Monitoring der Auswirkungen einer Umstellung auf den biologischen Landbau (MUBIL II). Abschlussbericht

Since 2003, a long-term field monitoring of the development of Organic Farming has been performed at the bio-farm “Rutzendorf“ in the Marchfeld region east of Vienna. The overall project focus includes three topics: (1) effects of organic farming on soil and plant characteristics depending on three organic fertilization systems (variant 1: green manure: mulching lucerne; variant 2: green manure plus communal compost; variant 3: farmyard manure: harvesting and removal of lucerne crop and cereal straw) (2) effects of hedges on micro climate, water capacity of the soils and crop performances, (3) analyses and cultivation of existing biotopes and establishment of new biotope structures, effects of biotopes and organic farming on the biodiversity of the farm. In the current phase of the project (MUBIL II, 2006 to March 2009), first effects of the conversion have been confirmed and new developments have occurred. (1) Soil monitoring in the period 2003 – 2008 has shown that the concentrations of plant available, CAL-extractable P and K pools remained in the range of “sufficient availability”. An investigation on five additional sites has shown that also for sites with long term organic farming (12 – 18 years) a sufficient or even high availability of P and K can be expected. This assumption is supported by the fact that in all studied soils a very large pool of organically bound phosphorous (which becomes plant available due to microbial degradation) has been detected. Measurements of the soil water balance showed that biologically farmed fields had higher soil water contents than conventional fields, especially in dry years. A significant impact of the kind of fertilization was not observed. Lucerne in the crop rotation had a positive influence on soil physical parameters like bulk density, saturated hydraulic conductivity, aggregate stability and the N mineralization potential. The densities and diversities of the soil fauna (oribatid and gamasid mites and springtails) were very low at the onset of the study in 2003. Except for the conventional site, the abundance and species richness of Collembola and Gamasida considerably increased in all organic land use types after an initial lag phase. Generally, the conversion to organic farming had a positive effect on Collembola and Gamasida; however, there was no discernible difference between three manure treatments. It is not yet clear if the resulting large numbers will sustain in the following years. Compared to the conventional managed field the number of weed species on the permanent plots is clearly higher but no continuous increase over the investigated years was detected. Under lucerne and under field pea the highest species numbers were found. Due to a decrease in numbers during the following years of the crop rotation, no problems for the practice are assumed. The different fertilizers have neither shown an effect on the emergence of weeds nor on the number of seeds. The yield of winter wheat following lucerne was significantly lower in variant 3 because of the removal of lucerne biomass in this system in contrast to the systems with lucerne mulching. No significantly positive effect of a fertilisation with communal compost and farmyard manure on crop yield has been detected. However, interesting results can be found by analysis of all fertilised trials of the last years. Overall, the fertilisation with farmyard manure (system 3) reached tendentiously the highest crop yields. The communal compost fertilisation did not show so constant results because of the lower nitrogen effect of the compost in contrast to the farmyard manure. The yield development of the three organic fertilization systems was confirmed by the results of nutrient and humus balances calculated with the agro software REPRO. The nutritional value of wheat from organic farms has been examined. Based on these results, it is recommended to conduct regular feed analysis, implying crude protein analysis at least, if home-grown grains are fed to livestock on organic farms. Variant 1 achieved the highest average gross margin during the six years period. The assumed costs for the organic manure in variant 2 and 3 could not be covered by higher revenues. The main influence on the level of the gross margin was, among the climatic conditions, the fluctuating prices of the cash crops during the sample period. (2) Field studies have shown a total sphere of influence of hedgerows in relation to their orientation, permeability and height of about the 15 to 20 fold of the height. Furthermore, available water resulting from precipitation, reduced evapotranspiration due to wind breaks or dislocation of snow has a high impact on (soil) water balance and hence on agriculture at this relatively dry location in Rutzendorf. The impact of the hedgerow lead to reduced water losses and higher soil water contents within a distance of 3 times the barrier height. These positive effects were higher in years with low precipitation amounts. Furthermore a positive effect of a hedge on crop yield in the adjacent field was shown. Yield increases ranged from 9.5 to 23.7 percent depending on the cultivated crop, the temperature and the amount of rain in the period of growth. (3) Hedges and tree rows on the farm proved to be species-poor and the structure is more and more degenerating. Therefore cultivation measures have been identified to improve the multi-functionality of landscape elements as well as biodiversity. These measures have been mapped in a preservation concept for the biotope structures. Along hedges and between fields 6 m broad “eco-stripes” were established. An increase in species diversity was achieved by sowing authochthonal wild flowers in one part of the stripes. In the other part of the stripes, which was left to natural succession, low diversity was recorded. A total of 139 species of wild bees was recorded in the project area Rutzendorf. The results show high diversity and rare species in five year old “eco-stripes” in the east. The species richness of two year old “eco-stripes” was also high, but only euryeicous species were found. Carabids and hoover flies were accumulated in and alongside the eco-stripes due to their rich blossom supply. By single-plant countings of pea aphids and their antagonists in three different distances of a flowering strip, lower aphid densities were recorded close to the eco-stripe. These could not be attributed to higher beneficial efficacy there. The spatial distribution of arthropod group numbers emphasizes the significance of hedges and eco-stripes for arthropod biodiversity. In 2006-2008, the territories of breeding birds in the research area Rutzendorf were censused using the mapping method. The impoverished breeding bird community was dominated by skylark and pheasant. Diversity and abundance of breeding birds have clearly increased since the beginning of the project in 2003

Alpha Interferon-Induced Antiretroviral Activities: Restriction of Viral Nucleic Acid Synthesis and Progeny Virion Production in Human Immunodeficiency Virus Type 1-Infected Monocytes

Alpha interferon (IFN-a) restricts multiple steps of the human immunodeficiency virus type 1 (HIV-i) life cycle. A well-described effect of IFN-a is in the modulation of viral nucleic acid synthesis. We demonstrate that IFN-α influences HIV-1 DNA synthesis principally by reducing the production of late products of reverse transcription. The magnitude of IFN-α-induced downregulation of HIV-1 DNA and/or progeny virion production was dependent on the IFN-α concentration, the duration of cytokine administration, the multiplicity of infection, the viral strain, and the cycles of viral infection. Interestingly, reductions in viral DNAs could not fully account for the observed IFN-a-induced abrogation of progeny virion production. These data, by our investigation of both single-cycle and spreading viral infections, support a predominant but not exclusive effect of IFN-α on viral DNA synthesis

Monitoring der Umstellung auf den Ökologischen Landbau

A long term field monitoring concerning the development of organic farming is performed at the bio-farm "Rutzendorf" of the BVW GmbH in the Marchfeld region East of Vienna. It is an interdisciplinary project of eleven scientific institutes which started in 2003. The aims of the project are: examination of changes concerning soil and plant parameters with the conversion to organic farming; investigation of the effects of different organic fertilisation systems (green manure, communal green forage compost, farmyard manure) on soil properties and on the development of crops; analysis of existing biotops (hedges and field stripes) on the farm and planning and selective realization of new biotops with the aim of enhancing the biodiversity of the area

Monitoring der Umstellung auf den biologischen Landbau (MUBIL). Abschlussbericht

Auf dem Biobetrieb Rutzendorf der BVW GmbH im Marchfeld wurde ein umfassendes Langzeitmonitoring zur Entwicklung des biologischen Landbaus eingerichtet. Das interdisziplinäre Projekt hat 2003 begonnen und untersucht die wichtigsten Systemkomponenten in einem Agrarökosystem. Ziele des Projekts: (a) Feststellen der Wirkungen der Umstellung auf Boden und Pflanzen, (b) Vergleichen der Nachhaltigkeit von drei Düngungsvarianten, (c) Analysieren der Auswirkungen von Biotopstrukturen und der Bewirtschaftung auf die Biodiversität am Betrieb. Im ersten Projektjahr wurden die Monitoringflächen eingerichtet und die Ausgangssituation erhoben. Ein Einfluss der biologischen Bewirtschaftung und der Düngung auf die untersuchten Bodenparameter konnte mit Ausnahme der Aggregatstabilität noch nicht festgestellt werden. Erste Ertragsdifferenzen aufgrund der unterschiedlichen Düngung liegen vor. Die biologische Bewirtschaftung und die Anlage von Ökostreifen hat sich positiv auf die Biodiversität, sowohl der Fauna als auch der Flora, ausgewirkt. In der Nähe einer Hecke waren die Erträge und die Bodenwassergehalte höher als im freien Feld

Auswirkungen unterschiedlicher Düngungssysteme im Ökologischen Landbau auf Bodenparameter und Entwicklung der Pflanzen

Auf dem landwirtschaftlichen Betrieb Rutzendorf soll ein umfassendes Langzeitmonitoring zur Entwicklung des biologischen Landbaus eingerichtet werden. Ein wissenschaftliches Konzepts soll erarbeitet und zum Teil schon umgesetzt werden. Die Wirkungen der Umstellung auf Ökologischen Landbau auf Boden, Wasser, Flora und Fauna soll anhand ausgewählter Eigenschaften erfasst werden. Entsprechend der Konzeption des Betriebs (vgl. ¿Konzept Biobetrieb Rutzendorf¿, Bericht an das BMLFUW, IfÖL, BOKU, März 2002) sollen drei Düngungsvarianten verglichen werden. Die Bedeutung verschiedener vorhandener Biotope (Gehölzstreifen, Hecken, ...) soll charakterisiert und neue, ergänzende Biotope geplant und angelegt werden. Versuchsort und -gegenstand ist der landwirtschaftliche Betrieb Rutzendorf der Bundesversuchswirtschaft Ges.m.b.H. Durchgeführt wird ein Monitoring der Auswirkungen von Düngungsvarianten unter Beibehaltung der Fruchtfolge sowie der Umstellung des Betriebes auf die Umwelt, Produktion und Wirtschaftlichkei

Auswirkungen unterschiedlicher Vorfrüchte und Düngungssysteme auf Ertrag und Qualität von Winterweizen

The effect of different preceding crops and fertilisation systems on winter wheat yieldand quality was assessed in a long-term field experiment in Eastern Austria. Winter wheat following a 2-years lucerne crop had lower yield but higher protein content than winter wheat following peas. Lucerne green manure use in a stockless system increased yield and protein content of a subsequent wheat crop compared to a livestock-keeping system with removal of the lucerne crop for fodder use. Wheat following peas that had received farmyard manure in the livestock-keeping system only, showed higher yield than in the stockless system but no differences in protein content. Likewise, an additional compost fertilisation in the stockless system increased yield of wheat following peas but had no effect on wheat protein content

Die Anbauwürdigkeit der Blauen Lupine in Bayern

Blue lupin (Lupinus angustifolius L.) could be an additional local protein crop in Bavaria for animal and human food production. It would also enlarge crop rotation in organic agriculture. At the moment, this crop is mainly cultivated in the northeastern parts of Germany. It is adapted to pH until 6.8 and sandy loamy soils. Currently, it is not re-commended for cultivation in Bavaria. In field trials, different varieties of blue lupins proved to be worth cultivating on organically managed sandy loam and loamy sand on three sites in Bavaria. Boregine and Probor were tested for four years, Mirabor and Boruta for one year. All varieties showed high crop and protein yield, also compared to white lupins. Boregine had the highest crop yield, whereas Probor the highest content of protein. Thus, blue lupin can be cultivated successfully on suitable sites in Bavaria

Auswirkungen unterschiedlicher Luzerneanteile in der Fruchtfolge auf Humus- und Stickstoffhaushalt

Fodder legumes, like lucerne, make a significant contribution to a positive humus balance and nitrogen supply on organic farms. To determine the required lucerne percentage to meet these targets, several shares of lucerne were modelled on the basis of empirical data of an eight-field crop rotation. The lower limit for ensuring optimum humus and nitrogen supply in this rotation was approximately 17 % lucerne. The calculation of the data was performed with the agricultural software REPRO

Auswirkungen einer Hecke auf Bodenwasserhaushalt, Bodenparameter und Ertrag in angrenzenden Ackerflächen

Bei trockenen Bedingungen wurde ein positiver Einfluss auf den Pflanzenertrag aufgrund des Verdunstungsschutzes von Hecken nachgewiesen In einem interdisziplinären Projekt auf einem ökologisch wirtschaftenden Betrieb, östlich von Wien, wird das Ausmaß des Einflusses einer Hecke auf das gespeicherten Bodenwasser, auf ausgewählte Bodenparameter und den Pflanzenertrag in die angrenzende Ackerfläche seit dem Jahr 2003 untersucht. Bei jedem Luzerneschnitt wurde der höchste Ertrag unmittelbar neben der Hecke erzielt. Die statistische Auswertung ergab jedoch nur beim dritten Luzerneschnitt und beim Gesamtluzerneertrag einen signifikanten Zusammenhang zwischen Ertrag und Entfernung zur Hecke. Beim dritten Schnitt Mitte August ist eine deutliche kontinuierliche Ertragsabnahme mit zunehmender Entfernung zur Hecke erkennbar, was durch den geringeren Bodenwassergehalt im Hochsommer mit größerem Heckenabstand erklärt werden kann