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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    Assessing the climate regulation potential of Agricultural soils using a decision support tool adapted to stakeholders' needs and possibilities
    Broek, Marijn Van de; Henriksen, Christian Bugge ; Ghaley, Bhim Bahadur ; Lugato, Emanuele ; Kuzmanovski, Vladimir ; Trajanov, Aneta ; Debeljak, Marko ; Sandén, Taru ; Spiegel, Heide ; Decock, Charlotte ; Creamer, Rachel ; Six, Johan - \ 2019
    Frontiers in Environmental Science 7 (2019). - ISSN 2296-665X
    Soils perform many functions that are vital to societies, among which their capability to regulate global climate has received much attention over the past decades. An assessment of the extent to which soils perform a specific function is not only important to appropriately value their current capacity, but also to make well-informed decisions about how and where to change soil management to align the delivered soil functions with societal demands. To obtain an overview of the capacity of soils to perform different functions, accurate and easy-to-use models are necessary. A problem with most currently-available models is that data requirements often exceed data availability, while generally a high level of expert knowledge is necessary to apply these models. Therefore, we developed a qualitative model to assess how agricultural soils function with respect to climate regulation. The model is driven by inputs about agricultural management practices, soil properties and environmental conditions. To reduce data requirements on stakeholders, the 17 input variables are classified into either (1) three classes: low, medium and high or (2) the presence or absence of a management practice. These inputs are combined using a decision tree with internal integration rules to obtain an estimate of the magnitude of N2O emissions and carbon sequestration. These two variables are subsequently combined into an estimate of the capacity of a soil to perform the climate regulation function. The model was tested using data from long-term field experiments across Europe. This showed that the model is generally able to adequately assess this soil function across a range of environments under different management practices. In a next step, this model will be combined with models to assess other soil functions (soil biodiversity, primary productivity, nutrient cycling and water regulation and purification). This will allow the assessment of trade-offs between these soil functions for agricultural land across Europe.
    A Field-Scale Decision Support System for Assessment and Management of Soil Functions
    Debeljak, Marko ; Trajanov, Aneta ; Kuzmanovski, Vladimir ; Schroder, J.J. ; Sandén, Taru ; Spiegel, Heide ; Wall, David ; Broek, Marijn van de; Rutgers, Michiel ; Bampa, Francesca ; Creamer, Rachel ; Henriksen, Christian Bugge - \ 2019
    Frontiers in Environmental Science 7 (2019). - ISSN 2296-665X
    Agricultural decision support systems (DSS) are mostly focused on increasing the supply of individual soil functions such as e.g. primary productivity or nutrient cycling, while neglecting other important soil functions, such as e.g. water purification and regulation, climate regulation and carbon sequestration, soil biodiversity and habitat provision. Making right management decisions for long-term sustainability is therefore challenging, and farmers and farm advisors would greatly benefit from an evidence-based DSS targeted for assessing and improving the supply of several soil functions simultaneously. To address this, need we designed the Soil Navigator DSS by applying a qualitative approach to multi criteria decision modelling using Decision Expert (DEX) integrative methodology. Multi-criteria decision models for the five main soil functions were developed, calibrated and validated using knowledge of involved domain experts and knowledge extracted from existing datasets by data mining. Subsequently, the five DEX models were integrated into a DSS to assess the soil functions simultaneously, and to provide management advises for improving the performance of prioritized soil functions. To enable communication between the users and the DSS, we developed a user-friendly computer-based graphical user interface, which enables users to provide the required data regarding their field to the DSS and to get textual and graphical results about the performance of each of the five soil functions in a qualitative way. The final output from the DSS is a list of soil mitigation measures that the end-users could easily apply in the field in order to achieve the desired soil function performance. The Soil Navigator DSS has a great potential to complement the Farm Sustainability Tools for Nutrients included in the Common Agricultural Policy 2021-2027 proposal adopted by the European Commission. The Soil Navigator has also a potential to be spatially upgraded to assist decisions on which soil functions to prioritize in a specific region or member state. Furthermore, the Soil Navigator DSS could be used as an educational tool for farmers, farm advisors and students, and its potential should be further exploited for the benefit of farmers and the society as a whole.
    Harvesting European knowledge on soil functions and land management using multi-criteria decision analysis
    Bampa, Francesca ; O'Sullivan, Lilian ; Madena, Kirsten ; Sandén, Taru ; Spiegel, Heide ; Henriksen, Christian Bugge ; Ghaley, Bhim Bahadur ; Jones, Arwyn ; Staes, Jan ; Sturel, Sylvain ; Trajanov, Aneta ; Creamer, Rachel E. ; Debeljak, Marko - \ 2019
    Soil Use and Management 35 (2019)1. - ISSN 0266-0032 - p. 6 - 20.
    DEX model - farmers and multi-stakeholders - locally relevant advice - participatory research - soil quality

    Soil and its ecosystem functions play a societal role in securing sustainable food production while safeguarding natural resources. A functional land management framework has been proposed to optimize the agro-environmental outputs from the land and specifically the supply and demand of soil functions such as (a) primary productivity, (b) carbon sequestration, (c) water purification and regulation, (d) biodiversity and (e) nutrient cycling, for which soil knowledge is essential. From the outset, the LANDMARK multi-actor research project integrates harvested knowledge from local, national and European stakeholders to develop such guidelines, creating a sense of ownership, trust and reciprocity of the outcomes. About 470 stakeholders from five European countries participated in 32 structured workshops covering multiple land uses in six climatic zones. The harmonized results include stakeholders’ priorities and concerns, perceptions on soil quality and functions, implementation of tools, management techniques, indicators and monitoring, activities and policies, knowledge gaps and ideas. Multi-criteria decision analysis was used for data analysis. Two qualitative models were developed using Decision EXpert methodology to evaluate “knowledge” and “needs”. Soil quality perceptions differed across workshops, depending on the stakeholder level and regionally established terminologies. Stakeholders had good inherent knowledge about soil functioning, but several gaps were identified. In terms of critical requirements, stakeholders defined high technical, activity and policy needs in (a) financial incentives, (b) credible information on improving more sustainable management practices, (c) locally relevant advice, (d) farmers’ discussion groups, (e) training programmes, (f) funding for applied research and monitoring, and (g) strengthening soil science in education.

    European long-term field experiments : knowledge gained about alternative management practices
    Sandén, T. ; Spiegel, H. ; Stüger, H.P. ; Schlatter, N. ; Haslmayr, H.P. ; Zavattaro, L. ; Grignani, C. ; Bechini, L. ; D′Hose, T. ; Molendijk, L. ; Pecio, A. ; Jarosz, Z. ; Guzmán, G. ; Vanderlinden, K. ; Giráldez, J.V. ; Mallast, J. ; Berge, H. ten - \ 2018
    Soil Use and Management 34 (2018)2. - ISSN 0266-0032 - p. 167 - 176.
    alternative management practices - Europe - Long-term experiment - productivity - soil quality

    Alternative management practices such as no-tillage compared to conventional tillage are expected to recover or increase soil quality and productivity, even though all of these aspects are rarely studied together. Long-term field experiments (LTEs) enable analysis of alternative management practices over time. This study investigated a total of 251 European LTEs in which alternative management practices such as crop rotation, catch crops, cover crops/green manure, no-tillage, non-inversion tillage and organic fertilization were applied. Response ratios of indicators for soil quality, climate change and productivity between alternative and reference management practices were derived from a total of 260 publications. Both positive and negative effects of alternative management practices on the different indicators were shown and, as expected, no alternative management practice could comply with all objectives simultaneously. Productivity was hampered by non-inversion tillage, FYM amendments and incorporation of crop residues. SOC contents were increased significantly following organic fertilizers and non-inversion tillage. GHG emissions were increased by slurry application and incorporation of crop residues. Our study showed that alternative management practices beneficial to one group of indicators (e.g. organic fertilizers for biological soil quality indicators) are not necessarily beneficial to other indicators (e.g. increase of crop yields). We conclude that LTEs are valuable for finding ways forward in protecting European soils as well as finding evidence-based alternative management practices for the future; however, experiments should focus more on biological soil quality indicators as well as GHG emissions to enable better evaluation of trade-offs and mutual benefits of management practices.

    Soil food web assembly and vegetation development in a glacial chronosequence in Iceland
    Leeuwen, J.P. van; Lair, G.J. ; Gísladóttir, G. ; Sandén, T. ; Bloem, J. ; Hemerik, L. ; Ruiter, P.C. de - \ 2018
    Pedobiologia 70 (2018). - ISSN 0031-4056 - p. 12 - 21.
    Ecosystem functioning - Glacial succession - Iceland - Soil food web structure - Vegetation development

    Worldwide human activities threaten soil quality in terms of the soil's ability to deliver ecosystem services. This ongoing process of land degradation asks for effective strategies of soil protection. In this context, it is important to understand processes that build up and regenerate soil. The present study investigated how the soil ecosystem, including soil organisms, vegetation and soil ecological processes, develops during the process of soil formation in a chronosequence in a glacier forefield in Iceland. We hypothesised that along successional age we see increases in nutrient content, vegetation cover, and plant species richness linked to increases in soil food webs biomass and complexity. In line with our expectations all measured pools of carbon and nitrogen, and vegetation cover increased with age in the glacial forefield, but plant species richness levelled off after 30 years. Soil organisms generally increased in biomass with successional age, although some of the groups of soil organisms peaked at an intermediate successional stage. In contrast to our expectations, some of the calculated food web complexity metrics such as the number of trophic groups and trophic chain length did not increase linearly, but showed an intermediate peak or even decreased with successional age. However, plant cover and pools of carbon and nitrogen still increased after 120 years. From these results we conclude that soil ecosystem development takes more than a century under Icelandic climatic conditions to fully develop in terms of vegetation succession, food web structure and biogeochemical cycling.

    Responses of soil biota to non-inversion tillage and organic amendments : An analysis on European multiyear field experiments
    Hose, Tommy D'; Molendijk, Leendert ; Vooren, Laura Van; Berg, Wim van den; Hoek, Hans ; Runia, Willemien ; Evert, Frits van; Berge, Hein ten; Spiegel, Heide ; Sandèn, Taru ; Grignani, Carlo ; Ruysschaert, Greet - \ 2018
    Pedobiologia 66 (2018). - ISSN 0031-4056 - p. 18 - 28.
    Earthworms - Microbial biomass - Multiyear field experiments - Nematodes - Non-inversion tillage - Organic amendments
    Over the last two decades, there has been growing interest on the effects of agricultural practices on soil biology in Europe. As soil biota are known to fluctuate throughout the season and as agro-environmental conditions may influence the effect of agricultural practices on soil organisms, conclusions cannot be drawn from a single study. Therefore, integrating the results of many studies in order to identify general trends is required. The main objective of this study was to investigate how soil biota are affected by repeated applications of organic amendments (i.e. compost, farmyard manure and slurry) or reduced tillage (i.e. non-inversion tillage and no till) under European conditions, as measured in multiyear field experiments. Moreover, we investigated to what extent the effects on soil biota are controlled by soil texture, sampling depth, climate and duration of agricultural practice. Experimental data on earthworm and nematode abundance, microbial biomass carbon and bacterial and fungal communities from more than 60 European multiyear field experiments, comprising different climatic zones and soil texture classes, were extracted from literature. From our survey, we can conclude that adopting no tillage or non-inversion tillage practices and increasing organic matter inputs by organic fertilization were accompanied by larger earthworm numbers (an increase between 56 and 125% and between 63 and 151% for tillage and organic amendments, respectively) and biomass (an increase between 108 and 416% and between 66 and 196% for tillage and organic amendments, respectively), a higher microbial biomass carbon content (an increase between 10 and 30% and between 25 and 31% for tillage and organic amendments, respectively), a marked increase in bacterivorous nematodes (an increase between 19 and 282% for organic amendment) and bacterial phospholipid-derived fatty acids (PLFA; an increase between 31 and 38% for organic amendment). Results were rarely influenced by soil texture, climate and duration of practice.
    Silence in Intercultural Collaboration : A Sino-Dutch Research Centre
    Verouden, Nick W. ; Sanden, Maarten C.A. Van der; Aarts, Noelle - \ 2018
    Advances in Applied Sociology 8 (2018)2. - ISSN 2165-4328 - p. 125 - 151.
    China is widely recognized as a significant scientific partner for Western universities. Given that many Western universities are now operating in the Chinese context, this study investigates the everyday conversations in which international partnerships are collaboratively developed and implemented. In particular, it draws attention to the interpretations of the meanings attached to silence in these conversations, and how these can have unintended consequences for how these joint partnerships are accomplished. The findings come from an ethnographic case study that investigated collaboration within the context of setting up a Sino-Dutch research centre between the Delft University of Technology (TU Delft) and South China University of Technology (SCUT) as experienced by Dutch researchers in their interaction with their Chinese partners. The findings reveal that the Dutch researchers attached meaning to what was not said by the Chinese, interpreting it as lack of communication, resulting in judgements, uncontested trusts, and distancing that negatively influenced the achievement of common goals. Finally, the relevance of the findings is discussed for those managing communication in international academic partnerships.
    An assessment of policies affecting Sustainable Soil Management in Europe and selected member states
    Turpin, Nadine ; Berge, Hein ten; Grignani, Carlo ; Guzmán, Gema ; Vanderlinden, Karl ; Steinmann, Horst-Henning ; Siebielec, Grzegorz ; Spiegel, Adelheid ; Perret, Eric ; Ruysschaert, Greet ; Laguna, Ana ; Giráldez, Juan Vicente ; Werner, Magdalena ; Raschke, Isabell ; Zavattaro, Laura ; Costamagna, Chiara ; Schlatter, Norman ; Berthold, Helen ; Sandén, Taru ; Baumgarten, Andreas - \ 2017
    Land Use Policy 66 (2017). - ISSN 0264-8377 - p. 241 - 249.
    This paper analyses soils-related policies in Europe and in selected member states and regions. Our approach breaks down policy packages at European, national and regional levels into strategic objectives, operational objectives, policy measures and expected impacts, and assesses the relationships between these elements and soil stakes. Four major policy packages, both at EU and national level (CAP-I, RDP, Environment, national initiatives) were analysed. A numerical scale was developed to quantify the level of “embeddedness” of soil stakes in these policy packages. We found that countries better embed soil stakes into their policies when they also put more efforts on environmental innovation. In turn, countries with a high embeddedness level, with high trust in European institutions and that make more efforts towards renewable energy, tend to propose a wider variety of management practices to farmers for dealing with soil stakes.
    Soil food web assembly and vegetation development in a glacial chronosequence in Iceland
    Leeuwen, J.P. van; Lair, G.J. ; Gisladottir, G. ; Sanden, T.M. ; Bloem, J. ; Hemerik, A. ; Ruiter, P.C. de - \ 2017
    In: Book of Abstracts Wageningen Soil Conference 2017. - Wageningen : Wageningen University & Research - ISBN 9789463430616 - p. 124 - 124.
    Soil aggregation and soil organic matter in conventionally and organically farmed Austrian Chernozems
    Sandén, Taru ; Lair, Georg J. ; Leeuwen, Jeroen P. Van; Gísladóttir, Guorún ; Bloem, Jaap ; Ragnarsdóttir, Kristín Vala ; Steffens, Markus ; Blum, Winfried E.H. - \ 2017
    Bodenkultur 68 (2017)1. - ISSN 0006-5471 - p. 41 - 55.
    Aggregate hierarchy - Aggregate stability - Organic matter dynamics - Particulate organic matter (POM) - Solid-state 13C NMR spectroscopy
    In order to study the soil aggregate distributions and soil organic matter (SOM), we sampled top- and subsoils in four intensively farmed croplands (two organic (Org-OB and Org-LA), and two conventional (Con-OB and Con-LA)) on Haplic Chernozems located in Marchfeld in the east of Vienna (Austria). Soil structure and SOM quantity, quality and distribution between free and occluded particulate organic matter and aggregate size fractions (<20 μm, 20-250 μm, 250-5000 μm) were studied by following a density fractionation procedure with low-energy ultrasound treatment. Te relation of the soil physicochemical (e.g., particle size distribution, pH, organic carbon, total nitrogen) and biological properties (e.g., fungal biomass, active fungi) with stable soil aggregate size fractions and SOM was studied. Te mean weight diameter (MWD) showed no significant difference between all studied sites and was between 3.8 mm and 10.0 mm in topsoils and between 6.7 mm and 11.9 mm in subsoils. In topsoils, the contents of calcium-acetate-lactate (CAL)-extractable P, active fungal biomass, dithionite-extractable Fe and sand were significantly positively correlated with the amount of the macroaggregates and with the MWD. We observed that most soil organic carbon, depending on soil texture, was stored in the microaggregate size classes <20 μm and 20-250 μm.
    Agronomic effects of bovine manure : A review of long-term European field experiments
    Zavattaro, Laura ; Bechini, Luca ; Grignani, Carlo ; Evert, Frits K. van; Mallast, Janine ; Spiegel, Heide ; Sandén, Taru ; Pecio, Alicja ; Giráldez Cervera, Juan Vicente ; Guzmán, Gema ; Vanderlinden, Karl ; Hose, Tommy D'; Ruysschaert, Greet ; Berge, Hein F.M. ten - \ 2017
    European Journal of Agronomy 90 (2017). - ISSN 1161-0301 - p. 127 - 138.
    Efficiency - Farmyard manure - Nitrogen - Response ratio - Slurry - Soil organic carbon

    To evaluate the agronomic value of animal manure, we quantified the effects of pedo-climatic, crop and management factors on crop productivity, N use efficiency, and soil organic matter, described with simple indicators that compare manures with mineral fertilizers. We selected 80 European long-term field experiments that used bovine farmyard manure or bovine liquid slurry, alone (FYM and SLU) or combined with mineral fertilizers (FYMm and SLUm), and compared them to mineral fertilizer only reference treatments. We collected 5570 measurements from 107 papers. FYM produced slightly lower crop yields (−9.5%) when used alone and higher (+11.3%) yields when used in combination with N fertilizer (FYMm), compared to those obtained using mineral fertilizers only. Conditions promoting manure-N mineralization (lighter soil texture, warmer temperature, longer growing season, and shallower incorporation depth) significantly increased the effect of FYM/FYMm on crop yield and yield N. The production efficiency of FYM (yield:N applied ratio) was slightly lower than that of mineral fertilizers (-1.6%). The apparent N recoveries of FYM and FYMm were 59.3% and 78.7%, respectively, of mineral fertilizers. Manured soils had significantly higher C (+32.9% on average for FYM and FYMm) and N (+21.5%) concentrations. Compared to mineral fertilizers, yield was reduced by 9.1% with SLU, but not with SLUm. Influencing factors were similar to those of FYM/FYMm. Efficiency indicators indicated SLU (but not SLUm) was less effective than mineral fertilizers. Slurry significantly increased SOC (on average for SLU and SLUm by +17.4%) and soil N (+15.7%) concentrations. In conclusion, compared to mineral N fertilizers, bovine farmyard manure and slurry were slightly less effective on the crop, but determined marked increases to SOC and soil N, and thus, to long-term soil fertility maintenance.

    The Impact of Policy Instruments on Soil Multifunctionality in the European Union
    Vrebos, Dirk ; Bampa, Francesca ; Creamer, Rachel ; Gardi, Ciro ; Ghaley, Bhim ; Jones, Arwyn ; Rutgers, Michiel ; Sandén, Taru ; Staes, Jan ; Meire, Patrick - \ 2017
    Sustainability 9 (2017)3. - ISSN 2071-1050
    Agricultural ecosystems provide a range of benefits that are vital to human well-being. These benefits are dependent on several soil functions that are affected in different ways by legislation from the European Union, national, and regional levels. We evaluated current European Union soil-related legislation and examples of regional legislation with regard to direct and indirect impacts on five soil functions: the production of food, fiber, and fuel; water purification and regulation; carbon sequestration and climate regulation; habitat for biodiversity provisioning; and the recycling of nutrients/agro-chemicals. Our results illustrate the diversity of existing policies and the complex interactions present between different spatial and temporal scales. The impact of most policies, positive or negative, on a soil function is usually not established, but depends on how the policy is implemented by local authorities and the farmers. This makes it difficult to estimate the overall state and trends of the different soil functions in agricultural ecosystems. To implement functional management and sustainable use of the different soil functions in agricultural ecosystems, more knowledge is needed on the policy interactions as well as on the impact of management options on the different soil functions
    Ken de stiltecodes!
    Verouden, Nick ; Sanden, M. van der; Aarts, M.N.C. - \ 2016
    Communicatie (2016). - ISSN 0771-7342 - p. 46 - 48.
    Engineers at the Patient’s Bedside: : The Case of Silence in Inter-institutional Educational Innovation
    Verouden, Nick ; Sanden, M.C.A. van der; Aarts, M.N.C. - \ 2016
    In: The Silences of Science / Mellor, Felicity, Webster, Stephen, London : Routledge - ISBN 9781472459978 - p. 89 - 112.
    Innovation in science and technology is increasingly linked with interdisciplinarity. Encouraging this trend depends in part on cutting-edge educational programmes that revise, reinvent and redesign curricula as interdisciplinary vehicles, establishing and re-establishing relations between traditional fields and areas of expertise (Stone et al., 1999; Casey, 1994). Such programmes are valuable because they can overcome ‘silo’ mentalities and equip prospective students with the skills and knowledge necessary for understanding and solving complex societal problems (Stone et al.,1999; McFadden et al., 2010). Although these programmes are very promising, their development and

    implementation also brings challenges. The literature on curriculum development shows that many programmes have struggled to achieve true integration (McFadden et al., 2010; Stone et al., 1999). Dam-Mieras et al. (2008), in their study of an international master’s programme in sustainable development and management developed collaboratively by nine universities, observed that universities have their own experts and own programmes and that the ‘not invented here’ argument influences how details about new programme are discussed. Focussing on innovative online instruction courses, Xu and Morris (2007) found that the absence of group cohesiveness between faculty and project coordinators can hinder the collaborative course development process and affect the quality of the end product. Stone et al. (1999) emphasize that faculty members and administrators work at cross-purposes and view each other’s initiatives with suspicion. Given the importance that scientists, academic institutions and policy makers ascribe to innovation, along with their assumption that such innovation is a sure result of interdisciplinarity, it is essential to gain a better understanding of how curriculum development in academic education actually works. For this chapter, we consider how processes of connecting and inter-

    relating could add to our understanding of the problems and dilemmas that arise in developing and implementing such programmes. Scholars of innovation, in science and technology and beyond, have explained that innovation is not some abstract algorithm: it relies on interaction and collaboration between

    multiple actors with different expertises, visions, priorities and investment (Van Bommel et al., 2011; Leeuwis and Aarts, 2011; Akrich et al., 2002; Fonseca, 2002). This process of interacting is very difficult, however, and creates many tensions. This is revealed by studies that show the lurking problems of connecting previously unconnected people around new ideas and technologies. These studies show how innovation processes become defined by competition for scarce resources, protracted negotiations over priorities and interests, and dynamics of inclusion and exclusion (Leeuwis andAarts, 2011; Pretty, 1995; Van Bommel et al., 2011). Fonseca (2002) hence explains that innovation always creates a paradoxical situation, in which organizations, in their search to accelerate change and adapt to and find solutions for external challenges and demands, unavoidably create new and unpredictable interactional patterns. Given that interacting is a complicated matter in innovation processes, a

    key question within the management of innovation literature is how we can account for the way relevant actors connect, or fail to connect (Akrich et al., 2002). In this respect, verbal communication is often cited as an essential mechanism for effectively connecting important actors and social groups around innovative ideas, products, or technologies (Van Bommel et al., 2011). In turn, the markers of effective verbal communication as a frame for innovation are seen to be openness, dialogue, and the ability to cooperate and be reflective on one’s thoughts and actions (Stilgoe et al., 2013). Thorp and Goldstein (2010), writing about university innovation, describe conversations as the fertile ground from which innovation grows and urge us to make time and space for those conversations. Dialogue and openness are seen as indicators of the quality of interaction, and process transparency as a decisive component of academic innovation. By being open or transparent in discussing issues and problems, actors build confidence that negotiation is ‘real’ and not a cover-up for private backroom deals (de Bruijn and ten Heuvelhof, 2008). Although there is a wealth of research on communication for innovation,

    most scholarly work focuses on what is exchanged verbally, on how actors collate all the relevant evidence, put it on the table and discuss it openly. As of yet, silence is absent from these studies of communication for innovation. Building on recent organizational and strategy scholarship, in which silence is approached as an intricate concept with powerful functions and meanings in social interaction (Van Assche and Costaglioli, 2012; Carter et al., 2008; Henriksen and Dayton, 2006; Panteli and Fineman, 2005; Tucker and Edmondson, 2003; Jaworski, 2005; Morrison and Milliken, 2000), we suggest that silence merits much more attention in analyses of academic innovation. This chapter therefore explores the role of moments of silence during interactions within networks developing and implementing educational innovation. The structure of this chapter is as follows. We start by looking at the litera-

    ture on dynamic innovation networks and communication and complement these insights with scholarship on silence within organization studies. After briefly introducing our approach, we present the findings of a study of an inter-institutional and interdisciplinary joint bachelor’s programme that was

    implemented at the interface of health and technology. The purpose of the study was to better understand the significance of moments of silence in developing and implementing this programme. We end with the implications of our findings for steering in the context of interdisciplinary innovation.
    Silence in Interdisciplinary Research Collaboration : Not Everything Said is Relevant, Not Everything Relevant is Said
    Verouden, Nick W. ; Sanden, Maarten C.A. van der; Aarts, Noelle - \ 2016
    Science as Culture 25 (2016)2. - ISSN 0950-5431 - p. 264 - 288.
    collaboration - communication - positioning - silence - situational analysis - university

    Solving publicly important issues asks for the development of socio-technical approaches, which demands collaboration between researchers with different perspectives, values, and interests. In these complex interdisciplinary collaborations, the course of communication is of utmost importance, including the moments when people, consciously or not, keep silent. In 2012, an interdisciplinary group of water management engineers and scientists collaborated to explore how the university's separate water management research fields could fit better in today's socio-technical trends. Studying the interactional process revealed that during the collaboration many issues were not said by various parties at various times. Results show that, in particular, engineers and scientists stayed silent to secure group performance, to keep disagreements from surfacing, and manage conflicts of interest in the bargaining process. Although silence served various interactional functions, it also shaped the course of interaction in ways that were not intended, resulting in the development of a latent conflict. It is concluded that the concept of silence adds a relevant dimension to our understanding of interaction among engineers and scientists participating in interdisciplinary collaboration that is currently absent in existing literature on scientific collaboration.

    Enhancing Responsible Innovation in Food Industry
    Flipse, S. ; Sanden, M. van der; Fortuin, F.T.J.M. ; Omta, S.W.F. - \ 2014
    Policy makers and researchers from the social sciences and humanities encourage innovators to adopt socially responsible innovation (SRI) practices. Also within industrial innovation networks, both consumers and companies increasingly ask for more sustainable, responsibly produced products. By and large, innovators are starting to implement SRI practices in their daily work by more explicitly taking into account social and ethical aspects, relating e.g. to ecological sustainability, health, safety and equity. However, the extent to which a more ‘inclusive’ innovation process, taking such aspects into account, actually contributes to the quality of on-going innovation practices, remains largely uninvestigated. We therefore set up a study to investigate this in a commercial contract research organization in the field of food products and processes. In this case study, we combined the use of Midstream Modulation (MM) as a method to stimulate SRI in Research and Development (R&D) practices with the Wageningen Innovation Assessment Toolkit (WIAT) as a tool to monitor the quality of such practices. In MM, the term ‘midstream’ pertains to the on-going R&D work that takes place between upstream R&D authorization decisions and downstream practical implementation of R&D results. The term ‘modulation’ relates to the practice of modulating decisions of innovators into subsequent opportunities, considerations, alternatives and projected outcomes of such decisions. During the MM study, a scholar from the social sciences or humanities interacts with innovating practitioners at the R&D floor for a period of 12 weeks. Together they investigate when and where in innovation-related decisions there is room to integrate social and ethical considerations, and as such, answer calls for SRI. Over this period of 12 weeks, the quality of on-going R&D work was monitored using an adapted version of the WIAT. WIAT was used first to make a benchmark, investigating which Key Performance Indicators (KPIs) distinguishes successful from less successful R&D projects. Secondly, it was used to monitor on-going R&D projects during the 12 weeks of interaction between the embedded humanist and the innovators by scoring projects on the identified KPIs. Our results show that over the course of 12 weeks, innovators more actively include social and ethical considerations into their work, while the quality and innovative potential of their R&D projects improved measurably. In contrast, a group of researchers that did not participate in MM, generally did not display a clear increase in quality and potential. After the study, the innovators acknowledged that they were better able to connect their on-going work to the wishes of their clients and acknowledged the value of SRI for their innovation practices. As such, our results spark optimism regarding the value of SRI in innovation networks and within society as a whole. Still, a further investigation is necessary to investigate to what extent SRI can be systematically integrated within innovation chains and networks, in order to harness the full innovative potential of SRI.
    Identifying key performance indicators in food technology contract R&D
    Flipse, S.M. ; Sanden, M.C.A. van der; Velden, T. van der; Fortuin, F.T.J.M. ; Omta, S.W.F. ; Osseweijer, P. - \ 2013
    Journal of Engineering and Technology Management 30 (2013)1. - ISSN 0923-4748 - p. 72 - 94.
    biotechnology firms - innovation - industry - perspectives - experience - success - future - model - news
    Innovating companies increasingly rely on outsourcing to Contract Research Organisations (CROs) for their Research and Development (R&D), which are largely understudied. This paper presents the outcome of a case study in the field of food technology contract research, identifying context specific Key Performance Indicators (KPIs) for a CRO. KPIs were identified with a modified version of the Wageningen Innovation Assessment Tool, with which 72 finished successful and less successful projects were analysed. We developed a benchmarking tool to evaluate starting or running innovation project quality, which allows for direct, in situ project improvements by project leaders at CROs.
    A quantification of phosphorus flows in The Netherlands through agriculture, industry and household
    Middelkoop, J.C. van; Smit, A.L. ; Dijk, W. van; Buck, A.J. de; Reuler, H. van; Sanden, P.A.C.M. van de - \ 2012
    A quantification of phosphorus flows in The Netherlands through agriculture, industry and households
    Middelkoop, J.C. van; Smit, A.L. ; Dijk, W. van; Buck, A.J. de; Reuler, H. van; Sanden, P.A.C.M. van de - \ 2012
    In: Proceedings of the 24th General Meeting of the European Grassland Federation, 03-07 June 2012, Lublin, Poland. - Poznan, Poland : Polish Grassland Society - ISBN 9788389250773 - p. 789 - 791.
    A quantification of phosphorus flows in the Netherlands through agricultural production, industrial processing and households
    Smit, A.L. ; Middelkoop, J.C. van; Dijk, W. van; Reuler, H. van; Buck, A.J. de; Sanden, P.A.C.M. van de - \ 2010
    Wageningen : Plant Research International (Rapport / Plant Research International 364) - 55
    fosfor - fosfaatuitspoeling - nutriëntenstromen - voedingsstoffenbalans - visualisatie van stroming - kringlopen - nederland - phosphorus - phosphate leaching - nutrient flows - nutrient balance - flow visualization - cycling - netherlands
    To investigate the possibilities for a more sustainable use of phosphorus it was necessary to have a complete picture of the national phosphorus flows in the Netherlands. In this report a material flow analysis was performed by dividing the national system into a number of subsystems: agricultural subsystems (arable, grazing, intensive livestock) but also non-agricultural subsystems (food industry, non-food industry, feed industry, household, waste management, environment) were included. Quantification of the various phosphorus flows between the subsystems was done for the year 2005 and was based on various data sources. The results showed that in the reference year 2005 a surplus of around 60 Mkg of P existed, roughly half of this amount accumulated in agricultural soil. The remaining part ended up in ground or surface water (around 7 Mkg) or was sequestered in one way or another (e.g. landfill, incineration ashes, sewage sludge etc.). Recycling from society (households and industry) back to agriculture was minimal. Options for a more sustainable use of phosphorus in the Netherlands are discussed.
    Inspiratie voor transitie : leren van pioniers en hun zoektochten
    Buurma, J.S. ; Potters, J.I. ; Sanden, P.A.C.M. van de; Migchels, G. - \ 2007
    innovatie adoptie - innovaties - innovation adoption - innovations
    Poster met beschrijving van een onderzoeksproject
    Kennisbenutting en kennisdoorstroming van energieonderzoek naar het agrarisch onderwijs : resultaten en aanbevelingen ter verbetering van de overdracht en de benutting van kennis tussen energieonderzoek en onderwijs
    Bruins, M.A. ; Bontsema, J. ; Balendonck, J. ; Gelder, A. de; Gieling, T.H. ; Henten, E.J. van; Poot, E.H. ; Beenen, E. ; Sanden, J. van der - \ 2007
    Wageningen : Wageningen UR, Glastuinbouw (Nota / Wageningen UR, Glastuinbouw 447) - 52
    energie - agrarisch onderwijs - glastuinbouw - beroepsopleiding - energy - agricultural education - greenhouse horticulture - vocational training
    Eindrapport van het project 'Kennisbenutting en kennisdoorstroming van energieonderzoek naar het agrarisch onderwijs'. In dit project is onderzocht hoe de resultaten van het energieonderzoek beter door moeten gaan stromen naar het onderwijs. Er is gewerkt met voorbeeld van het onderzoek naar gesloten en semi-gesloten kassen.
    Ontwikkelingsroutes naar duurzame landbouw; workshop met pioniers open teelten
    Buurma, J.S. ; Potters, J.I. ; Sanden, P.A.C.M. van de - \ 2006
    Wageningen : PPO (PPO Folder ) - 16 p.
    Review of relationships between grey-tone co-occurrence, semivariance, and autocorrelation based image texture analysis approaches
    Sanden, J.J. van der; Hoekman, D.H. - \ 2005
    Canadian Journal of Remote Sensing 31 (2005)3. - ISSN 1712-7971 - p. 207 - 213.
    land-cover - classification - matrix
    In the present paper we review relationships between commonly used statistical approaches to analysis of image texture. The approaches considered characterize image texture by means of the statistics of grey- tone co- occurrence contrast, grey- tone co- occurrence correlation, semivariance, and autocorrelation. In the literature, the relationships between these textural measures are rarely discussed and sometimes overlooked. Grey-tone co- occurrence contrast and semivariance are shown to represent identical statistics. The expectations for the statistic of grey-tone co- occurrence correlation and the coefficient of autocorrelation are demonstrated to agree. Grey-tone variance is shown to link the statistics of grey-tone co-occurrence contrast and grey-tone co-occurrence correlation.
    Nieuwe landbouw: inventarisatie van kansen
    Langeveld, J.W.A. ; Koops, A.J. ; Ketelaars, J.J.M.H. ; Marcelis, L.F.M. ; Hassink, J. ; Blom, M. ; Sanden, P.A.C.M. van de - \ 2005
    onbekend : PRI Agrosysteemkunde (Nota / Plant Research International 330) - 84
    landbouw - tuinbouw - teelt onder bescherming - biologische landbouw - natuurbescherming - bio-energie - non-food producten - landbouwproducten - zorgboerderijen - multifunctionele landbouw - biobased economy - biomassa productie - agriculture - horticulture - protected cultivation - organic farming - nature conservation - bioenergy - non-food products - agricultural products - social care farms - multifunctional agriculture - biobased economy - biomass production
    In opdracht van het Ministerie van LNV inventariseerde en evalueerde PRI de nieuwe productiekansen voor de Nederlandse plantaardige sectoren.Tevens doet PRI aanbevelingen voor beleid en onderzoek. Nieuwe landbouw is één van de projecten van het Transitieteam van het Ministerie. Behandelde thema's in dit rapport: landbouwgrondstoffen, zoutwater landbouw, kasteelt, sociale dienstverlening, ecologische dienstverlening, het nieuwe consumeren en Nederland regieland
    Perspectieven van 'Intersectoraliteit' in gangbare en biologische plantaardige bedrijfssystemen
    Sanden, P.A.C.M. van de; Hazelaar, W.J.M. ; Pronk, A.A. ; Reuler, H. van; Wolf, P.L. de - \ 2003
    Wageningen : PRI/PPO (Nota / PRI-PPO ) - 48
    biologische landbouw - duurzaamheid (sustainability) - leren - organic farming - sustainability - learning
    Het is begrijpelijk dat kansen voor verbetering van economische en ecologische duurzaamheid van het agrarisch bedrijf veelal binnen de eigen sector gezocht worden. Het kan echter geen kwaad eens 'over de schutting' te kijken naar elementen uit de bedrijfsvoering in een andere sector. Een werkgroep bestaande uit vertegenwoordigers van diverse sectoren van het Praktijkonderzoek Plant & Omgeving en van Plant Research International verrichtte binnen de plantaardige sectoren een oriënterende studie naar de mogelijkheden van deze intersectorale aanpak.
    The making of a nation-wide campaign fighting the nursing caries
    Sanden-Stoelinga, M.S.E. van; Koelen, M.A. ; Hielkema-de Meij, J.E. - \ 2003
    International Journal of Dental Hygiene 1 (2003)1. - ISSN 1601-5029 - p. 16 - 22.
    Although, in the Netherlands, the fight against tooth decay has been successful over the past decades, in 1994, the incidence of nursing caries made the Ivory Cross*, the Dutch National Association for the Promotion of Oral Hygiene, decide to develop and implement a campaign to address the phenomenon. The campaign is based on a two-step approach: a community strategy that exposes both the intermediaries and the target group to the message. It mainly focussed on intermediaries (step 1) such as child health clinic teams and care attendants, aiming to motivate and enable them to address the topic in their communication with parents of children aged 0–4 years (step 2). The development of this campaign lasted for about 1.5 years and will be described along the lines of the OPUS model: Orientation, Planning, execUtion and cloSure. The campaign was continuously assessed by means of research consisting of a pretest of materials, and a process and outcome evaluation. The research results gave the organisers a lot of information to monitor the campaign and useful insights for future activities.
    Farm Explorer : Designing sustainable arable farming systems.
    Ven, G.W.J. van de; Rossing, W.A.H. ; Ittersum, M.K. van; Boekhoud, H. ; Evert, F.K. van; Sanden, P.A.C.M. van de; Mauritz, R.F. - \ 2002
    In: Book of Proceedings 7th ESA Congress Cordoba, Spain : - ISBN 9788484740599 - p. 587 - 588.
    Biologische landbouw: conflicten, kansen en modelmatig verkennen
    Sanden, P.A.C.M. van de; Evert, F.K. van; Smid, H. ; Stokkers, R. ; Rossing, W. ; Ven, G.W.J. van de; Ittersum, M.K. van - \ 2002
    In: Biologisch bedrijf onder de loep (Rapport / Praktijkonderzoek Plant en Omgeving ; 303) / Wijnands, F.G., Schröder, J.J., Sukkel, W., Booij, R., - p. 55 - 61.
    biologische landbouw - duurzaamheid (sustainability) - bedrijfsvoering - milieubescherming - landschap - nederland - organic farming - sustainability - management - environmental protection - landscape - netherlands
    Het biologisch bedrijf is een meervoudig doelsysteem dat naast productie, werk en inkomen ook een maatschappelijke functie heeft ten aanzien van het milieu, de natuur, het landschap en gezondheid en welzijn van mens en dier. Het is niet eenvoudig deze verschillende doelen binnen de context van het bedrijf met elkaar in overeenstemming te brengen. In dit artikel wordt nader ingegaan op conflicten tussen doelen en op een methodische aanpak om deze conflicten in kaart te brengen als hulpmiddel bij het toekomstgerichte ontwerpen en innoveren van biologische bedrijfssystemen
    Evaluatie van de campagne tegen zuigflescarids "Beter een beker!"
    Hielkema- de Meij, J.E. ; Koelen, M.A. ; Sanden-Stoelinga, M.S.E. - \ 2001
    Tijdschrift voor Gezondheidswetenschappen 79 (2001). - ISSN 1388-7491 - p. 233 - 238.
    "Bottle it up - take a cup!" The fight against nursing caries in the Netherlands : the campaign and its results
    Koelen, M.A. ; Hielkema-de Meij, J.E. ; Sanden-Stoelinga, M.S.E. van der - \ 2000
    International journal of health promotion and education 38 (2000)2. - ISSN 1463-5240 - p. 47 - 53.
    Farming option for The Netherlands explored by multi-objective modelling
    Berge, H.F.M. ten; Ittersum, M.K. van; Rossing, W.A.H. ; Ven, G.W.J. van de; Schans, J. van de; Sanden, P.A.C.M. van de - \ 2000
    European Journal of Agronomy 13 (2000). - ISSN 1161-0301 - p. 263 - 277.
    Intensive agriculture in The Netherlands has a price in the form of environmental degradation and the diminution of nature and landscape values. A reorientation of farming is needed to find a new balance between economic goals and rural employment, and care for clean water and air, animal well-being, safe food, and the preservation of soil, landscape and biodiversity. The search for farm systems that meet such multiple goals requires a systematic combination of (a) agrotechnical, agroecological and agroeconomic knowledge, with (b) the stakeholders' joint agreement on normative objectives, to arrive at conceptual new designs followed by (c) empirical work to test, adapt and refine these under real commercial farming conditions. In this paper explorative modelling at the whole farm level is presented as a method that effectively integrates component knowledge at crop or animal level, and outlines the consequences of particular choices on scientific grounds. This enables quantitative consideration of a broad spectrum of alternative farming systems, including very innovative and risky ones, before empirical work starts. It thus contributes to a transparent learning and development process needed to arrive at farm concepts acceptable to both entrepreneurs and society. Three case studies are presented to illustrate the method: dairy farming on sandy soils; highly intensified flower bulb industry in sensitive areas in the western Netherlands; and integrated arable farming. Trade-offs between economic and environmental objectives were assessed in all three cases, as well as virtual farm configurations that best satisfy specified priority settings of objectives. In two of the three cases the mutual reinforcement and true integration of modelling and on-farm empirical research appeared difficult, but for obvious reasons. Only in the flower bulb case was the explorative approach utilized to its full potential by involving a broad platform of stakeholders. The other two case studies lacked such formalised platforms and their impact remained limited. Three critical success factors for explorative modelling are identified: to cover a well-differentiated spectrum of possible production technologies; early timing of modelling work relative to empirical farm prototyping; and involvement of stakeholders throughout.
    Scatterometer observations of seasonal backscatter variation over tropical rain forest
    Woodhouse, I.H. ; Sanden, J.J. van der; Hoekman, D.H. - \ 1999
    IEEE Transactions on Geoscience and Remote Sensing 37 (1999)2 I. - ISSN 0196-2892 - p. 859 - 861.
    A strong correlation between the C-band ERS-1 windscatterometer (WSC) backscatter and local precipitation in Guyana has been observed. The effect on the correlation of incidence angle and local time is also examined. Characterizing such fluctuations may be useful for precise calibration of active microwave instruments.
    Models linked with a database : the CAPS toolbox for evaluating land use options
    Evert, F.K. van; Berge, H.F.M. ten; Sanden, P.A.C.M. van de; Rossing, W.A.H. - \ 1999
    ASA Annual Meeting Abstracts 1999 (1999). - ISSN 1548-2553 - p. 20 - 20.
    Potential of airborne radar to support the assessment of land cover in a tropical rain forest environment
    Sanden, J.J. van der; Hoekman, D.H. - \ 1999
    Remote Sensing of Environment 68 (1999). - ISSN 0034-4257 - p. 26 - 40.
    The potential of airborne radar systems as tools for collecting information in support of the assessment of tropical primary forests and derived cover types was examined. SAR systems operating with high spatial resolutions and different wavelengths (i.e., X-, C-, L- and P-band) acquired data in Guyana and Colombia. Three fundamentally different information sources from the radar return signal were considered in the study: its strength or backscatter, polarization and phase, and spatial variability or texture. Radiometric, polarimetric, and textural attributes were computed from predefined image regions selected to represent five types of primary forest, selectively logged forest, secondary forest, and a mixture of nonforest cover types. Texture was found to be the most important source of information in high resolution X- and C-band images. Textural attributes computed per region made modest to good bases for automated classifications of the land cover types studied. Primary forests and logged-over forests were found to display particularly distinctive textural patterns. Backscatter values computed per region from L- and P-band radar images also made modest to good classification bases. Backscatter measurements in either a single L- or P-band channel enabled accurate classification of nonforest cover types. Reliable identification of secondary forests and logged-over forests generally asked for measurements in a minimum of two C-, L-, and/or P-band radar channels. Similarly, reliable assessment of primary forest types required observations in a minimum of three C-, L-, and/or P-band radar channels.
    Application of multiple criteria decision making for the design and analysis of greenhouse cropping systems
    Bakker, E.J. ; Sanden, P.A.C.M. van de - \ 1998
    In: Proceedings of the Second International Symposium on Models for Plant Growth, Environmental Control and Farm Management in Protected Cultivation / Marcelis, L.F.M., - p. 509 - 514.
    Greenhouse cropping systems have various objectives and can be controlled in various ways. Selection or design of an optimal cropping system requires weighing of the objectives as well as proper understanding of the input-output relations of the system. The field of Multiple Criteria Decision Making (MCDM) provides a set of mathematical techniques that may help to reach a decision in optimisation problems in which more than one objective play a role. Two examples of the use of MCDM are given. The benefit of simulation models to generate quantified production systems is shown using the model CHRYSIM for year-round chrysanthemum production. In the second example, Interactive Multiple Goal Linear Programming, an MCDM approach, is introduced and illustrated in the optimisation of water and nutrient use of rockwool-grown tomato.
    Model-based explorations to support design of sustainable farming systems.
    Berge, H.F.M. ten; Rossing, W.A.H. ; Ven, G.W.J. van de; Habekotté, B. ; Ittersum, M.K. van; Ruijter, F.J. de; Sanden, P.A.C.M. van de - \ 1998
    In: Active methodoloy: proceedings of a seminar series 1997/1998. A. Stein, M.K. van Ittersum, G.H.J. de Koning (eds.) Wageningen Agricultural University, The Netherlands - p. 137 - 147.
    Sabbelflesje op z'n retour.
    Hielkema-de Meij, J.E. ; Koelen, M.A. ; Sanden-Stoelinga, M.S.E. van der - \ 1998
    Tijdschrift voor Jeugdgezondheidszorg 30 (1998). - p. 23 - 25.
    Intensive Dutch farming systems: the search for new feasible configurations to meet environmental goals
    Berge, H.F.M. ten; Rossing, W.A.H. ; Ven, G.W.J. van de; Habekotté, B. ; Ittersum, M.K. van; Ruijter, F.J. de; Sanden, P.A.C.M. van de - \ 1997
    In: Model-based decision support in agriculture. Proceedings of the INRA-KCW workshop on Decision Support Systems, Laon, France, 22-23 October 1997. Quantitative Approaches in Systems Analysis No 15, AB-DLO Wageningen/Haren and PE, Wageningen / ten Berge, H.F.M., Stein, A., - p. 33 - 42.
    Radar remote sensing to support tropical forest management
    Sanden, J.J. van der - \ 1997
    Agricultural University. Promotor(en): R.A. Feddes; R.A.A. Oldeman; D.H. Hoekman. - S.l. : S.n. - ISBN 9789054857785 - 330
    bosbouw - remote sensing - luchtkarteringen - tropen - bosbedrijfsvoering - planning - tropische regenbossen - vegetatie - toepassingen - forestry - remote sensing - aerial surveys - tropics - forest management - planning - tropical rain forests - vegetation - applications

    This text describes an investigation into the potential of radar remote sensing for application to tropical forest management. The information content of various radar images is compared and assessed with regard to the information requirements of parties involved in tropical forest management at the global, national and local spatial levels. The study distinguishes between the use of radar remote sensing for application to forest resource assessment and forest resource monitoring. Both assessment and monitoring are essential components of procedures for sustainable forest management. The radar data studied are of tropical forest areas near the township of Mabura Hill in Guyana and the city of San José del Guaviare in Colombia. Mabura Hill is comprised of differing intact, primary forest types and forests that have been subjected to industrial selective logging. San José del Guaviare, on the other hand, is characterised by the presence of secondary forests and a variety of non-forest cover types. The available radar data set includes high resolution airborne radar images with differing wavelengths (i.e. X-, C-, L- and P-band) and polarizations, time-series images acquired by the first European remote sensing satellite ERS-1 and a collection of low altitude, nadir-looking, X-band scatterometer measurements.

    The study makes use of three fundamentally different information sources from the radar return signal: its strength or backscatter, polarization and phase, and spatial variability or texture. Results show that backscatter values computed from L- and P-band radar data and textural attributes computed from high resolution X- and C-band radar data make modest to good and complementary bases for region-based classification of tropical land cover at the level of primary forest types. Textural attributes and backscatter values computed per region from mono-temporal ERS-1 images make modest bases for classifying at the levels of primary forest, logged-over forest, secondary forest and non- forest and poor bases for classifying at the level of primary forest types. Roads are usually the most easily observable indicators of foregoing and/or forthcoming (selective) logging and other human activities in ERS-1 images. Detection of change in road networks by means of ERS-1 images would make a good first step in forest resource monitoring at the national spatial level, in particular. Textural attributes enable the ranking of forest types according to the degree of canopy roughness. Specific textural attributes also allow for quantification of canopy architectural properties. Despite differences in measurement scale, the canopy roughness of the land cover types studied was found to appear similarly in the texture of the available spaceborne and short wavelength airborne radar images.

    Beter een beker! Onderzoeksresultaten van de campagne over zuigflescaries.
    Hielkema-de Meij, J.E. ; Koelen, M.A. ; Sanden-Stoelinga, M.S.E. - \ 1997
    Woerden : Nationaal Instituut voor Gezondheidsbevordering en Ziektepreventie - 84 p.
    Analysis of ERS-1 SAR data for Mabura Hill, Guyana (TREES94.LAM17)
    Sanden, J.J. van der - \ 1996
    In: Radar remote sensing of tropical rain forests: ERS-1 studies in Guyana and Colombia / van der Sanden, J.J., Hoekman, D.H., Bijker, W., Delft : BCRS - ISBN 9789054111962 - p. 21 - 27.
    ERS-1 observations of tropical rain forests in Araracuara, Colombia : TREES ERS-1 '94 study: LAM-6
    Hoekman, D.H. - \ 1996
    In: Radar remote sensing of tropical rain forests: ERS-1 studies in Guyana and Colombia / van der Sanden, J.J., Hoekman, D.H., Bijker, W., Delft : BCRS - ISBN 9789054111962 - p. 9 - 19.
    Monitoring of tropical rain forests and pastures with ERS-1 : TREES ERS-1 '94 study: LAM-8
    Bijker, W. ; Hoekman, D.H. - \ 1996
    In: Radar remote sensing of tropical rain forests: ERS-1 studies in Guyana and Colombia / van der Sanden, J.J., Hoekman, D.H., Bijker, W., Delft : BCRS - ISBN 9789054111962 - p. 29 - 43.
    Radar remote sensing of tropical rain forests: the AIRSAR-93 campaign in Guyana and Colombia.
    Hoekman, D.H. ; Sanden, J.J. van der; Bijker, W. - \ 1996
    Delft : BCRS - ISBN 9789054111870 - 59
    bosbouw - remote sensing - luchtkarteringen - tropische regenbossen - vegetatie - toepassingen - guyana - colombia - forestry - remote sensing - aerial surveys - tropical rain forests - vegetation - applications - guyana - colombia
    Radar remote sensing of tropical rain forests: ERS-1 studies in Guyana and Colombia. Final Report.
    Sanden, J.J. van der; Hoekman, D.H. ; Bijker, W. - \ 1996
    Delft : BCRS - ISBN 9789054111962 - 43
    bosbouw - remote sensing - luchtkarteringen - tropische regenbossen - vegetatie - toepassingen - guyana - colombia - forestry - remote sensing - aerial surveys - tropical rain forests - vegetation - applications - guyana - colombia
    Stimulating self-regulated learning in vocational settings by means of Leittext.
    Jong, F.P.C.M. de; Berg, J.A.M. van den - \ 1996
    In: Zelfstandig leren en de Leittextmethode / van der Sanden, J.M.M., Tilburg : Katholieke Universiteit Brabant, Sectie Onderwijs en Opleidingspsychologie - p. 117 - 126.
    Towards independent learning and working by way of Leittext.
    Jong, F.P.C.M. de; Berg, J.A.M. van den; Sanden, J. van der - \ 1996
    In: Zelfstandig leren en de Leittextmethode / van der Sanden, J.M.M., Tilburg : Katholieke Universiteit Brabant, Sectie Onderwijs en Opleidingspsychologie - p. 107 - 116.
    Leren probleem oplossen via de Leittextmethode.
    Hornman, G.E.J.M. ; Jong, F.P.C.M. de; Teurlings, C.C.J. - \ 1996
    In: Zelfstandig leren en de Leittextmethode / van der Sanden, J.M.M., Tilburg : Katholieke Universiteit Brabant, Sectie Onderwijs en Opleidingspsychologie - p. 87 - 92.
    Root environment water potential and tomato fruit growth
    Sanden, P.A.C.M. van de; Uittien, J.J. - \ 1995
    Acta Horticulturae 401 (1995). - ISSN 0567-7572 - p. 531 - 536.
    Tomato plants were grown in a climate chamber in water culture at standard nutrient solution concentration with electrical conductivity of 2 mS-cm-1. At the start of the development of the fourth cluster the EC was increased to 6, 9 or 12 mS-cm-1, resulting in a water potential of the nutrient solution of -0.2, -0.3 or -0.4 MPa, respectively. We measured the growth in volume of all fruits with an electronic calliper and at specific periods individual fruit growth using displacement transducers. Plant water potential was measured with a pressure chamber. Fruit water status was determined by measuring the osmotic potential of the pericarp. Above a threshold value the total fruit growth rate was linearly related to EC, with a sensitivity of about 10ÈmS-cm-1)-1. The effect of EC on fruit growth was not only dependent on the level of EC, but also on the length of exposure to high EC during fruit development. Plant water potential changed concomitantly with EC. Fruit osmotic potential lagged behind and was also dependent on the length of exposure to high EC. We consider the water potential gradient between plant and fruit to be the driving force for import of water into the fruit and present a fruit growth simulation on the basis of the relationships between root environment water potential and plant-to-fruit water potential gradient.
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