Poultry litter application to loblolly pine forests: growth and nutrient containment

Forestland application of poultry manure offers an alternative to the conventional practice of pastureland application. Before such a practice is considered viable, however, it must be demonstrated that the forest ecosystem is capable of absorbing the nutrients contained in poultry manure, especially nitrogen (N) and phosphorus (P). From the forestry perspective, it must also be demonstrated that tree growth is not diminished. We investigated these questions using loblolly pine (Pinus taeda L.) stands growing in central Mississippi in an area of high poultry production. Stockpiled broiler litter was applied to newly thinned, 8-yr-old stands at 0, 4.6, and 18.6 dry Mg ha-1, supplying 0, 200, and 800 kg N ha-1 and 0, 92, and 370 kg P ha-1, respectively. Levels of nitrate in soil water, monitored at a 50-cm depth with porous cup tension lysimeters, exceeded 10 mg N L-1 during the first two years after application in the 18.6 Mg ha-1 rate but only on two occasions in the first year for the lower rate of application. Phosphate was largely absent from lysimeter water in all treatments. Other macronutrients (K, Ca, Mg, S) were elevated in lysimeter water in proportion to litter application rates. Soil extractable nitrate showed similar trends to lysimeter water, with substantial elevation during the first year following application for the 18.6 Mg ha-1 rate. Mehlich III-extractable phosphate peaked in excess of 100 microg P g-1 soil during the third year of the study for the 18.6 Mg ha-1 rate. The 4.6 Mg ha-1 rate did not affect extractable soil P. Tree growth was increased by the poultry litter. Total stem cross-sectional area, or basal area, was approximately 20% greater after 2 yr for both rates of litter application. Overall, the nutrients supplied by the 4.6 Mg ha-1 rate were contained by the pine forest and resulted in favorable increases in tree growth. The higher rate, by contrast, did pose some risk to water quality through the mobilization of nitrate. These results show that, under the conditions of this study, application of poultry litter at moderate rates of approximately 5 Mg ha-1 to young stands of loblolly pine offers an alternative disposal option with minimal impacts to water quality and potential increases in tree growth.     

Health and Welfare in Danish Dairy Cattle in the Transition to Organic Production: Problems, Priorities and Perspectives

During the past few years,organic dairy farming has grown dramatically inDenmark. Consequently, an increasing number ofpeople are encountering this method ofproduction for the first time. Amongst these,many veterinarians have suddenly had to dealwith organic herds in their home district, and,meeting examples of poor animal welfare, theyhave recently started to express some concerns.Against this background, a so-called``Synthesis of Knowledge' project was initiatedto examine the health and welfare of dairycattle and the use of medication in thetransition to organic production. The aim ofthe project was to investigate associatedproblems from the point of view of the dairyherd. Based on qualitative research interviewswith vets and agricultural advisors, as well asfocus group interviews with farmers who hadrecently converted from conventional to organicfarming, an expert panel attempted to identifyproblem areas and possible solutions. Theproblems related to (a) the adjustment to newand unknown practices, (b) poor management ingeneral, and (c) inappropriate legislation fororganic farming.One problem area was the rearing of dairycalves, particularly with regard to theestablishment of post partumrelationships between cow and calf, grouphousing, and the grazing of young animals. A``natural life' was identified as beingfundamental to organic animal husbandry. Interms of animal welfare, this concept can beunderstood as a way of living in which the calfis allowed to express its natural behavior andsatisfy its natural needs. Essentially, theconditions needed for good calf welfare requirethe compatibility and interplay of elementsfrom ``nature' (the natural life; includingopportunities to satisfy natural needs) and``culture' (farmer management skills; exerciseof care). These elements should be balanced toensure animal welfare in organic herds.     

Low VOC latex paints from a precipitation polymerization process

Even though paints and coatings have been very useful in protecting various substrates, their use has been accompanied by a heavy environmental price. There is a need to minimize the use of volatile organic compounds (VOCs) in the formulation of these materials. In the latex paint area, we have implemented a conventional precipitation process in emulsions to form binder particles that contain block copolymers and have softer blocks on the particle surface. The softer surface provides the binder film-forming properties without the need for the use of solvents or VOCs. The covalent connections between the soft blocks and the hard blocks are expected to impart good performance in the resulting dry coatings. Indeed, we have shown that our test coating from these binder particles containing block copolymer have similar properties in most performance categories to those of a semi-gloss control paint that has been formulated with typical amounts of VOCs.     

The effects of proximal and distal goals on performance on a moderately complex task

The effect of a proximal plus a distal goal was investigated relative to setting only a distal goal or urging participants to do their best. Young adults (N=39) were paid on a piece rate basis to make toys. An analysis of variance revealed that the amount of money earned by the participants who were urged to ‘do your best’ was significantly greater than the amount of money earned by the participants who were assigned a distal goal. However, the amount of money earned by the participants who were assigned proximal goals, in addition to a distal goal, was significantly greater than the amount of money earned by the participants in the ‘do your best’ condition. The correlation between perceived self‐efficacy and the amount of money earned was 0.45 (p<0.01). Perceived self‐efficacy significantly increased only for those participants in the proximal plus distal goal condition. Proximal goals, through self‐efficacy and performance feedback, appear to have focused attention on task appropriate strategies. The results suggest an informational explanation of proximal goals as opposed to a motivational one through goal commitment. Implications of these findings for mentoring and training are discussed. Copyright © 1999 John Wiley & Sons, Ltd.     

In Flanders Fields: De/politicization and Democratic Debate on a GM Potato Field Trial Controversy in News Media

In May 2011, a highly mediatized direct action in the form of a “field liberation” took place in Flanders, Belgium, against a field trial of genetically modified potatoes. This direct action and its aftermath revealed the conflictual and antagonistic nature of the genetically modified organisms debate in Flanders. Consequently, it serves as a particularly suitable case to investigate the post-political thesis with regard to environmental discourse and politics. The aim of this paper is to investigate in what ways news media in their reporting contribute to processes of depoliticization and, resultantly, impede a democratic debate on the issues at stake. This paper attempts to provide an answer to this question based on a critical discourse analysis of the reporting by Flanders’ two generalist, elite newspapers, De Standaard and De Morgen and the alternative online news site DeWereldMorgen. The findings reveal the existence of three ideological cultures, which are characterized by different degrees of de/politicization. We conclude by discussing how this study adds to our understanding of the relation between the depoliticization of environmental discourse, democratic debate and twenty-first-century news media.     

Assessing PAH and PCB emissions from the relocation of harbour sediments using equilibrium passive samplers

Large-scale dredging of contaminated sediments is taking place in the harbor of Oslo, Norway. The dredged sediment masses are transferred into a confined aquatic disposal facility (CAD) in a natural 70-m deep basin within the Oslofjord. Currently there is no established method to determine how much dissolved contaminants are released during relocation and deposition of these sediments. For this reason we tested the use of equilibrium passive samplers consisting of 55 microm thin polyoxymethylene (POM-55) for studying the release of freely dissolved and thus bioavailable PAHs and PCBs at the disposal site, and found this to be a suitable method. In order to use POM-55 for monitoring PCBs, it was necessary to measure their POM-55/water partition coefficients, which was also presented as part of this study. Elevated turbidity (average 4.1 mg l(-1)) was observed at one side of the basin where no natural sill exists. Analysis of POM-55 at this location before and after deposition revealed that there was an increase in freely dissolved concentrations (C(W,free)) during deposition by a factor 37.5 for PAHs and a factor of 2.9 for PCBs. In addition, during deposition phenanthrene-to-anthracene aqueous concentration ratios at this location (values of 3-4) were more similar to those of the deposited sediments (approximately 2) than to those of the CAD water prior to deposition (approximately 14). This was not observed for the other locations where a natural sill exists at approximately 30 m water depth. The POM-55 equilibrium passive samplers are here shown to be useful tools for measuring and understanding the dynamics involved in the release of dissolved contaminants during sediment relocation.     

Black carbon-dominated PCDD/Fs sorption to soils at a former wood impregnation site

The influence of black carbon (BC) on the sorption of 17 native polychlorinated-p-dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) was studied in five soil samples from a sawmill site where wood used to be impregnated with chlorophenol preservatives. The presence of BC caused measured total organic carbon (TOC)-water distribution ratios (K(TOC)) to be a median factor of 51 (interquartile range 18-68, n=85) higher than modeled amorphous organic carbon (AOC)-water distribution ratios (K(AOC)). K(TOC) was a factor of 73+/-27 above K(AOC) for PCDFs (n=10) and a factor of 20+/-13 (n=7) for PCDDs. The reason for this difference is probably that attaining a planar configuration after sorption to BC is less thermodynamically favorable for PCDDs than for PCDFs. BC-water distribution ratios were calculated from K(TOC), K(AOC) and BC contents, and ranged from 10(9.9) (2,3,7,8-Tetra-CDD) to 10(11.5) l kg(-1) (Octa-CDF). More than 90% of the PCDD/Fs in the soil was calculated to be BC-sorbed. Dissolved organic carbon (DOC)-water distribution ratios were measured to be in the same order of magnitude as K(AOC). This study shows that strong sorption to BC should be included when assessing ecotoxicological risk or modeling transport to groundwater of PCDD/Fs in soil.     

Spatial and temporal variation of metal concentrations in adult honeybees (Apis mellifera L.)

Honeybees (Apis mellifera L.) have great potential for detecting and monitoring environmental pollution, given their wide-ranging foraging behaviour. Previous studies have demonstrated that concentrations of metals in adult honeybees were significantly higher at polluted than at control locations. These studies focused at a limited range of heavy metals and highly contrasting locations, and sampling was rarely repeated over a prolonged period. In our study, the potential of honeybees to detect and monitor metal pollution was further explored by measuring the concentration in adult honeybees of a wide range of trace metals, nine of which were not studied before, at three locations in the Netherlands over a 3-month period. The specific objective of the study was to assess the spatial and temporal variation in concentration in adult honeybees of Al, As, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sb, Se, Sn, Sr, Ti, V and Zn. In the period of July-September 2006, replicated samples were taken at 2-week intervals from commercial-type bee hives. The metal concentration in micrograms per gram honeybee was determined by inductive coupled plasma-atomic emission spectrometry. Significant differences in concentration between sampling dates per location were found for Al, Cd, Co, Cr, Cu, Mn Sr, Ti and V, and significant differences in average concentration between locations were found for Co, Sr and V. The results indicate that honeybees can serve to detect temporal and spatial patterns in environmental metal concentrations, even at relatively low levels of pollution.     

Microscale investigations of the fate of heavy metals associated to iron-bearing particles in a highly polluted stream

As it flows through a dense steelmaking area, the Fensch River does transport iron-rich particles and colloids, displaying high contents in metallic contaminants (Zn, Cr, Pb, Cu, Ni, and As). Chemical analysis using inductively coupled plasma mass spectrometry (ICP-MS) was carried out on three compartments—waters, suspended materials, and sediments—along the river linear. The variations of metallic trace element concentrations along the river were shown to be partially related to external inputs (industrial and domestic wastewaters and urban surfaces leaching). However, some discrepancies of element partitioning were evidenced. Pb, Cu, and Mn tend to concentrate in suspended particulate and in dissolved fraction, while Cr and As follow the trend of Fe and concentrate within sediments of the most downstream station, just before the junction with Moselle waters. Zn appears strongly associated to iron-rich particles, resulting in a decrease of its concentration in waters for the last station. Along the Fensch linear, the variation of metal partitioning between water and particulate phases is accompanied with strong modifications of the nature and mineralogy of iron-rich particles, as evidenced by microanalyses using electron and X-ray beams. The combination of bulk analyses using ICP-MS and microanalyses applied to the three compartments allowed us to propose a three-step process “settling–weathering–resuspension” to explain Zn partitioning.     

In vivo genotoxicity assessment of titanium,zirconium and aluminium nanoparticles,and their microparticulated forms,in Drosophila

As in vivo system, we propose Drosophila melanogaster as a useful model for study the genotoxic risks associated with nanoparticle exposure. In this study we have carried out a genotoxic evaluation of titanium dioxide (TiO₂), zirconium oxide (ZrO₂) and aluminium oxide (Al₂O₃) nanoparticles and their microparticulated forms in D. melanogaster by using the wing somatic mutation and recombination assay. This assay is based on the principle that loss of heterozygosis and the corresponding expression of the suitable recessive markers, multiple wing hairs and flare-3, can lead to the formation of mutant clones in treated larvae, which are expressed as mutant spots on the wings of adult flies. Third instar larvae were feed with TiO₂, ZrO₂ and Al₂O₃ nanoparticles, and their microparticulated forms, at concentrations ranging from 0.1 to 10 mM. Although a certain level of aggregation/agglomeration was observed in solution, it must be noted than the constant digging activity of larvae ensures that treated medium pass constantly through the digestive tract ensuring exposure. The results showed that no significant increases in the frequency of all spots (e.g. small single, large single, twin, total mwh and total spots) were observed, indicating that these nanoparticles were not able to induce genotoxic activity in the wing spot assay of D. melanogaster. Negative data were also obtained with the microparticulated forms. This indicates that the nanoparticulated form of the selected nanomaterials does not modify the potential genotoxicity of their microparticulated versions. These in vivo results contribute to increase the genotoxicity database on the TiO₂, ZrO₂ and Al₂O₃ nanoparticles.