Staff Publications

Staff Publications

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

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

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

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

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

    We have a manual that explains all the features 

Records 1 - 20 / 10625

  • help
  • print

    Print search results

  • export
    A maximum of 250 titles can be exported. Please, refine your queryYou can also select and export up to 30 titles via your marked list.
  • alert
    We will mail you new results for this query: q=Field
Check title to add to marked list
Forest biomass retrieval approaches from earth observation in different biomes
Rodríguez-Veiga, Pedro ; Quegan, Shaun ; Carreiras, Joao ; Persson, Henrik J. ; Fransson, Johan E.S. ; Hoscilo, Agata ; Ziółkowski, Dariusz ; Stereńczak, Krzysztof ; Lohberger, Sandra ; Stängel, Matthias ; Berninger, Anna ; Siegert, Florian ; Avitabile, Valerio ; Herold, Martin ; Mermoz, Stéphane ; Bouvet, Alexandre ; Toan, Thuy Le; Carvalhais, Nuno ; Santoro, Maurizio ; Cartus, Oliver ; Rauste, Yrjö ; Mathieu, Renaud ; Asner, Gregory P. ; Thiel, Christian ; Pathe, Carsten ; Schmullius, Chris ; Seifert, Frank Martin ; Tansey, Kevin ; Balzter, Heiko - \ 2019
International Journal of applied Earth Observation and Geoinformation 77 (2019). - ISSN 0303-2434 - p. 53 - 68.
The amount and spatial distribution of forest aboveground biomass (AGB) were estimated using a range of regionally developed methods using Earth Observation data for Poland, Sweden and regions in Indonesia (Kalimantan), Mexico (Central Mexico and Yucatan peninsula), and South Africa (Eastern provinces) for the year 2010. These regions are representative of numerous forest biomes and biomass levels globally, from South African woodlands and savannas to the humid tropical forest of Kalimantan. AGB retrieval in each region relied on different sources of reference data, including forest inventory plot data and airborne LiDAR observations, and used a range of retrieval algorithms. This is the widest inter-comparison of regional-to-national AGB maps to date in terms of area, forest types, input datasets, and retrieval methods. The accuracy assessment of all regional maps using independent field data or LiDAR AGB maps resulted in an overall root mean square error (RMSE) ranging from 10 t ha−1 to 55 t ha−1 (37% to 67% relative RMSE), and an overall bias ranging from −1 t ha−1 to +5 t ha−1 at pixel level. The regional maps showed better agreement with field data than previously developed and widely used pan-tropical or northern hemisphere datasets. The comparison of accuracy assessments showed commonalities in error structures despite the variety of methods, input data, and forest biomes. All regional retrievals resulted in overestimation (up to 63 t ha−1) in the lower AGB classes, and underestimation (up to 85 t ha−1) in the higher AGB classes. Parametric model-based algorithms present advantages due to their low demand on in situ data compared to non-parametric algorithms, but there is a need for datasets and retrieval methods that can overcome the biases at both ends of the AGB range. The outcomes of this study should be considered when developing algorithms to estimate forest biomass at continental to global scale level.
The antiSMASH database version 2 : a comprehensive resource on secondary metabolite biosynthetic gene clusters
Blin, Kai ; Pascal Andreu, Victòria ; Los Santos, Emmanuel L.C. de; Carratore, Francesco Del; Lee, Sang Yup ; Medema, Marnix H. ; Weber, Tilmann - \ 2019
Nucleic Acids Research 47 (2019)D1. - ISSN 0305-1048 - p. D625 - D630.

Natural products originating from microorganisms are frequently used in antimicrobial and anticancer drugs, pesticides, herbicides or fungicides. In the last years, the increasing availability of microbial genome data has made it possible to access the wealth of biosynthetic clusters responsible for the production of these compounds by genome mining. antiSMASH is one of the most popular tools in this field. The antiSMASH database provides pre-computed antiSMASH results for many publicly available microbial genomes and allows for advanced cross-genome searches. The current version 2 of the antiSMASH database contains annotations for 6200 full bacterial genomes and 18,576 bacterial draft genomes and is available at

Exploring the adoption of precision agricultural technologies : A cross regional study of EU farmers
Barnes, A.P. ; Soto, I. ; Eory, V. ; Beck, B. ; Balafoutis, A. ; Sánchez, B. ; Vangeyte, J. ; Fountas, S. ; Wal, T. van der; Gómez-Barbero, M. - \ 2019
Land Use Policy 80 (2019). - ISSN 0264-8377 - p. 163 - 174.
EU Policy - Precision Agriculture - Random Intercept Logistic Regression

Precision agricultural technologies (PATs) allow more detailed management of in-field variability. Policy and advisory communities have championed PATs as a route to preserving natural capital whilst increasing productivity from agricultural land. A range of PATs are currently available for the agricultural producer but uptake varies by the type of technology and region. Whereas most studies on uptake have focused on US or Australia we empirically examine uptake of machine guidance (MG) and variable rate nitrogen technologies (VRNT) within European farming systems. Using primary information from 971 arable crop growers across five countries: Belgium, Germany, Greece, the Netherlands and the UK, a multilevel random intercept regression estimated a) the differences between adoption and non-adoption and b) the differences between VRNT and MG adoption. We find, aside from size and income differences, which reflect the economic cost barrier to adoption, an attitudinal difference, in terms of optimism towards the technology's economic return leading to more probability of uptake. Moreover innovative and information seeking behaviour also proved significant when upgrading from machine guidance to variable rate technologies. Subsidy and taxation were considered positive drivers of uptake within the community. However, results suggest that more indirect interventions, such as informational support to counteract industry bias, and demonstration to prove the viability of economic return may be effective at meeting land manager and policy expectations towards PATs.

Optimized sowing time windows mitigate climate risks for oats production under cool semi-arid growing conditions
Zhang, Yue ; Zhang, Lizhen ; Yang, Ning ; Huth, Neil ; Wang, Enli ; Werf, Wopke van der; Evers, Jochem B. ; Wang, Qi ; Zhang, Dongsheng ; Wang, Ruonan ; Gao, Hui ; Anten, Niels P.R. - \ 2019
Agricultural and Forest Meteorology 266-267 (2019). - ISSN 0168-1923 - p. 184 - 197.
APSIM-Oats - Climate change - Cumulative probability - Optimal sowing time window - Water limited potential yield - Yield gap

Year to year variability in weather poses serious risks to crop production in the environmentally fragile agro-ecosystems of cool semi-arid areas, and future climate changes might further aggravate those risks. This study aims to quantify the contribution of altered sowing time windows to reduce climate risk for the production of oats (Avena sativa), a crop that is well adapted to short growing seasons and low rainfall. The APSIM-Oats model was calibrated and validated for phenology, above-ground dry matter and yield using data from field experiments with five sowing dates, conducted from 2009 to 2013 in Inner Mongolia, China. The model was used to determine yield trends and yield-limiting factors under rain-fed conditions using historical weather data. Changes in temperature had greater impact on crop production than changes in rainfall and the simulations indicated the importance of changed sowing windows to lengthen the growth duration and optimize water use. Delayed sowing of oats, 10 days later than current practice, ensured more secure temperature and rainfall conditions from emergence to flowering and substantially increased yields and decreased climate risk. Delayed sowing also reduced climate risk under two future climate scenarios, RCP4.5 (stabilize growth) and RCP8.5 (high greenhouse gas emission). We conclude that adaptation of sowing time of oats provides a practical strategy for enhancing yield and mitigating climate risk under climate change.

Dynamics of glyphosate and AMPA in the soil surface layer of glyphosate-resistant crop cultivations in the loess Pampas of Argentina
Bento, Célia P.M. ; Hoeven, Siebrand van der; Yang, Xiaomei ; Riksen, Michel M.J.P.M. ; Mol, Hans G.J. ; Ritsema, Coen J. ; Geissen, Violette - \ 2019
Environmental Pollution (2019). - ISSN 0269-7491 - p. 323 - 331.
Aminomethylphosphonic acid (AMPA) - Field dissipation kinetics - Genetically modified crops (GM crops) - Glyphosate - Sediment transport

This study investigates the dynamics of glyphosate and AMPA in the soil surface layer of two fields growing glyphosate-resistant crops in the loess Pampas of Córdoba Province, Argentina. Glyphosate decay and AMPA formation/decay were studied after a single application, using decay kinetic models. Furthermore, glyphosate and AMPA concentrations were investigated in runoff to evaluate their off-site risk. During a 2.5-month study, cultivations of glyphosate-resistant soybean and maize received an application of 1.0 and 0.81 kg a.e. ha−1, respectively, of Roundup UltraMax©. Topsoil samples (0–1, 1–2 cm) were collected weekly (including before application) and analysed for glyphosate, AMPA and soil moisture (SM) contents. Runoff was collected from runoff plots (3 m2) and weirs after 2 erosive rainfall events, and analysed for glyphosate and AMPA contents (water, eroded-sediment). Under both cultivations, background residues in soil before application were 0.27–0.42 mg kg−1 for glyphosate and 1.3–1.7 mg kg−1 for AMPA. In the soybean area, the single-first-order (SFO) model performed best for glyphosate decay. In the maize area, the bi-phasic Hockey-Stick (HS) model performed best for glyphosate decay, due to an abrupt change in SM regimes after high rainfall. Glyphosate half-life and DT90 were 6.0 and 19.8 days, respectively, in the soybean area, and 11.1 and 15.4 days, respectively, in the maize area. In the soybean area, 24% of the glyphosate was degraded to AMPA. In the maize area, it was only 5%. AMPA half-life and DT90 were 54.7 and 182 days, respectively, in the soybean area, and 71.0 and 236 days, respectively, in the maize area. Glyphosate and AMPA contents were 1.1–17.5 times higher in water-eroded sediment than in soil. We conclude that AMPA persists and may accumulate in soil, whereas both glyphosate and AMPA are prone to off-site transport with water erosion, representing a contamination risk for surface waters and adjacent fields. Glyphosate and AMPA dynamics in the soil surface layer of cultivation areas from the loess Pampas of Argentina show high risk of AMPA accumulation, while water erosion represents a high risk for their transport to off-target areas.

The RED Fouling Monitor : A novel tool for fouling analysis
Bodner, E.J. ; Saakes, M. ; Sleutels, T. ; Buisman, C.J.N. ; Hamelers, H.V.M. - \ 2019
Journal of Membrane Science 570-571 (2019). - ISSN 0376-7388 - p. 294 - 302.
Fouling analysis - Ion-exchange membranes - Organic fouling - RED Fouling Monitor - Salinity gradient

RED is a technology for harvesting energy using the salinity gradient between river (RW) and seawater (SW). Membrane fouling can decrease the net power density. Fouling inhibition might be indispensable. For implementing antifouling strategies more detailed insights upon fouling are required. In RED stacks investigations of single membranes are practically impossible. We introduce the RED Fouling Monitor, in which one side of a single ion-exchange membrane in contact to a foulant-containing feed stream can be studied under OCV and current conditions. Fouling is detectable in four configurations: (1) SW/AEM, (2) RW/AEM, (3) SW/CEM and (4) RW/CEM. Functionality is provided by a novel flow-through salt bridge enabling ionic connection and the incorporation of reference electrodes in close proximity to the membrane surface. The results indicate a stable, reproducible performance under un-fouled conditions. Upon SDBS exposure RW/AEM fouling showed a more pronounced fouling response than SW/AEM fouling. Fouling is partly attributable to the current density and the current field direction. An irreversible, internal fouling of the AEM is indicated when exposed to SDBS in SW. RW/AEM fouling shows to be reversible. With prospect to future systematic investigations this tool can be used to test various configurational, operational designs, different pre-treatment schemes and the fouling potential of feed streams at different seasons. This will result in valuable insights for new constructional sites for future RED plants.

In vivo stability of supramolecular host–guest complexes monitored by dual-isotope multiplexing in a pre-targeting model of experimental liver radioembolization
Welling, Mick M. ; Spa, Silvia J. ; Willigen, Danny M. van; Rietbergen, Daphne D.D. ; Roestenberg, Meta ; Buckle, Tessa ; Leeuwen, Fijs W.B. van - \ 2019
Journal of Controlled Release 293 (2019). - ISSN 0168-3659 - p. 126 - 134.
Dual-labeling - Interventional radiology - Pre-targeting - Radioembolization - Supramolecular chemistry - Theranostics

Introduction: Cyclodextrin (CD)-based supramolecular interactions have been proposed as nanocarriers for drug delivery. We previously explored the use of these supramolecular interactions to perform targeted hepatic radioembolization. In a two-step procedure the appropriate location of the diagnostic pre-targeting vector can first be confirmed, after which the therapeutic vector will be targeted through multivalent host–guest interactions. Such a procedure would prevent therapeutic errors that come from a mismatch between diagnostic and therapeutic procedures. In the current study we explored the use of dual-isotope imaging to assess the in vivo stability of the formed complex and individual components. Methods: Dual-isotope imaging of the host and guest vectors was performed after labeling of the pre-targeted guest vector, being adamantane (Ad) functionalized macro-aggregated albumin (MAA) particles, with technetium-99 m (99mTc-MAA-Ad). The host vector, Cy50.5CD9PIBMA39, was labeled with indium-111 (111In-Cy50.5CD9PIBMA39). The in situ stability of both the individual vectors and the resulting [MAA-Ad–111In-Cy50.5CD9PIBMA39] complexes was studied over 44 h at 37 °C in a serum protein-containing buffer. In vivo, the host vector 111In-Cy50.5CD9PIBMA39 was administered two hours after local deposition of 99mTc-MAA-Ad in mice. Dual-isotope SPECT imaging and quantitative biodistribution studies were performed between 2 and 44 h post intravenous host vector administration. Results: The individual vectors portrayed <5% dissociation of the radioisotope over the course of 20 h. Dissociation of [MAA-Ad–111In-Cy50.5CD9PIBMA39] complexes remained within a 10–20% range after incubation in serum. In vivo dual-isotope SPECT imaging of host–guest interactions revealed co-localization of the tracer components. Quantitative assessment of the biodistribution revealed that the hepatic accumulation of the host vector nearly doubled between 2 h and 44 h post-injection (from 14.9 ± 6.1%ID/g to 26.2 ± 2.1%ID/g). Conclusions: Assessment of intra-hepatic host–guest complexation was successfully achieved using dual isotope multiplexing, underlining the complex stability that was found in situ (up to 44 h in serum). Overall, the results obtained in this study highlight the potential of supramolecular chemistry as a versatile platform that could advance the field of nanomedicine.

Beneficial use of dredged sediment to enhance salt marsh development by applying a ‘Mud Motor’
Baptist, Martin J. ; Gerkema, T. ; Prooijen, B.C. van; Maren, D.S. van; Regteren, M. van; Schulz, K. ; Colosimo, I. ; Vroom, J. ; Kessel, T. van; Grasmeijer, B. ; Willemsen, P. ; Elschot, K. ; Groot, A.V. de; Cleveringa, J. ; Eekelen, E.M.M. van; Schuurman, F. ; Lange, H.J. de; Puijenbroek, M.E.B. van - \ 2019
Ecological Engineering 127 (2019). - ISSN 0925-8574 - p. 312 - 323.
Building with Nature - Nature-based solutions - Cohesive sediment - Dredging - Salt marshes - intertidal flats
We test an innovative approach to beneficially re-use dredged sediment to enhance salt marsh development. A Mud Motor is a dredged sediment disposal in the form of a semi-continuous source of mud in a shallow tidal channel allowing natural processes to disperse the sediment to nearby mudflats and salt marshes. We describe the various steps in the design of a Mud Motor pilot: numerical simulations with a sediment transport model to explore suitable disposal locations, a tracer experiment to measure the transport fate of disposed mud, assessment of the legal requirements, and detailing the planning and technical feasibility. An extensive monitoring and research programme was designed to measure sediment transport rates and the response of intertidal mudflats and salt marshes to an increased sediment load. Measurements include the sediment transport in the tidal channel and on the shallow mudflats, the vertical accretion of intertidal mudflats and salt marsh, and the salt marsh vegetation cover and composition. In the Mud Motor pilot a total of 470,516 m 3
of fine grained sediment (D50 of ∼10 μm) was disposed over two winter seasons, with an average of 22 sediment disposals per week of operation. Ship-based measurements revealed a periodic vertical salinity stratification that is inverted compared to a classical estuary and that is working against the asymmetric flood-dominated transport direction. Field measurements on the intertidal mudflats showed that the functioning of the Mud Motor, i.e. the successful increased mud transport toward the salt marsh, is significantly dependent on wind and wave forcing. Accretion measurements showed relatively large changes in surface elevation due to deposition and erosion of layers of
watery mud with a thickness of up to 10 cm on a time scale of days. The measurements indicate notably higher sediment dynamics during periods of Mud Motor disposal. The salt marsh demonstrated significant vertical accretion though this has not yet led to horizontal expansion because there was more hydrodynamic stress than foreseen. In carrying out the pilot we learned that the feasibility of a Mud Motor depends on an assessment of additional travel time for the dredger, the effectiveness on salt marsh growth, reduced dredging volumes in a port, and many other practical issues. Our improved understanding on the transport processes in the channel and on the mudflats and salt marsh yields design lessons and guiding principles for future applications of sediment
management in salt marsh development that include a Mud Motor approach
Obstacles and features of Farm Management Information Systems : A systematic literature review
Tummers, J. ; Kassahun, A. ; Tekinerdogan, B. - \ 2019
Computers and Electronics in Agriculture 157 (2019). - ISSN 0168-1699 - p. 189 - 204.
Farm Management Information System - Features of FMIS - Obstacles to FMIS - Systematic literature review

Various Farm Management Information Systems (FMISs) have been developed to support the management of the farm businesses. These FMISs typically support the different domains of the agricultural sector, such as arable and dairy farming; and include different set of features, such as crop, field, and financial management. These FMISs also have to deal with diverse obstacles during their development and adoption, such as lack of standardized data, cost and usability. Though several papers have been published in the past several years on this topic, there has been no explicit attempt to systematically review these papers to identify and characterize the features and obstacles. The objective of this study is to identify and describe the state-of-the-art of FMISs and as such pave the way for further research and development of FMISs. We applied a systematic literature review protocol in which we included the literature published from 2008 to 2018. We found 1048 papers of which 38 papers were selected as primary studies that we analyzed further in detail. From the detailed analysis, we identified 81 unique FMIS features and 51 unique obstacles of FMISs. We have systematically ranked the identified features and obstacles and describe the key associated aspects. These aspects include the agricultural domains, modeling approaches, delivery models, and identified stakeholders.

Next generation physiologically based kinetic (NG-PBK) models in support of regulatory decision making
Paini, A. ; Leonard, J.A. ; Joossens, E. ; Bessems, J.G.M. ; Desalegn, A. ; Dorne, J.L. ; Gosling, J.P. ; Heringa, M.B. ; Klaric, M. ; Kliment, T. ; Kramer, N.I. ; Loizou, G. ; Louisse, J. ; Lumen, A. ; Madden, J.C. ; Patterson, E.A. ; Proença, S. ; Punt, A. ; Setzer, R.W. ; Suciu, N. ; Troutman, J. ; Yoon, M. ; Worth, A. ; Tan, Y.M. - \ 2019
Computational Toxicology 9 (2019). - ISSN 2468-1113 - p. 61 - 72.
In silico - In vitro - PBPK - PBTK - Physiologically based kinetic models - Toxicokinetics

The fields of toxicology and chemical risk assessment seek to reduce, and eventually replace, the use of animals for the prediction of toxicity in humans. In this context, physiologically based kinetic (PBK) modelling based on in vitro and in silico kinetic data has the potential to a play significant role in reducing animal testing, by providing a methodology capable of incorporating in vitro human data to facilitate the development of in vitro to in vivo extrapolation of hazard information. In the present article, we discuss the challenges in: 1) applying PBK modelling to support regulatory decision making under the toxicology and risk-assessment paradigm shift towards animal replacement; 2) constructing PBK models without in vivo animal kinetic data, while relying solely on in vitro or in silico methods for model parameterization; and 3) assessing the validity and credibility of PBK models built largely using non-animal data. The strengths, uncertainties, and limitations of PBK models developed using in vitro or in silico data are discussed in an effort to establish a higher degree of confidence in the application of such models in a regulatory context. The article summarises the outcome of an expert workshop hosted by the European Commission Joint Research Centre (EC-JRC) – European Union Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM), on “Physiologically-Based Kinetic modelling in risk assessment – reaching a whole new level in regulatory decision-making” held in Ispra, Italy, in November 2016, along with results from an international survey conducted in 2017 and recently reported activities occurring within the PBK modelling field. The discussions presented herein highlight the potential applications of next generation (NG)-PBK modelling, based on new data streams.

Options to model the effects of tillage on N2O emissions at the global scale
Lutz, Femke ; Stoorvogel, Jetse J. ; Müller, Christoph - \ 2019
Ecological Modelling 392 (2019). - ISSN 0304-3800 - p. 212 - 225.
Agriculture - GHG emissions - Global ecosystem models - Mitigation - Soil management

Strategies on agricultural management can help to reduce global greenhouse gas (GHG) emissions. However, the potential of agricultural management to reduce GHG emissions at the global scale is unclear. Global ecosystem models often lack sufficient detail in their representation of management, such as tillage. This paper explores whether and how tillage can be incorporated in global ecosystem models for the analysis of nitrous oxide (N2O) emissions. We identify the most important nitrogen processes in soils and their response to tillage. We review how these processes and tillage effects are described in field-scale models and evaluate whether they can be incorporated in the global-scale models while considering the data requirements for a global application. The most important processes are described in field-scale models and the basic data requirements can be met at the global scale. We therefore conclude that there is potential to incorporate tillage in global ecosystem models for the analysis of N2O emissions. There are several options for how the relevant processes can be incorporated into global ecosystem models, so that generally there is potential to study the effects of tillage on N2O emissions globally. Given the many interactions with other processes, modelers need to identify the modelling approaches that are consistent with their modelling framework and test these.

Sensitivity analysis of a source partitioning method for H2O and CO2 fluxes based on high frequency eddy covariance data : Findings from field data and large eddy simulations
Klosterhalfen, A. ; Moene, A.F. ; Schmidt, M. ; Scanlon, T.M. ; Vereecken, H. ; Graf, A. - \ 2019
Agricultural and Forest Meteorology 265 (2019). - ISSN 0168-1923 - p. 152 - 170.
Flux partitioning - Latent heat flux - LES - Net ecosystem exchange - Sensitivity analysis - Water use efficiency

Scanlon and Sahu (2008) and Scanlon and Kustas (2010) proposed a source partitioning method (SK10 in the following) to estimate contributions of transpiration, evaporation, photosynthesis, and respiration to H2O and CO2 fluxes obtained by the eddy covariance method. High frequency eddy covariance raw data time series are needed, and the source partitioning is estimated based on separate application of the flux-variance similarity theory to stomatal and non-stomatal components of the regarded fluxes, as well as on additional assumptions on leaf-level water use efficiency (WUE). We applied SK10 to data from two test sites (forest and cropland) and analyzed partitioning results depending on various ways to estimate WUE from available data. Also, we conducted large eddy simulations (LES), simulating the turbulent transport of H2O and CO2 for contrasting vertical distributions of the canopy sinks/sources, as well as for varying relative magnitudes of soil sources and canopy sinks/sources. SK10 was applied to the synthetic high frequency data generated by LES and the effects of canopy type, measurement height, given sink-source-distributions, and input of varying WUEs were tested regarding the partitioning performance. SK10 requires that the correlation coefficient between stomatal and non-stomatal scalar fluctuations is determined by the ratio of the transfer efficiencies of these scalar components, an assumption (transfer assumption in the following) that could be tested with the generated LES data. The partitioning results of the field sites yielded satisfactory flux fractions, when fair-weather conditions (no precipitation) and a high productive state of the vegetation were present. Further, partitioning performance with regard to soil fluxes increased with crop maturity. Results also showed relatively large dependencies on WUE, where the partitioning factors (median) changed by around -57% and +36%. Measurements of outgoing longwave radiation used for the estimation of foliage temperature and WUE could slightly increase the plausibility of the partitioning results in comparison to soil respiration measurements by decreasing the partitioning factor by up to 42%. The LES-based analysis revealed that for a satisfying performance of SK10, a certain degree of decorrelation of the H2O and CO2 fluctuations (here, |ρq'c’| < 0.975) was needed. This decorrelation is enhanced by a clear separation between soil sources and canopy sinks/sources, and for observations within the roughness sublayer. The expected dependence of the partitioning results on the WUE input could be observed. However, due to violation of the abovementioned transfer assumption, the known true input WUE did not yield the known true input partitioning. This could only be achieved after introducing correction factors for the transfer assumption, which were known however only in the special case of the LES experiments.

Estimation of the water cycle related to shale gas production under high data uncertainties : Dutch perspective
Butkovskyi, Andrii ; Cirkel, Gijsbert ; Bozileva, Elvira ; Bruning, Harry ; Wezel, Annemarie P. Van; Rijnaarts, Huub H.M. - \ 2019
Journal of Environmental Management 231 (2019). - ISSN 0301-4797 - p. 483 - 493.
Fracturing fluid - Posidonia shale - Produced water - Shale gas - Wastewater recycling

The potential water demand for fracturing fluids along with the possible flowback and produced water production is assessed for the Dutch Posidonia shale. Total water demand estimated for 25 years of the field development using historic data from the U.S. plays varies between 12.2 and 36.9 Mm3. The maximal annual water consumption of 0.95–2.88 Mm3 is expected in the peak years of shale gas production. These figures are much lower than the availability of any potential water sources, which include drinking water, fresh and brackish groundwater, river water, effluents of wastewater treatment plants (WWTP) and sea water. River water is considered the most promising water source for fracturing fluids in the Dutch Posidonia shale based on its availability (>6·104 Mm3/year) and quality (only bacterial composition needs to be controlled). Total wastewater production for the whole period of the field development is estimated between 6.6 and 48.0 Mm3. Wastewater recycling can cover significant part of the source water demand for fracturing fluid. However, high mineral content of the wastewater as well as temporal and spatial discrepancies between wastewater production and water demand will form obstacles for wastewater recycling. The assessment framework developed in this study may be applied for other shale gas fields with high uncertainties regarding subsurface properties, connate formation water characteristics and future legislative framework.

Wild lobster (Panulirus ornatus) fry fishery in Balete bay, Davao Oriental : Catch trends and implications to fisheries management
Macusi, Edison D. ; Laya-Og, Manilyn E. ; Abreo, Neil Angelo S. - \ 2019
Ocean & Coastal Management 168 (2019). - ISSN 0964-5691 - p. 340 - 349.
Davao Oriental - Fisher's knowledge - Fisheries - Fry - Growth overfishing - Lobster fry - Mati City - Puerulus

The coastal ecosystem of the Philippines is one of the richest and most diverse on earth. Lobsters are one of the commercially exploited species targeted by small-scale fishers for their livelihood and income. This study aims to determine the catch, and catching pattern of the wild lobster fry fishery, quantify the catch per unit effort (CPUE) and identify issues and challenges present in the lobster fry fishery for improved conservation and management. A combination of semi-structured interviews (n = 90), focus group discussion (n = 35) and actual catch monitoring for three months of lobster fry fishers (n = 20) were conducted to elicit information on lobster catch, composition, fishing practices and issues and challenges. Results from the interview and focus groups showed that majority of fishers catch the fries of Panulirus ornatus, Parribacus antarcticus and Panulirus versicolor. They catch most of the lobster fries using bamboo traps and beach seine. The analysis of the CPUE also revealed significant results (P ≤ 0.05) with the good catch having the highest CPUE value (0.30 g) followed by the normal catch (0.16 g) and worst catch of (0.02 g). In terms of weekly field monitoring of the catches of 20 fishers, temporal variation in terms of weeks was highly significant (P = 0.000; R2 = 22). Some management issues mentioned by fishers include effluents from shrimp farming, illegal fishing, chemical residues from mango farms and improper waste disposal. The lack of a management plan, as well as a system to control who has access to the fishing ground of lobster fries, can negatively affect the long-term sustainability of the lobster fry fishery.

Experimental design of a mobile landing platform to Assist Aerial Surveys in fluvial environments
Borreguero, David ; Velasco, Omar ; Valente, João - \ 2019
Applied Sciences 9 (2019)1. - ISSN 2076-3417
Field robotics - Fluvial environments - Mechatronics - Unmanned aerial vehicles - Unmanned surface vehicles

Sampling aquatic ecosystems is a laborious and expensive task, especially when covering large areas. This can be improved using unmanned aerial vehicles (UAVs) equipped with various remote sensing sensors. However, the UAV performance and autonomy may vary due to external factors when it is operated outdoors. In some cases, an emergency landing maneuver is necessary to avoid an accident, since in fluvial environments, the UAV control landing becomes a difficult operation. Therefore, it is important to have a backup platform on the water to fix this problem. This paper presents the design and development of a custom-built unmanned surface vehicle using open-source tools and with two types of operation-remotely piloted and autonomous-to support remote sensing practices with UAVs in fluvial environments. Finally, part of the software developed within this project was released in an open-source repository.

Bridging global, basin and local-scale water quality modeling towards enhancing water quality management worldwide
Tang, Ting ; Strokal, Maryna ; Vliet, Michelle T.H. van; Seuntjens, Piet ; Burek, Peter ; Kroeze, Carolien ; Langan, Simon ; Wada, Yoshihide - \ 2019
Current Opinion in Environmental Sustainability 36 (2019). - ISSN 1877-3435 - p. 39 - 48.

Global water quality (WQ) modeling is an emerging field. In this article, we identify the missing linkages between global and basin/local-scale WQ models, and discuss the possibilities to fill these gaps. We argue that WQ models need stronger linkages across spatial scales. This would help to identify effective scale-specific WQ management options and contribute to future development of global WQ models. Two directions are proposed to improve the linkages: nested multiscale WQ modeling towards enhanced water management, and development of next-generation global WQ models based-on basin/local-scale mechanistic understanding. We highlight the need for better collaboration among WQ modelers and policy-makers in order to deliver responsive water policies and management strategies across scales.

Finite element analysis of trees in the wind based on terrestrial laser scanning data
Jackson, T. ; Shenkin, A. ; Wellpott, A. ; Calders, K. ; Origo, N. ; Disney, M. ; Burt, A. ; Raumonen, P. ; Gardiner, B. ; Herold, M. ; Fourcaud, T. ; Malhi, Y. - \ 2019
Agricultural and Forest Meteorology 265 (2019). - ISSN 0168-1923 - p. 137 - 144.
Critical wind speed - Finite element analysis - Resonant frequency - Terrestrial laser scanning - TLS - Wind damage

Wind damage is an important driver of forest structure and dynamics, but it is poorly understood in natural broadleaf forests. This paper presents a new approach in the study of wind damage: combining terrestrial laser scanning (TLS) data and finite element analysis. Recent advances in tree reconstruction from TLS data allowed us to accurately represent the 3D geometry of a tree in a mechanical simulation, without the need for arduous manual mapping or simplifying assumptions about tree shape. We used this simulation to predict the mechanical strains produced on the trunks of 21 trees in Wytham Woods, UK, and validated it using strain data measured on these same trees. For a subset of five trees near the anemometer, the model predicted a five-minute time-series of strain with a mean cross-correlation coefficient of 0.71, when forced by the locally measured wind speed data. Additionally, the maximum strain associated with a 5 ms−1 or 15 ms-1 wind speed was well predicted by the model (N = 17, R2 = 0.81 and R2 = 0.79, respectively). We also predicted the critical wind speed at which the trees will break from both the field data and models and find a good overall agreement (N = 17, R2 = 0.40). Finally, the model predicted the correct trend in the fundamental frequencies of the trees (N = 20, R2 = 0.38) although there was a systematic underprediction, possibly due to the simplified treatment of material properties in the model. The current approach relies on local wind data, so must be combined with wind flow modelling to be applicable at the landscape-scale or over complex terrain. This approach is applicable at the plot level and could also be applied to open-grown trees, such as in cities or parks.

Opinion paper about organic trace pollutants in wastewater : Toxicity assessment in a European perspective
Pedrazzani, Roberta ; Bertanza, Giorgio ; Brnardić, Ivan ; Cetecioglu, Zeynep ; Dries, Jan ; Dvarionienė, Jolanta ; García-Fernández, Antonio J. ; Langenhoff, Alette ; Libralato, Giovanni ; Lofrano, Giusy ; Škrbić, Biljana ; Martínez-López, Emma ; Meriç, Süreyya ; Pavlović, Dragana Mutavdžić ; Papa, Matteo ; Schröder, Peter ; Tsagarakis, Konstantinos P. ; Vogelsang, Christian - \ 2019
Science of the Total Environment 651 (2019). - ISSN 0048-9697 - p. 3202 - 3221.
Aquatic ecosystem - Bioassays - Ecotoxicity - Micro-pollutants - Risk assessment - Wastewater treatment

This opinion paper focuses on the role of eco-toxicological tools in the assessment of possible impacts of emerging contaminants on the aquatic ecosystem, hence, on human health. Indeed, organic trace pollutants present in raw and treated wastewater are the pivot targets: a multidisciplinary approach allows defining the basic principles for managing this issue, from setting a proper monitoring campaign up to evaluating the optimal process treatment. Giving hints on trace pollutants fate and behaviour, attention is focused on the choice of the bioassay(s), by analysing the meaning of possible biological answers. Data interpretation and exploitation are detailed with the final goal of providing criteria in order to be able to select the best targeted treatment options. The manuscript deals with conventional and innovative analytical approaches for assessing toxicity, by reviewing laboratory and field assays; illustrative real scale and laboratory applications integrate and exemplify the proposed approach.

An improved methodology to evaluate crop salt tolerance from field trials
Straten, G. van; Vos, A.C. de; Rozema, J. ; Bruning, B. ; Bodegom, P.M. van - \ 2019
Agricultural Water Management 213 (2019). - ISSN 0378-3774 - p. 375 - 387.
Crop salinity tolerance - Parameter estimation - Salinization

The salt tolerance of crops is commonly expressed in descriptive parameters such as threshold or 50%-yield soil salinity and shape parameters describing the yield curve. Estimation by visual or simplified ordinary least squares (OLS) regression methods has multiple issues: parameter bias due to uncertainty in soil salinity, lack of independent estimates of the reference yield, questionable robustness of the threshold parameter and missing information about uncertainty and correlation of the parameter estimates. Here, we present a comprehensive OLS method together with an analysis of its statistical properties to alleviate and overcome such issues, on the basis of a numerical experiment that mimics observed yield responses to saline groundwater across a range of salinities in the experimental test facility Salt Farm Texel. The results indicate under which experimental conditions bias is not a major problem. The method allows estimation of the zero-observed-effect yield from the data, which is relevant to agricultural practice. Estimates for zero-observed-effect yield and threshold ECe are negatively correlated, underlining the difficulty of obtaining reliable threshold values. The estimated confidence regions are reliable and robust against soil salinity uncertainty, but large observation error jeopardizes the confidence intervals, especially for the slope parameter. Data uncertainty alone can be responsible for substantial differences from experiment to experiment, providing a partial explanation for the wide variety in reported parameters in the literature, and stressing the need for long-term repetitions. Given the lack of robustness of the threshold parameter, we propose to adopt the 90%-yield EC (ECe90) as tolerance parameter. Its confidence bounds can be obtained from a simple reformulation of the original models. We also present uncertainty ellipses as a suitable tool to unite multiple-year estimates. The method is offered as a solid and generic basis for reliable assessment of the cultivation potential of varieties and crops on salt-affected soils.

Agrohydrological analysis of groundwater recharge and land use changes in the Pampas of Argentina
Kroes, Joop ; Dam, Jos van; Supit, Iwan ; Abelleyra, Diego de; Verón, Santiago ; Wit, Allard de; Boogaard, Hendrik ; Angelini, Marcos ; Damiano, Francisco ; Groenendijk, Piet ; Wesseling, Jan ; Veldhuizen, Ab - \ 2019
Agricultural Water Management 213 (2019). - ISSN 0378-3774 - p. 843 - 857.
Argentina - Capillary rise - Groundwater recharge - Land use - Pampas - Soybean - SWAP - WOFOST

This paper studies the changes of groundwater, climate and land use in the Pampas of Argentina. These changes offer opportunities and threats. Lowering groundwater without irrigation causes drought and successive crop and yield damage. Rising groundwater may alleviate drought as capillary rise supports root water uptake and crop growth, thus narrowing the difference between potential and actual yields. However, rising groundwater may also limit soil water storage, cause flooding in metropolitan areas and have a negative impact on crop yields. Changing land use from continuous soy bean into crop rotations or natural vegetation may decrease groundwater recharge and thus decrease groundwater levels. In case of crop rotation however, leaching of nutrients like nitrate may increase. We quantified these impacts using integrated dynamic crop growth and soil hydrology modelling. The models were tested at field scale using a local dataset from Argentina. We applied distributed modelling at regional scale to evaluate the impacts on groundwater recharge and crop yields using long term weather data. The experiments showed that threats arise from continuous monotone land use. Opportunities are created when a proper balance is found between supply and demand of soil water using a larger differentiation of land use. Increasing the areas of land use types with higher evapotranspiration, like permanent grassland and trees, will contribute to a more stable hydrologic system with more water storage capacities in the soil system and lower groundwater levels. Modelling tools clearly support the evaluation of the impact of land use and climate change on groundwater levels and crop yields.

Check title to add to marked list
<< previous | next >>

Show 20 50 100 records per page

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