87 research outputs found
Low Greenhouse Gas Agriculture: Mitigation and Adaptation Potential of Sustainable Farming Systems
Is low greenhouse gas emission (GHG) agriculture possible? Is it, in fact, desirable? In seeking answers to these two basic but extremely relevant questions, this study examines current farming practices, and incorporates scientific databases from longterm field experiments as case studies for low GHG agriculture. Further, the study examines the changes that will be needed for low greenhouse gas agriculture systems to become a reality. It also elucidates the adaptive capacity of agro-ecological farming system approaches, using organic system case studies from the scientific literature.
Each year, agriculture emits 10 to 12 percent of the total estimated GHG emissions, some 5.1 to 6.1 Gt CO2 equivalents per year. Smith, et al. (2007) and Bellarby, et al. (2008) have proposed mitigation options for GHG emissions, finding that both farmers and policymakers will face challenges from the GHG-related changes needed in agriculture. Areas for improvement include increased use of no-till cropping, agro-forestry, and integrated crop and animal farming, and decreased use of external inputs in food and agriculture. The techniques offered by organic agriculture are valuable for consideration in these efforts
N released from organic amendments is affected by soil management history
A ryegrass bioassay was conducted to investigate the effect of soil management history on nitrogen mineralisation from composted manure and pelleted poultry manure. Soils were used from 2 field experiments comparing conventional and organic/low input management systems. When composted manure was added, soils which had received high rates of composted FYM under biodynamic management released a greater amount of nitrogen for plant uptake than those with a history of mineral or fresh manure fertilisation, suggesting that biological preconditioning may result in greater efficiency of composted FYM as a nitrogen source for plants. “Native” N mineralisation was found to be related to total soil N content
Strukturelle und funktionelle Charakterisierung von mikrobiellen Gemeinschaften in ökologisch und konventionell bewirtschafteten Agrarböden
Soil samples from the DOK long-term field trial were investigated to study influences of different farming systems on structure and function of soil microbial communities. The DOK long-term field trial in Switzerland consists of plots managed bio-dynamically (D), bio-organically (O), conventionally (K) and of those which are managed conventionally but only receive mineral fertilizer (M).
In spring 2003 soil samples from these differently managed plots were taken. All investigated fields were planted with winter wheat in 2003, but with different croppings in 2002: potato and maize cultivation, respectively. Analyses of phospholipid fatty acids (PLFA) and phospholipid etherlipids (PLEL) were carried out to determine bacterial, eukaryotic and archaeal phenotypic diversity. By combining this technique with isotope ratio mass spectrometry (GC/MS-C-IRMS) it was possible to analyse simultaneously 13C/12C ratios in PLFA and PLEL biomarkers for functional analyses of the soil microbiota.
First results revealed differences in the total microbial biomass and community structure among the compared farming systems. Furthermore, the incorporation of the maize derived carbon could be detected in several PLFA at the natural abundance level. This may be an indication for the role of different microbial groups during organic matter degradation
Gesellschaftliche Leistungen der biologischen Landwirtschaft
Zusammenfassuung:
In diesem Bericht werden die wissenschaftlichen Ergebnisse nationaler und internationaler Studien zu den gesellschaftlichen Leistungen des Biolandbaus zusammengefasst. Als Referenzen werden dabei sowohl die konventionelle wie auch die integrierte Landwirtschaft herangezogen.
Es ist den Autoren bewusst, dass alle Landwirtschaftsmethoden in der Schweiz und im Ausland eine grosse Streubreite aufweisen, da der Einfluss der regionalen sozioökonomischen Rahmenbedingungen, der Standortfaktoren, der Betriebsleiter und der unterschiedlichen staatlichen und privaten Regulierungen gross ist. Trotzdem ergeben sich für die verschiedenen Landwirtschaftsmethoden klare Unterschiede, die bei den agrarpolitischen Massnahmen berücksichtigt werden müssen.
Bezüglich der positiven Externalitäten weist der Biolandbau klare Mehrleistungen in der Biodiversität auf. Dies sowohl auf der Ebene der Genetik, der Arten und besonders auch der Habitate. Deutlich sind die Mehrleistungen des Biolandbaus auch im Bereich des Humusaufbaus, was eine höhere CO2-Sequestrierung zur Folge hat.
Obwohl eine dauerhafte Honorierung der Vermeidung negativer Externalitäten im bisherigen Konzept der Weiterentwicklung des Direktzahlungssystems (WDZ) nicht vorgesehen ist, sind
hier die Vorteile der biologischen Landwirtschaft beträchtlich. Dies betrifft die Nährstoff- und Pflanzenschutzmittelverluste in Grund- und Oberflächengewässer sowie in andere Umweltkompartimente, der Verbrauch von nicht erneuerbarer Energie, die Emissionen von Klimagasen und die Belastungen mit Tiermedikamenten.
Die nationalen und internationalen Studien zeigen auf, dass der Biolandbau sich besonders durch Systemwirkungen auszeichnet: erhöhte Biodiversität, verbesserter Schutz des Bodens, wirksame Vermeidung von Umweltbelastungen, effiziente Nutzung von natürlichen Ressourcen, geringer Verbrauch nicht erneuerbarer Energie und verbessertes Tierwohl. Dies sind die Effekte von komplexen Response-Massnahmen der Betriebsleiter auf einfach zu kontrollierende Einschränkungen und Verbote. Dadurch entstehen nicht zu unterschätzende Zusatzleistungen und Synergien bei der Erreichung der vom Bund definierten Ziele.
Um den Mehrleistungen des Biolandbaus gerecht zu werden, schlagen die Autoren zwei neue Massnahmen vor:
1) Biodiversitätsbeitrag für Acker, Sonderkulturen und intensive Wiesen und
2) CO2-Sequestrationsbeiträge.
Damit sind aber die gesellschaftlich wichtigen Mehrleistungen des Biolandbaus noch nicht abgegolten. Bei der Vermeidung negativer Externalitäten werden höhere umweltschutzrelevante Effekte erzielt.
Diese können
i) durch die EinfĂĽhrung eines negativen Anreizsystems nach dem Polluter-Pays-Principle (z.B. Stickstoffsteuer, CO2 - Abgabe),
ii) durch ein höheres Einstiegsniveau bei den Cross-Compliance-Massnahmen für alle Betriebe (ÖLNplus) oder
iii) durch einen finanziellen Ausgleich fĂĽr die Mehrleistungen des Biolandbaus abgegolten werden.
Die „Förderung des Biolandbaus“ als systemorientierte Massnahme macht auch nach dem Grundsatz des effizienten Einsatzes von Steuermitteln Sinn und stellt eine kosteneffektive Massnahme dar. Einerseits können damit die deutlich höheren positiven Externalitäten abgegolten werden, andererseits wird die stärkere Vermeidung von negativen Externalitäten genügend berücksichtigt
Identification of a protein encoded in the EB-viral open reading frame BMRF2
Using monospecific rabbit sera against a peptide derived from a potential antigenic region of the Epstein-Barr viral amino acid sequence encoded in the open reading frame BMRF2 we could identify a protein-complex of 53/55 kDa in chemically induced B95-8, P3HR1 and Raji cell lines. This protein could be shown to be membrane-associated, as predicted by previous computer analysis of the secondary structure and hydrophilicity pattern, and may be a member of EBV-induced membrane proteins in lytically infected cells
Compared to conventional, ecological intensive management promotes beneficial proteolytic soil microbial communities for agro-ecosystem functioning under climate change-induced rain regimes
Projected climate change and rainfall variability will affect soil microbial communities, biogeochemical cycling and agriculture. Nitrogen (N) is the most limiting nutrient in agroecosystems and its cycling and availability is highly dependent on microbial driven processes. In agroecosystems, hydrolysis of organic nitrogen (N) is an important step in controlling soil N availability. We analyzed the effect of management (ecological intensive vs. conventional intensive) on N-cycling processes and involved microbial communities under climate change-induced rain regimes. Terrestrial model ecosystems originating from agroecosystems across Europe were subjected to four different rain regimes for 263 days. Using structural equation modelling we identified direct impacts of rain regimes on N-cycling processes, whereas N-related microbial communities were more resistant. In addition to rain regimes, management indirectly affected N-cycling processes via modifications of N-related microbial community composition. Ecological intensive management promoted a beneficial N-related microbial community composition involved in N-cycling processes under climate change-induced rain regimes. Exploratory analyses identified phosphorus-associated litter properties as possible drivers for the observed management effects on N-related microbial community composition. This work provides novel insights into mechanisms controlling agro-ecosystem functioning under climate change
Multicenter Tract-Based Analysis of Microstructural Lesions within the Alzheimer's Disease Spectrum: Association with Amyloid Pathology and Diagnostic Usefulness
Diffusion changes as determined by diffusion tensor imaging are potential indicators of microstructural lesions in people with mild cognitive impairment (MCI), prodromal Alzheimer’s disease (AD), and AD dementia. Here we extended the scope of analysis toward subjective cognitive complaints as a pre-MCI at risk stage of AD. In a cohort of 271 participants of the prospective DELCODE study, including 93 healthy controls and 98 subjective cognitive decline (SCD), 45 MCI, and 35 AD dementia cases, we found reductions of fiber tract integrity in limbic and association fiber tracts in MCI and AD dementia compared with controls in a tract-based analysis (p < 0.05, family wise error corrected). In contrast, people with SCD showed spatially restricted white matter alterations only for the mode of anisotropy and only at an uncorrected level of significance. DTI parameters yielded a high cross-validated diagnostic accuracy of almost 80% for the clinical diagnosis of MCI and the discrimination of Aβ positive MCI cases from Aβ negative controls. In contrast, DTI parameters reached only random level accuracy for the discrimination between Aβ positive SCD and control cases from Aβ negative controls. These findings suggest that in prodromal stages of AD, such as in Aβ positive MCI, multicenter DTI with prospectively harmonized acquisition parameters yields diagnostic accuracy meeting the criteria for a useful biomarker. In contrast, automated tract-based analysis of DTI parameters is not useful for the identification of preclinical AD, including Aβ positive SCD and control cases
Dietary patterns are related to cognitive functioning in elderly enriched with individuals at increased risk for Alzheimer's disease
PURPOSE: To investigate cross-sectional associations between dietary patterns and cognitive functioning in elderly free of dementia. METHODS: Data of 389 participants from the German DELCODE study (52% female, 69 ± 6 years, mean Mini Mental State Score 29 ± 1) were included. The sample was enriched with elderly at increased risk for Alzheimer's disease (AD) by including participants with subjective cognitive decline, mild cognitive impairment (MCI) and siblings of AD patients. Mediterranean and MIND diets were derived from 148 Food Frequency Questionnaire items, and data-driven patterns by principal component analysis (PCA) of 39 food groups. Associations between dietary patterns and five cognitive domain scores were analyzed with linear regression analyses adjusted for demographics (model 1), and additionally for energy intake, BMI, other lifestyle variables and APOe4-status (model 2). For PCA-derived dietary components, final model 3 included all other dietary components. RESULTS: In fully adjusted models, adherence to Mediterranean and MIND diet was associated with better memory. The 'alcoholic beverages' PCA component was positively associated with most cognitive domains. Exclusion of MCI subjects (n = 60) revealed that Mediterranean and MIND diet were also related to language functions; associations with the alcoholic beverages component were attenuated, but most remained significant. CONCLUSION: In line with data from elderly population samples, Mediterranean and MIND diet and some data-derived dietary patterns were related to memory and language function. Longitudinal data are needed to draw conclusions on the putative effect of nutrition on the rate of cognitive decline, and on the potential of dietary interventions in groups at increased risk for AD
Alterações nas propriedades quĂmicas e microbianas de solos cultivados com videiras sob manejo orgânico e convencional no sul do Brasil
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