Burning Issues in Soil Science - Österreichische Bodenkundliche

Transcription

Annual Conference of the Austrian Soil Science
Society
“Burning Issues in Soil
Science”
September 22, 2014
University for Natural Resources and Life
Sciences
Institute of Soil Research
Peter-Jordan-Straße 82, 1190 Vienna, Austria
Venue: Morning, Lecture Hall 01, Exnerhaus,
Lunch and Afternoon, Aula and Seminarroom 06,
Schwackhöferhaus
1
Impressum
Eigentümer, Herausgeber, Verleger:
Österreichische Bodenkundliche Gesellschaft
Peter-Jordanstraße 82b, A-1190 Wien
Alle Rechte vorbehalten. © 2014
Alle Rechte, auch die der Übersetzung, des auszugsweisen Nachdrucks, der Herstellung von
Mikrofilmen und der photomechanischen Wiedergabe vorbehalten.
Redakteur: Michael Englisch
2
Schedule:
Lecture Hall 01, Exnerhaus:
08:00 – 09:00 Registration
09:00 – 09:15 Welcome Notes
09:15 – 10:00 Keynote Univ.-Prof. Dr. Stephan Glatzel, Universität Wien, „Carbon
sequestration in old-growth forests”
10:00 – 11:00 Session 1 Chair: Univ. Prof. DI Dr. Dr. h.c. mult. Martin Gerzabek,
University for Natural Resources and Life Sciences
10:00-10:20 Karin N. ASCHAUER, Georg J. LAIR, Nicola RAMPAZZO, Elisabeth
PÖTZELSBERGER, Marcela VAN LOO: Impact of Soil Properties on Plant
Community Composition in Riparian Forests near Bratislava
10:20-10:40 Jakob Santner, Rainer Muehlbacher, Andreas Kreuzeder, Walter W.
Wenzel: Phosphorus efflux from maize roots is highly localised to the root tip
10:40-11:00 Erich Inselsbacher: Soil organic N supply from the perspective of a root – a
microdialysis approach
11:00 – 11:30 Coffee break
11:30 – 13:10 Session 2 Chair: Univ. Prof. Dr. Sophie Zechmeister-Boltenstern,
University for Natural Resources and Life Sciences
11:30-11:50 Katrin HOFMANN, Sieglinde FARBMACHER, Paul ILLMER: Effects of Land
Cover, Abiotic and biotic soil properties on In situ methane flux of Montane
and Subalpine soils
11:50-12:10 Fuchslueger Lucia, Kienzl Sandra, Fritz Karina, Hasibeder Roland, Hofhansl
Florian, Ingrisch Johannes, Ladreiter-Knauss Thomas, Schmitt Michael,
Schnecker Jörg, Bahn Michael, Richter Andreas: Effects of recurring droughts
on microbial functioning in mountain grassland
12:10-12:30 Sonja Leitner, Michael Zimmermann, Christian Holtermann, Katharina
Keiblinger, Nermina Saronjic, Sophie Zechmeister-Boltenstern: Impact of
repeated dry-wet cycles on soil CO2 efflux and extracellular enzyme activities
in a beech forest
12:30-12:50 Christine Gritsch, Michael Zimmermann, Sophie Zechmeister-Boltenstern:
Effects of temperature and moisture variability on soil CO2 emissions in
European land ecosystems
3
12:50-13:10 Jörg Schnecker, Birgit Wild, Mounir Takriti, Ricardo J. Eloy Alves, Norman
Gentsch, Antje Gittel , Angelika Hofer, Karoline Klaus, Anna Knoltsch,
Nikolay Lashchinskiy, Robert Mikutta, Andreas Richter: Enzyme patterns in
topsoil and subsoil horizons along a latitudinal transect in Western Siberia
Aula and Seminarroom 06, Schwackhöferhaus:
13:10 – 14:15 Buffet Lunch
14:15 – 15:00 Flash presentation of posters, Chair: DI Dr. Michael Englisch,
Austrian Research Centre for Forests
15:00 – 16:00 Poster session and Coffee
16:00 – 17:00 Session 3 Chair: Dr. Andreas Baumgarten, Austrian Agency for
Health and Food Safety
16:00-16:20 Eva Oburger, Markus Puschenreiter, Stephan Hann, Davey Jones, Walter
Wenzel: Root exudates affecting P phytoavailability in soils - biogeochemical
mechanisms and experimental approaches
16:20-16:40 Evi Deltedesco, Lisa-Maria Bauer, Hans Unterfrauner, Robert Peticzka,
Franz Zehetner, Katharina M. Keiblinger: Microbiological assessment of lime
application to agricultural soils
16:40-17:00 Stephanie Kloss, Kubiena laureate: Biochar characterization and
impacts on temperate agricultural soils - effects on soil fertility, crop
yield and trace element behavior
17:00 – 18:00 Panel discussion „Research strategies for soil“ with Rektor Prof.
Martin Gerzabek, University for Natural Resources and Life Sciences; Prof. Stephan
Glatzel, University of Vienna; Prof. Douglas Godbold, Prof. Walter Wenzel, Prof.
Sophie Zechmeister-Boltenstern University for Natural Resources and Life Sciences.
Chair: Dr. Andreas Baumgarten, Austrian Agency for Health and Food Safety
from 18:00 Fade out with bread, spreads and BOKU-Wine and BOKU-Beer
4
IMPACT OF SOIL PROPERTIES ON PLANT COMMUNITY
COMPOSITION IN RIPARIAN FORESTS NEAR BRATISLAVA
Karin N. ASCHAUER1, Georg J. LAIR1,3, Nicola RAMPAZZO1, Elisabeth
PÖTZELSBERGER2, Marcela VAN LOO2
1
Institute of Soil Research, Department of Forest and Soil Sciences, University of Natural
Resources and Life Sciences Vienna (BOKU), Peter Jordanstraße 82, 1190 Vienna
2
Institute of Silviculture, Department of Forest and Soil Sciences, University of Natural
Resources and Life Sciences Vienna (BOKU), Peter Jordanstraße 82, 1190 Vienna
3
Institute of Ecology, University of Innsbruck, Sternwartestraße 15, 6020 Innsbruck
Natural flood plains are among the Earth’s most biologically productive and diverse
ecosystems. At the same time, they are threatened on a global scale, being sensitive towards
anthropogenic impacts such as river regulations and silvicultural management practises,
which in turn may alter plant species composition. Yet, one of the most distinctive features of
flood plains is the high spatial variability of soils due to hydrological (e.g. flood pulse) and
geomorphological processes (e.g. sedimentation and erosion) which may also influence plant
species composition. In an interdisciplinary study linking plant sociology and soil
characterisation we therefore aimed at clarifying which abiotic factors have the most decisive
impact on plant species composition at even a small spatial scale.
Six Populus alba communities south-east of Bratislava exhibiting significant differences in
plant species composition of the herbaceous layer were studied from a phytosociological and
physicochemical point of view. Of these six sites, one is still flooded periodically and three
are silviculturally managed.
Multivariate analyses of variance (MANOVA) showed significant differences between the
sites regarding soil nutrient stocks, soil texture as well as water retention characteristics.
Principal component analysis (PCA) based on the phytosociological relevés revealed soil
moisture and nutrient gradients as well as solar shading as principal components.
Biogeochemical-mechanistic ecosystem modelling on the basis of data from 2000 to 2011
also emphasised discriminating effects of soil texture. Plant species composition (65 different
plant species) was related to the measured environmental parameters using canonical
correspondence analysis (CCA). Clustering of sites within the CCA and PCA plots has lead
us to distinguish between two habitats among the six sites: floodplains offering (a) moister
and more nutrient-rich conditions and (b) seasonally dryer and nutrient-poorer conditions.
Our study therefore highlights that the nature of soil, shaped by its physicochemical
properties, plays a key role in determining plant community composition at a small spatial
scale.
5
PHOSPHORUS EFFLUX FROM MAIZE ROOTS IS HIGHLY
LOCALISED TO THE ROOT TIP
Jakob Santner, Rainer Muehlbacher, Andreas Kreuzeder and Walter W. Wenzel
University of Natural Resources and Life Sciences, Department of Forest and Soil Sciences,
Institute of Soil Research,3430 Konrad-Lorenz-Strasse 24, Tulln, Austria
In addition to phosphorus influx, efflux is regarded an important component of P uptake by
plant roots. Several studies demonstrated that generally both, apical as well as basal root parts
contribute to P influx. However, data on the localization of efflux is hardly available in
literature. In previous studies we observed high concentrations of P in closely confined
regions around root tips of soil-grown Brassica napus L. and Zea mays L. plants. Supported
by numerical simulation we hypothesized P efflux as a potential cause for these P hotspots.
To clarify the nature of our observation, we labelled the shoot P of Z. mays plants grown in
soil-filled rhizotrons by puncturing the coleoptile and placing a droplet containing 33P on the
lesion. Phosphorus is phloem-mobile, therefore the radioactive spike is readily redistributed in
the whole plant after labelling. Using a 2D sampling and imaging technique for P, we
acquired images of the distribution of 33P release by the maize roots.
After a sampling period of 48 h the efflux images showed that P release from maize roots is
highly confined to the apical region of the root, with only negligible contribution of more
basal root axes. Although the roots were actively growing during the sampling period and
efflux localization at the mm scale is complicated, our data indicate that the route of P efflux
is mainly via the apoplastic phloem-soil continuum at the initial, unsuberised phloem. We
conclude that P influx and efflux are not co-localized in maize roots and discuss the
consequences on root ion uptake and rhizosphere ecology.
6
SOIL ORGANIC N SUPPLY FROM THE PERSPECTIVE OF A ROOT –
A MICRODIALYSIS APPROACH
Erich Inselsbacher
Institut für Geographie und Regionalforschung - Geoökologie, Universität Wien
The availability of nitrogen (N) for root uptake largely regulates plant biomass production in
terrestrial ecosystems and directly influences plant-soil interactions. Detailed knowledge
about the concentration and composition of soil N pools are therefore crucial for studying and
understanding plant N nutrition. Until now this remained a challenging task, due to the
disruptive nature of current sampling techniques, further implying that results from
destructive soil sampling are only poor indicators for in situ soil N concentrations. Further,
plant N acquisition is determined by the flux of N from the surrounding soil to root surfaces
rather than by soil N concentrations. Recently, a non-invasive sampling technique based on
passive microdialysis was presented as a possible tool to estimate concentrations and fluxes of
N in soils in-situ. Unlike other sampling methods the miniaturized design and the passive
sampling approach allows for continuous monitoring of soil N fluxes at an unrivalled spatial
and temporal resolution. Further, microdialysis has the potential to study N dynamics in soil
microsites and to simulate the formation of depletion zones around the microdialysis probes,
similar to zones in the rhizosphere. I discuss advantages and disadvantages of microdialysis
for studying plant-available N compared to other sampling techniques.
7
EFFECTS OF LAND COVER, ABIOTIC AND BIOTIC SOIL
PROPERTIES ON IN SITU METHANE FLUX OF MONTANE AND
SUBALPINE SOILS
Katrin HOFMANNa*, Sieglinde FARBMACHERa and Paul ILLMERa
a
University of Innsbruck, Institute of Microbiology, Technikerstraße 25, 6020 Innsbruck,
Austria
*[email protected]
The ongoing debate on climate change led to a proliferation of studies concerning methane
(CH4) flux rates of soils as well as the microbial key players involved in the consumption
(methanotrophic bacteria) and production (methanogenic archaea) of this greenhouse gas.
Nevertheless, in spite of the global concern of this topic major ecosystems such as alpine
regions have been poorly studied so far.
Therefore, we examined CH4 flux rates of 16 forest and 14 grassland soils which were
sampled on calcareous or siliceous parent material at approximately 500, 1000, 1500, and
2000 m above sea level in order to reflect the regional topography of North Tyrol. Field
measurements were conducted by using manually operated closed static chambers. Gas
samples were collected in pre-evacuated tubes and analyzed by gas chromatography in the
laboratory. To reveal possible connections and functional similarities with CH4 flux, soil
physicochemical factors, microbial biomass, and soil microbial activities were determined.
Our results implied that 23 of the soils had the capacity to consume CH4, whereas net CH4
emission occurred at five grassland sites. Land cover type not only influenced the
physicochemical and microbiological properties, but beyond that significantly affected the
CH4 flux rates of the soils. Forest soils tended to act as sinks while grasslands showed a
significantly reduced capacity to remove CH4. With respect to CH4 flux rates, soils formed
on calcareous rocks did not differ from those formed on siliceous rocks although general
microbial activities and abundance were higher in calcareous soils. We could also detect a
distinct effect of the altitude on CH4 flux. Soils located at 500 to 1500 m a.s.l. strongly
removed CH4. By contrast, soils at 2000 m a.s.l. tended to be sources of CH4. Multiple
regression analysis pointed to positive influences of pH, organic matter, NH4+-N, and Cmic
on CH4 flux.
8
EFFECTS OF RECURRING DROUGHTS ON MICROBIAL
FUNCTIONING IN MOUNTAIN GRASSLAND
Fuchslueger Lucia1, Kienzl Sandra1, Fritz Karina2, Hasibeder Roland2, Hofhansl Florian1,
Ingrisch Johannes2, Ladreiter-Knauss Thomas2, Schmitt Michael2,3, Schnecker Jörg1, Bahn
Michael2, Richter Andreas1
1
University of Vienna, Department of Microbiology and Ecosystem Science, Division of
Terrestrial Ecosystem Research, Vienna, Austria
2
3
University of Innsbruck, Institute of Ecology, Innsbruck, Austria
Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research,
Garmisch-Partenkirchen, Germany
Climate projections suggest increasing variability of precipitation inducing more frequent
extreme drought periods also in many regions which are to date well water supplied. Water
availability is a key factor for physical, physiological and biogeochemical processes and
determines microbial activity and functioning in soils by affecting the osmotic potential, soil
pore connectivity, substrate diffusion and eventually nutrient availability. Thus drought could
directly affect microbial activity and functioning; however, effects of drought could persist
and might enhance or decrease the susceptibility of microbial functioning during further
drought periods. We therefore investigated effects of 1-5 recurring experimental extreme
drought periods on microbial activity in mountain grassland soils in situ during the growing
season by measuring a set of extracellular enzyme activities (EEA) targeting different
substrates as a proxy for microbial functioning.
Drought distinctly affected carbon (Cellobiohydrolase, CBH), nitrogen (Leucine amino
peptidase, LAP) and phosphorus (Phosphatase, PHOS) substrate targeting, as well as
oxidative potential EEA (phenoloxidase , POX), indicating a shift of microbial functioning.
All EEA showed a strong temporal fluctuation. During drought simulation potential CBH
activity was only marginally reduced compared to controls, while the extractable organic C
content in soils increased. LAP, PHOS and POX, in contrast, decreased during drought, but
the extractable organic N increased. This on the one hand proves a higher drought sensitivity
of N- than C-acquiring enzymes, and on the other hand could indicate altered microbial
physiology, activity, or hint towards an altered active microbial community composition.
Nonetheless, under recurrent drought effects were similar and moreover, whenever EEA were
altered during drought, they quickly recovered after drought. Overall, our data suggest that
microbial functioning in mountain grassland appears to be sensitive to drought, but also
highly resilient even after 5 years of recurring drought.
9
IMPACT OF REPEATED DRY-WET CYCLES ON SOIL CO2 EFFLUX
AND EXTRACELLULAR ENZYME ACTIVITIES IN A BEECH
FOREST
Sonja Leitner, Michael Zimmermann, Christian Holtermann, Katharina Keiblinger, Nermina Saronjic,
Sophie Zechmeister-Boltenstern
Institute of Soil Research, BOKU University of Natural Resources and Life Sciences, Vienna, Austria
Climate change research predicts that both frequency and intensity of weather extremes such
as severe droughts and heavy rainfall events will increase in mid Europe over the next
decades. Because soil moisture is one of the major factors controlling microbially-driven soil
processes, this might have a major impact on soil organic matter decomposition and nutrient
cycling. This in turn can lead to feedback effects between altered precipitation and changed
soil CO2 fluxes which can intensify climate change. Decomposition of plant litter and soil
organic matter is driven by microbial extracellular enzymes and thus highly susceptible to
water stress. Furthermore, drought enhances soil hydrophobicity and formation of cracks that
represent preferential flow paths for soil water, which in combination with rapid soil wetting
during heavy rainfalls can lead to substantial nutrient loss via leaching.
To investigate the impact of repeated dry-wet cycles on soil nutrient cycling and CO2 efflux
we are conducting a precipitation manipulation experiment in a temperate Austrian beech
forest. Roofs exclude rainfall and simulate drought periods, and heavy rainfall events are
simulated with a sprinkler system. We apply repeated dry-wet cycles in two intensities: one
treatment receives 6 cycles of 1 month drought followed by 75mm irrigation, and a parallel
treatment receives 3 cycles of 2 months drought followed by 150mm irrigation. Soil samples
are taken before and after rewetting events and analyzed for soil nutrients and extracellular
enzyme activities. Soil CO2 efflux is constantly monitored with an automated flux chamber
system, and environmental parameters recorded via dataloggers.
The results of the first year show that experimental rainfall manipulation has influenced soil
extracellular enzymes. Potential phenoloxidase activity was significantly reduced in stressed
treatments compared to control plots. All measured hydrolytic enzymes (cellulase, chitinase,
phosphatase and protease) and phenoloxidase responded strongly to rewetting events with
significantly increased activities. Furthermore, we observed a pulsed release of inorganic
nitrogen which resulted in high concentrations of NH4+ and NO3- in the first 24h after soil
rewetting, especially in summer when soil temperatures were high. Emissions of CO2 were
increased in the first 24 to 48h after rewetting, and then slowly decreased. Overall, our results
indicate that repeated dry-wet cycles strongly influence microbial soil processes, even in the
first year of experimental rainfall manipulation. The next 2 years will show whether these
changes are permanent, or if the system adapts to the new precipitation regime.
10
EFFECTS OF TEMPERATURE AND MOISTURE VARIABILITY ON
SOIL CO2 EMISSIONS IN EUROPEAN LAND ECOSYSTEMS
Christine Gritsch, Michael Zimmermann, Sophie Zechmeister-Boltenstern
Institute of Soil Research, Department of Forest and Soil Science, University of Natural
Resources and Life Sciences, Vienna
Soil respiration is one of the largest terrestrial fluxes of carbon dioxide (CO2) to the
atmosphere. Hence, small changes in soil respiration rates could have large effects on
atmospheric CO2. In order to assess CO2 emissions from diverse European soils under
different land-use and climate (soil moisture and temperature) we conducted a laboratory
incubation experiment.
Therefore, we incubated soil cores (Ø 7 cm; height 7 cm) from nine European sites which are
spread all over Europe; from the United Kingdom (west) to the Ukraine (east) and Italy
(south) to Finland (north). In addition these sites can be clearly distinguished between their
land use into forests, arable lands, grasslands and one peat land. Soil cores were incubated in a
two-factorial experimental design at 5 different temperatures (5, 10, 15, 20, and 25°C) and 6
different moisture contents (5, 20, 40, 60, 80, and 100 % water filled pore space (WFPS)). An
automated laboratory incubation measurement system was used to measure CO2 emissions.
Results show that highest CO2 emissions occurred with intermediate moisture content (40%
to 70%) over all sites. We found that the relationship between CO2 emissions and temperature
could be well described by a Gaussian model with the equation ( )
(R²
ranges from 0.87 to 1) over all sites. In general CO2 emissions were strongly related with
both variables temperature and moisture. Temperature sensitivity (Q10) was negatively
correlated with temperature for all land-uses investigated. Moisture sensitivity was calculated
as the slope of a quadratic function and showed highest values at very low and high moisture
content for all land-uses investigated. Moisture sensitivity was increasing with temperature
for all arable lands investigated. All coniferous forest sites investigated showed a strong
increase of the temperature sensitivity at lower temperatures at a moisture range of 20 – 40
% WFPS.
In summary our results showed not only the relationship between temperature sensitivity of
CO2 emissions and moisture content for a broad range of land-uses within Europe but also
investigated the relationship between moisture sensitivity of CO2 emissions and temperature
for said land-uses for the first time
11
ENZYME PATTERNS IN TOPSOIL AND SUBSOIL HORIZONS
ALONG A LATITUDINAL TRANSECT IN WESTERN SIBERIA
Jörg Schnecker 1 , Birgit Wild1 , Mounir Takriti 1 , Ricardo J. Eloy Alves 2 , Norman
Gentsch3 , Antje Gittel 4 , Angelika Hofer 1 , Karoline Klaus 1 , Anna Knoltsch1 ,
Nikolay Lashchinskiy5 , Robert Mikutta 3 , Andreas Richter 1
1 University of Vienna, Department of Microbiology and Ecosystem Science, Division
of Terrestrial Ecosystem Research, Vienna, Austria
2 University of Vienna, Department of Ecogenomics and Systems Biology, Division of
Archaea Biology and Ecogenomics, Vienna, Austria
3 Leibniz Universität Hannover, Institut für Bodenkunde, Hannover, Germany
4 University of Bergen, Centre for Geobiology, Department of Biology, Bergen, Norway
5 Central Siberian Botanical Garden, Siberian Branch of Russian Academy of
Sciences, Novosibirsk, Russia
Soil horizons below 30 cm contain up to 60% of the carbon stored in soils. Although we gain
more and more insight into physical and chemical stabilisation mechanisms and into
microbial community composition in these horizons, we lack information on functions
of subsoil microbial communities and consequently on microbial processes. We investigated
activities of six extracellular enzymes (cellobiohydrolase, leucine-amino- peptidase, Nacetylglucosaminidase, chitotriosidase, phosphatase and phenoloxidase), and the resulting
enzyme patterns. We sampled soils from organic topsoil horizons (0-10 cm), mineral topsoil
horizons (6-28 cm) and mineral subsoil horizons (23-75 cm) from seven biomes along a
1,500 km long latitudinal transect in Western Siberia. To identify controls on enzyme
patterns, we correlated enzyme patterns with biotic and abiotic soil parameters, as well
as with microbial community composition (estimated using phospholipid fatty acid analysis).
We found that hydrolytic enzyme activities decreased rapidly with depth, whereas oxidative
enzyme activities in mineral horizons were as high as, or higher than in organic
topsoil horizons. To our surprise, enzyme patterns varied stronger between ecosystems
in mineral subsoils than in organic topsoil horizons. This might have been caused by a
diverging chemical composition of soil organic matter with ongoing decomposition, or
by a higher variability in microbial community composition in mineral horizons. The
enzyme patterns in topsoil horizons were mainly correlated with SOM content (C and
N) and microbial community composition. The enzyme patterns in mineral subsoil
horizons, in contrast, were related to water content, pH and microbial community
composition. The consistent correlations of enzyme patterns with microbial community
composition in all three horizons suggest that enzyme patterns reflect the functional
capacity of the microbial community. The lack of correlations of enzyme patterns and SOM
quantity in the mineral subsoil indicates that SOM chemistry, spatial separation or physical
stabilization of SOM rather than SOM content might determine substrate availability for
enzymatic breakdown and calls for caution when considering subsoils in ecosystem
models and in upscaling exercises.
12
ROOT EXUDATES AFFECTING P PHYTOAVAILABILITY IN SOILS BIOGEOCHEMICAL MECHANISMS AND EXPERIMENTAL
APPROACHES
Eva Oburger1, Markus Puschenreiter1, Stephan Hann2, Davey Jones3, Walter Wenzel1
1
Institute of Soil Research, Konrad-Lorenz-Strasse 24, A-3430 Tulln, Austria
2
University of Natural Resources and Life Sciences, Department of Chemistry, Division for
Analytical Chemistry Muthgasse 18, A-1190 Vienna, Austria
3
School of Environment,Natural Resources & Geography, Bangor University, Bangor,
Gwynedd LL57 2UW, UK
Roots release a range of organic as well as inorganic molecules of which some (particularly
organic acids) have been implicated to play an important role in increasing plant P nutrition.
Accurate sampling and determination of release rates of root exudates is a prerequisite for
further mechanistic investigations that will lead to a better understanding of the processes and
dynamics involved in P mobilisation. Different experimental approaches (soil vs hydroponic
culture) to sample root exudates will be presented and compared, including a new, rhizoboxbased approach that enables us to repeatedly collect unaltered root exudates from soil grown
plants. Implications of the differences in results obtained by the different experimental
approaches will be discussed.
Furthermore we aim to summarize the biogeochemical mechanisms that can be triggered by
roots to increase P solubility, with particular focus on the effectiveness of various root
exudate compounds in contrasting soil types with differing P amounts and chemistries.
Supported by experimental data we will demonstrate that depending on soil properties plants
should ideally pursue different strategies to improve P phytoavailability in the rhizosphere.
13
MICROBIOLOGICAL ASSESSMENT OF LIME APPLICATION TO
AGRICULTURAL SOILS
Evi Deltedesco1, Lisa-Maria Bauer2, Hans Unterfrauner3, Robert Peticzka2, Franz Zehetner1,
Katharina M. Keiblinger1
1
University of Natural Resources and Life Sciences, Vienna, Department of Forest and Soil
Sciences, Institute of Soil Research
2
University of Vienna, Department of Geography and Regional Research
3
Technical Office for landscape ecology, landscape planning and landscape management,
Vienna
Lime is commonly applied on agricultural lands for ameliorating soil acidity. Furthermore the
high input of mechanical energy in common agricultural practice can negatively affect soil
structure. A promising approach to stabilize the structure and improve the water- and air
permeability, is the addition of polyvalent ions like Ca2+ which can be added for example in
the form of quicklime (CaO) and limestone (CaCO3). The soil pore system serves as a habitat
for soil biota. Microorganisms are essential for the integrity of terrestrial ecosystems as they
are key players of many soil functions such as biogeochemical cycling, plant productivity or
climate regulation.
In this study, we conducted a greenhouse pot experiment using two different sources of
calcium ions in order to examine the effect of these amendments on microbial parameters
over time. Silty and clayey soils from three different locations in Austria were sampled and
incubated with and without the liming materials (application rate 1000 kg ha-1) for 3 months
in four replicates. Soil samples were taken with a plastic probe 2, 30 and 86 days after the
application of quicklime and limestone to assess short-term and medium-term microbial
effects. By adding water in regular intervals the moisture content was kept at ~ 50 % water
holding capacity throughout the duration of the experiment. To evaluate the effect of lime on
changes in soil microbiology, we determined parameters like pH, extracellular hydrolytic
(cellulase, phosphatase, chitinase and protease) and oxidative (phenoloxidase and peroxidase
activity) enzyme activities, PLFAs, microbial biomass carbon and nitrogen, dissolved organic
carbon and nitrogen, nitrate nitrogen and ammonium nitrogen.
Initially, soil pH and DOC were strongly increased by quicklime; however, after the second
sampling (30 days) the pH values of all tested soils returned to levels comparable to the soils
treated with limestone but the DOC values declined continuously during incubation time.
Most microbial results show an immediate inhibition effect of quicklime on potential
hydrolytic enzyme activities and an increase in oxidative enzyme activities. These effects
seem to be less pronounced in the medium term.
In summary our results indicate that the application of quicklime is a feasible measure for
immediate stabilization of the structure of compaction-prone soils, showing only short-term
impact on most microbial parameters.
14
Vortrag der Kubiena-Preisträgerin
BIOCHAR CHARACTERIZATION AND IMPACTS ON TEMPERATE
AGRICULTURAL SOILS - EFFECTS ON SOIL FERTILITY, CROP
YIELD AND TRACE ELEMENT BEHAVIOR
Dipl.-Geogr.univ. Dr.nat.techn. Stefanie Kloss
Pyrolysis is the thermal decomposition of biomass under low-oxic conditions, which results in
the formation of a solid, carbonaceous residue called biochar. The application of biochar to
soils has been increasingly investigated in terms of soil amendment and long-term carbon
sequestration. This dissertation studied the characteristics of various biochar types and
investigated the effects of biochar on soil fertility, plant yield and trace element behavior in a
greenhouse pot experiment. For the biochar characterization, various plant residues (wheat
straw, poplar wood, spruce wood) were pyrolyzed at three different temperatures (400°C,
460°, 525°C) and analyzed for physico-chemical and molecular characteristics as well as
polycyclic aromatic hydrocarbons and trace elements. The pot experiment included three
agricultural soils and biochars produced from wheat straw, woodchips and vineyard pruning.
All pots were equipped with an outlet to collect leachate water and planted with mustard
(Sinapis alba L.), barley (Hordeum vulgare L.) and clover (Trifolium pratense L.). Results of
the biochar characterization revealed that biochar properties were dependent on both
feedstock and pyrolysis temperature. Increasing biochar aromaticity and thermal stability with
increasing pyrolysis temperature demonstrate their potential for long-term C sequestration in
the soil, but the accumulation of trace elements and the formation of polycyclic aromatic
hydrocarbons have to be considered. Results of the pot experiment showed that biochar
initially had detrimental effects on plant yield; only wheat straw biochar did not impair yields
and even significantly increased barley yield. Generally, biochar application was most
beneficial on a sandy, acidic soil. Effects of biochar on trace elements were dependent on soil
and biochar type as well as trace element contents of the biochars. Biochar application
increased the solubility and leaching of anionic trace elements and caused elevated anionic
trace element concentrations in plants, but decreased cationic trace element concentrations.
The dissertation highlights that the application of biochar to temperate soils can have
beneficial effects but may also depress plant yield and entail environmentally and
ecotoxicologically relevant consequences that affect soil, leachates and plants to different
extents.
15
Poster
16
ABUNDANCE, ACTIVITY, SENSIBILITY AND EFFICIENCY OF
METHANOGENIC ORGANISMS IN NATURAL HABITATS
Mira Mutschlechner*a, Nadine Präga, Paul Illmera
Institute of Microbiology, University of Innsbruck
*[email protected]
Methane (CH4) constitutes a potent greenhouse gas that is emitted from anthropogenic and
natural origins. Wetlands comprise the largest individual natural sources of CH4, accounting
for 20-40% of the total methane budget. Although wetlands cover only 3% of the earth´s
surface, these ecosystems are of significant importance in terms of carbon storage and
sequestration. Apart from aquatic ecosystems, there is abundant evidence of methanogenic
activity in aerobic upland soils, thus playing a major role in the global carbon cycle.
Methanogenesis, the biogenic formation of methane, represents the final step in the anaerobic
decay of organic matter by methanogenic archaea inhabiting natural soil and wetland
ecosystems, which are characterized by a high spatial and temporal heterogeneity as well as
seasonal and climatic variability. Methane generation in biogas plants, however, requires the
maintenance of favorable conditions, since methanogenic archaea are highly sensitive to
changed parameters causing process failure. This leads to the question whether methanogenic
organisms in natural habitats are adapted to frequently changing environmental conditions and
whether this ability can be used to improve the efficiency and stability of anaerobic
degradation processes in biogas plants.
To address this question, the present study focusses on the isolation as well as enrichment of
methanogenic organisms from soil and wetland ecosystems. Soil and peat samples will be
collected from local study sites. With the purpose of evaluating the contributing biotic and
abiotic factors exerting an impact on the establishment and activity of the microbiocenosis in
lab scale culture experiments, single parameter variation studies (e.g., pH, temperature,
oxygen content) will be performed to detect indications of possible adaptive capabilities of the
engaged microorganisms. Common molecular-biological techniques are intended to provide
an insight into microbial diversity of these cultures, particularly into the functional
relationship of the dominant phylogenetic groups, thus improving the understanding of
environment-organism interactions. Further studies shall ultimately contribute to implement
methanogenic organisms with a broad eco-physiological potential and high resilience into
fermentations, with the aim of achieving a higher efficiency and productivity of biogas plants.
17
SOIL PROTEIN EXTRACTIONS – COMPARATIVE EVALUATION OF
POOLING STRATEGY FOR METAPROTEOME ANALYSIS
Dong Liu1, Katharina M. Keiblinger1,, Stephan Fuchs2, Uwe Wegner2, Christian Hentschker 2,
Dörthe Becher2 Kathrin Riedel2, Sophie Zechmeister-Boltenstern1
1
Institute for Soil Research, Department of Forest and Soil Sciences, University of Natural
Resources and Life Sciences Vienna (BOKU), Peter Jordanstrasse 82, 1190 Vienna, Austria
2
Institute of Microbiology, University of Greifswald, Friedrich-Ludwig-Jahnstrasse 15,
17489 Greifswald, Germany
Soil metaproteomic studies present a major challenge since the soil matrix is spatially and
temporally heterogeneous., The objective of the present study was the evaluation of pooling
strategy by taking independent and spatially separated soil samples to obtain a consistent
sample that encompasses variability. The application of pooling for protein extraction aimed
to reduce time and costs of soil metaproteome analysis.
A pooling experiment was conducted to evaluate the applicability and suitability for the
analysis of the soil metaproteome in field plots of a mature beech stand. To this end, we
pooled five individual soil samples (2 g each) to form a composite of 10 g sample before the
protein extraction procedure was conducted. This was compared with the results obtained
from the five individual samples (5 g each), replicated twice. Individual replicate soil samples
from small plots on the larger plot scale were analyzed and put together into one pooled
sample prior to protein extraction. Proteins were analyzed by 1D PAGE followed by liquid
chromatography/tandem mass spectrometry (LC-MS/MS), and peptides were assigned to
protein groups for each sample.
We found that most abundant microbial taxa and functions were present in the pooled sample:
(a) In the pooled sample individual species or functions were well representative compared to
separate individual samples. (b) The functional categorization of proteins within the pooled
sample was similar to the individual samples.
Our study demonstrated that pooling strategy for soil protein extraction protocol resulted in
similar results to those of analyses of individual soil samples. Generally it will be necessary to
test soils from each site or experiment individually if pooling is not suitable. We conclude
that, the application of pooling for extraction purpoes should be considered for
metaproteomics from field studies that do not focus on within-site variability.
18
EUROPEAN LAND QUALITY AS A FOUNDATION FOR THE
SUSTAINABLE INTENSIFICATION OF AGRICULTURE
Jasmin Schiefer1, Georg J. Lair1,2 and Winfried E.H. Blum1
1
University of Natural Resources and Life Sciences (BOKU), Institute of Soil Research, 1190
Vienna
2
University of Innsbruck, Institute of Ecology, 6020 Innsbruck
Sustainable Intensification (SI) is a concept for increasing agricultural production under
sustainable conditions by 2050 to meet the needs of worlds growing population.
Generally the concept of SI is the increase of yields without harming the environment. For
reaching this goal, the intrinsic potential of soils has to be considered. This report aims at
identifying arable soils in Europe which have the best natural resilience and performance and
therefore can be used for SI. New data from arable sites across 23 European member states
from LUCAS topsoil survey 2009 were taken and attributed to arable land using the Arc
Geographical Information System (ArcGIS). The results show that almost half (47%) of the
currently used arable agricultural area cannot be recommended for SI. Even 4% of this area
should be extensified in order to reduce environmental harm. 12% of arable soils in Europe
can only be recommended for SI with restrictions and 41% can be used for SI without
impacting the delivery of goods and services provided by land and soil (water, air and
biodiversity). The comparison of our results with a detailed Soil Quality Rating in Germany
showed similar results and proved that our concept also reflects the yield potential and
hazardous factors.
19
AWARENESS RAISING FOR SOIL AND NECESSARILY FOR
CONTAMINATED SITES WITHIN THE GREENLAND PROJECT
Wolfgang FRIESL-HANLa, Karin ASCHAUERb, Cecilie FOLDALc
a
AIT Austrian Institute of Technology, Konrad-Lorenz-Straße 24, 3430 Tulln
b
BOKU Institute of Soil Science, Peter-Jordan-Straße 82, A-1190 Wien
c
ASSS Austria Soil Science Society, Peter-Jordan-Straße 82, A-1190 Wien
One aim of the GREENLAND-project (http://www.greenland-project.eu) was the dissemination of the output of each involved field experiment. Several approaches where chosen,
differently by each field site manager. The approach of awareness raising for soil and
remediation on a Pb/Zn-contaminated site in the village Arnoldstein (Carinthia, Austria) was
to include and invite scholars from the neighbouring villages. For that purpose the Austrian
Soil Science Society runs a workshop series, aiming at awareness raising of the value and
functions of soil (“Boden macht Schule” – “Soil meets Schools”) has been commissioned.
Based on the workshop in February 2014 in two schools scholars worked at the topic of soil
and remediation over the following two months – creating posters, sculptures, short
presentations and a summary in a kind of abstract book.
As highlight of the dissemination process a field day in May 2014 was conducted. At that day
approximately 100 scholars from 4 different classes walked to the remediation field plots to
see the efforts which have to be undertaken for improving a contaminated site. At that time
the farmer prepared the plots for the new vegetation period and the field experiment was
established. Additionally, due to the vicinity of the industrial site an industry representative
gave important information about industry history, actual situation and the positive example
of the re-use of the industrial area for industrial companies – instead of greenfield strategy.
Finally in June 2014 a presentation of scholars of their outputs in front of their parents were
conducted. The topics of soil, soil functions and the necessity of remediation of contaminated
sites were discussed and disseminated in a cross-generation manner.
20
IMMOBILISATION OF HEAVY METALS TO ENHANCE
BIOLOGICAL DEGRADATION OF ORGANIC SOIL CONTAMINANTS
Anna WAWRAa, Wolfgang FRIESL-HANLa, Markus PUSCHENREITERb, Gerhard
SOJAa, Andrea WATZINGERa
a
AIT Austrian Institute of Technology; Konrad-Lorenz-Straße 24, 3430 Tulln
BOKU Institut für Bodenforschung, Konrad Lorenz-Straße 24, 3430 Tulln
b
According to the Austrian Environment Agency (UBA) there are more than 2000
contaminated sites in Austria in need of remediation. Mixed contaminations (organic plus
inorganic pollutants) represent a frequently occurring contamination type. Conventional
remediation techniques like “dig and dump” are costly and limited in scale. Plant- and
microbe-based alternatives, e.g. phytoremediation options, offer a cheap and environmentally
friendly approach that can be applied on larger areas. However, the application of
phytoremediation techniques to mixed contaminated sites may be tricky due to the potential
inhibition of biodegradation processes by the presence of heavy metals in soil. Therefore, the
objective of this study is to test the hypothesis that the degradation of organic pollutants can
be enhanced by immobilising interfering heavy metals.
As part of the ISOMON project (“Isotope application for remediation, aftercare and
monitoring of contaminated sites”), this 3 year study aims to identify the influence of heavy
metal immobilisation on the degradation of organic pollutants, and to determine chemical,
physical and biological measures further accelerating these processes. Degradation of organic
pollutants is monitored by analysis of the carbon isotope ratio (12C/13C) using compound
specific isotope analysis (CSIA). The influence of heavy metals on organic pollutant
degradation will be assessed by using 13C-phospholipid fatty acid analysis (13C-PLFA).
Application of 13C-labeled phenanthrene will allow the identification of microbial groups
responsible for the degradation process. The influence of heavy metal immobilisation on the
degradation of organic pollutants will first be analyzed in a laboratory batch trial, followed by
a greenhouse experiment and a field trial. For metal immobilisation and enhanced
biodegradation, distinct mineral and organic soil amendments (iron oxides, gravel sludge,
biochar) are deployed, partly in combination with fast-growing and pollution-tolerant woody
plants (willow, black locust and alder).
21
EFFECTIVENESS OF BIOCHAR FOR INCREASING SOIL QUALITY
AND REDUCING METAL BIOAVAILABILITY OF THREE
DIFFERENT SOILS
Jakob FESSL1, Wolfgang FRIESL - HANL2, Gerald DUNST3, Mario WAGNER4, Franz
ZEHETNER1, Jasmin KARER2, Christoph HOEFER1,Gerhard SOJA2, Markus
PUSCHENREITER1
1
University of Natural Resources and Life Sciences Vienna, Department of Forest and Soil Sciences,
Peter Jordan Straße 82, A-1190 Wien; and Konrad Lorenz Straße 24, A-3430 Tulln, Austria
2
AIT Austrian Institute of Technology GmbH, Health & Environment Department, Konrad Lorenz
Straße 24, A-3430 Tulln, Austria
3
Sonnenerde Gerald Dunst - Kulturerden GmbH, Oberwarterstraße 100, A-7422 Riedlingsdorf,
Austria
4
Mario Wagner, Kaiser Franz-Josef-Straße 6, A-1230 Wien
Intensive agriculture and industrial activities have led to a general decline of soil quality in the
last decades. In this context, the loss of organic matter in soils and the contamination with
heavy metals are two major problems. Since large areas are affected, low-cost and environmentally friendly approaches are needed for the remediation of degraded or polluted soils.
The application of amendments may improve the soil quality, increase productivity and reduce the bioavailability of pollutants. In the research project “NAWAROSAN”, co-funded by
the Austrian Research Promotion Agency (FFG), biochar amendments are tested on two agricultural soils low in organic matter and one agricultural soil contaminated with Pb, Zn and
Cd.On the two depleted soils, N and C balance as well as biomass yield are in main focus.
Whereas in case of the contaminated site, the study aims towards heavy metal stabilization in
the soil along with the cultivation of an excluder plant for renewable biomass production.
According to preliminary results, treatments for a two year field experiment and a greenhouse
- pot experiment were selected as follows: (i) Biochar from fibre sludge and cereal husk; (ii)
Poplar wood chips biochar; both types enriched with compost and nitrogen ((NH4)2SO4).
Additionally, a (iii) 50:50 mixture of gravel sludge andsiderite bearing was applied on the
contaminated site. Either Miscanthus or maize was planted on the sites as well as in the
greenhouse in springand harvested in autumn2013.
Relevant analysistargeting shoot biomass, extractable metal concentrations (Cd, Pb, Zn),
nitrogen supply and organic matter content were undertaken in both, plant and soil samples.
So far, a reduction of extractable Zn (NH4NO3) from 181 mg kg-1 to 81 mg kg-1, 96 mg kg1 and 103 mg kg-1 in the gravel sludge/ siderite bearing treatment, the poplar biochar and
gravel sludge / siderite bearing combination and the poplar biochar treatment, respectively
compared to the control, was shown.
The plant analyses did show not significant differences between the single treatments
regarding the metal incorporation into the biomass. In the field trial, a relative increase in
maize yield was observed in the biochar treatment on the humus-depleted soil (up to 50%) in
comparison to the mineral-fertilized control. On the contrary, the biochar treatments did not
increase the biomass growth on the contaminated soil. These findings indicate differential
effects of the different amendments on biomass productivity as well as the reduction of the
bioavailability of the metals. Moreover, the Ct and Nt analysis did not show any relevant
differences among the treatments yet. Further tests will provide more data on relevant metal
22
concentration changes in soil and plant as well as on nutrient and carbon supply of the first
year of the main experiment.More information on the long-term effectiveness of the tested
amendments will be provided in the second year.
23
THE ROLE OF PLANTS IN METHANE FLUX OF UPLAND SOILS
Nadine Präg a*, Paul Illmer a
a
Institute of Microbiology, University of Innsbruck, Technikerstrasse 25d, 6020 Innsbruck,
Austria
* [email protected]
Methane is an important greenhouse gas that is produced and consumed in soils by
microorganisms. Soils play an important role in the global methane cycle as soils can be
methane sources and/or sinks depending on abiotic and biotic parameters. Until recently,
studies of the contribution of plants to the global methane flux have focused on the role of
plants as conduits for soil-borne methane emissions from wetlands. Barely examined to date
are the influence of plants on methane flux and the presence of methanogenic and
methanotrophic microorganisms in aerobic upland soils.
The present study used soils from two grassland sites located in the Inn Valley in Northern
Tyrol at ~750 m a.s.l. Soil sites were chosen to represent soils from siliceous and calcareous
bedrock. Besides in situ methane measurements and profound soil microbiology analyses, labscale gas measurements were performed. In special pots with sieved soils from the study sites,
two site typical plants Poa pratensis and Plantago lanceolata were grown from surface
sterilized seeds in six parallel pots per soil site. To determine methane flux from soil itself,
pots without plant coverage were analyzed as well. The pots were incubated at 10, 25 and
37°C and water content was kept at in situ conditions by rewetting with a.deion. To measure
methane flux, the pots were closed with special plastic-hoods. Gas samples were withdrawn
through inserted septa at the top of the plastic hoods and subsequently analyzed on CH4 and
CO2 by gas chromatography.
In our investigations, we could prove a distinct influence of plants on methane fluxes in
upland soils on a lab-scale basis. Temperature was a crucial factor that influenced the effect of
plants on the methane flux significantly. At 25°C Poa pratensis showed significant lower
methane oxidation rates than soils covered with Plantago lanceolata and uncovered soil
whereas no significant difference could be detected between flux measurements of the pots
from siliceous bedrock and those of calcareous parent material. Our data proved not only a
clear influence of plants on methane flux in grassland soils in comparison to uncovered soil
but between the investigated plants as well.
The study emphasizes the need to better resolve the influence of plants on the methane cycle
and its involved microorganisms. Future studies will focus on microbial and molecular studies
that should give an insight in how the differences in the net methane flux measurements are
reflected in community compositions of methanogenic and methanotrophic microorganisms.
24
AMMONIA EMISSIONS FROM PEATLAND SOILS MEASURED WITH
A CUSTOMIZED DEVICE
Helmut Haller, Boku
A customized device was built at the Institute of Soil Research (BOKU) to hold soil samples
to conduct ammonia emission measurements of soils on a very sensitive scale (parts per
billion). The device is moreover connected to an ammonia detector (Picarro G2103). Certain
specificities (e.g. in terms of material and temperature) were considered in the construction
process for the handling and measuring of ammonia due to its properties and the small scale
of gas concentrations. The newly built device was tested with reference gases and various soil
samples and then used to measure ammonia emissions of Scottish peat land soils. Samples are
received of WHIM bog, UK, a research site where long-term Nitrogen deposition experiments
are conducted. Further measurements of other compounds of the N cycle (e.g. NH4+, NO3-,
NO, NO2, N2O, possibly N2) will be undertaken and results will be put in biogeochemical
context.
25
EXAMINATION OF THE EFFECT OF APPLICATION OF
LIMESTONE AND QUICKLIME ON SELECTED SOILS - A STUDY
REGARDING KEY PARAMETERS OF SOIL PHYSICS
LISA-MARIA BAUER1, EVI DELTEDESCO2, HANS UNTERFRAUNER3, ROBERT
PETICZKA1, KATHARINA M. KEIBLINGER2, FRANZ ZEHETNER2
1
UNIVERSITY OF VIENNA, DEPARTMENT OF GEOGRAPHY AND REGIONAL
RESEARCH, AUSTRIA
2
UNIVERSITY OF NATURAL RESOURCES AND LIFE SCIENCES, INSTITUTE OF SOIL
RESEARCH, AUSTRIA
3
TECHNICAL OFFICE FOR LANDSCAPE ECOLOGY, LANDSCAPE PLANNING AND
LANDSCAPE MANAGEMENT, VIENNA, AUSTRIA
Soils, having a high content of clay – e.g Pseudogleys - are very susceptible to compaction –
naturally or anthropogenic – what causes negative effects of essential soil functions.
Compaction results in a decrease of pore space, especially of macropores, and an increase of
bulk density. It further impairs the water- and air permeability and results in degradation of
aggregate stability. With application of limestone and quicklime this negative effects should
be eliminated.
In this study a greenhouse pot experiment was conducted to evaluate effects of limestone and
quicklime on selected physical properties over a time of three months. The soil of three
different locations in Austria (Strengberg, Pollham, Kemeten) were sampled and incubated
with an application rate of 2000 kg ha-1 in the first 7-10 cm. Additionally pots without adding
any substance were created, but equally handled. As a whole there were taken and
investigated 27 (3 soils x 3 variants x 3 samplings) pots. Throughout the duration of the
experiment the moisture content was kept at the same level according to water holding
capacity by adding water in regular intervals.
Soil samples were taken two days, one month and three months after the application. To
evaluate the short- and medium-term effects soil physical properties such as Water Retention,
Aggregate Stability and Bulk Density were investigated. In addition both Grain Size
Distribution within an interval of 1cm and water content as basic soil physical analysis were
examined.
In contrast to limestone, the application of quicklime results in a significant improvement of
soil aggregate stability in all tested soils throughout the whole duration of the examination.
Effects of limestone and quicklime on the other analysed parameters could not – or just
insignificant- be recognized.
26
POST-DROUGHT EFFECTS ON THE PLANT-MICROBE CARBON
TRANSFER IN A MOUNTAIN MEADOW
Lucia Fuchslueger1, Michael Bahn2, Roland Hasibeder2, Sandra Kienzl1, Karina Fritz2,
Michael Schmitt2,3, Margarete Watzka1, Andreas Richter1
1
University of Vienna, Department of Microbiology and Ecosystem Science, Division of
Terrestrial Ecosystem Research, Vienna, Austria
2
University of Innsbruck, Institute of Ecology, Innsbruck, Austria
3
Karlsruhe Institute of Technology, Institute of Meteorology and Climate Research,
Garmisch-Partenkirchen, Germany
Drought has been projected to become more frequent in many European regions. While there
is growing evidence that drought can severely affect plant and microbial carbon dynamics it is
still not clear if and how plant and microbial carbon dynamics recover from drought, and to
which extent effects of drought persist and alter the response to subsequent dry conditions. To
address these questions we took advantage of a multi-year rain-exclusion experiment on a
mountain meadow in the Austrian Central Alps. During a dry period following rewetting after
a severe experimental drought a 13C-pulse labelling experiment was conducted to trace postdrought effects on the transfer dynamics of recently plant assimilated carbon from plants to
microbial phospholipid fatty acids (PLFAs).
In post-drought plots the soil water content was still at a lower level, but the plant biomass
was similar as in controls, exhibiting similar carbon but lower nitrogen concentrations. The
13C uptake in shoots of plants in the post-drought plots was reduced compared to controls
reflecting decreased photosynthesis. Moreover, the allocation of recent C to fine roots and
into fine root respiration was reduced. However, the earlier drought treatment induced no
lasting effects on the microbial biomass and community structure. Nonetheless, 13C uptake of
plant derived C into microbial groups was slower in post-drought plots, but surprisingly
summed up to the same total amounts as in control plots. This indicates a disproportionately
higher transfer of recent C to soil microbes. We conclude that in the studied mountain
meadow severe drought could have lasting effects on plant C uptake and belowground
allocation dynamics, while the soil microbial community is highly resilient and can thereby
alter C dynamics in the plant-soil system.
27
MICROBIOLOGICAL ASSESSMENT OF LIME APPLICATION TO
AGRICULTURAL SOILS
Evi Deltedesco1, Lisa-Maria Bauer2, Hans Unterfrauner3, Robert Peticzka2, Franz Zehetner1,
Katharina M. Keiblinger1
1
2
University of Vienna, Department of Geography and Regional Research
3
Technical Office for landscape ecology, landscape planning and landscape management,
Vienna
Lime is commonly applied on agricultural lands for ameliorating soil acidity. Furthermore the
high input of mechanical energy in common agricultural practice can negatively affect soil
structure. A promising approach to stabilize the structure and improve the water- and air
permeability, is the addition of polyvalent ions like Ca2+ which can be added for example in
the form of quicklime (CaO) and limestone (CaCO3). The soil pore system serves as a habitat
for soil biota. Microorganisms are essential for the integrity of terrestrial ecosystems as they
are key players of many soil functions such as biogeochemical cycling, plant productivity or
climate regulation.
In this study, we conducted a greenhouse pot experiment using two different sources of
calcium ions in order to examine the effect of these amendments on microbial parameters
over time. Silty and clayey soils from three different locations in Austria were sampled and
incubated with and without the liming materials (application rate 1000 kg ha-1) for 3 months
in four replicates. Soil samples were taken with a plastic probe 2, 30 and 86 days after the
application of quicklime and limestone to assess short-term and medium-term microbial
effects. By adding water in regular intervals the moisture content was kept at ~ 50 % water
holding capacity throughout the duration of the experiment. To evaluate the effect of lime on
changes in soil microbiology, we determined parameters like pH, extracellular hydrolytic
(cellulase, phosphatase, chitinase and protease) and oxidative (phenoloxidase and peroxidase
activity) enzyme activities, PLFAs, microbial biomass carbon and nitrogen, dissolved organic
carbon and nitrogen, nitrate nitrogen and ammonium nitrogen.
Initially, soil pH and DOC were strongly increased by quicklime; however, after the second
sampling (30 days) the pH values of all tested soils returned to levels comparable to the soils
treated with limestone but the DOC values declined continuously during incubation time.
Most microbial results show an immediate inhibition effect of quicklime on potential
hydrolytic enzyme activities and an increase in oxidative enzyme activities. These effects
seem to be less pronounced in the medium term.
In summary our results indicate that the application of quicklime is a feasible measure for
immediate stabilization of the structure of compaction-prone soils, showing only short-term
impact on most microbial parameters.
28
SPATIAL VARIABILITY OF PHYSICAL SOIL PROPERTIES AT A
LONG TERM FIELD MONITORING IN RUTZENDORF/LOWER
AUSTRIA
Johannes Krammer1*, Andreas Schwen1, Stefan Strohmeier1 and Andreas Klik1
1 Institute of Hydraulics and Rural Water Management, Department of Water, Atmosphere
and Environment, University of Natural Resources and Life Sciences Vienna,
* Corresponding author: [email protected]
The impact of organic farming on soil physical properties at a long term field monitoring
in Rutzendorf (Lower Austria) have been monitored by our working group since 2003.
Strong fluctuations of the measured soil properties complicated the interpretation of the
soil data. Therefore, a study determining spatial variability was performed in spring 2013.
The objective of the study was to reduce the scatter of the measured values and to facilitate
the interpretation of the arithmethic means of the soil properties. In addition, different
soil bonitations were examined and brought in correlation to the soil properties. Disturbed
and undisturbed soil samples (n = 131) were taken along a 200 m-transect at distances of 2 m
and nested parts with a higher sampling density. The samples were analyzed for particle size
distribution, total and organic carbon contents, aggregate stability, bulk density, saturated
hydraulic conductivity, and volumetric water contents at three pressure potentials (30, 50, 150
hPa). (Geo-)statistical analysis was performed to derive experimental semivariograms
and reveal the spatial variation and association among observations. The study showed a
differential spatial behavior of the observed properties along the transect: The particle size
distribution (by means of sand, silt, and clay contents), total and organic carbon contents,
bulk density, and volumetric water contents at the three pressure potentials exhibited
moderate or strong spatial dependencies, whereas aggregate stability and saturated hydraulic
conductivity were only weakly spatial dependent. According to correlation analysis,
soil bonitation showed a strong correlation to particle size distribution, organic carbon
contents and volumetric water contents at the three pressure potentials. The high spatial
variability of hydraulic conductivity and aggregate stability – in contrast to the other
measured parameters – enabled no reliable analysis according to the impact of organic
farming.
Key words: physical soil properties, spatial variability, organic farming
29
Elisabeth Deinhofer, Simone Johnen, Katharina Keiblinger, Franz Zehetner, Walter Wenzel
Since the end of the 19th Century, copper-based pesticides have been used in
viniculture to prevent and reduce fungal diseases. The long-term application of copperbased pesticides in vineyard soils has resulted in soil concentrations significantly
exceeding biological effect levels (above 55-65 mg Cu kg-1 ). A longer-term mitigation
strategy to reduce the copper bioavailability in topsoil layers from vineyard soils is of key
importance as there are currently little alternatives for copper in plant protection in organic
viniculture. In the present study, we explore the application of organic soil additives compost and biochar - which are both characterized by high heavy metal sorption
capacity and soil amelioration potential. To evaluate the optimal biochar-compostmixtures, six copper polluted vineyard soils from conventional vinefarms with different
soil properties (differing in pH, organic C, texture, and Cu concentration) are treated with 12
different combinations of additives (including pure wood- biochar, pure compost, compost
+ wood-biochar (75:25), compost + wood-biochar (25:75), , compost + 3 different
activated wood-biochars (25:75), compost + wheat husk-biochar (25:75)). All combinations
will be incubated for 8 weeks at constant temperature with 50% water holding capacity in
three replicates. During incubation, respiration will be measured to evaluate differences
in microbial activity. After 8 weeks, the desorption of copper will be determined. The
additive mixtures that were most effective in terms of Cu immobilization will be
chosen for potential enzyme activity measurements (cellulase, phosphatase, urease,
chitinase, protease, phenoloxidase and peroxidase activity) to determine Cu and additive
effects on soil microbiology. Furthermore, soil samples and seepage water samples of a
greenhouse pot experiment with grapevine and cover crops including legumes will be
analysed for their Cu-leaching in micro- lysimeters and DGT, their enzyme activity and the
impacts on the microbial community by PLFA. In this contribution, we will present the
design of the above-mentioned studies along with first results and conclusions.
30
IMPACT OF DROUGHTS AND HEAVY RAINFALL ON SOIL
MICROBIAL COMMUNITIES IN A BEECH FOREST
Nermina Saronjic, Sonja Leitner, Katharina Keiblinger, Sophie Zechmeister-Boltenstern,
Michael Zimmermann
Institute for Soil Research, Department of Forest and Soil Sciences, University of Natural
Resources and Life Sciences (BOKU), Peter-Jordan-Strasse 82, 1190 Vienna, Austria
Soil represents a major habitat for microorganisms that are involved in biogeochemical
cycles, nutrient cycling, and decomposition, and are highly sensitive to environmental
changes. Climate change alters the incidence and duration of weather conditions like drought
and rainfall, influencing soil stoichiometry that is a major driver of microbial processes. To
determine the response of microbial communities to drought and rewetting cycles, their
structure and function are assayed in a temperate beech forest located in the Rosalien
Mountains in Austria at about 640 m above sea level with a mean annual temperature of
6.5°C and a precipitation of 796 mm, respectively. Climate manipulation experiments are
conducted by means of roofs and an irrigation system. The dominant soil type at the site is
podzolic cambisol and dominant tree species: Common beech (Fagus sylvatica), Norway
spruce (Picea abies), and Silver fir (Abies alba). Changes in community structure will be first
determined by the phospholipid fatty acid analysis (PLFA) and most pronounced changes
further subjected to metaproteomics. This will link microbial diversity and functionality and
determine functional proteins and enzymes responsible for the present microbial processes.
Metaproteomic, assigns function to a certain microbial community by isolation and
identification of expressed proteins. Finally, the outcomes will be correlated to greenhouse
gas fluxes monitored for the whole duration of the experiment. Our expectation is to see
shifts in microbial community structures that will promote functional changes with an
increase in the less sensitive and the most adaptable microorganisms. This will ultimately
lead to changes in biogeochemical processes including changes in greenhouse gas fluxes.
31
EFFECTS OF EXTREME EVENTS ON CARBON CYCLING ALONG A
TERRESTRIAL-AQUATIC CONTINUUM AT THE CATCHMENT
SCALE
Jasmin Schomakers 1, Franz Zehetner 1, , Axel Mentler 1, Tz-Ching Yeh 2 , Thomas Hein 2 ,
Herwig Mayer 3 , Jr-Chuan Huang 4 , Zeng-Yei Hseu 5 , Shih-Hao Jien 6 , Chien-Sen Liao
7 , Ming-Hsi Lee 6 , Tsung-Yu Lee 4
1Institute of Soil Research and 3 Institute of Physics and Material Sciences, University of
Natural Resources and Life Sciences, Vienna, Austria;
2 Institute of Hydrobiology, University of Natural Resources and Life Sciences, Vienna,
Austria & WasserCluster Lunz, Inter University Research Institute, Lunz/See, Austria;
4 Department of Geography, National Taiwan University, Taipei, Taiwan;
5 Department of Environmental Science and Engineering, National Pingtung University of
Science and Technology, Pingtung, Taiwan;
6 Department of Soil and Water Conservation, National Pingtung University of Science and
Technology, Pingtung, Taiwan;
7 Department of Civil and Ecological Engineering, I-Shou University, Kaohsiung, Taiwan
The Intergovernmental Panel on Climate Change predicts a further global average surface
warming - depending on future emission scenarios - in the range of 1.1 to 6.4°C until the end
of the 21st century2 , which may entail dramatic consequences for biophysical and socioeconomic systems. As a result of the above-mentioned temperature rise, extreme events, such
as high-intensity rainfall events and resulting landslides and debris flows are expected to
increase in both frequency and magnitude. For example, the top 10% of precipitation
intensity is predicted to increase by about 95% for each degree Kelvin increase in global
mean temperature3 . These extreme events episodically export large amounts of terrestrial
organic carbon (OC) into fluvial ecosystems3,4 . This resets vegetation succession and soil
formation on land, and exposes terrestrial OC of varying sources, age and composition to
physical and (bio)chemical reactions in aquatic ecosystems. Through the former (terrestrial)
processes, C is fixed from the atmosphere and re-accumulated in biomass and soils; through
the latter (aquatic) processes, the exported OC may partly be respired to the atmosphere,
physically or (bio)chemically modified and hence stabilized or destabilized, buried for
longer-term storage in deposited sediments, or transported to the ocean5,6 . These processes
depend on the contribution of different terrestrial OC pools, such as litter and biomass, soil
and rock OC, which in turn is controlled by characteristics of the extreme events. The rates
and extents of these processes and their driving forces are still poorly understood and scarcely
quantified but are recently understood to be of major significance at global scale7 . For an
improved assessment of the effects of extreme events on carbon cycling it is therefore crucial
to better understand and quantify the associated terrestrial and aquatic processes. The study
focuses on a mountainous catchment in southern Taiwan where typhoons are a frequent cause
of landslides and export of terrestrial OC to aquatic ecosystems is high. The re-accumulation
and stabilization of OC in terrestrial ecosystems will be quantified, and the processing of
exported biomass- , soil-, and rock-derived OC in freshwater systems will be characterized.
The poster introduces the project and presents first results from the investigated watershed.
32
QUANTITATIVE PREDICTION OF PLANT P UPTAKE BY INFINITE
SINK EXTRACTION
Jakob Santner, Martina Mannel, Leigh Burell, Christoph Hoefer, Andreas Kreuzeder
and Walter W. Wenzel
Institute of Soil Research, Konrad-Lorenz-Strasse 24, 3430 Tulln, Austria
Besides batch extraction methods, infinite sink extraction techniques like Fe-oxide papers,
anion resin methods and diffusive gradients in thin films have been applied to estimate soil
phosphorus availability to plants. These methods selectively sample the reversibly adsorbed
inorganic soil P fraction by the continuous removal of porewater P, which induces P
desorption from soil surfaces. To date, the application of these methods for bioavailability
estimation is confined to the use as P indices. In this work we explored infinite sink extraction
for quantitative prediction of the P uptake in plants from soil.
We used a modified infinite sink extraction protocol to exclude release of P from organic
compounds through microbial degradation and P solubilisation by reductive dissolution of P
sorption sites such as Fe (oxy)hydroxides. The extracted P quantities were compared to the P
uptake of Zea mays L. in a pot experiment and to the amounts extracted by several standard
soil P tests (CAL P, Colwell P, Ca(NO3)2 P, cDGT P).
Plant P uptake was correlated with the P amounts extracted by all extraction techniques. The
strongest correlation was found with the infinite sink approach (Pmax). More importantly, the
absolute amounts of P taken up by plant roots quantitatively matched Pmax almost
quantitatively, with the deviation of Pplant to Pmax being ≤ 30%.
We conclude that plant P uptake may quantitatively be assessed by suitable infinite sink
methods. Although this approach may be too tedious for routine use it can be employed as a
research tool and as a benchmark test for calibrating routine soil P tests.
33
TEMPORAL VARIATION OF SOIL GAS DIFFUSIVITY AND SOIL
RESPIRATION WITH RESPECT TO SOIL MANAGEMENT
Eva Jeitler1, Gernot Bodner2, Peter Liebhard2, Andreas Klik1 und Andreas Schwen1*
1: Institute of Hydraulics and Rural Water Management, Department for Water, Atmosphere
and Environment, University of Natural Resources and Life Sciences Vienna (BOKU)
2: Division of Agronomy, Department for Crop Sciences - University of Natural Resources
and Life Sciences Vienna (BOKU)
*Corresponding author: [email protected]
Soils are known to be an important source and sink for carbon and could contribute to
reducing the worldwide CO2 emissions. Numerous studies have shown that soil management
can help to increase the amount of carbon that is binded in the soil. Increased budgets of
stable organic matter can be achieved by crop residuals remaining in the soil after harvest.
Reduced tillage operations have also been reported to increase soil organic matter budgets,
probably due to a hampered mineralization of organic components (microbial respiration). It
is well known that soil respiration depends on soil microbial activity that can be limited by the
soil pore system acting as transport pathway for the involved gases (oxygen, carbon dioxide)
between the soil and the atmosphere. The capability of the soil pore system for gas transport is
mainly controlled by the gas diffusion coefficient that is a function of the pore geometry and
connectivity, that is dynamically controlled by the soil water content. Many studies captured
seasonal variations of soil respiration by repeated measurements at the soil surface and related
the observed respiration rates to mainly climatic and biological influences. Despite its
importance, temporal variations of soil gas diffusivity as a controlling factor for soil
respiration have not been assessed on the basis of regular field measurements. Therefore, the
objective of this study was to capture temporal variations of soil respiration and gas
diffusivity with respect to different soil tillage methods (conventional and no-tillage). The
study was conducted on a longterm field tillage trial with a silty-loam textured soil in
Hollabrunn, Lower Austria. The field was cropped to maize. Soil respiration (CO2
production) was measured with an automated chamber and actual gas diffusivities were
derived from gas chamber experiments with undisturbed soil samples on a weekly basis over
the vegetation period. Additionally, the diffusion coefficients as a function of water content
and soil hydraulic properties were determined for both treatments by diffusion experiments
during stepwise desaturation. On the basis of climatic data (soil temperature and water
content) as well as soil physical properties, we analyzed the temporal and spatial variation of
soil gas diffusivity and respiration using time-series analysis (state-time modeling).
34
IMPACT OF EXTREME WEATHER EVENTS ON PLANT AVAILABLE
NITROGEN AND AMINO ACIDS USING MICRODIALYSIS
Pia Minixhofer, Sonja Leitner, Michael Zimmermann
Contact: [email protected]
Climate change will most likely result in increased weather extremes, not only in
frequency but also in intensity. These events of heavy droughts and rainfalls will have severe
impacts on biological nutrient cycles.
A field experiment in the BOKU forest
demonstration centre Rosalia investigates possible effects of drought and rainfall events. At
the study site, artificial roofs and an automated irrigation system simulate different rainfall
intensities after varying drought periods. The research questions we try to answer are
“What impact has the conducted drought-rewetting-cycle on plant available nitrogen and
amino acids?” and “What are the differences in diffusion rates between rewetted and control
plots?”. For this, soil samples are taken every month and pH, microbial biomass, NO3 +
, NH4 - , DOC, DON and amino acids analysed in the lab to assess changes in soil
nutrient fluxes. Additionally, the results obtained by soil extractions are compared to data
gathered with an in situ microdialysis system. The microdialysis method is based on passive
diffusion sampling. Its potential for monitoring soil solution N is based on the
possibility of in-situ analysis with minimal disturbance of the soil system and very high
spatial and temporal resolution. Nitrogen compounds have fast turnover rates and
microdialysis allows a continuous analysis of the diffusion rates of the individual N
compounds to the root surface. The results will contribute to a better understanding of the
effects of climate change on plant-available nutrients.
35
CHEMICAL IMAGING OF PHOSPHORUS DYNAMICS IN THE
RHIZOSPHERE
Andreas Kreuzeder, Vanessa Scharsching, Jakob Santner, Eva Oburger, Christoph Hoefer,
and Walter W. Wenzel
University of Natural Resources and Life Sciences,
Department of Forest and Soil Sciences, Institute of Soil Research
Konrad-Lorenz-Strasse 24, A-3430 Tulln, Austria
Phosphorus (P) is one of the most limiting nutrients to plant growth and crop yield. To
increase P uptake, plants can actively solubilise P by releasing e.g. protons or organic anions.
Innovative approaches for 2D chemical imaging of rhizosphere processes can be used to
investigate the complex interactions of plant roots and soil. Diffusive gradients in thin films
(DGT) combined with laser ablation – inductively coupled plasma mass spectrometry (LAICP-MS) allow for the 2D visualisation of the distribution of cationic and anionic solute
species in the rhizosphere. Furthermore, pH-sensitive planar optodes can map the rhizophere
pH.
The aim of this work was the development and testing of a combined setup of DGT-LA-ICPMS and pH-sensitive planar optodes to investigate biogeochemical processes controlling P
solubility in the rhizosphere. This was achieved by simultaneous imaging of P, Al, Ca, Fe and
pH to assess if P solubilisation is related to the dissolution of P sorption sites (Fe- and Al(oxy)-hydroxides) and of soil P minerals such as Ca-, Fe-, Al-phosphates. To this end, a plant
experiment using Triticum aestivum L., Fagopyrum esculentum L., and Lupinus albus L. on
calcareous and non-calcareous soils was conducted.
We show the applicability of simultaneous 2D chemical imaging of soluble Ca-, Fe-, and Al
together with P using DGT-LA-ICP-MS as well as 2D mapping of plant induced pH-changes
based on planar optodes. We conclude that this combined imaging approach offers great
potential for investigating P depletion around roots, mineral dissolution due to root activities
as well as plant induced pH-changes at sub-mm resolution.
36
POTATOFARMERS´ PERCEPTION OF SOILEROSION BY WATER –
A COMPARISON BETWEEN ECOLOGICAL AND CONVENTIONAL
FARMERS IN THE AUSTRIAN WEINVIERTEL AND TENERIFE
(CANARY ISLANDS)
Julia Molnar 1, Rainer Weisshaidinger 2, Robert Peticzka 1
1
University of Vienna, Department of Geography and Regional Research, Austria
2
Research Institute of Organic Agriculture (FiBL), Austria
Soil erosion by water is one of the most severe type of soil degradation worldwide. On areas
influenced by human activity, especially on agricultural surfaces the process of watererosion
often exceeds the process of soil development. Potatofields can be effected even worse
because of their way of being cultivated in ridges. Soil erosion by water is influenced by
parameters of the erosivity of rain on the one hand and soil properties and status on the other
hand. The latter can be influenced by human activity and thereby soils could be protected
from watererosion with often simple measures.
But do famers realize the problem of water erosion on their potatofields and are they willing
to actively counteract?
The knowledge and conduct of farmers is one important constituent to avoid soil erosion. The
work of scientist and decision-makers, whose aim is exactly at least minimizing watererosion,
are dependent on how the main players, that means the farmers, perceive and act against
erosion.
To find out whether and to what extent potatofarmers are aware and concerned about water
erosion on their fields, twelve farmers were interviewed (3 conventional farmers from the
Weinviertel, 3 ecological farmers from the Weinviertel, 3 conventional farmers from Tenerife
and 3 ecological farmers from Tenerife). Being a qualitative method, the semistructured
interviews are not to be taken as representative for a basic population, which is not their aim,
but intent to illuminate a scarcy treated issue by letting the informants come up with their
perception about it.
The interviews were all transcribed and later interpreted with the aid of inductive categoryformation. The category systems of the four groups (ecological, conventional Weinviertel,
Tenerife) were compared in their contents.
In the twelve studied cases it turned out that knowledge and consciousness about soil erosion
do not have to with being a ecological or a conventional farmer. It depends much more on
information and education, (which in some cases can be required to become an ecological
farmer), and the actual soil erosion on the field. Measures are taken if they are seen to be
efficient in other farmers fields. On ecological fields it is often more difficult to take actions
against soil erosion because of the intense mechanic handling in consequence of the nonuse of
non-organic phytosanitary products. The difference of the perception of erosion between
farmers of the Weinviertel and Tenerife consist largely in the differences of cultivation
methods.
37
THE HUMUS-TREND-SCALE – A METHOD TO GET A FEELING FOR
HUMUS DYNAMICS IN SOIL.
Marie-Luise WOHLMUTH
Baumgasse 52/20, 1030 Wien
The assessment of humus dynamics of agricultural soils is of high interest from an
agronomical and an ecological point of view. The content of humus in soils is linked to many
important parameters like e.g. water holding capacity, stability of aggregates, and storage
capacity of nutrients and is influenced by land management. Humus balance methods intend
to support farmers in maintaining soil fertility of their land. Interestingly, in parts of Germany
financial transfers for farmers are linked to the application of humus balance spreadsheet
programs. My aim was to broaden this important topic for a wider range of people e.g. pupils,
people interested in ecology, farmers and teachers. This had to be done by finding a
didactically different concept.
The Humus-Trend-Scale is based on the humus balance methods according to Leithold, G.;
Hülsbergen, K.-J.; Michel, D. & Schönmeier, H. (1997) and the standards of VDLUFA- from
30. April 2004 according to Körschens, M., Rogasik, J., Schulz, E. et al. From the point of
didactics it is based on the method of Maria Montessori and Sensory Integration (Jane Ayres,
Ulla Kiesling) where material, which addresses several senses, is used. The method is
didactically prepared in a way that visual (colours, size) and tactile (weight) stimuli help the
user to “understand” the effect of cultures and organic fertilization on arable farm land.
The users can easily discover if a crop rotation shows a positive or negative trend on the
content of humus within the soil. People with no or little knowledge of farming get a basic
understanding what farming means to soil fertility. Especially farmers get a better feeling
about the humus dynamics in relations of cash crops to one another and between cash crops
and organic fertilization like green manure, cover crops, compost, legumes, straw etc.
First applications of the Humus-Trend-Scale on field days and as part of the “BOKU-Mobil”
program brought very positive response from farmers as well as from pupils and teachers.
38
Short and mid-term effects of different biochar additions on soil GHG
fluxes
Regine MAIERa, Gerhard SOJA b, Wolfgang FRIESL-HANL b and Barbara KITZLERa
a
Federal Research and Training Centre for Forests, Natural Hazards and Landscape,
Seckendorff-Gudent-Weg 8, 1130 Vienna
b
AIT Austrian Institute of Technology GmbH, Konrad-Lorenz-Straße 24, 3430 Tulln
The application of biochar (BC) to soils may have positive influence on physico-chemical soil
properties and the mitigation of greenhouse gas (GHG) emissions. Furthermore, biochar
contributes to a long-term soil carbon sequestration.
The aim of this study is to explore the short- and mid-term effects (one day up to six months)
of biochar on GHG emissions, particularly CO2, CH4 and N2O. In addition, compounds of the
nitrogen cycle like NH4+, NO3- and the microbial biomass nitrogen and carbon (C) were
measured.
For this purpose a field experiment in Kaindorf (Styria, gleyic Cambisol, loamy, 376 m.a.s.l.)
with 16 plots and four different treatments (K = mineral fertilizer corresponding to T3 without
BC, in 2013; T1 = 1 % BC without addition of nitrogen (N) (in 2013 and 2014), T2 = 0.5 %
BC with addition of 175 kg N ha-1 in 2013 and 2014); T3 = 1% BC with addition 350 kg N
ha-1 in 2013) was conducted. Nitrogen was added directly to the BC as NH4SO4.
Greenhouse gas fluxes were measured in closed chambers in the field over a period of six
months. Mineral N contents were analyzed by the extraction with KCl-solution and the
microbial biomass N and C with chloroform-fumigation extraction (CFE).
Our results show that in treatment T2 significantly higher GHG emissions, especially N2O
and NOx were measured. Other treatments with nitrogen fertilized BC also affect those fluxes
but not in that extent.
39

Burning Issues in Soil Science - Österreichische Bodenkundliche

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