, Groene Ruimte en Vollegrondsgroenten - 13
bemesting - akkerbouw - organische meststoffen - samenstelling - voedingsstoffenbeschikbaarheid - gebruikswaarde - mineralenboekhouding - modules - onderzoeksprojecten - fertilizer application - arable farming - organic fertilizers - composition - nutrient availability - use value - nutrient accounting system - research projects
De mest- en mineralen wetgeving is en wordt verder aangescherpt. Telers moeten daardoor steeds scherper het aanbod van meststoffen afstemmen op de gewasbehoefte. Bij gebruik van kunstmest is dat makkelijker dan bij gebruik van organische mestsoorten en composten. Deze beweging veroorzaakt dus een tendens naar verminderd gebruik van organische meststoffen. Dat is om diverse redenen een zorgelijke ontwikkeling, o.a. door een lagere organische stof aanvoer. Door beter gebruik te maken van de aanwezige kennis, zowel oude als recente, kan de onzekerheid over de werking van de meststoffen voor een deel weggenomen worden en kunnen ook betere keuzes gemaakt worden in de organische meststoffen die goed bij gewas en bedrijf passen. Daardoor kan het gebruik van organische meststoffen bevorderd worden en kan de mineralenbenutting uit die meststoffen verhoogd worden.
Strategies to reduce losses and improve utilisation of nitrogen from solid cattle manure
Shah, G.M. - \ 2013
University. Promotor(en): Oene Oenema, co-promotor(en): Egbert Lantinga; Jeroen Groot. - S.l. : s.n. - ISBN 9789461735188 - 156
stikstof - dierlijke meststoffen - ammoniakemissie - mineralisatie - stikstofverliezen - stikstofbalans - bodem - uitspoelen - rundveemest - opslag - voedingsstoffenbeschikbaarheid - nitrogen - animal manures - ammonia emission - mineralization - nitrogen losses - nitrogen balance - soil - leaching - cattle manure - storage - nutrient availability

Background and objectives

The number of domesticated cattle in the world has steadily increased during the last decades, and thereby also the amount of manure produced annually. The excrements of grazing cattle are dropped in pastures and left unmanaged, but that of confined and housed cattle are collected and managed. The collected manure is often a variable mixture of urine, faeces, bedding material and spoiled feed and (drinking) water. On most modern farms, excrements are usually collected in leak-tight storages and handled as slurry: a mixture of urine, faeces and spoiled water. However, on a significant fraction of farms, cattle excrements are ‘source-separated’ in a liquid fraction and a solid fraction. The solid cattle manure (SCM) is usually a mixture of faeces and bedding material with some absorbed urine. The production of SCM is increasing due to the renewed interest in straw-based housing systems for better animal health and welfare. It has been observed that a significant loss of N can occur, especially from the storage and application phases of the SCM management chain. This N loss pollutes the air, groundwater and surface waters, and also reduces its N fertiliser value. Thus the challenge is to develop an effective SCM management system that retains as much of the excreted N in the system as possible, and thereby improving on-farm N cycling through the cattle-manure-soil-crop continuum (Chapter 1). Themain objective of this PhD thesis research was to increase the understanding of the factors controlling N losses during storage and after field application, and to develop and test strategies to decrease N losses and improve crop utilisation of N from SCM. The specific objectives were:

To study the interactions between a number of animal manures and soil types on N mineralisation and plant N recovery (Chapter 2) To investigate the effects of storage conditions on (i) magnitude and pathways of C and N losses during storage of SCM, and (ii) crop apparent N recovery (ANR) and DM yield (Chapter 3) To examine manure disappearance rates, N release pattern and herbage ANR during the year of application and the year thereafter from surface applied SCM subjected to different storage conditions (Chapter 4), and To analyse the effect of various application strategies on NH3 emission and/or crop ANR from applied SCM to grassland and arable (maize) land (Chapters 3 and 5)

To pursue these objectives a pot experiment in a glasshouse (Chapter 2) and a number of field experiments (Chapters 3 to 5) were conducted on experimental facilities of Wageningen University, the Netherlands. The pot experiment dealt with net N mineralisation and herbage ANR from SCM, cattle slurry and poultry manure, all applied to peat, sandy and clay soils. The field experiments examined (i) total C and N losses from stockpiled, composted, covered and roofed SCM heaps, (ii) manure decomposition, N release and herbage ANR after surface application of fresh and stored SCM on grassland, and (iii) the effects of irrigation and soil incorporation after SCM application, and lava meal as an additive on NH3 emission and/or crop ANR by grassland herbage or arable maize.

Major findings of the thesis

Results of the pot experiment showed that net N mineralisation and herbage ANR varied as function of manure storage method and soil type. Irrespective of the manure types, net N mineralisation and herbage ANR were highest in peat soil, which was characterised by the greatest N delivering capacity. Between the clay and sandy soils, both having similar N delivering capacity, net N mineralisation and herbage ANR were lower in the clay soil than in the sandy soil, likely because of immobilisation and fixation of ammonium-N by its inherited higher clay content. On each soil type,ANR was lower from SCM than cattle slurry and poultry manure(Chapter 2). The N recovery fraction was low when SCM was stored traditionally (i.e. stockpiling or composting) due to (i) loss of the initial mineral N content and readily degradable organic N compounds, and (ii) conversion of part of the remaining N into more stable forms as compared to that originally present before storage. Up to 31% of the initial total N from the stockpiled and 46% from the composted SCM heaps were lost during a period of about four months. Covering and roofing of SCM heaps reduced the losses down to 6 and 12%, respectively. Of the total N losses from each storage method, only about one fourth could be traced back as NH3-N and N2O-N emissions, and/or N leaching. The remainder could not be accounted for and constituted, in all probability, of harmless N2 gas. Of the total measured gaseous and liquid N losses together, N leaching contributed the most. The leaching N losses were reduced by almost three times through protection of SCM heap against precipitation either by its covering or roofing when compared to its stockpiling or composting in the open air. Although stockpiling of SCM under a roof significantly reduced overall total N losses, NH3 and N2O emissions were much higher as compared to stockpiling of SCM in the open air. Composting of SCM resulted in higher gaseous N emissions as well as N leaching with respect to the other storage methods. In view of these finding I conclude that covering of SCM heaps with an impermeable sheet is the best option to reduce storage N losses (Chapters 3 and 4).

In addition, because of N conservation and slow mineralisation of the organically bound N during the covered storage, mineral N content of SCM increased at the end of the storage phase. This, together with high mineralisation activities after field application of covered SCM, led to greater crop ANR and DM yield especially when compared to composted SCM, both in the year of application and in the subsequent year. When N losses during storage was taken into account to arrive at the crop ANR of the collected manure from the barn, it turned out that the ANR value was about three times larger in case of covered storage compared to composting of SCM, both for grassland (21 vs. 7%; Chapter 4) and arable land (37 vs. 13%, Chapter 3). Interestingly, despite of some N losses during covered storage (~10% of the initial N), crop ANR and DM yield were significantly larger from covered than fresh SCM taken directly from the barn, again in both situations.

Irrigation immediately after SCM spreading and use of lava meal as an additive significantly (i) reduced NH3 emission and (ii) improved crop ANR as well as DM yield (Chapters 3 and 5).Irrigation at a level of 5 mm immediately after surface application of fresh and covered SCM to grassland reduced NH3 emission by 30 and 65%, respectively, whereas it was not effective in case of composted SCM, likely because of its greater DM content. Addition of lava meal before application at a rate of 80 g per kg of covered SCM resulted in an emission reduction of 46%. By combining it with 10 mm irrigation, an almost 100% reduction in NH3 emissions from covered SCM was realised, whereas herbage ANR increased from 18 to 26% of the applied N over a growing period of five months (Chapter 5). Incorporation of SCM just before sowing of maize resulted in an ANR value of 39% from covered SCM, whereas this fraction was 20, 29 and 31% in case of composted, stockpiled and roofed manure, respectively (Chapter 3).

Overall conclusions

The ANR from applied manure in harvested herbage depends on manure type and soil type, and varies widely. It is lower from SCM than from cattle slurry Total N losses during storage of SCM can be reduced remarkably by covering the heap with an impermeable sheet. Covering reduced two N loss pathways: (i) gaseous N emissions to air, and (ii) N leaching to surface waters and groundwater. Field application of SCM that was covered by a sheet during storage, decomposed faster and more N was available for plant uptake, both in the year of application and the subsequent year, when compared to SCM that was stored in traditional ways Emission of NH3 following land application of SCM can be reduced greatly by irrigation or incorporation immediately after SCM spreading, and using lava meal as an additive. Irrigation appeared to be more effective in reducing NH3 emission than the addition of lava meal. All these NH3 emission abatement measures substantially increased crop ANR and DM yield Overall, combining covered storage with either direct irrigation following application of SCM to vegetated soil or direct incorporation in the soil following application of SCM to arable land is the best practical option to reduce losses and improve utilisation of N from SCM management systems. Depending on the farm infrastructure, losses may be further reduced by the use of lava meal, preferably as a bedding additive in the barn

Implication for efficient manure management

In many industrialised countries, animal manure is a major source of environmental pollution. In contrast, in most of the developing countries animal manure is considered as a key nutrient source to maintain or improve crop productivity and therefore N losses from manure management are more seen as ‘loss of plant nutrient’ rather than ‘pollution problems’. In either case development of efficient SCM management systems is highly important. Based on the results of this thesis, I propose some key management actions to improve the agro-environmental value of SCM.

If economically attractive, apply lava meal to straw bedding in the barn (Chapter 5) Store the barn-produced SCM under impermeable sheet (Chapters 3 and 4) Crop and soil-specific SCM application rates must take into account the potential available N (Chapter 2) and degradability of organic N compounds (Chapter 4) Incorporate the SCM from covered storages directly into the soil when applied to arable land (Chapter 3) In situations where incorporation is not feasible, like on grassland, spread SCM just before a predicted rainfall event or apply irrigation otherwise (Chapter 5) Take into account the expected residual N contribution from earlier manure input when determining the manure application rate(Chapter 4)
Root plasticity maintains growth of temperate grassland species
Padilla, F.M. ; Aarts, B.H.J. ; Roijendijk, Y.O.A. ; Caluwe, H. de; Mommer, L. ; Visser, E.J.W. ; Kroon, H. de - \ 2013
Plant and Soil 369 (2013)1-2. - ISSN 0032-079X - p. 377 - 386.
plant functional traits - nutrient availability - potential growth - gas-exchange - responses - precipitation - rainfall - productivity - variability - differentiation
Background and aims The frequency of rain is predicted to change in high latitude areas with more precipitation in heavy, intense events interspersed by longer dry periods. These changes will modify soil drying cycles with unknown consequences for plant performance of temperate species. Methods We studied plant growth and root traits of juveniles of four grasses and four dicots growing in a greenhouse, when supplying the same total amount of water given either regular every other day or pulsed once a week. Results Pulsed water supply replenished soil moisture immediately after watering, but caused substantial drought stress at the end of the watering cycle, whereas regular watering caused more moderate but consistent drought. Grasses had lower water use efficiency in the pulsed watering compared to regular watering, whereas dicots showed no difference. Both grasses and dicots developed thinner roots, thus higher specific root length, and greater root length in the pulsed watering. Growth of dicots was slightly increased under pulsed watering. Conclusions Temperate species coped with pulsed water supply by eliciting two responses: i) persistent shoot growth, most likely by maximizing growth at peaks of soil moisture, thus compensating for slower growth during drought periods; ii) plasticity of root traits related to increased resource uptake. Both responses likely account for subtle improvement of growth under changed water supply conditions.
Hoeveel fosfaat zit er in de bodem
Balen, Derk van - \ 2012
soil chemistry - phosphorus - soil analysis - soil plant relationships - phosphate - nutrient availability - soil fertility - arable farming - outdoor cropping
Evaluation of the NDICEA model
Rietberg, P.I. ; Burgt, G.J.H.M. van der - \ 2012
Driebergen : Louis Bolk Institute (Publication 2012-026 LbP) - 39 p.
bemesting - modellen - beslissingsmodellen - stikstof - stikstofmeststoffen - stikstofkringloop - voedingsstoffenbeschikbaarheid - fertilizer application - models - decision models - nitrogen - nitrogen fertilizers - nitrogen cycle - nutrient availability
Within the N-Toolbox project the NDICEA nitrogen model, one of the key tools in the virtual Toolbox, has been improved and tested in England, Denmark and Spain. The model performance was evaluated on datasets from these three countries by means of visual observation, RMSE and RSR from the soil nitrogen dynamics. In England the scenarios with organic fertilizer performed better than those with artificial fertilizer, leading to the suggestion that the calculated nitrogen release out of fertilizer could be improved. Timing of the soil sampling on soil inorganic nitrogen is important to realize a good model evaluation; two samples only, before sowing and after harvest, is not enough. When soil mineral nitrogen samples were taken during crop growth, model calculation and measured values showed sometimes big differences. It is suggested to improve the plant nitrogen uptake sub-model.
Stikstofwerking van mest op bouwland : informatieblad 46
Schröder, J.J. - \ 2012
bouwland - bemesting - dierlijke meststoffen - nitraatuitspoeling - voedingsstoffenbeschikbaarheid - stikstof - veldproeven - ondergewassen - akkerbouw - arable land - fertilizer application - animal manures - nitrate leaching - nutrient availability - nitrogen - field tests - catch crops - arable farming
Informatieblad Mest, Milieu en Klimaat over een proef naar de stikstofwerking van dierlijke mest. De conclusie van deze proef is dat als aan dierlijke mest een juiste N-werking wordt toegekend, de uitspoeling van N uit mest op korte termijn niet hoger is dan bij gebruik van kunstmest-N. Voor zover uitspoeling dreigt op te treden, kunnen tijdig gezaaide vanggewassen de N-uitspoeling verlagen en de N-beschikbaarheid voor een volgteelt verhogen.
Telen bij lage fosfaatniveaus in de biologische landbouw; achtergronden en literatuurstudie : het gedrag van fosfaat in de bodem en de interactie met gewassen
Timmermans, B. ; Sukkel, W. ; Bokhorst, J. - \ 2012 2012 (2012)16 aug.
fosfaat - bodemchemie - bemesting - biologische landbouw - voedingsstoffenbeschikbaarheid - akkerbouw - phosphate - soil chemistry - fertilizer application - organic farming - nutrient availability - arable farming
Fosfaat is belangrijk in de biologische landbouw. Het opraken van fossiele voorraden en emissies naar het oppervlaktewater maken het noodzakelijk het gebruik van fosfaatmeststoffen te beperken en kringlopen na te streven. In de praktijk van de biologische landbouw is er al gauw een fosfaatoverschot op de mineralenbalans wanneer men niet oplet. Aan de andere kant blijkt dat er in de praktijk ook goed geteeld kan worden bij zeer lage fosfaatgehalten in de bodem. Redenen genoeg om een en ander nader te analyseren.
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