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 / 282274

  • 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: status=OK
Check title to add to marked list
Sensor-based management of container nursery crops irrigated with fresh or saline water
Incrocci, Luca ; Marzialetti, Paolo ; Incrocci, Giorgio ; Vita, Andrea Di; Balendonck, Jos ; Bibbiani, Carlo ; Spagnol, Serafino ; Pardossi, Alberto - \ 2019
Agricultural Water Management 213 (2019). - ISSN 0378-3774 - p. 49 - 61.
The objective of this study was to design and test a prototype fertigation controller for the management of container ornamental nursery stocks irrigated with different water sources, including saline water or reclaimed municipal/industrial wastewater. The prototype could schedule irrigation in various ways, i.e. as a time clock, or by means of a soil moisture dielectric sensor, or using a crop evapotranspiration (ET) model. The prototype also monitored the salinity in the root zone using a dielectric sensor that measured both substrate moisture and electrical conductivity (EC), or a probe measuring the EC of the water draining out of the containers. Excessive substrate salinization of the containers irrigated with saline water (containing 10 mM of sodium chloride) was prevented by the automated adoption of a series of measures: irrigation with fresh water or a mixture of fresh water and saline water; progressive increase of irrigation dose for each event, and progressive reduction of fertilizer concentration in the nutrient solution delivered to the crop. The system was tested in three experiments conducted in Pistoia (Italy) between 2008 and 2010 with two ornamental species: Photinia × fraseri Dress (a salt-medium tolerant species) and Prunus laurocerasus L. (a salt-sensitive species). When irrigation with fresh water was controlled with a dielectric sensor or an ET model, total irrigation water use and the loss of both N and P were reduced by 17% to 84% compared with the time-controlled irrigation. The sensor-based control of saline water irrigation reduced the salinity effects on dry matter accumulation in both species; however, it did not prevent the occurrence of leaf damages (leaf scorch) on Prunus plants, which were unmarketable by the end of growing season. On the contrary, no leaf damages were visible on Photinia plants irrigated with saline and/or fresh water, such that all were classified in the top quality market category. The controller developed in this work could be used in commercial nurseries to improve profitability and sustainability of container hardy ornamental nursery stock production.
The relevance of spatial scales in nutrient balances on dairy farms
Leeuwen, M.W.J. van; Middelaar, C.E. van; Oenema, J. ; Dam, J.C. van; Stoorvogel, J.J. ; Stoof, C.R. ; Boer, I.J.M. de - \ 2019
Agriculture, Ecosystems and Environment 269 (2019). - ISSN 0167-8809 - p. 125 - 139.
Policy makers and farmers use tools, such as a nutrient balance, to gain insight into the environmental impact of agricultural practices. A discrepancy, however, exists between the needs of policy makers and farmers, about the use and the spatial scale of such tools. Farm balances calculate nutrient balances across all agricultural fields within a farm without distinguishing separate fields, whereas field balances calculate a nutrient balance on a delineated field. For farmers, a nutrient balance at field level is more useful than at crop or farm level, because decision making and fine-tuning management occurs at the field level. A field balance, however, requires more detailed data than a farm balance and therefore is less easy to implement. As soil types influence nutrient balances, we hypothesize that if within-farm variation in soil types is low, there is no need to replace a farm balance by a field balance. To test this hypothesis, we computed nutrient balances at farm and field level on five Dutch dairy farms (three on sand, two on clay), varying in degree of within-farm variation in soil series. A full year of soil nitrogen (N) and phosphorus (P) input and output data on farm and field level were provided by farmers, while soil variation was determined using the Dutch 1:50.000 soil map. The Annual farm Nutrient Cycle Assessment (ANCA) was used to calculate soil N and P surpluses, and soil nutrient fluxes such as nitrate leaching and nitrous oxide emission at farm and field level. Even on farms with few soil series, a considerable variation in N and P inputs, outputs and balances across fields was found, due to management differences and soil properties not represented by the soil map. Furthermore, field-level balances better represented nitrogen leaching than farm-level balances on farms with diverse soils (reflected by different leaching factors) and negative nitrogen field balances (deficits). Also, using field balances, for one case study farm the highest soil N surplus (kg ha−1) was found on grass fields with the highest risk of N leaching. A field balance, therefore, provides more meaningful information than a farm balance when variation in soil types and/or management factors is found within the farm, because soil types and management factors affect N and P balances, N leaching and N emissions. For farms with the highest variation in soil types and/or management, we recommend using field-level nutrient balances in order to detect extreme surpluses, deficits, leaching and/or emissions, to improve management decisions.

Towards globally customizable ecosystem service models
Martínez-López, Javier ; Bagstad, Kenneth J. ; Balbi, Stefano ; Magrach, Ainhoa ; Voigt, Brian ; Athanasiadis, Ioannis ; Pascual, Marta ; Willcock, Simon ; Villa, Ferdinando - \ 2019
Science of the Total Environment 650 (2019)2. - ISSN 0048-9697 - p. 2325 - 2336.
ARIES - Cloud-based modelling - Context-aware modelling - decision making - semantic modelling - spatial multi-criteria analysis
Scientists, stakeholders and decision makers face trade-offs between adopting simple or complex approaches when modeling ecosystem services (ES). Complex approaches may be time- and data-intensive, making them more challenging to implement and difficult to scale, but can produce more accurate and locally specific results. In contrast, simple approaches allow for faster assessments but may sacrifice accuracy and credibility. The ARtificial Intelligence for Ecosystem Services (ARIES) modeling platform has endeavored to provide a spectrum of simple to complex ES models that are readily accessible to a broad range of users. In this paper, we describe a series of five “Tier 1” ES models that users can run anywhere in the world with no user input, while offering the option to easily customize models with context-specific data and parameters. This approach enables rapid ES quantification, as models are automatically adapted to the application context. We provide examples of customized ES assessments at three locations on different continents and demonstrate the use of ARIES' spatial multi-criteria analysis module, which enables spatial prioritization of ES for different beneficiary groups. The models described here use publicly available global- and continental-scale data as defaults. Advanced users can modify data input requirements, model parameters or entire model structures to capitalize on high-resolution data and context-specific model formulations. Data and methods contributed by the research community become part of a growing knowledge base, enabling faster and better ES assessment for users worldwide. By engaging with the ES modeling community to further develop and customize these models based on user needs, spatiotemporal contexts, and scale(s) of analysis, we aim to cover the full arc from simple to complex assessments, minimizing the additional cost to the user when increased complexity and accuracy are needed.
Spatial variation of carbon and nutrients stocks in Amazonian Dark Earth
Brazao Vieira Alho, C.F. ; Samuel Rosa, A. ; Coimbra Martins, Gilvan ; Hiemstra, T. ; Kuijper, T.W.M. ; Teixeira, Wenceslau G. - \ 2019
Geoderma 337 (2019). - ISSN 0016-7061 - p. 322 - 332.
Amazonian Dark Earths (ADE) are anthropic soils that are enriched in carbon (C) and several nutrients, particularly calcium (Ca) and phosphorus (P), when compared to adjacent soils from the Amazon basin. Studies on ADE empower the understanding of complex pre-Columbian cultural development in the Amazon and may also provide insights for future sustainable agricultural practices in the tropics. ADE are highly variable in size, depth and soil physico-chemical characteristics. Nonetheless, the differentiation between ADE and the adjacent soils is not standardized and is commonly done based on visual field observations. In this regard, the pretic horizon has been recently proposed as an attempt to classify ADE systematically. Spatial modelling techniques can be of great use to study the structure of the spatial variation of soil properties in highly variable areas. Here, we predicted the carbon and nutrients stocks in ADE by applying spatial modelling techniques using an environmental covariate (i.e. expected anthropic enrichment gradient) in our model. In addition, we used the pretic horizon criteria to classify pretic and non-pretic areas and evaluate their relative contribution to the total stocks. In this study, we collected soil samples from five 20-cm soil layers at n = 53 georeferenced points placed in a grid of about 10 to 60 m spacing in a study area located in Central Amazon (~9.4 ha). Ceramic fragments were weighed and quantified. Samples were analysed for: Total C, Total Ca, Total P, Exchangeable Ca + Mg, Extractable P, soil pH, potential CEC (pH = 7.0) and the clay content. The use of the pretic horizon criteria allowed us to clearly distinguish two unambiguous areas with a sharp transition, rather than a smooth continuum, in contrast to previous studies in ADE. Depth- and profile-wise linear regression model parameters indicated a greater importance of the chosen environmental covariate (i.e. expected anthropic enrichment gradient) to explain the spatial variation of Total Ca and Total P stocks than Total C stocks. The overall Total Ca and Total P stocks were twice as large in the pretic area when compared to the non-pretic area.
Exploring optimal catch crops for reducing nitrate leaching in vegetable greenhouse in North China
Zhang, Hongyuan ; Hu, Kelin ; Zhang, Lijuan ; Ji, Yanzhi ; Qin, Wei - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 273 - 282.
Catch crop - Greenhouse vegetable field - N uptake - Nitrate leaching - Soil-crop system model

Chinese intensive greenhouse vegetable systems are characterized by high input of water and nutrients, which are not sustainable. There is an urgent need to explore smart and practical strategies to convert the “high input-low output” systems to “optimal input-output” ones. This study aimed to evaluate the effects of different catch crops on reducing nitrate leaching in the vegetable greenhouse during the summer fallow season. A two-year field experiment with three catch crops, i.e., sweet corn (SC), amaranth (A) and sweet sorghum (SG), and no catch crop (CK) were conducted in vegetable greenhouse in Dingzhou city, Hebei province, China. The measured soil water content and inorganic nitrogen (N) content in soil profile, biomass and crop N uptake were used to validate the WHCNS (Soil Water Heat Carbon Nitrogen Simulator) model, soil water movement and nitrate leaching were simulated. The results showed that the catch crops decreased the water drainage by 18.2–29.0% and nitrate leaching by 23.3–42.3% respectively, compared with CK. The water drainage reduction ranked as SC > SG > A, while the nitrate leaching reduction was A > SC > SG. The biomass was SC > SG > A, while the crop N uptake was SC > A > SG. Sweet corn could absorb the residual nitrate in the deep soil layers due to the long root system, while amaranth could absorb most residual nitrate in the surface soil. Amaranth showed greater N-uptake capacity than sweet corn, and the nitrate was mainly accumulated in the surface soil. Planting amaranth as summer catch crop reduced nitrate leaching in the vegetable greenhouses. Our study provides a guideline for selecting effective catch crops in intensive vegetable greenhouses in North China.

Quantitative proteomics reveals the crucial role of YbgC for Salmonella enterica serovar Enteritidis survival in egg white
Qin, Xiaojie ; He, Shoukui ; Zhou, Xiujuan ; Cheng, Xu ; Huang, Xiaozhen ; Wang, Yanyan ; Wang, Siyun ; Cui, Yan ; Shi, Chunlei ; Shi, Xianming - \ 2019
International Journal of Food Microbiology 289 (2019). - ISSN 0168-1605 - p. 115 - 126.
Chicken egg white - iTRAQ - Salmonella - Survival mechanisms - YbgC

Salmonella enterica serovar Enteritidis (S. Enteritidis) is a food-borne bacterial pathogen that can cause human salmonellosis predominately by contamination of eggs and egg products. However, its survival mechanisms in egg white are not fully understood, especially from a proteomic point of view. In this study, the proteomic profiles of S. Enteritidis in Luria-Bertani (LB) broth containing 50% and 80% egg white, and in whole egg white were compared with the profile in LB broth using iTRAQ technology to identify key proteins that were involved in S. Enteritidis survival in egg white. It was found that there were 303, 284 and 273 differentially expressed proteins in S. Enteritidis after 6 h exposure to whole, 80% and 50% egg white, respectively. Most of up-regulated proteins were primarily associated with iron acquisition, cofactor and amino acid biosynthesis, transporter, regulation and stress responses, whereas down-regulated proteins were mainly involved in energy metabolism, virulence as well as motility and chemotaxis. Three stress response-related proteins (YbgC, TolQ, TolA) of the tol-pal system responsible for maintaining cell membrane stability of Gram-negative bacteria were up-regulated in S. Enteritidis in response to whole egg white. Interestingly, deletion of ybgC resulted in a decreased resistance of S. Enteritidis to egg white. Compared with the wild type and complementary strains, a 3-log population reduction was observed in △ybgC mutant strain after incubation in whole egg white for 24 h. Cellular morphology of △ybgC mutant strain was altered from rods to spheres along with cell lysis in whole egg white. Furthermore, deletion of ybgC decreased the expression of tol-pal system-related genes (tolR, tolA). Collectively, these proteomic and mutagenic analysis reveal that YbgC is essential for S. Enteritidis survival in egg white.

Self-assembly of ellipsoidal particles at fluid-fluid interfaces with an empirical pair potential
Luo, Alan M. ; Vermant, Jan ; Ilg, Patrick ; Zhang, Zhenkun ; Sagis, Leonard M.C. - \ 2019
Journal of Colloid and Interface Science 534 (2019). - ISSN 0021-9797 - p. 205 - 214.
Capillary interactions - Ellipsoidal particles - Empirical pair potential - Fluid-fluid interfaces - Self-assembly

Colloidal particles adsorbed at fluid-fluid interfaces interact via mechanisms that can be specific to the presence of interfaces, for instance, lateral capillary interactions induced by nonspherical particles. Capillary interactions are highly relevant for self-assembly and the formation of surface microstructures, however, these are very challenging to model due to the multibody nature of capillary interactions. This work pursues a direct comparison between our computational modelling approach and experimental results on surface microstructures formed by ellipsoidal particles. We begin by investigating the accuracy of using pairwise interactions to describe the multibody capillary interaction by contrasting exact two- and three-particle interaction energies and we find that the pairwise approximation appears reasonable for the experimentally relevant configurations studied. We then develop an empirical pair potential and use it in Monte-Carlo type simulations to efficiently model the structure formation process for relevant particle properties such as aspect ratio, contact angle and surface coverage, and succeed in reproducing our experimental observations where we spread sterically-stabilised ellipsoidal particles onto an oil-air interface at high surface coverage. At lower surface coverages, we find that the self-assembly process falls into the diffusion-limited colloid aggregation universality class.

The effects of carbon dioxide on growth performance, welfare, and health of Atlantic salmon post-smolt (Salmo salar) in recirculating aquaculture systems
Mota, Vasco C. ; Nilsen, Tom Ole ; Gerwins, Jascha ; Gallo, Michele ; Ytteborg, Elisabeth ; Baeverfjord, Grete ; Kolarevic, Jelena ; Summerfelt, Steven T. ; Terjesen, Bendik Fyhn - \ 2019
Aquaculture 498 (2019). - ISSN 0044-8486 - p. 578 - 586.
Closed systems - CO - Hypercapnia - RAS - Salmonids

High carbon dioxide (CO2) concentrations negatively impact fish, which makes data on its tolerance especially relevant for production systems that can accumulate CO2 such as recirculating aquaculture system (RAS). The current study evaluates the effect of CO2 on the growth performance, welfare, and health of Atlantic salmon post-smolts in RAS. This study consisted of two phases. The first was a CO2 exposure phase, where eighteen tanks were used with six treatments in triplicate: 5, 12, 19, 26, 33 and 40 mg/L of CO2 during 12 weeks in a 12 ppt salinity RAS (hereafter RAS phase). In the second phase, PIT-tagged fish were transferred to a 34 ppt salinity single flow-through tank at CO2 < 5 mg/L (hereafter seawater phase) for an additional 6-week experimental period mimicking a seawater phase. Overall, mortality of fish exposed to CO2 was low and not related to treatments. The mean final body weight was significantly higher in the 5 mg/L treatment compared to CO2 treatments ≥12 mg/L at the end of RAS phase and to CO2 treatments ≥33 mg/L at the end of seawater phase. Moreover, regressions showed that growth significantly decreased linearly with increasing CO2 in the water. Eye cataracts and visible external damage on skin, operculum, and fins were inexistent and similar among CO2 treatments. Kidneys showed no signs of mineral deposits in any of the structures of the tissue. However, skin analysis showed that fish exposed to high CO2 concentrations had a significantly thinner dermis layer (both at the end of RAS and seawater phase) and a significantly thinner epidermis layer and lower mucus cells count (at the end of seawater phase). In conclusion, Atlantic salmon post-smolts cultured in brackish water RAS showed a maximum growth performance at CO2 concentrations below 12 mg/L. Except skin, no major effects of health and welfare were observed, including cataracts and nephrocalcinosis. Further studies should evaluate the molecular and physiological responses to both short-term and long-term carbon dioxide exposure.

Hatching failure and accumulation of organic pollutants through the terrestrial food web of a declining songbird in Western Europe
Oosten, H.H. van; Burg, Arnold B. van den; Arlt, Debora ; Both, Christiaan ; Brink, Nico W. van den; Chiu, Suzanne ; Crump, Doug ; Jeppsson, Tobias ; Kroon, Hans de; Traag, Wim ; Siepel, Henk - \ 2019
Science of the Total Environment 650 (2019). - ISSN 0048-9697 - p. 1547 - 1553.
Dioxin - DLC - Embryo - Inbreeding - Malformation - Passerine

Population growth in passerine birds is largely driven by fecundity. If fecundity is affected, for instance by hatching failure, populations may decline. We noted high hatching failure of up to 27% per year in relict populations of the Northern wheatear (Oenanthe oenanthe) in The Netherlands, a strongly declining, migratory passerine in Europe. This hatching failure itself can cause population decline, irrespective of other adverse factors. Additionally, we investigated the cause of hatching failure. Unhatched eggs showed egg yolk infections or embryonic malformations, part of which is associated with the actions of dioxin-like compounds (DLCs). Indeed, DLCs appear to bioaccumulate in the local foodweb, where the soil contained only background concentrations, similar to those found at many other locations. DLC concentrations in Dutch eggs were six-fold higher than those in a reference population in Sweden, where egg failure was only 6%. However, Northern wheatears appear to be only moderately sensitive to the actions of DLCs, because of their specific Ah-receptor type which may moderate the receptor mediated effects of DLCs. This indicates that the concentrations of DLCs, although elevated, may not have caused the embryo malformations or the low hatching rates. We discuss whether other toxins may be important or imbalances in the nutrition and if inbreeding may play a larger role than expected.

Influence of synthesis method on molybdenum carbide crystal structure and catalytic performance in stearic acid hydrodeoxygenation
Souza Macedo, Luana ; Oliveira, Ricardo R. ; Haasterecht, Tomas van; Teixeira da Silva, Victor ; Bitter, Harry - \ 2019
Applied Catalysis B-Environmental 241 (2019). - ISSN 0926-3373 - p. 81 - 88.
Crystal structure - Hydrodeoxygenation - Molybdenum carbide - Site density - Synthesis method

The role of the synthesis method of molybdenum carbide nanoparticle catalysts supported on carbon nanofibers on crystal structure and on catalytic performance in hydrodeoxygenation of stearic acid was investigated. We obtained the cubic phase of molybdenum carbide (α-MoC1-x) by impregnating carbon nanofibers with a solution of (NH4)2MoO4, then exposing them to 20% CH4/H2 at 650 °C for 2 h. When increasing the Mo loading from 7.5 wt% to 20 wt% or using the carbothermal reduction method, i.e. using carbon from the support to reduce the (NH4)2MoO4 precursor at 800 °C for 6 h, the hexagonal phase (β-Mo2C) resulted. Experiments with stearic acid hydrodeoxygenation showed that both phases (7.5 wt% Mo) displayed similar intrinsic activities. However, α-MoC1-x/CNF reached 80% stearic acid conversion after 240 min while the β-Mo2C/CNF catalyst attained the same conversion after 360 min. CO chemisorption results showed that α-MoC1-x/CNF and β-Mo2C/CNF have a similar number of potential active sites (66 and 56 μmol g−1, respectively). We attribute the difference in catalytic performance between α-MoC1-x/CNF and β-Mo2C/CNF to differences in the catalyst's crystal structure, more specifically, the associated site density. The face-centered cubic α-MoC1-x/CNF has a lower site density (0.1096 Mo atoms Ų) than the hexagonal close-packed β-Mo2C/CNF (0.1402 Mo atoms Ų), making the Mo atoms at the surface of the α-MoC1-x phase more accessible for large reactant molecules such as stearic acid thus allowing its convertion in shorter times.

Agricultural nitrogen and phosphorus emissions to water and their mitigation options in the Haihe Basin, China
Zhao, Zhanqing ; Qin, Wei ; Bai, Zhaohai ; Ma, Lin - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 262 - 272.
Crop-livestock system - Haihe Basin - Nitrogen - NUFER - Phosphorus - Water pollution

Agricultural nitrogen (N) and phosphorus (P) emissions to water bodies remain largely unknown in China, mainly due to the lack of reliable data sources and quantification tools. In this study, we constructed a grid-based NUFER (NUtrient Flow in food chains, Environment and Resources use) model in order to quantify a high-resolution agricultural N and P emissions to water bodies in Haihe Basin in 2012, based on data collected from county-level statistics, farm interview, and spatial data of topography, climate, soil texture, and land use. We also explored the mitigation strategies in 2030 via scenario analysis. The results showed that total agricultural N emission to water bodies in Haihe Basin was 1079 Gg N in 2012, of which cropland contributed 54%; total agricultural P emission to water bodies was 208 Gg P, livestock contributed 78%. There were large spatial variations in agricultural N and P emissions. Overall, the plain areas accounted for around 80% of the total agricultural N and P emissions to water in 2012. The highest N and P emission intensities were 10 t N km−2 and 2 t P km−2, respectively. N and P emissions were significantly related to anthropogenic factors (such as the livestock density and cropland) in the plain areas; whereas in mountainous areas, both anthropogenic and natural factors (e.g., slope deviation and soil texture) significantly affected N and P emissions. Our scenario analysis suggests that agricultural N and P emissions can be reduced by up to 45% and 77%, respectively for N and P in 2030, via improved agricultural and environmental policies, technologies and managements. The prohibition of direct animal manure discharge to the water system seems to be the most effective measure to mitigate the emissions. Our study provided a high-resolution agricultural N and P emissions to the water bodies of Haihe Basin and identified the most effective options to reduce these emissions in highly intensified agricultural areas.

Research idea to science for impact : Tracing the significant moments in an innovation based irrigation study
Srinivasan, M.S. ; Jongmans, C. ; Bewsell, D. ; Elley, G. - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 181 - 192.
Co-innovation - Co-learning - Irrigation - Stakeholder management - Weather forecast

Uptake of irrigation scheduling tools by New Zealand (NZ) farmers has remained static for many years and some researchers consider the use of linear, tech-transfer approaches as the main reason for this. To understand the controls and drivers that influence the uptake of these tools and to evaluate the effectiveness of a co-innovation approach in improving their (tools) uptake, a team of biophysical (hydrologists) and social researchers undertook a pilot study in an irrigation scheme in the South Island of NZ. Co-innovation offers a multi-directional, multi-level, multi-actor approach, in which input from stakeholders is valued in every part of the process, from problem definition to solution adoption. In this study, we focused on the adaptive aspect of co-innovation that allows stakeholders to periodically review their actions and respond to it in a way that is inclusive others’ views and reflective of feedback received. The pilot study activities were analysed retrospectively to develop a systemic view to the implementation of a co-innovation-based multi-stakeholder hydrology project. While implementing a co-innovation approach, five chronologically-distinct yet overlapping phases emerged in the project: 1. concept development, where the hydrologists came up with the research idea and seed concept; 2. trust building, where researchers (hydrologists and social) interacted with key on-farm stakeholders in developing and implementing the research idea into a pilot field study; 3. knowledge synthesis, where researchers collected on-farm biophysical and behavioural data to record practice change; 4. extended outreach, where stakeholders, including researchers, devised pathways to sustain the lessons learned and practices changed, and disseminated the learnings to the wider irrigation community; and 5. project legacy, where the researchers, after the development of the seed concept into a practice change, evolved an exit strategy. Apart from core research activities, such as data collection on irrigation water use and changes in irrigation scheduling practices, each one of the five phases included actions that were unique to that phase as well as to achieving the wider pilot study goal of improving water use efficiency. This paper discusses the learnings from these phases, including insights, and key identifiers and indicators of pilot study progression during each phase, which may serve as an example to other biophysical studies that propose to employ co-innovation-based multi stakeholder approach.

An accurate evaluation of water availability in sub-arid Mediterranean watersheds through SWAT : Cega-Eresma-Adaja
Rivas-Tabares, David ; Tarquis, Ana M. ; Willaarts, Bárbara ; Miguel, Ángel De - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 211 - 225.
Land use - Modelling - Semi-arid regions - Streamflow - SWAT

Simulation of flow processes in hyper-regulated Mediterranean watersheds is critical when examining general water demand and established ecological flows of River Basin Management Plans. Weather dynamics in the Mediterranean zone in recent decades have been characterised by a natural variation of drought cycles. In addition, exacerbated climate change proves that water fluxes must be estimated with more exhaustive models. The aim of this study is to assess the water balance of the Cega-Eresma-Adaja (CEA) watershed, including a detailed assessment of land uses and management practices to quantify agricultural water demand for the time period 2004–2014. We used the Soil and Water Assessment Tool (SWAT), given that it is a widespread tool that involves complex processes of the water cycle on a basin scale, providing information on water dynamics related to land use as a fundamental characteristic for water balance calculation. The Nash-Sutcliffe coefficient efficiency value, the main index of calibration and validation performance, was 0.86 for the Eresma-Adaja River and 0.67 for the Cega River. This presents a good result considering the large-scale watershed studied. Analysing dry hydrological years, we found that the estimation of ecological flows for sub-arid zones needs to consider the shallow aquifer-river relationship. During spring-summer periods, with very low flow, monitoring the shallow aquifer levels ensures a good ecological status. The study reveals that aspects such as crop rotation, soil management and their associated measures in Mediterranean basins are key factors for water resource management during drought periods. These results are expected to serve stakeholders and river basin authorities in conducting better-integrated water management practices in the watershed.

Mapping topsoil organic carbon concentrations and stocks for Tanzania
Kempen, Bas ; Dalsgaard, Soren ; Kaaya, Abel K. ; Chamuya, Nurdin ; Ruiperez Gonzalez, Maria ; Pekkarinen, Anssi ; Walsh, Markus G. - \ 2019
Geoderma 337 (2019). - ISSN 0016-7061 - p. 164 - 180.
Tanzania is one of the countries that has embarked on a national programme under the United Nations collaborative initiative on Reducing Emissions from Deforestation and forest Degradation (REDD). Tanzania is currently developing the capacity to enter into a carbon monitoring REDD+ regime. In this context spatially representative soil carbon datasets and accurate predictive maps are important for determining the soil organic carbon pool. The main objective of this study was to model and map the SOC stock for the 0–30-cm soil layer to provide baseline information for REDD+ purposes. Topsoil data of over 1400 locations spread throughout Tanzania from the National Forest Monitoring and Assessment (NAFORMA), were used, supplemented by two legacy datasets, to calibrate simple kriging with varying local means models. Maps of SOC concentrations (g kg−1) were generated for the 0–10-cm, 10–20-cm, 20–30-cm, 0–30-cm layers, and maps of bulk density and SOC stock (kg m−2) for the 0–30-cm layer. Two approaches for modelling SOC stocks were considered here: the calculate-then-model (CTM) approach and the model-then-calculate approach (MTC). The spatial predictions were validated by means of 10-fold cross-validation. Uncertainty associated to the estimated SOC stocks was quantified through conditional Gaussian simulation. Estimates of SOC stocks for the main land cover classes are provided. Environmental covariates related to soil and terrain proved to be the strongest predictors for all properties modelled. The mean predicted SOC stock for the 0–30-cm layer was 4.1 kg m−2 (CTM approach) translating to a total national stock of 3.6 Pg. The MTC approach gave similar results. The largest stocks are found in forest and grassland ecosystems, while woodlands and bushlands contain two thirds of the total SOC stock. The root mean squared error for the 0–30-cm layer was 1.8 kg m−2, and the R2-value was 0.51. The R2-value of SOC concentration for the 0–30-cm layer was 0.60 and that of bulk density 0.56. The R2-values of the predicted SOC concentrations for the 10-cm layers vary between 0.46 and 0.54. The 95% confidence interval of the predicted average SOC stock is 4.01–4.15 kg m−2, and that of the national total SOC stock 3.54–3.65 Pg. Uncertainty associated with SOC concentration had the largest contribution to SOC stock uncertainty. These findings have relevance for the ongoing REDD+ readiness process in Tanzania by supplementing the previous knowledge of significant carbon pools. The soil organic carbon pool makes up a relatively large proportion of carbon in Tanzania and is therefore an important carbon pool to consider alongside the ones related to the woody biomass. Going forward, the soil organic carbon data can potentially be used in the determination of reference emission levels and the future monitoring, reporting and verification of organic carbon pools.
Predicting soil microplastic concentration using vis-NIR spectroscopy
Corradini, Fabio ; Bartholomeus, Harm ; Huerta Lwanga, Esperanza ; Gertsen, Hennie ; Geissen, Violette - \ 2019
Science of the Total Environment 650 (2019). - ISSN 0048-9697 - p. 922 - 932.
Microplastics - Near-infrared spectroscopy - Soil pollution - Spectroradiometer - Vis-NIR

Microplastic accumulation in soil may have a detrimental impact on soil biota. The lack of standardized methods to identify and quantify microplastics in soils is an obstacle to research. Existing techniques are time-consuming and field data are seldom collected. To tackle the problem, we explored the possibilities of using a portable spectroradiometer working in the near infrared range (350–2500 nm) to rapidly assess microplastic concentrations in soils without extraction. Four sets of artificially polluted soil samples were prepared. Three sets had only one polymer polluting the soil (low-density polyethylene (LDPE), polyethylene terephthalate (PET), or polyvinyl chloride (PVC)). The fourth set contained random amounts of the three polymers (Mix). The concentrations of microplastics were regressed on the reflectance observed for each of the 2150 wavelengths registered by the instrument, using a Bayesian approach. For a measurement range between 1 and 100 g kg−1, results showed a root-mean-squared-deviation (RMSD) of 8, 18, and 10 g kg−1 for LDPE, PET, and PVC. The Mix treatment presented an RMSD of 8, 10, and 5 g kg−1 for LDPE, PET, and PVC. The repeatability of the proposed method was 0.2–8.4, 0.1–5.1, and 0.1–9.0 g kg−1 for LDPE, PET, and PVC, respectively. Overall, our results suggest that vis-NIR techniques are suitable to identify and quantify LDPE, PET, and PVC microplastics in soil samples, with a 10 g kg−1 accuracy and a detection limit ≈ 15 g kg−1. The method proposed is different than other approaches since it is faster because it avoids extraction steps and can directly quantify the amount of plastic in a sample. Nevertheless, it seems to be useful only for pollution hotspots.

Applicability of the poultry qPCR method to detect DNA of poultry processed animal protein materials
Scholtens, Ingrid M.J. ; Prins, Theo W. ; Margry, Rob J.C.F. ; Dahlmans, Harald ; Raamsdonk, Leo W.D. van - \ 2019
Food Control 96 (2019). - ISSN 0956-7135 - p. 53 - 58.
Bovine spongiform encephalopathy (BSE) - Chicken - Duck - Feed - Geese - Poultry - Processed animal proteins (PAPs) - Sensitivity - Species-to-species ban - Transmissible spongiform encephalopathy (TSE) - Turkey

After the Bovine Spongiform Encephalitis (BSE) crisis most processed animal proteins (PAPs) were banned from use in animal feed. For the foreseen reintroduction of pork PAPs in poultry feed, and poultry PAPs in pork feed and to comply with the species-to-species ban that prohibits cannibalism, a sensitive and specific TaqMan PCR detection method for poultry DNA has been designed and published. This poultry method is able to detect DNA of chicken, turkey, duck and geese in one PCR reaction. PAPs however, are a difficult and variable matrix. Therefore, the usability of the poultry method was investigated on a range of different poultry PAPs. It was shown that the poultry detection method is capable of detecting poultry DNA in eight out of nine different poultry PAPs mixed at a 0.1% level in chicken feed. The method can also detect at least 0.1% poultry PAPs mixed in pork PAPs. These results show that the poultry method fulfils the 0.1% detection limit requirement in the EU legislation.

Visual modeling of laser-induced dough browning
Chen, Peter Yichen ; Blutinger, Jonathan David ; Meijers, Yorán ; Zheng, Changxi ; Grinspun, Eitan ; Lipson, Hod - \ 2019
Journal of Food Engineering 243 (2019). - ISSN 0260-8774 - p. 9 - 21.
Browning - Deconvolution - Deep learning - Dough - Generative model - Infrared laser

A data-driven model that predicatively generates photorealistic RGB images of dough surface browning is proposed. This model was validated in a practical application using a CO2 laser dough browning pipeline, thus confirming that it can be employed to characterize visual appearance of browned samples, such as surface color and patterns. A supervised deep generative network takes laser speed, laser energy flux, and dough moisture as an input and outputs an image (of 64×64 pixel size) of laser-browned dough. Image generation is achieved by nonlinearly interpolating high-dimensional training data. The proposed prediction framework contributes to the development of computer-aided design (CAD) software for food processing techniques by creating more accurate photorealistic models.

Plastic film cover during the fallow season preceding sowing increases yield and water use efficiency of rain-fed spring maize in a semi-arid climate
Zhang, Zhe ; Zhang, Yanqing ; Sun, Zhanxiang ; Zheng, Jiaming ; Liu, Enke ; Feng, Liangshan ; Feng, Chen ; Si, Pengfei ; Bai, Wei ; Cai, Qian ; Yang, Ning ; Werf, Wopke van der; Zhang, Lizhen - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 203 - 210.
Film cover - Soil temperature - Water availability - Yield components

Plastic film mulch increases crop yields in rain-fed agriculture in cool semi-arid climates by warming the soil and reducing evaporative water losses. The semi-arid Khorchin area in Northeast China is an important production area for rain-fed maize. Drought stress occurs frequently, even if plastic film mulch is applied at sowing. We hypothesized that the yield and water capture of maize could be increased by reducing evaporative loss of water by use of plastic film cover during the autumn and winter preceding sowing. In this study, we compared maize growth, water uptake and yield in three film cover treatments: (1) film cover from the autumn before maize sowing until maize harvest (autumn mulching: AM), (2) film cover from maize sowing till harvest (conventional practice) (spring mulching: SM), (3) no film cover (no mulch: NM). Field experiments were conducted in Fuxin city, Khorchin region, Liaoning province, China in 2013/2014 and 2014/2015. Autumn mulching increased grain yield on average by 18% when compared to spring mulching and by 36% when compared to no mulching. The 1000-kernel weight in AM was 7% higher than in SM, and 12% higher than in NM. Soil water content in the root zone before sowing was 35 mm greater in AM than in SM and NM. Water uptake during the growing season was 34 mm greater in AM than in SM and NM. Water use efficiency for grain yield (yield per unit water uptake) in AM was on average 2.5% higher than in conventional mulching (SM) and 27% higher than in NM. Autumn mulching advanced development, with an advance of 5 days in tasseling time as compared to SM and 10 days when compared to NM. These results show that film cover during the fallow period before maize sowing can increase crop yield and water use efficiency, and reduce climate risks in rain-fed agriculture under semi-arid conditions.

When food systems meet sustainability – Current narratives and implications for actions
Béné, Christophe ; Oosterveer, Peter ; Lamotte, Lea ; Brouwer, Inge D. ; Haan, Stef de; Prager, Steve D. ; Talsma, Elise F. ; Khoury, Colin K. - \ 2019
World Development 113 (2019). - ISSN 0305-750X - p. 116 - 130.
Discourse analysis - Food security and nutrition - Food systems - Healthy diet - Sustainability

The concept of food system has gained prominence in recent years amongst both scholars and policy-makers. Experts from diverse disciplines and backgrounds have in particular discussed the nature and origin of the “unsustainability” of our modern food systems. These efforts tend, however, to be framed within distinctive disciplinary narratives. In this paper we propose to explore these narratives and to shed light on the explicit -or implicit- epistemological assumptions, mental models, and disciplinary paradigms that underpin those. The analysis indicates that different views and interpretations prevail amongst experts about the nature of the “crisis”, and consequently about the research and priorities needed to “fix” the problem. We then explore how sustainability is included in these different narratives and the link to the question of healthy diets. The analysis reveals that the concept of sustainability, although widely used by all the different communities of practice, remains poorly defined, and applied in different ways and usually based on a relatively narrow interpretation. In so doing we argue that current attempts to equate or subsume healthy diets within sustainability in the context of food system may be misleading and need to be challenged. We stress that trade-offs between different dimensions of food system sustainability are unavoidable and need to be navigated in an explicit manner when developing or implementing sustainable food system initiatives. Building on this overall analysis, a framework structured around several entry points including outcomes, core activities, trade-offs and feedbacks is then proposed, which allows to identify key elements necessary to support the transition toward sustainable food systems.

Modeling nutrients in Lake Dianchi (China) and its watershed
Li, Xiaolin ; Janssen, Annette B.G. ; Klein, Jeroen J.M. de; Kroeze, Carolien ; Strokal, Maryna ; Ma, Lin ; Zheng, Yi - \ 2019
Agricultural Water Management 212 (2019). - ISSN 0378-3774 - p. 48 - 59.
Critical loading - MARINA nutrient model - Mining - PCLake ecosystem model - River export of nutrients

Lake Dianchi suffered from severe eutrophication for decades. Past efforts to reduce the eutrophication were not very effective. The objective of this study is to improve our understanding of nitrogen (N) and phosphorus (P) loadings and to analyze to what extent they exceed critical nutrient loadings of Lake Dianchi. To this end, we applied the nutrient MARINA model and the ecosystem model PCLake. Results show that river export of dissolved N and P was high in 2012. About 6 209 ton of total dissolved N (TDN) was exported to the lake (i.e. 23.6 kg ha−1), of which more than two-thirds in the form of dissolved inorganic N. For total dissolved P, this export was about 413 ton (i.e. 1.6 kg ha−1), of which 75% dissolved inorganic P. Urban sewage is a major source of nutrients in rivers in the northern sub-basins. In southern sub-basins, agriculture is an important source of both N and P, while P mining and processing is a major source of dissolved inorganic P. Nutrient inputs to the lake are particularly high from urbanization sub-basins draining into the northern part of the lake (Caohai). Critical nutrient loadings for the northern part of the lake (Caohai) are 0.34 mg P m−2d−1 (3.06 mg N m−2d−1) and for the southern part (Waihai) 0.38 mg P m−2d−1 (3.42 mg N m−2d−1). Actual loadings exceed the critical nutrient loadings by 82 times and 17 times of Caohai and Waihai, respectively. Our study illustrates how linking MARINA with PCLake helped to quantify the causes of lake eutrophication and to identify critical loadings for N and P in the lake. Our study can assist local authorities to formulate management options to reduce nutrient pollution in Lake Dianchi in the future.

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.