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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Distributed Evaluation of Local Sensitivity Analysis (DELSA), with application to hydrological models
Rakovec, O. ; Hill, M.C. ; Clark, M.P. ; Weerts, A.H. ; Teuling, A.J. ; Uijlenhoet, R. - \ 2014
Water Resources Research 50 (2014)1. - ISSN 0043-1397 - p. 409 - 426.
measuring uncertainty importance - coupled reaction systems - groundwater-flow system - net ecosystem exchange - parameter-estimation - information-content - rate coefficients - climate-change - land model - indexes
1] This paper presents a hybrid local-global sensitivity analysis method termed the Distributed Evaluation of Local Sensitivity Analysis (DELSA), which is used here to identify important and unimportant parameters and evaluate how model parameter importance changes as parameter values change. DELSA uses derivative-based “local” methods to obtain the distribution of parameter sensitivity across the parameter space, which promotes consideration of sensitivity analysis results in the context of simulated dynamics. This work presents DELSA, discusses how it relates to existing methods, and uses two hydrologic test cases to compare its performance with the popular global, variance-based Sobol' method. The first test case is a simple nonlinear reservoir model with two parameters. The second test case involves five alternative “bucket-style” hydrologic models with up to 14 parameters applied to a medium-sized catchment (200 km2) in the Belgian Ardennes. Results show that in both examples, Sobol' and DELSA identify similar important and unimportant parameters, with DELSA enabling more detailed insight at much lower computational cost. For example, in the real-world problem the time delay in runoff is the most important parameter in all models, but DELSA shows that for about 20% of parameter sets it is not important at all and alternative mechanisms and parameters dominate. Moreover, the time delay was identified as important in regions producing poor model fits, whereas other parameters were identified as more important in regions of the parameter space producing better model fits. The ability to understand how parameter importance varies through parameter space is critical to inform decisions about, for example, additional data collection and model development. The ability to perform such analyses with modest computational requirements provides exciting opportunities to evaluate complicated models as well as many alternative models.
How climate seasonality modifies drought duration and deficit
Loon, A.F. van; Tijdeman, E. ; Wanders, N. ; Lanen, H.A.J. van; Teuling, A.J. ; Uijlenhoet, R. - \ 2014
Journal of Geophysical Research: Atmospheres 119 (2014)8. - ISSN 2169-897X - p. 4640 - 4656.
hydrological drought - low flows - catchment - reanalysis - indexes
Drought propagation through the terrestrial hydrological cycle is associated with a change in drought characteristics (duration and deficit), moving from precipitation via soil moisture to discharge. Here we investigate climate controls on drought propagation with a modeling experiment in 1271 virtual catchments that differ only in climate type. For these virtual catchments we studied the bivariate distribution of drought duration and standardized deficit for the variables precipitation, soil moisture, and discharge. We found that for meteorological drought (below-normal precipitation), the bivariate distributions of drought characteristics have a linear shape in all climates and are thus not affected by seasonality in climate. Despite the linear shape of meteorological drought, soil moisture drought (below-normal storage in the unsaturated zone) and hydrological drought (below-normal water availability in aquifers, lakes, and/or streams) show strongly nonlinear shapes in drought characteristics in climates with a pronounced seasonal cycle in precipitation and/or temperature. These seasonality effects on drought propagation are found in monsoonal, savannah, and Mediterranean climate zones. In these regions, both soil moisture and discharge show deviating shapes in drought characteristics. The effect of seasonality on drought propagation is even stronger in cold seasonal climates (i.e., at high latitudes and altitudes), where snow accumulation during winter prevents recovery from summer hydrological drought, and deficit increases strongly with duration. This has important implications for water resources management in seasonal climates, which cannot solely rely on meteorology-based indices as proxies for hydrological drought duration and deficit and need to include seasonal variation in both precipitation and temperature in hydrological drought forecasting.
Identifying the methodological characteristics of European green city rankings
Meijering, J.V. ; Kern, K. ; Tobi, H. - \ 2014
Ecological Indicators 43 (2014). - ISSN 1470-160X - p. 132 - 142.
quality-of-life - environmental sustainability - composite indicators - urban areas - construction - pitfalls - indexes
City rankings that aim to measure the environmental sustainability of European cities may contribute to the evaluation and development of environmental policy of European cities. The objective of this study is to identify and evaluate the methodological characteristics of these city rankings. First, a methodology was developed to systematically identify methodological characteristics of city rankings within different steps of the ranking development process. Second, six city rankings European Energy Award, European Green Capital Award, European Green City Index, European Soot-free City Ranking, RES Champions League, Urban Ecosystem Europe were examined. Official websites and any methodological documents found on those websites were content analyzed using the developed methodology. Interviews with representatives of the city rankings were conducted to acquire any additional information. Results showed that the city rankings varied greatly with respect to their methodological characteristics and that all city rankings had methodological weaknesses. Developers of city rankings are advised to use the methodology developed in this study to find methodological weaknesses and improve their ranking. In addition, developers ought to be more transparent about the methodological characteristics of their city rankings. End-users of city rankings are advised to use the developed methodology to identify and evaluate the methodological characteristics of city rankings before deciding to act on ranking results.
Impact of diet and individual variation on intestinal microbiota composition and fermentation products in obese men
Salonen, A. ; Lahti, L.M. ; Salojärvi, J. ; Holtrop, G. ; Korpela, K. ; Duncan, S.H. ; Date, P. ; Farquharson, F. ; Johnstone, A.M. ; Lobley, G.E. ; Louis, P. ; Flint, H.J. ; Vos, W.M. de - \ 2014
ISME Journal 8 (2014). - ISSN 1751-7362 - p. 2218 - 2230.
gut microbiota - phylogenetic microarray - resistant starch - metabolic syndrome - health - bifidobacteria - bacterial - capacity - indexes - adults
There is growing interest in understanding how diet affects the intestinal microbiota, including its possible associations with systemic diseases such as metabolic syndrome. Here we report a comprehensive and deep microbiota analysis of 14 obese males consuming fully controlled diets supplemented with resistant starch (RS) or non-starch polysaccharides (NSPs) and a weight-loss (WL) diet. We analyzed the composition, diversity and dynamics of the fecal microbiota on each dietary regime by phylogenetic microarray and quantitative PCR (qPCR) analysis. In addition, we analyzed fecal short chain fatty acids (SCFAs) as a proxy of colonic fermentation, and indices of insulin sensitivity from blood samples. The diet explained around 10% of the total variance in microbiota composition, which was substantially less than the inter-individual variance. Yet, each of the study diets induced clear and distinct changes in the microbiota. Multiple Ruminococcaceae phylotypes increased on the RS diet, whereas mostly Lachnospiraceae phylotypes increased on the NSP diet. Bifidobacteria decreased significantly on the WL diet. The RS diet decreased the diversity of the microbiota significantly. The total 16S ribosomal RNA gene signal estimated by qPCR correlated positively with the three major SCFAs, while the amount of propionate specifically correlated with the Bacteroidetes. The dietary responsiveness of the individual’s microbiota varied substantially and associated inversely with its diversity, suggesting that individuals can be stratified into responders and non-responders based on the features of their intestinal microbiota.
Effects of growth pattern and dietary protein level during rearing on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing and laying period
Emous, R.A. van; Kwakkel, R.P. ; Krimpen, M.M. van; Hendriks, W.H. - \ 2014
Applied Animal Behaviour Science 150 (2014)1. - ISSN 0168-1591 - p. 44 - 54.
food restriction - welfare assessment - improve - indexes - hunger - age - performance - parameters - allocation - chickens
An experiment was conducted to evaluate the effect of growth patterns (GP) and dietary crude protein levels (CP) during rearing (2–22 weeks of age) on feed intake, eating time, eating rate, behavior, plasma corticosterone concentration, and feather cover in broiler breeder females during the rearing and laying period. A total of 768 day-old Ross 308 broiler breeder chicks, of which 288 hens were followed during the laying period, were allotted to 6 different treatments during the rearing period according to a 2 × 3 factorial design, with 8 replicates (pens) per treatment. Two growth patterns were followed by a restricted feeding regime up to a target body weight (BW) at 20 weeks of age of 2200 g (standard growth pattern = SGP) and 2400 g (high growth pattern = HGP) and 3 dietary protein levels (high = CPh, medium = CPm, and low = CPl). During lay, all birds were fed a standard breeder diet and followed a standard growth pattern. During rearing, HGP birds were fed on average 6.5% more feed than SGP birds. In HGP birds, eating time (min/day) during the rearing period increased by 17%, whereas eating rate (g feed/min) decreased by 8%, compared to SGP birds. This prolonged feeding behavior of HGP birds, but stereotypic object pecking and animal pecking was not reduced. Feather cover was not affected by growth pattern during the rearing and laying period. Only at 16 weeks of age a lower plasma corticosterone concentration was found for the HGP birds. HGP birds showed more feeding and sitting behavior, but less foraging behavior during the rearing period, while during the laying period only more walking behavior was observed. In order to maintain target weights, feed intake levels of CPm and CPl during rearing were set 4.6 and 10.0% higher than CPh, whereas eating time was increased by 22 and 63% and eating rate was decreased by 9 and 26%, respectively. A prolonged eating time during rearing for CPm and CPl birds resulted in more time spend feeding and resting and less stereotypic object pecking and animal pecking compared to CPh birds during rearing. In contrast to the rearing period, feed intake and eating time were not affected by CP level during rearing at 22 weeks of age, whereas eating rate was increased by 8 and 16% for CPm and CPl, respectively, compared to CPh. At 27 weeks of age the effect of CP level during rearing on eating rate had disappeared. Plasma corticosterone concentrations were not affected by dietary protein level during the rearing and laying period. Feather cover was inferior by lowering the dietary protein level, in particularly during the first 11 weeks of rearing. No effect of GP was found on feather cover. It is concluded that dietary protein levels positively affected some behavioral traits during the rearing period, whereas these traits were only slightly affected by growth patterns. However, the physiological parameter (plasma corticosterone concentration) was not affected.
Spatial precipitation patterns and trends in The Netherlands during 1951–2009
Daniels, E.E. ; Lenderink, G. ; Hutjes, R.W.A. ; Holtslag, A.A.M. - \ 2014
International Journal of Climatology 34 (2014)6. - ISSN 0899-8418 - p. 1773 - 1784.
neerslag - klimaatverandering - statistische analyse - regionale verkenningen - seizoenen - nederland - precipitation - climatic change - statistical analysis - regional surveys - seasons - netherlands - coastal precipitation - urban land - europe - rainfall - temperatures - extremes - feedback - impacts - indexes - soils
Significant increases in precipitation have been observed in The Netherlands over the last century. At the same time persistent spatial variations are apparent. The objective of this study is to analyse and explain these spatial patterns, focussing on changes in means and extremes for the period 1951–2009. To investigate different possibilities for the causes of spatial variations, a distinction was made between six regions based on mean precipitation, soil type and elevation, and four zones at different distances to the coast. Spatial maxima in mean precipitation inland and over elevated areas are mainly formed in winter and spring, while maxima along the coast are generated in autumn. Daily precipitation maxima are found in the central West coast and over elevated areas. Upward trends in daily precipitation are highest from February to April and lowest from July to September. The strongest and most significant increases are found along the coast. For several seasonal and climatological periods diverging behaviour between coastal and inland zones is observed. We find that distance to the coast gives a more consistent picture for the seasonal precipitation changes than a classification based on surface characteristics. Therefore, from the investigated surface factors, we consider sea surface temperature to have the largest influence on precipitation in The Netherlands.
Ervaringen met kengetal en dagdoseringen in melkveehouderij
Kuipers, A. ; Wemmenhove, H. - \ 2013
Veehouder en Veearts 27 (2013)1. - p. 28 - 30.
melkveehouderij - antibiotica - dosering - indexen - registratie - dairy farming - antibiotics - dosage - indexes - registration
Afgelopen paar jaar is het aantal dagdoseringen als kengetal voor antibioticagebruik ingevoerd. Wat kun je daar nu mee? In dit artikel geven we impressies van enkele toepassingen.
Groeien in rendement : hulpmiddelen om rendabeler te groeien
Zijlstra, Jelle - \ 2013
dairy farming - farm management - milk production - investment - indexes - financial management
Normen en economische waarderingen voor: de rentabiliteitsindex 2012 en het productiegetal 2013 zeugenhouderij
Animal Sciences Group (ASG), - \ 2013
[Lelystad] : Livestock Research Wageningen UR - 6
varkenshouderij - zeugen - rentabiliteit - indexen - bedrijfsresultaten in de landbouw - normen - prestatieniveau - pig farming - sows - profitability - indexes - farm results - standards - performance
Wageningen UR Livestock Research berekent jaarlijks de waarderingsnormen voor de rentabiliteitsindex en het productiegetal voor de zeugenhouderij. Dit vindt plaats in opdracht van het Productschap Vee en Vlees (PVV). In het kort wordt beschreven wat de rentabiliteitsindex en het productiegetal voor de varkenshouder betekenen. Vervolgens worden in het kort de berekeningsmethode en de uitgangspunten voor de berekeningen van de waarderingsnormen uiteengezet. Met behulp van deze waarderingsnormen zijn de rentabiliteitsindex en het productiegetal per individueel bedrijf te berekenen.
Normen en economische waarderingen voor: de rentabiliteitsindex 2012 en het productiegetal 2013 vleesvarkenshouderi
Animal Sciences Group (ASG), - \ 2013
[Lelystad] : Livestock Research Wageningen UR - 6
varkenshouderij - vleesproductie - rentabiliteit - indexen - bedrijfsresultaten in de landbouw - normen - prestatieniveau - pig farming - meat production - profitability - indexes - farm results - standards - performance
Wageningen UR Livestock Research berekent jaarlijks de waarderingsnormen voor de rentabiliteitsindex en het productiegetal. Dit vindt plaats in opdracht van het Productschap Vee en Vlees (PVV). In het kort wordt beschreven wat de rentabiliteitsindex en het productiegetal voor de varkenshouder betekenen. Vervolgens worden in het kort de berekeningsmethode en de uitgangspunten voor de berekeningen van de waarderingsnormen uiteengezet. Met behulp van deze waarderingsnormen zijn de rentabiliteitsindex en het productiegetal per individueel bedrijf te berekenen.
Buffercapaciteit : bedrijfsstijlen in de melkveehouderij, volatiele markten en kengetallen
Oostindië, H.A. ; Ploeg, J.D. van der; Broekhuizen, R.E. van - \ 2013
Wageningen : Wageningen UR etc. - 50
melkveehouderij - melkprijzen - agrarische bedrijfsvoering - bedrijfssystemen - karakteristieken - veehouders - indexen - buffercapaciteit - dairy farming - milk prices - farm management - farming systems - characteristics - stockmen - indexes - buffering capacity
Dit rapport doet verslag van een statistische analyse uitgevoerd op een bestand van Nederlandse melkveehouderijbedrijven. Het doel van deze analyse was na te gaan wat de effecten waren van de melkprijsdaling, die zich voordeed in de tweede helft van 2008 en de eerste helft van 2009. De toenmalige prijsdaling beschouwen we als een voorbode van de situatie die steeds meer de zuivelmarkt zal typeren: een volatiele markt met scherpe prijswisselingen. Het onderzoek toont aan dat de effecten van een melkprijsdaling differentieel van aard zijn, ze variëren al naar gelang het type bedrijf. Om deze verschillen te vatten is een bedrijfsstijlenanalyse uitgevoerd die 4 strategische grondpatronen naar voren brengt: schaalvergroting, fijnregulering, kostenreductie en arbeidsbesparing. In ‘normale’ jaren kan via elk strategisch grondpatroon een goed inkomen worden verworven. Naarmate men meer ‘stijlspecifiek’ is, is het inkomen beter. In ‘slechte’ jaren ligt dit anders: dan blijken strategieën, die draaien om kostenreductie en fijnregulering, tot de beste resultaten te leiden. Ook de balans van vreemd en eigen vermogen speelt in slechte jaren een grote rol. Op haar beurt hangt die balans ook weer op significante wijze samen met de verschillende stijlen. Daarmee brengt de analyse een verschil naar voren dat in de komende jaren wellicht van groot belang zal worden: dat is het verschil tussen boerenlandbouw en ondernemerslandbouw. Met dit onderscheid wordt hier geen moreel of maatschappelijk oordeel gegeven. Waar het om gaat is de vraag welke vorm van landbouwbeoefening het best moeilijke marktomstandigheden weet te weerstaan. In de tweede helft van dit verslag staat de vraag centraal: welk kengetal biedt de melkveehouder het meeste houvast om na te gaan of zijn bedrijf over voldoende veerkracht beschikt om periodes van lage prijzen het hoofd te bieden? Er wordt een nieuw kengetal voorgesteld: buffercapaciteit. Daarnaast kijken we bij welke bedrijfsopzet (stijl) de buffercapaciteit het hoogst is en hoe deze verder is op te voeren
Betere sturing met vernieuwde kengetallen varkenshouder
Vermeij, I. ; Holster, H.C. - \ 2012
Lelystad : Wageningen UR Livestock Research (Rapport / Wageningen UR Livestock Research 678) - 141
varkenshouderij - zeugen - vleesvee - beren (varkens) - indexen - standaardisering - registratie - bedrijfsvergelijking in de landbouw - pig farming - sows - beef cattle - boars - indexes - standardization - registration - farm comparisons
Dit rapport bevat een gedetailleerde beschrijving van de afspraken, die gemaakt zijn voor het uniform berekenen en presenteren van kengetallen voor varkensbedrijven (versie 2012). In deze versie zijn de technische en economische kengetallen beschreven voor zowel de zeugenhouderij, de vleesvarkenshouderij als voor combi-varkensbedrijven. De noodzaak van uniform berekende kengetallen wordt behalve door de behoefte aan externe bedrijfsvergelijking, steeds meer ingegeven door de behoefte aan interne bedrijfsvergelijking.
Monitoring Least Weasels after a Winter Peak of Lemmings in Taimyr: Body Condition, Diet and Habitat Use
Feige, N. ; Enrich, D. ; Popov, I.Y. ; Broekhuizen, S. - \ 2012
Arctic 65 (2012)3. - ISSN 0004-0843 - p. 273 - 282.
stable-isotopes - dicrostonyx-groenlandicus - dynamics - nitrogen - residuals - greenland - abundance - selection - ecology - indexes
Least weasels are highly specialized small-rodent predators. Despite the fact that they are hypothesized to play an important role in generating the lemming cycles, a key process for the functioning of the terrestrial tundra ecosystem,. very little is known about the biology of these miniature carnivores in the Arctic. At Mys Vostochny in western Taimyr, Russia, least weasels were observed for the first time during a lemming peak in 2005, but not in two subsequent years with low lemming densities. Here we report observations about weasel signs in lemming winter nests, body condition, habitat use, and diet in summer 2008, a year when lemmings had been numerous under the snow but populations crashed before the summer, and least weasels were abundant. Stable isotope analyses revealed that weasel diet was dominated by Siberian lemmings during spring. As expected, given lower resource availability when the lemming population crashed, weight (taking into account body length) was somewhat lower in 2008 than in 2005. Tracking tunnels and trapping showed that in summer least weasels mostly used sheltered habitats such as rocky outcrops and driftwood. Together with surveys of lemming winter nests, tracking tunnels appeared to be a promising method for monitoring least weasels in the Arctic tundra.
Exploring variation in economic, environmental and societal performance among Dutch fattening pig farms
Dolman, M.A. ; Vrolijk, H.C.J. ; Boer, I.J.M. de - \ 2012
Livestock Science 149 (2012)1-2. - ISSN 1871-1413 - p. 143 - 154.
egg-production systems - welfare quality(r) project - sustainability indicators - indexes
Sustainable production of pork requires farms that are economically viable, ecologically sound and socially acceptable, both now and in the future. Promising mitigation options to improve the integrated sustainability of a pig farm can be deduced from variation in their economic, environmental and societal performance. This study explores the variation in sustainability performance among 27 specialized fattening pig farms in the Dutch Farm Accountancy Data Network. Moreover, the combined sustainability performance is quantified, in order to identify the characteristics of best performing farms. To quantify the economic performance we used the net farm income (NFI) and labor productivity. With a life cycle assessment (LCA) the environmental performance was quantified for land occupation (LO), non-renewable energy use (NREU), global warming potential (GWP), eutrophication potential (EP) and acidification potential (AP). To quantify the societal performance the usage of antibiotics and the pig mortality rate were used. The average NFI was -€3.1 per 100 kg slaughtered weight (SW), produced with a labor productivity of 0.4 h per 100 kg SW. To produce 100 kg of SW, a total LO and NREU were needed of respectively 1121 m2 and 2802 MJ. GWP was 546 kg CO2-eq per 100 kg SW, of which 31% CO2, 7% from CH4, and 62% from N2O. Total EP was 61.4 kg NO3--eq/100 kg SW, of which 53% from leaching of nitrate and 23% from phosphate. Total AP was 5.3 kg SO2-eq per 100 kg SW, of which 79% NH3, 11% from NOx and 10% from SO2. The use of antibiotics per 100 kg SW averaged 18.9 daily dosages per animal year. The number of deceased pigs per 100 kg SW averaged 0.03. There is a high variation in economic, environmental and societal performance among fattening pig farms. Farm characteristics related to scale positively affect economic and environmental performance. A low feed intake and a feeding ration with a high share of wet by-products positively affect the environmental performance. To identify explanatory farm characteristics from FADN for societal performance, more suitable indicators are needed. Best performing farms, which outperform on economic, environmental and societal performance do exist and are on average larger and are feeding a higher proportion of by-products. To understand the characteristics of an integrative sustainable fattening pig farm, more insight is needed in the entrepreneurial characteristics and the drivers to manage and perform in a more profitable, environmental friendly and societally acceptable way.
Predicting soil N mineralization using organic matter fractions and soil properties: A re-analysis of literature data
Ros, G.H. - \ 2012
Soil Biology and Biochemistry 45 (2012). - ISSN 0038-0717 - p. 132 - 135.
nitrogen mineralization - indexes - availability - management - relevance - systems
Extractable organic matter (EOM) fractions have been used to assess the capacity of soils to supply nitrogen (N), but their role in N mineralization and their potential to improve agricultural fertilizer management are still under debate. This paper shows evidence that the relationship between EOM and soil N supply is an indirect relationship reflecting the soils’ organic matter content. Data from 59 published experiments were re-analyzed using multivariate PLS modelling. Nitrogen mineralization was primarily related to the size of total and extractable organic matter fractions whereas variables reflecting soil texture and organic matter quality were less important. All EOM fractions reflected the soil organic matter content of the soil rather than a specific bioavailable fraction. There is strong need for research that explores the biochemical basis for relationships among total organic matter, extractable organic matter and soil N mineralization using mechanistic approaches.
Identifying plant species using mid-wave infrared (2.5-6µm) and thermal infrared (8-14µm) emissivity spectra
Ullah, S. ; Schlerf, M. ; Skidmore, A.K. ; Hecker, C. - \ 2012
Remote Sensing of Environment 118 (2012)4. - ISSN 0034-4257 - p. 95 - 102.
salt-marsh vegetation - hyperspectral data - biomass estimation - reflectance - discrimination - indexes - imagery - leaves - classification - spectroscopy
Plant species discrimination using remote sensing is generally limited by the similarity of their reflectance spectra in the visible, NIR and SWIR domains. Laboratory measured emissivity spectra in the mid infrared (MIR; 2.5µm-6µm) and the thermal infrared (TIR; 8µm-14µm) domain of different plant species, however, reveal significant differences. It is anticipated that with the advances in airborne and space borne hyperspectral thermal sensors, differentiation between plant species may improve. The laboratory emissivity spectra of thirteen common broad leaved species, comprising 3024 spectral bands in the MIR and TIR, were analyzed. For each wavelength the differences between the species were tested for significance using the one way analysis of variance (ANOVA) with the post-hoc Tukey HSD test. The emissivity spectra of the analyzed species were found to be statistically different at various wavebands. Subsequently, six spectral bands were selected (based on the histogram of separable pairs of species for each waveband) to quantify the separability between each species pair based on the Jefferies Matusita (JM) distance. Out of 78 combinations, 76 pairs had a significantly different JM distance. This means that careful selection of hyperspectral bands in the MIR and TIR (2.5µm-14µm) results in reliable species discrimination.
The potential of spectral mixture analysis to improve the estimation accuracy of tropical forest biomass
Basuki, T.M. ; Skidmore, A.K. ; Laake, P.E. van; Duren, I.C. van; Hussin, Y.A. - \ 2012
Geocarto International 27 (2012)4. - ISSN 1010-6049 - p. 329 - 345.
urban vegetation abundance - landsat tm data - aboveground biomass - satellite estimation - kyoto protocol - indexes - amazon - carbon - reflectance - information
A main limitation of pixel-based vegetation indices or reflectance values for estimating above-ground biomass is that they do not consider the mixed spectral components on the earth's surface covered by a pixel. In this research, we decomposed mixed reflectance in each pixel before developing models to achieve higher accuracy in above-ground biomass estimation. Spectral mixture analysis was applied to decompose the mixed spectral components of Landsat-7 ETM+ imagery into fractional images. Afterwards, regression models were developed by integrating training data and fraction images. The results showed that the spectral mixture analysis improved the accuracy of biomass estimation of Dipterocarp forests. When applied to the independent validation data set, the model based on the vegetation fraction reduced 5 – 16% the root mean square error compared to the models using a single band 4 or 5, multiple bands 4, 5, 7 and all non-thermal bands of Landsat ETM+.
Normen en economische waarderingen voor: de rentabiliteitsindex 2011 en het productiegetal 2012 zeugenhouderij
Animal Sciences Group (ASG), - \ 2011
[Lelystad] : Livestock Research Wageningen UR - 6
varkenshouderij - zeugen - rentabiliteit - indexen - bedrijfsresultaten in de landbouw - normen - prestatieniveau - pig farming - sows - profitability - indexes - farm results - standards - performance
Wageningen UR Livestock Research berekent jaarlijks de waarderingsnormen voor de rentabiliteitsindex en het productiegetal voor de zeugenhouderij. Dit vindt plaats in opdracht van het Productschap Vee en Vlees (PVV). In het kort wordt beschreven wat de rentabiliteitsindex en het productiegetal voor de varkenshouder betekenen. Vervolgens worden in het kort de berekeningsmethode en de uitgangspunten voor de berekeningen van de waarderingsnormen uiteengezet. Met behulp van deze waarderingsnormen zijn de rentabiliteitsindex en het productiegetal per individueel bedrijf te berekenen.
Normen en economische waarderingen voor: de rentabiliteitsindex 2011 en het productiegetal 2012 vleesvarkenshouderi
Animal Sciences Group (ASG), - \ 2011
[Lelystad] : Livestock Research Wageningen UR - 8
varkenshouderij - vleesproductie - rentabiliteit - indexen - bedrijfsresultaten in de landbouw - normen - prestatieniveau - pig farming - meat production - profitability - indexes - farm results - standards - performance
Wageningen UR Livestock Research berekent jaarlijks de waarderingsnormen voor de rentabiliteitsindex en het productiegetal. Dit vindt plaats in opdracht van het Productschap Vee en Vlees (PVV). In het kort wordt beschreven wat de rentabiliteitsindex en het productiegetal voor de varkenshouder betekenen. Vervolgens worden in het kort de berekeningsmethode en de uitgangspunten voor de berekeningen van de waarderingsnormen uiteengezet. Met behulp van deze waarderingsnormen zijn de rentabiliteitsindex en het productiegetal per individueel bedrijf te berekenen.
Waar staan de biologische melkveehouders?
Nauta, W.J. - \ 2011
V-focus 8 (2011)6. - ISSN 1574-1575 - p. 30 - 32.
melkveehouderij - biologische landbouw - indexen - vragenlijsten - statistische gegevens - dairy farming - organic farming - indexes - questionnaires - statistical data
In 2009 en 2010 zijn de biologische melkveehouders binnen het onderzoek ‘Type koe – type bedrijf’ gevraagd een enquête in te vullen, waarin bedrijfskengetallen, specifieke managementaspecten en fokkerijdoelstellingen centraal stonden. Van de 320 bedrijven hebben 180 bedrijven aan de enquête meegedaan. Op basis hiervan wordt in dit artikel een beeld van de huidige biologische melkveehouderij gegeven.
Using MERIS fused images for land-cover mapping vegetation status assessment in heterogeneous landscapes
Zurita Milla, R. ; Clevers, J.G.P.W. ; Gijsel, J.A.E. ; Schaepman, M.E. - \ 2011
International Journal of Remote Sensing 32 (2011)4. - ISSN 0143-1161 - p. 973 - 991.
spatial-resolution improvement - cloud-cover - data fusion - ndvi data - sensor - productivity - acquisition - indexes - fapar - tm
In this paper we evaluate the potential of ENVISAT–Medium Resolution Imaging Spectrometer (MERIS) fused images for land-cover mapping and vegetation status assessment in heterogeneous landscapes. A series of MERIS fused images (15 spectral bands; 25 m pixel size) is created using the linear mixing model and a Landsat Thematic Mapper (TM) image acquired over the Netherlands. First, the fused images are classified to produce a map of the eight main land-cover types of the Netherlands. Subsequently, the maps are validated using the Dutch land-cover/land-use database as a reference. Then, the fused image with the highest overall classification accuracy is selected as the best fused image. Finally, the best fused image is used to compute three vegetation indices: the normalized difference vegetation index (NDVI) and two indices specifically designed to monitor vegetation status using MERIS data: the MERIS terrestrial chlorophyll index (MTCI) and the MERIS global vegetation index (MGVI). Results indicate that the selected data fusion approach is able to downscale MERIS data to a Landsat-like spatial resolution. The spectral information in the fused images originates fully from MERIS and is not influenced by the TM data. Classification results for the TM and for the best fused image are similar and, when comparing spectrally similar images (i.e. TM with no short-wave infrared bands), the results of the fused image outperform those of TM. With respect to the vegetation indices, a good correlation was found between the NDVI computed from TM and from the best fused image (in spite of the spectral differences between these two sensors). In addition, results show the potential of using MERIS vegetation indices computed from fused images to monitor individual fields. This is not possible using the original MERIS full resolution image. Therefore, we conclude that MERIS–TM fused images are very useful to map heterogeneous landscapes.
Analysis of multi-temporal SPOT NDVI images for small-scale land-use mapping
Bie, C.A.J.M. de; Khan, M.R. ; Smakhtin, V.U. ; Venus, V. ; Weir, M.J.C. ; Smaling, E.M.A. - \ 2011
International Journal of Remote Sensing 32 (2011)21. - ISSN 0143-1161 - p. 6673 - 6693.
cover change - vegetation cover - noaa-avhrr - drought - indexes - africa - plains - system - area
Land-use information is required for a number of purposes such as to address food security issues, to ensure the sustainable use of natural resources and to support decisions regarding food trade and crop insurance. Suitable land-use maps often either do not exist or are not readily available. This article presents a novel method to compile spatial and temporal land-use data sets using multi-temporal remote sensing in combination with existing data sources. Satellite Pour l'Observation de la Terre (SPOT)-Vegetation 10-day composite normalized difference vegetation index (NDVI) images (1998–2002) at 1km2 resolution for a part of the Nizamabad district, Andhra Pradesh, India, were linked with available crop calendars and information about cropping patterns. The NDVI images were used to stratify the study area into map units represented by 11 distinct NDVI classes. These were then related to an existing land-cover map compiled from high resolution Indian Remote Sensing (IRS)-images (Liss-III on IRS-1C), reported crop areas by sub-district and practised crop calendar information. This resulted in an improved map containing baseline information on both land cover and land use. It is concluded that each defined NDVI class represents a varying but distinct mix of land-cover classes and that the existing land-cover map consists of too many detailed ‘year-specific’ features. Four groups of the NDVI classes present in agricultural areas match well with four categories of practised crop calendars. Differences within a group of NDVI classes reveal area specific variations in cropping intensities. The remaining groups of NDVI classes represent other land-cover complexes. The method illustrated in this article has the potential to be incorporated into remote sensing and Geographical Information System (GIS)-based drought monitoring systems
Solid phase extraction in combination with comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry for the detailed investigation of volatiles in South African red wines
Weldegergis, B.T. ; Crouch, A.M. ; Górecki, T. ; Villiers, A. de - \ 2011
Analytica Chimica Acta 701 (2011)1. - ISSN 0003-2670 - p. 98 - 111.
bar sorptive extraction - organic-compounds - oak - components - aroma - aldehydes - modulator - pinotage - barrels - indexes
Comprehensive two-dimensional gas chromatography in combination with time-of-flight mass spectrometry (GC × GC–TOFMS) has been applied for the analysis of volatile compounds in three young South African red wines. In spite of the significant benefits offered by GC × GC–TOFMS for the separation and identification of volatiles in such a complex matrix, previous results utilizing headspace solid phase micro extraction (HS-SPME) demonstrated certain limitations. These were primarily associated with the choice of sample preparation technique, which failed to extract some influential semi-volatile wine constituents. Therefore, in the current report, we utilized solid phase extraction (SPE) in combination with GC × GC–TOFMS for the detailed investigation of particularly low-level semi-volatiles in South African wine. 214 compounds previously reported in grapes and related beverages were tentatively identified based on mass spectral data and retention indices, while 62 additional compounds were positively identified using authentic standards. The method proved particularly beneficial for the analysis of terpenes, lactones and volatile phenols, and allowed us to report the presence of numerous volatile compounds for the first time in Pinotage wines.
Predicting soil N mineralization: Relevance of organic matter fractions and soil properties.
Ros, G.H. ; Hanegraaf, M.C. ; Hoffland, E. ; Riemsdijk, W.H. van - \ 2011
Soil Biology and Biochemistry 43 (2011)8. - ISSN 0038-0717 - p. 1714 - 1722.
nitrogen mineralization - microbial biomass - chemical methods - grassland soils - forest soils - indexes - availability - carbon - respiration - temperature
Distinct extractable organic matter (EOM) fractions have been used to assess the capacity of soils to supply nitrogen (N). However, substantial uncertainty exists on their role in the N cycle and their functional dependency on soil properties. We therefore examined the variation in mineralizable N and its relationship with EOM fractions, soil physical and chemical properties across 98 agricultural soils with contrasting inherent properties and management histories. Mineralizable N was determined by aerobic incubation at 20 °C and optimum moisture content for 20 weeks. We used multivariate statistical modelling to account for multi-collinearity, an issue generally overlooked in studies evaluating the predictive value of EOM fractions. Mineralization of N was primarily related to the size of OM pools and fractions present; they explained 78% of the variation in mineralizable N whereas other soil variables could explain maximally 8%. Both total and extractable OM expressed the same soil characteristic from a mineralization perspective; they were positively related to mineralizable N and explained a similar percentage of the variation in mineralizable N. Inclusion of mineralizable N in fertilizer recommendation systems should be based on at least one OM variable. The most appropriate EOM fraction can only be identified when the underlying mechanisms are known; regression techniques are not suitable for this purpose. Combination of single EOM fractions is not likely to improve the prediction of mineralizable N due to high multi-collinearity. Inclusion of texture-related soil variables or variables reflecting soil organic matter quality may be neglected due to their limited power to improve the prediction of mineralizable N.
Nitrogen mineralization: a review and meta-analysis of the predictive value of soil tests.
Ros, G.H. ; Temminghoff, E.J.M. ; Hoffland, E. - \ 2011
European Journal of Soil Science 62 (2011)1. - ISSN 1351-0754 - p. 162 - 173.
available organic nitrogen - stabilization mechanisms - microbial biomass - matter fractions - chemical methods - grassland soils - land-use - indexes - plantations - management
Accurate estimation of mineralizable nitrogen (N) from soil organic matter is essential to improve fertilizer management in agricultural systems. Mineralizable N refers to the amount of N in soil that is released during a certain period (ranging from 1 week to the length of a growing season). It has been estimated from increases in inorganic N during incubation or from N uptake by plants grown in a greenhouse or field. Many chemical soil tests measuring extractable organic N (EON) fractions have been proposed to predict mineralizable N. We evaluated the predictive value of these soil tests, using 2068 observations from 218 papers. Meta-analysis was used to find the best soil test, to analyse differences between field and laboratory experiments, and to determine whether their predictive value is affected by extraction intensity (% of total soil N that is extracted). The concentration of EON was positively related to mineralizable N, explaining on average 47% of the variation. It did not, however, explain more of the variation than total N. Best predictions (57%
Improved phosphorus use efficiency in agriculture: A key requirement for its sustainable use
Schroder, J.J. ; Smit, A.L. ; Cordell, D. ; Rosemarin, A. - \ 2011
Chemosphere 84 (2011)6. - ISSN 0045-6535 - p. 822 - 831.
organic farming systems - soil fertility - nitrogen use - maize - release - erosion - indexes - quality - europe - crops
Mineral phosphorus (P) fertilizers processed from fossil reserves have enhanced food production over the past 50 years and, hence, the welfare of billions of people. Fertilizer P has, however, not only been used to lift the fertility level of formerly poor soils, but also allowed people to neglect the reuse of P that humans ingest in the form of food and excrete again as faeces and urine and also in other organic wastes. Consequently, P mainly moves in a linear direction from mines to distant locations for crop production, processing and consumption, where a large fraction eventually may become either agronomically inactive due to over-application, unsuitable for recycling due to fixation, contamination or dilution, and harmful as a polluting agent of surface water. This type of P use is not sustainable because fossil phosphate rock reserves are finite. Once the high quality phosphate rock reserves become depleted, too little P will be available for the soils of food-producing regions that still require P supplements to facilitate efficient utilization of resources other than P, including other nutrients. The paper shows that the amounts of P applied in agriculture could be considerably smaller by optimizing land use, improvement of fertilizer recommendations and application techniques, modified livestock diets, and adjustment of livestock densities to available land. Such a concerted set of measures is expected to reduce the use of P in agriculture whilst maintaining crop yields and minimizing the environmental impact of P losses. The paper also argues that compensation of the P exported from farms should eventually be fully based on P recovered from ‘wastes’, the recycling of which should be stimulated by policy measures. Keywords: Fertilizer; Land use; Manure; Phosphorus; Efficiency; Surplus
Normen en economische waarderingen voor: de rentabiliteitsindex 2010 en het productiegetal 2011 zeugenhouderij
Animal Sciences Group (ASG), - \ 2011
[Lelystad] : Livestock Research Wageningen UR - 5
varkenshouderij - zeugen - rentabiliteit - bedrijfsresultaten in de landbouw - normen - prestatieniveau - indexen - pig farming - sows - profitability - farm results - standards - performance - indexes
De Animal Sciences Group berekent jaarlijks de waarderingsnormen voor de rentabiliteitsindex en het productiegetal voor de zeugenhouderij. Dit vindt plaats in opdracht van het Productschap Vee en Vlees (PVV). Deze indexen geven de zeugenhouder een beeld van het financieel voor- of nadeel bij verbetering respectievelijk verslechtering van de technische resultaten. De rentabiliteitsindex en het productiegetal geven een toegevoegde waarde aan het administratieprogramma voor de varkenshouder.
Normen en economische waarderingen voor: de rentabiliteitsindex 2010 en het productiegetal 2011 vleesvarkenshouderi
Animal Sciences Group (ASG), - \ 2011
[Lelystad] : Livestock Research Wageningen UR - 8
varkenshouderij - vleesproductie - rentabiliteit - bedrijfsresultaten in de landbouw - normen - prestatieniveau - indexen - pig farming - meat production - profitability - farm results - standards - performance - indexes
Wageningen UR Livestock Research berekent jaarlijks de waarderingsnormen voor de rentabiliteitsindex en het productiegetal. Dit vindt plaats in opdracht van het Productschap Vee en Vlees (PVV). Deze indexen geven de vleesvarkenshouder een beeld van het financieel voor of nadeel bij verbetering respectievelijk verslechtering van de technische resultaten. De rentabiliteitsindex en het productiegetal geven een toegevoegde waarde aan het administratieprogramma voor de varkenshouder.
Soil organic carbon mapping of partially vegetated agricultural fields with imaging spectroscopy
Bartholomeus, H. ; Kooistra, L. ; Stevens, A. ; Leeuwen, M. van; Wesemael, B. van; Ben-Dor, E. ; Tychon, B. - \ 2011
International Journal of applied Earth Observation and Geoinformation 13 (2011)1. - ISSN 0303-2434 - p. 81 - 88.
infrared reflectance spectroscopy - least-squares regression - spectral reflectance - aviris data - indexes - tm - spectrometry - parameters - prospect - nitrogen
Soil Organic Carbon (SOC) is one of the key soil properties, but the large spatial variation makes continuous mapping a complex task. Imaging spectroscopy has proven to be an useful technique for mapping of soil properties, but the applicability decreases rapidly when fields are partially covered with vegetation. In this paper we show that with only a few percent fractional maize cover the accuracy of a Partial Least Square Regression (PLSR) based SOC prediction model drops dramatically. However, this problem can be solved with the use of spectral unmixing techniques. First, the fractional maize cover is determined with linear spectral unmixing, taking the illumination and observation angles into account. In a next step the influence of maize is filtered out from the spectral signal by a new procedure termed Residual Spectral Unmixing (RSU). The residual soil spectra resulting from this procedure are used for mapping of SOC using PLSR, which could be done with accuracies comparable to studies performed on bare soil surfaces (Root Mean Standard Error of Calibration = 1.34 g/kg and Root Mean Standard Error of Prediction = 1.65 g/kg). With the presented RSU approach it is possible to filter out the influence of maize from the mixed spectra, and the residual soil spectra contain enough information for mapping of the SOC distribution within agricultural fields. This can improve the applicability of airborne imaging spectroscopy for soil studies in temperate climates, since the use of the RSU approach can extend the flight-window which is often constrained by the presence of vegetation.
Sturen op verantwoord antibioticagebruik
Kuipers, A. ; Wemmenhove, H. ; Bakker, J. ; Kuipers, F. - \ 2010
Veeteelt (2010). - ISSN 0168-7565 - p. 3 - 4.
melkveehouderij - melkkoeien - mastitis - antibiotica - dosering - uiers - indexen - statistische analyse - antibioticaresistentie - dairy farming - dairy cows - mastitis - antibiotics - dosage - udders - indexes - statistical analysis - antibiotic resistance
Resistentieontwikkeling verscherpt de aandacht voor het antibioticumgebruik in de veehouderij. Het project ‘Transparant en efficiënt medicijngebruik’ brengt antibioticumgebruik in kaart via aantal dagdoseringen. Dat getal varieert van bedrijf tot bedrijf.
Evaluating the performance of survey-based operational management procedures
Pomarede, M. ; Hillary, R. ; Ibaibarriaga, L. ; Bogaards, J.A. ; Apostolaki, P. - \ 2010
Aquatic Living Resources 23 (2010)1. - ISSN 0990-7440 - p. 77 - 94.
international-whaling-commission - stock assessment methods - african pelagic fishery - strategy evaluation - south - experiences - indexes - model - flr
The design and evaluation of survey-based management strategies is addressed in this article, using three case-study fisheries: North Sea herring, Bay of Biscay anchovy and North Sea cod, with a brief history and the main management issues with each fishery outlined. A range of operational management procedures for the case study stocks were designed and evaluated using trends that may be derived from survey indices (spawner biomass, year-class strength and total mortality) with an array of simple and more structured observation error regimes simulated. Model-free and model-based indicators of stock status were employed in the management procedures. On the basis of stochastic stock-specific simulations, we identified the following key determinants of successful management procedures: (i) adequate specification of the stock-recruit relationship (model structure, parameter estimates and variability), (ii) knowledge of the magnitude and structure of the variation in the survey indices, and (iii) explication of the particular management objectives, when assessing management performance. More conservative harvesting strategies are required to meet specified targets in the presence of increasing stochasticity, due to both process and observation error. It was seen that survey-based operational management procedures can perform well in the absence of commercial data, and can also inform aspects of survey design with respect to acceptable levels of error or bias in the surveys.
Spectral mixture analysis to monitor defoliation in mixed-aged Eucalyptus globulus Labill plantations in southern Australia using Landsat 5-TM and EO-1 Hyperion data
Somers, B. ; Verbesselt, J. ; Ampe, E.M. ; Sims, N. ; Verstraeten, W.W. ; Coppin, P. - \ 2010
International Journal of applied Earth Observation and Geoinformation 12 (2010)4. - ISSN 0303-2434 - p. 270 - 277.
forest health surveillance - mountain pine-beetle - hyperspectral data - endmember variability - indexes - vegetation - imagery - damage - tree - classification
Defoliation is a key parameter of forest health and is associated with reduced productivity and tree mortality. Assessing the health of forests requires regular observations over large areas. Satellite remote sensing provides a cost-effective alternative to traditional ground-based assessment of forest health, but assessing defoliation can be difficult due to mixed pixels where vegetation cover is low or fragmented. In this study we apply a novel spectral unmixing technique, referred to as weighted Multiple Endmember Spectral Mixture Analysis (wMESMA), to Landsat 5-TM and EO-1 Hyperion data acquired over a Eucalyptus globulus (Labill.) plantation in southern Australia. This technique combines an iterative mixture analysis cycle allowing endmembers to vary on a per pixel basis (MESMA) and a weighting algorithm that prioritizes wavebands based on their robustness against endmember variability. Spectral mixture analysis provides an estimate of the physically interpretable canopy cover, which is not necessarily correlated with defoliation in mixed-aged plantations due to natural variation in canopy cover as stands age. There is considerable variability in the degree of defoliation as well as in stand age among sites and in this study we found that results were significantly improved by the inclusion of an age correction algorithm for both the multi-spectral (R2no age correction = 0.55 vs R2age correction = 0.73 for Landsat) and hyperspectral (R2no age correction = 0.12 vs R2age correction = 0.50 for Hyperion) image data. The improved accuracy obtained from Landsat compared to the Hyperion data illustrates the potential of applying SMA techniques for analysis of multi-spectral datasets such as MODIS and SPOT-VEGETATION.
Combining somatic cell count traits optimal selection against mastitis
Windig, J.J. ; Ouweltjes, W. ; Napel, J. ten; Jong, de, G. ; Veerkamp, R.F. ; Haas, Y. de - \ 2010
Journal of Dairy Science 93 (2010)4. - ISSN 0022-0302 - p. 1690 - 1701.
1st 3 lactations - clinical mastitis - genetic-parameters - dairy-cattle - score - cows - infection - indexes - model
Test-day records of somatic cell counts (SCC) can be used to define alternative traits to decrease genetic susceptibility to clinical mastitis (CM) and subclinical mastitis (SCM). This paper examines which combination of alternative SCC traits can be used best to reduce both CM and SCM and whether direct information on CM is useful in this respect. Genetic correlations between 10 SCC traits and CM and SCM were estimated from 3 independent data sets. The SCC traits with the strongest correlations with CM differed from those with the strongest correlations with SCM. Selection index calculations were made for a breeding goal of 50% CM and 50% SCM resistance using these correlations. They indicated that a combination of 5 SCC traits (SCC early and late in lactation, suspicion of infection based on increased SCC, extent of increased SCC, and presence of a peak pattern in SCC) gave a high accuracy, almost without loss, compared with the full set of 10 SCC traits. The estimated accuracy of this index was 0.91, assuming that the correlations had been estimated without error. To take errors in estimation into account, correlations were resampled from a normal distribution with mean and standard errors as originally estimated. The accuracy of the index calculated with the original correlations was then recalculated using the resampled correlations. The average accuracy based on 50,000 resamplings decreased to 0.81. Use of direct information on CM improved the accuracy (uncorrected for errors in correlations) only slightly, to 0.92.
Classification of sugar beet and volunteer potato reflection spectra with a neural network and statistical discriminant analysis to select discriminative wavelengths
Nieuwenhuizen, A.T. ; Hofstee, J.W. ; Zande, J.C. van de; Meuleman, J. ; Henten, E.J. van - \ 2010
Computers and Electronics in Agriculture 73 (2010)2. - ISSN 0168-1699 - p. 146 - 153.
hyperspectral data - winter-wheat - crop - identification - indexes - corn
The objectives of this study were to determine the reflectance properties of volunteer potato and sugar beet and to assess the potential of separating sugar beet and volunteer potato at different fields and in different years, using spectral reflectance characteristics. With the ImspectorMobile, vegetation reflection spectra were successfully repeatedly gathered in two fields, on seven days in 2 years that resulted in 11 datasets. Both in the visible and in the near-infrared reflection region, combinations of wavelengths were responsible for discrimination between sugar beet and volunteer potato plants. Two feature selection methods, discriminant analysis (DA) and neural network (NN), succeeded in selecting sets of discriminative wavebands, both for the range of 450–900 and 900–1650 nm. First, 10 optimal wavebands were selected for each of the 11 available datasets individually. Second, by calculating the discriminative power of each selected waveband, 10 fixed wavebands were selected for all 11 datasets analyses. Third, 3 fixed wavebands were determined for all 11 datasets. These three wavebands were chosen because these had been selected by both DA and NN and were for sensor 1: 450, 765, and 855 nm and for sensor 2: 900, 1440, and 1530 nm. With the resulting three sets of wavebands, classifications were performed with a DA, a neural network with 1 hidden neuron (NN1) and a neural network with two hidden neurons (NN2). The maximum classification performance was obtained with the near-infrared sensor coupled to the NN2 method with an optimal adapted set of 10 wavebands, where the percentages were 100 ± 0.1 and 1 ± 1.3% for true negative (TN) classified volunteer potato plants and false negative (FN) classified sugar beet plants respectively. In general the NN2 method gave the best classification results, followed by DA and finally the NN1 method. When the optimal adapted waveband sets were generalized to a set of 10 fixed wavebands, the classification results were still at a reasonable level of a performance at 87% TN and 1% FN for the NN2 classification method. However, when a further reduction and generalization was made to 3 fixed wavebands, the classification results were poor with a minimum performance of 69% TN and 3% FN for the NN2 classification method. So, these results indicate that for the best classification results it is required that the sensor and classification system adapt to the specific field situation, to optimally discriminate between volunteer potato and sugar beet pixel spectra
Investigating agreement between different data sources using Bayesian state-space model: an application to estimating NE Atlantic mackerel catch and stock abundance
Simmonds, E.J. ; Portilla, E. ; Skagen, D. ; Beare, D.J. ; Reid, D.G. - \ 2010
ICES Journal of Marine Science 67 (2010)6. - ISSN 1054-3139 - p. 1138 - 1153.
egg mortality - age data - parameters - management - indexes
Bayesian Markov chain Monte Carlo methods are ideally suited to analyses of situations where there are a variety of data sources, particularly where the uncertainties differ markedly among the data and the estimated parameters can be correlated. The example of Northeast Atlantic (NEA) mackerel is used to evaluate the agreement between available data from egg surveys, tagging, and catch-at-age using multiple models within the Bayesian framework WINBUGS. The errors in each source of information are dealt with independently, and there is extensive exploration of potential sources of uncertainty in both the data and the model. Model options include variation by age and over time of both selectivity in the fishery and natural mortality, varying the precision and calculation method for spawning-stock biomass derived from an egg survey, and the extent of missing catches varying over time. The models are compared through deviance information criterion and Bayesian posterior predictive p-values. To reconcile mortality estimated from the different datasets the landings and discards reported would have to have been between 1.7 and 3.6 times higher than the recorded catches.
Estimating canopy water content using hyperspectral remote sensing data
Clevers, J.G.P.W. ; Kooistra, L. ; Schaepman, M.E. - \ 2010
International Journal of applied Earth Observation and Geoinformation 12 (2010)2. - ISSN 0303-2434 - p. 119 - 125.
leaf optical-properties - radiative-transfer models - imaging spectrometer data - dynamic vegetation model - reflectance data - indexes - retrieval - information - variables - products
Hyperspectral remote sensing has demonstrated great potential for accurate retrieval of canopy water content (CWC). This CWC is defined by the product of the leaf equivalent water thickness (EWT) and the leaf area index (LAI). In this paper, in particular the spectral information provided by the canopy water absorption feature at 970 nm for estimating and predicting CWC was studied using a modelling approach and in situ spectroradiometric measurements. The relationship of the first derivative at the right slope of the 970 nm water absorption feature with CWC was investigated with the PROSAIL radiative transfer model and tested for field spectroradiometer measurements on two test sites. The first site was a heterogeneous floodplain with natural vegetation like grasses and various shrubs. The second site was an extensively grazed fen meadow. PROSAIL simulations (using coupled SAIL/PROSPECT-5 models) showed a linear relationship between the first derivative over the 1015–1050 nm spectral interval and CWC (R2 = 0.97). For 8 plots at the floodplain site the spectral derivative over the 1015–1050 nm interval obtained with an ASD FieldSpec spectroradiometer yielded an R2 of 0.51 with CWC. For 40 plots at the fen meadow ASD FieldSpec spectral measurements yielded an R2 of 0.68 for the derivative over the 1015–1050 nm interval with CWC. Consistency of the results confirmed the potential of using simulation results for calibrating the relationship between this first derivative and CWC
Trend analysis of the water requirements, consumption and deficit
Supit, I. ; Diepen, C.A. van; Boogaard, H.L. ; Ludwig, F. ; Baruth, B. - \ 2010
Agricultural and Forest Meteorology 150 (2010)1. - ISSN 0168-1923 - p. 77 - 88.
climate-change - global radiation - pan evaporation - temperature - scenarios - soil - simulation - indexes - models - range
Recent trends in European seasonal weather conditions and related crop water requirements, crop water consumption and crop water deficits were studied using the Crop Growth Monitoring System of the Joint Research Centre of the European Commission for the period 1976–2005. Soft wheat was selected as a typical winter crop. Sugar beet was selected as a typical spring/summer crop. First we analyzed the spatial and temporal variation of the average seasonal mean temperature and the average seasonal estimated global radiation, subsequently the spatial and temporal variation of the simulated seasonal water requirement, water consumption and water deficit of wheat and sugar beets were studied. We found that the weather pattern changes are not uniformly distributed across Europe. A seasonal dependence was found. The impacts of the changing weather patterns differ per crop and per region. In various European regions the wheat water requirement showed a downward trend which can be attributed to a shorter growing season as a result of higher temperatures in spring. This downward trend can also be attributed to a lower evaporative demand in winter and spring as a result of diminishing global radiation values. Only a limited number of regions showed an upward trend. For sugar beets the Mediterranean regions of France and Spain showed a downward trend in the water requirement which can be attributed to a lower evaporative demand due to reduced solar radiation in summer and autumn. Large areas with an upward trend in the water requirement are spread across the rest of Europe. These upward trends can be attributed to higher temperatures in summer and autumn. The regional trend patterns in actual crop water consumption and water deficit are less distinct than found for the crop water requirements. Changes in these variables can be attributed to the combined effect of variations in crop water requirements and rainfall.
Accumulated effects on landscape pattern by hydroelectric cascade exploitation in the Yellow River basin from 1977 to 2006
Ouyang, W. ; Skidmore, A.K. ; Hao, F.H. ; Toxopeus, A.G. ; Abkar, A. - \ 2009
Landscape and Urban Planning 93 (2009)3-4. - ISSN 0169-2046 - p. 163 - 171.
environmental-impact - metrics - hydropower - region - forest - indicator - projects - indexes - quality - models
The accumulated impacts of hydroelectric cascade exploitation (HCE) on the landscape are greater than the simple sum of the impacts from a single dam. The spatial–temporal landscape characteristics resulting from the accumulated impacts of HCE from 1977 to 2006 in Longliu Watershed, a part of the Yellow River basin, were investigated. In this innovative approach, the FRAGSTATS model was employed to calculate landscape indices, which characterized landscape in term of its fragmentation, shape and diversity. Three fragmentation indicators and four shape indicators were analyzed at patch scale for each land use type in period of 1977–2006. The diversity simulators were calculated also at landscape scale. Furthermore, two hydroelectric cascade exploitation indicators, summed dam heights and hydroelectric generator capacities, were used to explore the correlated impact with landscape pattern. The analysis revealed that landscape fragmentation variations are strongly dependent on the magnitude of exploitation. The correlation coefficients ranged from 0.65 to 0.95. Except for PAFRAC value of water area, all other shape metric variations were closely linked to the level of HCE and the correlation coefficients ranged from 0.5267 to 0.9514. This study also demonstrated that landscape diversity changes were exponentially related to hydro-exploitation parameters, with correlation coefficients arranging from 0.7487 to 0.9856. The correlation analysis also demonstrated that HCE a critical factor determining regional landscape variation. It is concluded that these correlation analysis assist in predicting landscape variation about future HCE. The findings will also be helpful for regional environmental management and for the understanding expected landscape transformations.
Laboratory and greenhouse assessment of plant availability of organic N in animal manure
Antil, R.S. ; Janssen, B.H. ; Lantinga, E.A. - \ 2009
Nutrient Cycling in Agroecosystems 85 (2009)1. - ISSN 1385-1314 - p. 95 - 106.
0.01 m cacl2 - cattle slurry - nitrogen mineralization - soil fertility - management - indexes - carbon - fresh - farm
Laboratory data (thermal fractionation, pepsin extraction, C:No ratio) of dung and manure were mutually compared and contrasted with plant-availability of organic N (No) as found in a greenhouse experiment according to the double-pot technique. Two types of fresh cow dung (one with a relatively wide and the other with a relatively narrow C:No ratio) and four types of manure (from poultry, sheep, pigs and cow) were compared with ammonium nitrate as chemical reference fertilizer. Relative effectiveness of organic N (REo) was used as characteristic; it was calculated as the fraction of organic N that has the same availability to plants as inorganic N. REo for poultry and sheep manure could not be assessed, probably because of NH3 volatilization causing direct damage to plants and N losses. REo values decreased in the order: dung with narrow C:No > dung with wide C:No > pig manure > cow manure. Thermal fractionation did not provide a suitable index of plant-availability of organic N. Pepsin extracted organic N gave a positive, and C:No ratio a negative relationship with REo. Also between pepsin extracted organic N and C:No ratio a negative relationship was found. As C:No ratio is relatively easy to determine, it is considered the most practical laboratory index for plant availability of organic N in animal manures low in ammonia. When using the double-pot technique, application rates of manure types high in ammonia should be restricted
Spatial and temporal patterns in pupal and adult production of the dengue vector Aedes aegypti in Kamphaeng Phet, Thailand
Koenraadt, C.J.M. ; Aldstadt, J. ; Kijchalao, U. ; Sithiprasasna, R. ; Getis, A. ; Jones, J.W. ; Scott, T.W. - \ 2008
American Journal of Tropical Medicine and Hygiene 79 (2008)2. - ISSN 0002-9637 - p. 230 - 238.
primary-school children - iquitos - peru - surveillance - population - culicidae - dynamics - diptera - bangkok - indexes
We investigated how temporal and spatial effects confound the functional relationship between pupal and adult populations of Aedes aegypti and thus the value of pupal numbers as predictors of dengue transmission risk in Kamphaeng Phet, Thailand. We found considerable seasonal shifts in productivity of key containers. Tires contained much less pupae in the dry season than in the wet season. Earthenware jars and cement tanks for washing purposes were consistent producers over the entire study period. Houses in the two villages, with approximately twice as many houses per unit area, were significantly more likely to have adults and pupae. No significant annual, seasonal, or spatial effects on the strength of correlations between pupal and adult populations were found. Except for 2 (of 16) occasions, pupal, and adult populations were correlated strongly in time and space. Our results are consistent with application of the pupal survey technique for assessing dengue transmission risk.
Retrieval of chlorophyll concentration from leaf reflectance spectra using wavelet analysis
Blackburn, G.A. ; Ferwerda, J.G. - \ 2008
Remote Sensing of Environment 112 (2008)4. - ISSN 0034-4257 - p. 1614 - 1632.
hyperspectral data - vegetation - calibration - prospect - pigment - spectroscopy - indexes - models - red
The dynamics of foliar chlorophyll concentrations have considerable significance for plant¿environment interactions, ecosystem functioning and crop growth. Hyperspectral remote sensing has a valuable role in the monitoring of such dynamics. This study focussed upon improving the accuracy of chlorophyll quantification by applying wavelet analysis to reflectance spectra. Leaf-scale radiative transfer models were used to generate very large spectral data sets with which to develop and rigorously test refinements to the approach and compare it with existing spectral indices. The results demonstrated that by decomposing leaf spectra, the resultant wavelet coefficients can be used to generate accurate predictions of chlorophyll concentration, despite wide variations in the range of other biochemical and biophysical factors that influence leaf reflectance. Wavelet analysis outperformed predictive models based on untransformed spectra and a range of spectral indices. The paper discusses the possibilities for further refining the wavelet approach and for extending the technique to the sensing of a variety of vegetation properties at a range of spatial scales.
Vergelijking inkomensschommelingen melkveehouderij Nieuw-Zeeland, Verenigde Staten en Nederland
Bruchem, C. van - \ 2008
[S.l.] : S.n. - 4
melkveehouderij - indexen - melkprijzen - inkomsten uit het landbouwbedrijf - quota's - nederland - vs - nieuw-zeeland - dairy farming - indexes - milk prices - farm income - quotas - netherlands - usa - new zealand
Een vergelijking van kengetallen van de melkveehouderij, van melkprijzen en van inkomen om voorzichtig te voorspellen wat de gevolgen zijn van afschaffing van prijsbescherming en melkquotering voor de inkomens in de Nederlandse melkveehouderij
Remote sensing of nitrogen and water stress in wheat
Tilling, A.K. ; O'Leary, G.J. ; Ferwerda, J.G. ; Jones, S.D. ; Fitzgerald, G.J. ; Rodriguez, D. ; Belford, R. - \ 2007
Field Crops Research 104 (2007)1-3. - ISSN 0378-4290 - p. 77 - 85.
spectral reflectance - crop - chlorophyll - indexes - temperature - leaves - plants - area
Nitrogen (N) is the largest agricultural input in many Australian cropping systems and applying the right amount of N in the right place at the right physiological stage is a significant challenge for wheat growers. Optimizing N uptake could reduce input costs and minimize potential off-site movement. Since N uptake is dependent on soil and plant water status, ideally, N should be applied only to areas within paddocks with sufficient plant available water. To quantify N and water stress, spectral and thermal crop stress detection methods were explored using hyperspectral, multispectral and thermal remote sensing data collected at a research field site in Victoria, Australia. Wheat was grown over two seasons with two levels of water inputs (rainfall/irrigation) and either four levels (in 2004; 0, 17, 39 and 163 kg/ha) or two levels (in 2005; 0 and 39 kg/ha N) of nitrogen. The Canopy Chlorophyll Content Index (CCCI) and modified Spectral Ratio planar index (mSRpi), two indices designed to measure canopy-level N, were calculated from canopy-level hyperspectral data in 2005. They accounted for 76% and 74% of the variability of crop N status, respectively, just prior to stem elongation (Zadoks 24). The Normalised Difference Red Edge (NDRE) index and CCCI, calculated from airborne multispectral imagery, accounted for 41% and 37% of variability in crop N status, respectively. Greater scatter in the airborne data was attributable to the difference in scale of the ground and aerial measurements (i.e., small area plant samples against whole-plot means from imagery). Nevertheless, the analysis demonstrated that canopy-level theory can be transferred to airborne data, which could ultimately be of more use to growers. Thermal imagery showed that mean plot temperatures of rainfed treatments were 2.7 °C warmer than irrigated treatments (P <0.001) at full cover. For partially vegetated fields, the two-Dimensional Crop Water Stress Index (2D CWSI) was calculated using the Vegetation Index-Temperature (VIT) trapezoid method to reduce the contribution of soil background to image temperature. Results showed rainfed plots were consistently more stressed than irrigated plots. Future work is needed to improve the ability of the CCCI and VIT methods to detect N and water stress and apply both indices simultaneously at the paddock scale to test whether N can be targeted based on water status. Use of these technologies has significant potential for maximising the spatial and temporal efficiency of N applications for wheat growers.
Coupled soil-leaf-canopy and atmosphere radiative transfer modeling to simulate hyperspectral multi-angular surface reflectance and TOA radiance data
Verhoef, W. ; Bach, H. - \ 2007
Remote Sensing of Environment 109 (2007)2. - ISSN 0034-4257 - p. 166 - 182.
photosynthetically active radiation - light interaction-model - vegetation canopies - plant-canopy - sail model - scattering - inversion - prospect - spectra - indexes
Coupling radiative transfer models for the soil background and vegetation canopy layers is facilitated by means of the four-stream flux interaction concept and use of the adding method. Also the coupling to a state-of-the-art atmospheric radiative transfer model like MODTRAN4 can be established in this way, thus enabling the realistic simulation of top-of-atmosphere radiances detected by space-borne remote sensing instruments. Possible applications of coupled modeling vary from mission design to parameter retrieval and data assimilation. This paper introduces a modified Hapke soil BRDF model, a robust version of the PROSPECT leaf model, and a modernized canopy radiative transfer model called 4SAIL2. The latter is a hybrid two-layer version of SAIL accommodating horizontal and vertical heterogeneities, featuring improved modeling of the hot spot effect and output of canopy absorptances. The integrated model is simply called SLC (soil¿leaf-canopy) and has been implemented as a speed-optimized Windows DLL which allows efficient use of computer resources even when simulating massive amounts of hyperspectral multi-angular observations. In this paper various examples of possible model output are shown, including simulated satellite image products. First validation results have been obtained from atmospherically corrected hyperspectral multi-angular CHRIS-PROBA data of the Upper Rhine Valley in Germany.
Automatic identification of erosion gullies with ASTER imagery in the Brazilian Cerrados
Vrieling, A. ; Rodrigues, S.C. ; Bartholomeus, H. ; Sterk, G. - \ 2007
International Journal of Remote Sensing 28 (2007)12. - ISSN 0143-1161 - p. 2723 - 2738.
soil-erosion - discrimination - reflectance - vegetation - indexes - growth
Gully erosion is a serious problem at many locations worldwide, but little is known about its importance at large spatial scales. The remote sensing contribution for the spatial assessment of gullies has thus far been confined to visual image interpretation. The current study was conducted to determine whether automatic classification of optical ASTER imagery could accurately discern permanent erosion gullies in the Brazilian Cerrados. A maximum likelihood classifier (MLC) was trained with two classes, gullies and non-gullies, and applied to images of March (wet season) and August (dry season). Moreover, a bi-temporal classification was performed by labelling a pixel as gully when both for the March and August image it was classified as such. Validation was done with a gully map obtained from a panchromatic QuickBird image and field data. For mono-temporal classification, the March image performed much better than the August image, because spectral differences are more pronounced during the wet season. Based on spatial analysis of output maps, the bi-temporal classification performed best in identifying gullies, as user's accuracy was above 90%, while two of 17 actual gullies were not detected and two small locations were erroneously identified as gully. The combination of ASTER bands 1, 2, 3, and 4 gave highest accuracies. It is concluded that accurate automatic identification of permanent gullies is possible with optical satellite data. Because the Cerrados occupy a vast area, it is expected that the approach presented could be applied to larger areas with similar characteristics.
Dierenwelzijn in transitie; Thema's rond de implementatie van de dierenwelzijnsindex
Ingenbleek, P.T.M. ; Backus, G.B.C. ; Binnekamp, M.H.A. ; Bondt, N. ; Goddijn, S.T. ; Hoste, R. ; Immink, V.M. ; Oosterkamp, E.B. ; Vlieger, J.J. de - \ 2006
Den Haag : Landbouw-Economisch Instituut (Rapport / LEI : Domein 5, Ketens ) - ISBN 9789086150717 - 103
landbouwbeleid - dierenwelzijn - recht - indexen - duurzaamheid (sustainability) - dierhouderij - overheidsbeleid - organisaties - pressiegroepen - gedragscode - nederland - agricultural policy - animal welfare - law - indexes - sustainability - animal husbandry - government policy - organizations - pressure groups - code of practice - netherlands
LNV wil het proces van dierenwelzijnsverbetering in de veehouderij tot een bovenwettelijk niveau stimuleren en ondersteunen met onderzoek waarin de dierenwelzijnsindex centraal staat. Dit rapport bespreekt verschillende thema's rond de implementatie van die dierenwelzijnsindex. De implementatie van de index wordt gezien binnen de structurele ontwikkeling naar een meer duurzame veehouderij. Specifiek is er in het rapport aandacht voor gedragscodeorganisaties, dierenbeschermingsgroepen, meerkosten van dierenwelzijnsmaatregelen en financiële beleidsinstrumenten. Tevens wordt er een 'doorkijk' geformuleerd naar de implementatie van de index.
Quantum chemistry based QSAR prediction and priority setting for toxicity of nitrobenzenes on EINECS list
Zvinavashe, E. ; Murk, A.J. ; Vervoort, J.J.M. ; Soffers, A.E.M.F. ; Freidig, A. ; Rietjens, I.M.C.M. - \ 2006
Environmental Toxicology and Chemistry 25 (2006)9. - ISSN 0730-7268 - p. 2313 - 2321.
nitrobenzene derivatives - partition-coefficients - qsar - prediction - information - validation - pollutants - indexes
Fifteen experimental literature data sets on the acute toxicity of substituted nitrobenzenes to algae (Scenedesmus obliquus, Chlorella pyrenoidosa, C. vulgaris), daphnids (Daphnia magna, D. carinata), fish (Cyprinus carpio, Poecilia reticulata), protozoa (Tetrahymena pyriformis), bacteria (Phosphobacterium phosphoreum), and yeast (Saccharomyces cerevisiae) were used to establish quantum chemistry based quantitative structure¿activity relationships (QSARs). The logarithm of the octanol/water partition coefficient, log Kow, and the energy of the lowest unoccupied molecular orbital, Elumo, were used as descriptors. Suitable QSAR models (0.65
A linear model to predict with a multi-spectral radiometer the amount of nitrogen in winter wheat
Reyniers, M. ; Walvoort, D.J.J. ; Baardemaaker, J. De - \ 2006
International Journal of Remote Sensing 27 (2006)19. - ISSN 0143-1161 - p. 4159 - 4179.
spectral reflectance - vegetation - indexes - leaves - water - corn - experience - radiance - biomass - canopy
The objective was to develop an optimal vegetation index (VIopt) to predict with a multi-spectral radiometer nitrogen in wheat crop (kg[N] ha-1). Optimality means that nitrogen in the crop can be measured accurately in the field during the growing season. It also means that the measurements are stable under changing light conditions and vibrations of the measurement platform. Different fields, on which various nitrogen application rates and seeding densities were applied in experimental plots, were measured optically during the growing season. These measurements were performed over three years. Optical measurements on eight dates were related to calibration measurements of nitrogen in the crop (kg[N] ha-1) as measured in the laboratory. By making combinations of the wavelength bands, and whether or not the soil factor was taken into account, numerous vegetation indices (VIs) were examined for their accuracy in predicting nitrogen in wheat. The effect of changing light conditions in the field and vibrations of the measurement platform on the VIs were determined based on tests in the field. VIopt ((1+L)*(R2NIR+1)/(Rred+L) with L=0.45), the optimal vegetation index found, was best in predicting nitrogen in grain crop. The root mean squared error (RMSE), determined by means of cross-validation, was 16.7 kg[N] ha-1. The RMSE was significantly lower compared to other frequently used VIs such as NDVI, RVI, DVI, and SAVI. The L-value can change between 0.16 and 1.6 without deteriorating the RMSE of prediction. Besides being the best predictor for nitrogen, VIopt had the advantage of being a stable vegetation index under circumstances of changing light conditions and platform vibrations. In addition, VIopt also had a simple structure of physically meaningful bands.
The STAR project: context, objectives and approaches
Furse, M. ; Hering, D. ; Moog, O. ; Verdonschot, P.F.M. ; Johnson, R.K. ; Brabec, K. ; Gritzalis, K. ; Buffagni, A. ; Pinto, P. ; Friberg, N. ; Murray-Bligh, J. ; Kokes, J. ; Alber, R. ; Usseglio-Polatera, P. ; Haase, P. ; Sweeting, R. ; Bis, B. ; Szoszkiewicz, K. ; Soszka, H. ; Springe, G. ; Sporka, F. ; Krno, I. - \ 2006
Hydrobiologia 566 (2006)1. - ISSN 0018-8158 - p. 3 - 29.
ecological quality - indexes - europe - system - rivers
STAR is a European Commission Framework V project (EVK1-CT-2001-00089). The project aim is to provide practical advice and solutions with regard to many of the issues associated with the Water Framework Directive. This paper provides a context for the STAR research programme through a review of the requirements of the directive and the Common Implementation Strategy responsible for guiding its implementation. The scientific and strategic objectives of STAR are set out in the form of a series of research questions and the reader is referred to the papers in this volume that address those objectives, which include: (a) Which methods or biological quality elements are best able to indicate certain stressors? (b) Which method can be used on which scale? (c) Which method is suited for early and late warnings? (d) How are different assessment methods affected by errors and uncertainty? (e) How can data from different assessment methods be intercalibrated? (f) How can the cost-effectiveness of field and laboratory protocols be optimised? (g) How can boundaries of the five classes of Ecological Status be best set? (h) What contribution can STAR make to the development of European standards? The methodological approaches adopted to meet these objectives are described. These include the selection of the 22 stream-types and 263 sites sampled in 11 countries, the sampling protocols used to sample and survey phytobenthos, macrophytes, macroinvertebrates, fish and hydromorphology, the quality control and uncertainty analyses that were applied, including training, replicate sampling and audit of performance, the development of bespoke software and the project outputs. This paper provides the detailed background information to be referred to in conjunction with most of the other papers in this volume. These papers are divided into seven sections: (1) typology, (2) organism groups, (3) macrophytes and diatoms, (4) hydromorphology, (5) tools for assessing European streams with macroinvertebrates, (6) intercalibration and comparison and (7) errors and uncertainty. The principal findings of the papers in each section and their relevance to the Water Framework Directive are synthesised in short summary papers at the beginning of each section. Additional outputs, including all sampling and laboratory protocols and project deliverables, together with a range of freely downloadable software are available from the project website at www.eu_star.at.
Betalen voor dierenwelzijn: barrières en oplossingsrichtingen in consumentenmarkten en business-to-business markten
Ingenbleek, P.T.M. ; Binnekamp, M.H.A. ; Trijp, J.C.M. van - \ 2006
DEN HAAG : LEI (Rapport / LEI : Domein 5, Ketens ) - ISBN 9086150616 - 96
agrarische economie - dierenwelzijn - markten - landbouwbeleid - indexen - kosten - vee - vleesproductie - consumenten - nederland - ketenmanagement - agricultural economics - animal welfare - markets - agricultural policy - indexes - costs - livestock - meat production - consumers - netherlands - supply chain management
Het verbeteren van dierenwelzijn tot een niveau dat uitstijgt boven het wettelijke minimum wordt overgelaten aan de markt. LNV wil dit proces onder andere stimuleren door een dierenwelzijnsindex te ontwikkelen. Omdat een verbetering van het dierenwelzijn onvermijdelijk lijkt verbonden met extra kosten, is de prijs in zowel de consumentenmarkt als in de rest van de keten een belangrijke barrière voor de verbetering van dierenwelzijn in de veehouderij. Dit rapport is gericht op hoe deze meerkosten van dierenwelzijn gemanaged kunnen worden. Daartoe is een literatuuronderzoek uitgevoerd gericht op consumenten, retailers en ketens. The improvement of animal welfare to a level that is significantly higher than the statutory minimum is currently left down to market forces. The Ministry of Agriculture, Nature and Food Quality is keen to encourage this process through the development of an animal welfare index, for example. Since an improvement in animal welfare would inevitably appear to be connected with extra costs, the price forms a significant barrier to the improvement of animal welfare in livestock production, both in the consumer market and in the rest of the chain. This report focuses on how these additional costs of animal welfare can be managed. To this end, a literature study was carried out, focusing on consumers, retailers and chains.
Inventarisatie Paardenhouderij
Rijksen, C. ; Visser, E.K. - \ 2005
Lelystad : Animal Sciences Group (Rapport / Animal Sciences Group ) - 50
paarden - landbouwsector - agrarische economie - bedrijfsontwikkeling in de landbouw - indexen - horses - agricultural sector - agricultural economics - farm development - indexes
ASG heeft voor de beleidslijn van MLV een overzicht gegeven van de aanwezige kennis over de structuur, omvang en organisatiegraad van de paardenhouderij. Naast kengetallen gaat het rapport in op de economische waarde van de paardenhouderij voor de sport, recreatie, handel en slacht in relatie tot de landbouwsectoren
Biologisch niet per se duurzaam
Calker, K.J. van; Berentsen, P.B.M. ; Galama, P.J. ; Giesen, G.W.J. ; Huirne, R.B.M. - \ 2005
Veeteelt 22 (2005)23. - ISSN 0168-7565 - p. 80 - 81.
melkveehouderij - landbouw bedrijven - biologische landbouw - duurzaamheid (sustainability) - indexen - bedrijfsvergelijking in de landbouw - proefbedrijven - dairy farming - farming - organic farming - sustainability - indexes - farm comparisons - pilot farms
De vraag is of gangbare melkveebedrijven op het gebied van duurzaamheid onderdoen voor biologische melkveebedrijven. De bedrijfsduurzaamheidsindex geeft via duurzaamheidsscores antwoord voor 4 praktijkcentra van de Animal Science Group
Een score voor duurzaamheid. Bedrijfsduurzaamheidsindex mogelijke kapstok voor melkprijsdifferentiatie
Calker, K.J. van; Berentsen, P.B.M. ; Galama, P.J. ; Giesen, G.W.J. ; Huirne, R.B.M. - \ 2005
Veeteelt 22 (2005)22. - ISSN 0168-7565 - p. 42 - 43.
melkveehouderij - melkveebedrijven - duurzaamheid (sustainability) - indexen - prestatie-indexen - melkprijzen - dairy farming - dairy farms - sustainability - indexes - performance indexes - milk prices
In een promotieonderzoek is op Wageningen UR in samenwerking met ASG een index ontwikkeld, die duurzaamheid van Nederlandse melkveebedrijven bepaalt
Relationship between landscape structure metrics and wetland nutrient retention function: a case study of Liaohe Delta, China
Li, X. ; Jongman, R.H.G. ; Hu, Y. ; Bu, Y. ; Bu, R. ; Harms, B. ; Bregt, A.K. ; He, H.S. - \ 2005
Ecological Indicators 5 (2005)4. - ISSN 1470-160X - p. 339 - 349.
quantify spatial-patterns - indexes - range
The relationship between landscape pattern and the function of nutrient reduction in the natural reed marsh of Liaohe Delta is studied with the help of some landscape metrics. The results discovered that not all the metrics selected are explanative in representing the function of nutrient reduction. Network connectivity, area size, and source to centre metrics are closely related to the simulation results from different pattern scenarios, while other metrics like area-weighted mean shape, fractal, contagion and aggregation are not related with the reduction process at all. Different metrics should be chosen according to the purpose of the study, based on the criteria of simplicity, generality and ecological meaning.
Bedrijfsduurzaamheidindex hoog op het lagekostenbedrijf
Calker, K.J. van; Verhagen, C.A. - \ 2004
Praktijkkompas. Rundvee 18 (2004)1. - ISSN 1570-8586 - p. 24 - 25.
melkveebedrijven - duurzaamheid (sustainability) - indexen - proefbedrijven - agrarische bedrijfsvoering - dairy farms - sustainability - indexes - pilot farms - farm management
Door de BedrijfsDuurzaamheidIndex (BDI) is duurzaamheid op melkveebedrijven meetbaar gemaakt. De BDI is voor het eerst berekend op de praktijkcentra van het Praktijkonderzoek. Het Lagekostenbedrijf haalt een goede score voor bijna alle onderdelen van duurzaamheid. Alleen voor de landschappelijke waarde kunnen verbeteringen worden geboekt. De strategie van het Lagekostenbedrijf leidt tot een goede score voor de BDI.
Een cijfer voor duurzaamheid. Nieuwe index BDI biedt houvast voorbepaling duurzaamheid van melkveebedrijven
Calker, K.J. van - \ 2003
Veeteelt December 1 (2003). - ISSN 0168-7565 - p. 46 - 47.
melkveehouderij - melkveebedrijven - duurzaamheid (sustainability) - indexen - prestatie-indexen - dairy farming - dairy farms - sustainability - indexes - performance indexes
Uitleg over de nieuwe Bedrijfsduurzaamheidsindex, die onderverdeeld is in 4 deelgebieden: economische duurzaamheid, interne sociale duurzaamheid, externe sociale duurzaamheid en ecologische duurzaamheid
Annual variation in weather: its implications for sustainability in the case of optimising nitrogen input in sugar beet
Koeijer, T.J. de; Buck, A.J. de; Wossink, G.A.A. ; Oenema, J. ; Renkema, J.A. ; Struik, P.C. - \ 2003
European Journal of Agronomy 19 (2003). - ISSN 1161-0301 - p. 251 - 264.
damage control - agricultural production - fertilizer application - netherlands 1948-1989 - vonliebig - model - crop - econometrics - efficiency - indexes
Efficient crop husbandry is crucial in order to prevent unnecessary emissions of environmentally damaging inputs and to maintain economic soundness, but it raises the question of which productivity and efficiency levels should be realised. Agronomists and economists are still debating this issue, as they base their insights on different production functions: economists assume decreasing returns of input use, whereas the response curve used by agronomists is often described as linear with a plateau (LRP). The first objective of this paper is to reconcile these points of view by showing that due to annual variation in weather individual LRP curves turn into a concave function with decreasing returns when aggregated. The second objective is to present empirical evidence on the impact of weather variation on optimal input levels for the case of nitrogen in sugar beet in The Netherlands. Two methods were used: bio-physical simulation and estimation with a regression model using panel data. Optimal crop growth and nitrogen input were simulated with the Water and Agro-chemicals in the soil and Vadose Environment (WAVE) model, using weather data for 43 years. Parameters were assessed with and without additional weather effects. An agronomic crop growth simulation model such as WAVE might underestimate the effect of variation in weather on the agronomic efficiency of nitrogen, because pests, weeds and diseases as well as the effectiveness of biocides, the sowing date and possible harvesting problems are strongly influenced by the weather. To test for this effect, weather indexes that include these indirect weather effects on the occurrence of pests and diseases were derived from panel data by means of a regression model. These weather indexes were used to re-assess the impact of weather variability on the agronomic efficiency of nitrogen in sugar beet cropping. The results of the bio-physical simulation showed that due to annual variation in weather the agronomic efficiency of nitrogen use was reduced by 10% at the current ratio of prices of nitrogen and sugar beet. The variation in weather, including indirect effects, caused the agronomic efficiency to decrease by 13%. This relatively small decrease suggests that at least some of the indirect weather effects might have an opposite effect on the agronomic efficiency of nitrogen use compared with the direct weather effects. This hypothesis seems to be supported by the absence of a significant correlation between the two weather indexes and by the lower estimated variance of the weather indexes based on panel data. (C) 2002 Elsevier Science B.V. All rights reserved.
Zoektocht naar meten van duurzaamheid
Calker, K.J. van; Galama, P. - \ 2001
Praktijkonderzoek Rundvee, Schapen en Paarden. Praktijkonderzoek 15 (2001)6. - ISSN 1386-8470 - p. 16 - 18.
duurzaamheid (sustainability) - melkveehouderij - bepaling - kenmerken - karakteristieken - indexen - agrarische bedrijfsvoering - sustainability - dairy farming - determination - traits - characteristics - indexes - farm management
Voedselveiligheid en diergezondheid scoren hoog als belangrijke meetpunten voor duurzaamheid. Nitraat in het oppervlaktewater scoort hoger dan nitraat in het grondwater. Dit is een belangrijk signaal om de komende jaren alert op te zijn. Experts van verschillende belangengroepen vinden het gebruik van genetisch gemodificeerde producten minder belangrijk t.a.v. duurzaamheid. Verschillende meetpunten voor duurzaamheid zijn geïnventariseerd. De volgende stap is om na te gaan welke meetpunten daadwerkelijk goed gemeten kunnen worden en hoe verschillende aspecten van duurzaamheid ingewogen kunnen worden tot een totaalindex.
Doelstellingen, inrichting en fasering van de Dierveiligheidsindex
Bokma-Bakker, M.H. ; Vesseur, P.C. - \ 1999
Rosmalen : Praktijkonderzoek varkenshouderij (Proefverslag / Praktijkonderzoek Varkenshouderij P1.222) - 32
varkenshouderij - dierenwelzijn - veiligheid - varkensziekten - regelingen - indexen - nederland - pig farming - animal welfare - safety - swine diseases - regulations - indexes - netherlands
Het Praktijkonderzoek Varkenshouderij heeft in opdracht van de Stichting tot bevordering van de Dierveiligheid van het Nederlandse Varken de doelstellingen van de in ontwikkeling zijnde Dierveiligheidsindex per niveau beschreven. Hierbij is voortgebouwd op het prototype 05.98 van de Dierveiligheidsindex, die reeds eerder onder regie van de Stichting Dierveiligheid door diverse werkgroepen was opgesteld. De Dierveiligheidsindex heeft tot doel om de risico’s op insleep en verspreiding van besmettelijke ziekten versneld weg te nemen en het welzijnsniveau van de varkens te verbeteren. Voorlopers (top-25% van de bedrijven) moeten ermee worden gestimuleerd om (sneller) door te groeien naar hogere niveaus van diergezondheid en welzijn, waardoor uiteindelijk sectorbreed hogere gezondheids- en welzijnsniveaus gerealiseerd kunnen worden
Kwaliteit verbeteren met de Kwaliteit Productie Index. Extra aandacht voor peen en aardappelen
Kloen, H. ; Visser, R. - \ 1999
Ekoland 19 (1999)2. - ISSN 0926-9142 - p. 14 - 15.
veldgewassen - groenten - alternatieve landbouw - biologische landbouw - kwaliteit - indexen - gewaskwaliteit - kwaliteitsnormen - kwaliteitscontroles - opbrengsten - oogstverliezen - gewasverliezen - verliezen na de oogst - opslagverliezen - marketing - prijzen - agrarische bedrijfsvoering - innovaties - vollegrondsteelt - prijsbepalende factoren - field crops - vegetables - alternative farming - organic farming - quality - indexes - crop quality - quality standards - quality controls - yields - yield losses - crop losses - postharvest losses - storage losses - prices - farm management - innovations - outdoor cropping - price determining factors
De KPI is ontwikkeld in het Innovatieproject Ecologische Akkerbouw en Groenteteelt in Flevoland en combineert twee effecten van productkwaliteit, namelijk de vermarktbare opbrengst en de gerealiseerde prijs. Voor een aantal gewassen op tien innovatiebedrijven is de KPI berekend en nagegaan welke maatregelen in vruchtwisseling, rassenkeuze, teelt en bewaring kunnen bijdragen aan een verhoging van de kwaliteitsproductie. Extra aandacht is nodig voor peen en aardappel
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