Stakeholder involvement in policy evaluation and development in 11 European countries: synthesis results

In an effort in bringing together stakeholders of the organic farming and general agricultural policy sector within the EU in April Mai 2004 a group of stakeholders met for a one day-workshop in 11 European countries (AT, GB, DE, DK, IT, CH, CZ, PL, SI, EE, HU) to formulate policy recommen¬dations for the development of organic farming sector. Close personal contact of participants in these workshops facilitated policy learning and innovation at the national level and provided a platform to form alliances to decide on further actions. This contribution presents the synthesised results from all national workshops highlighting the current situation of organic farming policy in Europe and providing recommendations for future policy instruments

Der optimale Erntezeitpunkt für tanninhaltige Futterpflanzen

Depending on the concentration in which they are fed, condensed tannins (CT) can have various beneficial or detrimental effects on ruminants. In organic farming the anthelmintic effects of CT are of special interest. In an outdoor experiment, the sea-sonal dynamics of the CT concentration of the harvestable biomass was investigated as a function of the biomass allocation to leaves and stems in Onobrychis viciifolia, Lotus corniculatus and Cichorium intybus in the course of a vegetation period in Zu-rich, Switzerland. Such knowledge is indispensable for a practical application of tan-niferous plants in farming systems. In line with our expectations, CT concentrations were higher in leaves than in stems and the leaf fraction of the harvestable biomass decreased steeply with time in all investigated plant species. In contrast to our expec-tations, within 20 weeks from sowing, the concentration of CT in leaves approximately doubled in Lotus (from 2 to 5% of DM) and in Onobrychis (from 5 to 9% of DM) and was nearly stable in Cichorium (0.5% of DM). Over time, the effect of the declining proportion of leaves in the harvestable biomass was almost exactly neutralized by the increasing concentration of CT in leaves, resulting in close to constant CT concentra-tions in the harvestable biomass during the season. We conclude that among the investigated species, the tannin concentration in Onobrychis seems most promising for the application against gastro-intestinal nematodes. As the CT concentration of harvestable biomass was found to be constant during the season, an optimal time for harvest can be determined in relation to agronomic properties such as fodder quality and yield

Biomass Allocation is an Important Determinant of the Tannin Concentration in Growing Plants

Background and aims Condensed tannins (CTs) in the diet affect consumers in a concentration-dependent manner. Because of their importance in plant defence against herbivores and pathogens as well as their potential application against gastrointestinal parasites of ruminants in agronomy, an understanding of the seasonal dynamics of CT concentrations during plant growth is essential. Methods Over a vegetation period, CT concentrations in leaves, stems and roots and the biomass proportions between these organs were investigated in Onobrychis viciifolia, Lotus corniculatus and Cichorium intybus. Based on the experimental data, a model has been suggested to predict CT concentrations in harvestable biomass of these species. Key Results During the experiment, leaf mass fractions of plants decreased from 85, 64, 85 to 30, 18, 39% d. wt in Onobrychis, Lotus and Cichorium, respectively, and proportions of stems and roots increased accordingly. While CT concentrations almost doubled in leaves in Onobrychis (from 52 to 86mg g−1 d. wt, P<0·001) and Lotus (from 25 to 54mg g−1 d. wt, P<0·001), they were stable at low levels in expanding leaves of Cichorium (5mg g−1 d. wt) and in stems and roots of all investigated species. Due to an inverse effect of the increasing CT concentrations in leaves and simultaneous dilution from increasing proportions of ‘CT-poor' stems, CT concentrations in harvestable biomass were stable over time in all investigated species: 62, 26 and 5mg g−1 d. wt for Onobrychis, Lotus and Cichorium, respectively. Conclusions As a consequence of the unequal distribution of tannins in different plant parts and due to the changing biomass proportions between them, various herbivores (e.g. a leaf-eating insect and a grazing ruminant) may find not only different concentrations of CT in their diets but also different CT dynamics during the season. For the prediction of seasonal variations of CT concentrations, biomass allocation and accumulation of none-CT plant material are likely to be as important predictors as the knowledge of CT synthesis and its regulatio

Plant Enemy-derived Elicitors Increase the Foliar Tannin Concentration of Onobrychis viciifolia Without a Trade-off to Growth

Background and Aims Molecular experiments suggest that the regulation of the biosynthesis of condensed tannin (CT) is sensitive to the presence of plant enemies. The enemy-specific response of CT concentrations to simulated attacks by pathogenic fungi, bacteria or herbivores was studied in Onobrychis viciifolia grown at four levels of nutrient availability. It was hypothesized that CT concentrations increase in response to an attack, and that constitutive and induced levels of CT are higher at low than at high nutrient availability. Investment in CT was also predicted to be negatively related to plant growth. Methods Recently discovered substances by which plants recognize their opponents (i.e. elicitors) were used to simulate attacks to Onobrychis viciifolia grown at 0·0027, 0·075, 0·67 or 2 mm phosphorus in the nutrient solution. Key Results Relative growth rate and final biomass (P < 0·001) were highest at 0·67 mm of phosphorus. CT concentrations decreased with increasing phosphorus availability, from 94·9 to 69·0 mg g−1 leaf dry weight (P < 0·001). Compared with unscathed plants, sterile mere mechanical wounding reduced tannin concentrations from 83·8 to 69·3 mg g−1 leaf dry weight (P < 0·01). Local CT concentrations were higher when wounded leaves were additionally treated with fungal (+15·9 %), bacterial (+19·6 %) or insect (+31·0 %) elicitors (each elicitor; P < 0·05); however, only the insect elicitor (saliva of the lepidopteron Spodoptera littoralis) induced CT concentrations higher than those of unscathed leaves. Conclusions CT concentrations were inducible in the vicinity of the wound but the level of induction was unrelated to the nutrient status of the plant. There was no evidence of a growth-defence trade-off. The inverse relathionship between CT concentrations and nutrient availability appears to reflect passive growth dilution at high nutrient availability, rather than surplus CT production at low nutrient availabilit

Regulatory parameters of self-healing alginate hydrogel networks prepared via mussel-inspired dynamic chemistry

Several key parameters that influence both the self-healing properties and water retention capacity of biohydrogel networks made of alginate-dopamine (Alg-DA) conjugates have been studied. A judicious combination of biopolymer concentration, dopamine content, pH-dependent cross-linking of catechol groups and the Fe3+-coordination of the networks allowed control over the self-healing ability of these bioinspired materials. Moreover, the thixotropic nature of model hydrogels was confirmed using oscillatory rheological loop tests

Urban-Rural Gradient Analysis of Amount and Distribution of Carbon and Nitrogen in Soils of Kumasi Region, Ghana

While urbanisation is a global phenomenon, cities in developing countries exhibit particularly high levels of growth in recent years. In Ghana, this phenomenon of rapid growth from 31% of the people living in urban areas in 1984 to 51% urban population in 2010 has created expansive urban forms, impacting natural resources. The aim of this study is to analyse some of the impacts on soils of this rapid urban development. A stratified random sampling design was used to sample soils from 70 maize fields on Acrisols within the area of Kumasi, which was urban already in 1986, and other areas that became urban later. Rural maize fields and forests were also sampled. Three replicates were taken at each site of maize mono-crop and/or mixed-crop subsistence farms to keep consistency. Topsoil samples (0-10 cm depth) were taken volumetrically in 250 cm3 steel cylinders. The samples are currently analysed for soil pH, and for C and N by use of a Leco TruSpec CHN analyser. An ANOVA will be calculated to analyse the differences in means between urban and non-urban areas. A variogram will then be fitted to characterise spatial correlations in the urban to rural continuum of C and N amounts, and consequently mapped out. We hypothesise that C and N contents of soils under maize in urbanised areas of Kumasi exceed those of comparable soils and land-use in adjacent rural areas as reported by Bellwood-Howard et al. 2015, for other West-African cities. Among other reasons, disposal of household waste including organic materials, which is generally practised in urban Ghana due to inadequate waste management, is expected to increase C and N contents. We suggest that urban farms, if well-coordinated into urban planning and management, can provide a viable source of food security to urban dwellers in developing countries. Although analyses of additional parameters are needed pH as well as C and N amounts already provide relevant information on the critical role urbanisation play in the sustainable development of cities in Ghana

Spectroastrometry of rotating gas disks for the detection of supermassive black holes in galactic nuclei. II. Application to the galaxy Centaurus A (NGC 5128)

We measure the black hole mass in the nearby active galaxy Centaurus A (NGC 5128) using a new method based on spectroastrometry of a rotating gas disk. The spectroastrometric approach consists in measuring the photocenter position of emission lines for different velocity channels. In a previous paper we focused on the basic methodology and the advantages of the spectroastrometric approach with a detailed set of simulations demonstrating the possibilities for black hole mass measurements going below the conventional spatial resolution. In this paper we apply the spectroastrometric method to multiple longslit and integral field near infrared spectroscopic observations of Centaurus A. We find that the application of the spectroastrometric method provides results perfectly consistent with the more complex classical method based on rotation curves: the measured BH mass is nearly independent of the observational setup and spatial resolution and the spectroastrometric method allows the gas dynamics to be probed down to spatial scales of ~0.02", i.e. 1/10 of the spatial resolution and ~1/50 of BH sphere of influence radius. The best estimate for the BH mass based on kinematics of the ionized gas is then log(MBH (sin i)^2/M\odot)=7.5 \pm 0.1 which corresponds to MBH = 9.6(+2.5-1.8) \times 10^7 M\odot for an assumed disk inclination of i = 35deg. The complementarity of this method with the classic rotation curve method will allow us to put constraints on the disk inclination which cannot be otherwise derived from spectroastrometry. With the application to Centaurus A, we have shown that spectroastrometry opens up the possibility of probing spatial scales smaller than the spatial resolution, extending the measured MBH range to new domains which are currently not accessible: smaller BHs in the local universe and similar BHs in more distant galaxies

Tanniferous forage plants: Agronomic performance, palatability and efficacy against parasitic nematodes in sheep

Tanniferous forage plants can have beneficial effects on ruminant productivity and health (improved protein supply, bloat safety and antiparasitic properties). However, condensed tannins can also lower palatability, voluntary feed intake and digestibility. The aim of our interdisciplinary project was to generate basic knowledge on plant management, feed palatability and the antiparasitic properties of tanniferous forage plants for their practical application in agronomy, focusing on their usefulness in controlling gastrointestinal nematodes in organic farming. We found that Onobrychis viciifolia (sainfoin), Lotus corniculatus (birdsfoot trefoil) and Cichorium intybus (chicory) were suitable for cultivation under the given temperate climatic conditions, whereas Lotus pedunculatus (big trefoil) was soon outcompeted by unsown species. Growing the tanniferous plant species in a mixture with Festuca pratensis (meadow fescue) rather than in a monoculture had the advantage of increasing total dry matter (DM) yield (especially in the case of tanniferous legumes) and of reducing the DM proportions of unsown species. However, due to dilution by non-tanniferous F. pratensis, the tannin concentrations of mixtures were clearly lower and the seasonal fluctuations in tannin concentrations greater than that of monocultures. Across species, tannin concentrations were highest for O. viciifolia, followed by L. corniculatus and very low for C. intybus. Palatability of all tanniferous forages was comparable to that of a ryegrass/clover mixture when fed as dried forage and, when offered as silage, palatability of O. viciifolia was clearly superior to that of the respective ryegrass/clover control. Administration of dried or ensiled O. viciifolia reduced parasite egg counts in feces of lambs co-infected with the gastrointestinal nematode species Haemonchus contortus and Cooperia curticei. We conclude that O. viciifolia is the most promising among the tested tanniferous forage plant species due to its suitability for cultivation, its high tannin concentration, its high palatability and its antiparasitic activity even in dried or ensiled for

The Effects of X-Ray Feedback from AGN on Host Galaxy Evolution

Hydrodynamic simulations of galaxies with active galactic nuclei (AGN) have typically employed feedback that is purely local: i.e., an injection of energy to the immediate neighborhood of the black hole. We perform GADGET-2 simulations of massive elliptical galaxies with an additional feedback component: an observationally calibrated X-ray radiation field which emanates from the black hole and heats gas out to large radii from the galaxy center. We find that including the heating and radiation pressure associated with this X-ray flux in our simulations enhances the effects which are commonly reported from AGN feedback. This new feedback model is twice as effective as traditional feedback at suppressing star formation, produces 3 times less star formation in the last 6 Gyr, and modestly lowers the final BH mass (30%). It is also significantly more effective than an X-ray background in reducing the number of satellite galaxies.Comment: 9 emulateapj pages, 8 figures; accepted to Ap