10 Jahre Forschungsschwerpunkt Ökologischer Landbau und extensive Landnutzungssysteme

Der vorliegende Band gibt einen kompakten Überblick über die Forschungsaktivitäten der vergangenen 10 Jahre im Forschungsschwerpunkt "Ökologischer Landbau und extensive Landnutzungssysteme" der Universität Kiel

Comparative analysis of conventional and organic farming systems: Nitrogen surpluses and nitrogen losses

Nutrient management is a key factor for both economic viability and environmental performance of farming systems. On 32 representative conventional and organic farms in Northern Germany, nutrient management was analyzed in the interdisciplinary monitoring project “COMPASS”. Organic farms had significantly lower nitrogen (N) surpluses compared with conventional farms. The majority of organic farms had very low or even negative N surpluses, indicating insufficient N supply in the cropping system. Nitrogen leaching, however, was too high in many cases on both conventional and organic farms. Strategies for a more targeted nutrient supply in organic farming need to be developed and implemented

The Spatial Clustering of Low Luminosity AGN

We present the first multi-parameter analysis of the narrow line AGN clustering properties. Estimates of the two-point correlation function (CF) based on SDSS DR2 data reveal that Seyferts are clearly less clustered than normal galaxies, while the clustering amplitude (r_0) of LINERs is consistent with that of the parent galaxy population. The similarities in the host properties (color and concentration index) of Seyferts and LINERs suggest that the difference in their r_0 is not driven by the morphology-density relation. We find that the luminosity of [O I] emission shows the strongest influence on AGN clustering, with low L([O I]) sources having the highest r_0. This trend is much stronger than the previously detected dependence on L([O III]), which we confirm. There is a strong correspondence between the clustering patterns of objects of given spectral type and their physical properties. LINERs, which exhibit high r_0, show the lowest luminosities and obscuration levels, and relatively low gas densities (n_e), suggesting that these objects harbor black holes that are relatively massive yet weakly active or inefficient in their accretion, probably due to the insufficiency of their fuel supply. Seyferts, which have low r_0, are luminous and show large n_e, suggesting that their black holes are less massive but accrete quickly and efficiently enough to clearly dominate the ionization. The low r_0 of the H II galaxies can be understood as a consequence of both the morphology-density and star formation rate-density relations, however, their spectral properties suggest that their centers hide amidst large amounts of obscuring material black holes of generally low mass whose activity remains relatively feeble. Our own Milky Way may be a typical such case.[abridged]Comment: 27 pages, color figures, some are severely degraded in resolution, emulateapj. See http://www.physics.drexel.edu/~constant/work/agnclustering.ps for high resolution version. Accepted to Ap

N-Auswaschung unter ökologisch und konventionell bewirtschafteten Praxisflächen in Norddeutschland – Ergebnisse aus dem Projekt COMPASS

Nitrogen (N) leaching, especially in the form of nitrate (NO3-), still represents a major environmental impact from agriculture. In order to estimate potential N leaching losses under conditions on commercial farms in Northern Germany, N leaching was analyzed by using ceramic suction cups on representative fields on eight organic and conventional farms. On dairy farms, permanent grassland and maize for silage were analyzed as the main fodder crops. On arable farms, one crop with a high risk and one with a low risk of N leaching losses were selected. On permanent grassland, N leaching was pronouncedly lower on organic farms. If grass/clover on organic farms was ploughed, high amounts of N were leached in the following winter, irrespective if grass/clover was ploughed in spring or in late summer. N management on organic farms, especially the management of crop residues, still needs to be improved to meet the N demand of crops and to reduce N losses

Change of Muscle Activity as Well as Kinematic and Kinetic Parameters during Headers after Core Muscle Fatigue

In soccer, headers are a tactical measure and influenced by numerous factors. The goal of this study was to identify whether changes in kinematics and muscular activity, especially of the head-stabilizing muscles, occur during headers when the core musculature is fatigued. In two subgroups, muscular activity (12 amateur players, age 23.6 ± 4.2 years) and kinematics and dynamics (29 amateur players, age 23.7 ± 2.8 years) were examined during straight headers on a pendulum header. Data were collected before and after the core muscles were fatigued by an exercise program. Telemetric surface EMG, 3D acceleration sensor, force plate, and video recordings were used. Under fatigue, the activity of M. erector spinae and M. rectus abdominis was significantly reduced in the preparation phase of the header. The activity of M. sternocleidomastoideus was significantly increased during the jump phase, and the hip extension angle during maximum arched body tension was significantly reduced under fatigue. Jumping height, acceleration force impulse, and linear head acceleration were also significantly reduced. We conclude that fatigue of the core muscles affects the motion technique of the header and the activity of the muscle groups stabilizing the head. Therefore, the necessity of specific training in soccer should be emphasized from a medical-preventive point of view

Digital Campaigning on the Rise? A Long-term Perspective on German Federal Elections

In den letzten zehn Jahren sind digitale Werkzeuge zu zentralen Elementen von Wahlkampagnen geworden. Dieser Trend könnte sich im Jahr 2021 noch verstärkt haben, da die Möglichkeiten für persönliche Interaktionen aufgrund der starken Einschränkungen durch die COVID-19-Pandemie begrenzt waren. Es ist jedoch wenig darüber bekannt, ob sich der Einsatz digitaler Instrumente am Wahltag auszahlt. Der Beitrag geht daher der Frage nach, inwieweit die Bundestagskandidaten bei den vergangenen Bundestagswahlen digitale Instrumente genutzt haben und ob diese Aktivitäten mit besseren Wahlergebnissen im Jahr 2021 verbunden sind. Analysen der Kandidatenbefragungen der German Longitudinal Election Study (GLES) deuten darauf hin, dass Wahlkreiskandidaten zunehmend digitale Kampagnen nutzen. Dieser Trend hat sich durch die Wahl 2021 nicht verstärkt. Vielmehr ist ein "natürlicher" Anstieg zu beobachten. Zudem ist die Nutzung einer eigenen Website oder eines Blogs mit leicht besseren Wahlergebnissen verbunden.In the last decade, digital tools have become central elements of electoral campaigns. This trend might have been amplified in 2021, as the possibilities for personal interactions were limited due to the severe restrictions of the COVID-19 pandemic. However, little is known about whether the use of digital tools pays off on election day. Thus, this research note asks to what extent Bundestag candidates used digital tools in the past federal elections and whether the activities are associated with better election results in 2021. Analyses of the candidate surveys of the German Longitudinal Election Study (GLES) indicate that constituency candidates increasingly use digital campaigning. This trend was not boosted by the 2021 election. Instead, a 'natural' increase is observable. Moreover, using a personal website or blog is associated with slightly better election results

Wissen, wo man steht. Ergebnisse des Projektes "COMPASS".

Das Projekt "COMPASS" der Agrar- und Ernährungswissenschaftlichen Fakultät der Universität Kiel beschäftigt sich seit 2004 mit dem Monitoring von Leistungen und ökologischen Effekten auf 32 konventionellen und ökologischen Praxisbetrieben. Im vorliegenden Band sind die zentralen Ergebnisse aus den Bereichen Nährstoffmanagement, Pflanzenschutz, Rückstandsproblematik, Tiergesundheit und Biodiversität (EU-Projekt AVI-LAND) umfassend und gleichzeitig anschaulich dargestellt

N-Bilanzen ökologischer und konventioneller Praxisbetriebe in Norddeutsch-land – Ergebnisse aus dem Projekt COMPASS

Nutrient balances are important agri-environmental indicators, which describe the magnitude of potential nutrient losses from farming systems to the environment. In order to analyze production systems at the entire farm scale, nitrogen balances and other agri-environmental indicators were assessed on 32 organic and conventional farms in Northern Germany. On organic farms, nitrogen fixation of legumes was determined on representative fields. Irrespective of the specialization (all-arable farms, dairy farms), nitrogen surpluses were always pronouncedly lower on organic farms compared to conventional farms. Organic farms generally conducted a sustainable nutrient management. However, the total nitrogen supply at the farm scale was not sufficient on many organic arable farms