@misc{AhmedGypserLeinweberetal., author = {Ahmed, Ashour A. and Gypser, Stella and Leinweber, Peter and Freese, Dirk and K{\"u}hn, Oliver}, title = {New insights into IR spectroscopic characterization of phosphate binding at the goethite-water interface}, series = {IPW9, ETH Zurich, Switzerland, 8-12 July, 2019 - Abstracts}, journal = {IPW9, ETH Zurich, Switzerland, 8-12 July, 2019 - Abstracts}, address = {Z{\"u}rich}, pages = {108}, abstract = {Facing the projected peak phosphorus (P) scenario, substantial research activities have been triggered to improve our knowledge towards a more efficient and sustainable use of P resources. One major factor playing a role in the P immobilization and thus its availability for plants is the strong interaction between phosphates and soil mineral surfaces, such as Fe- and Al-(oxyhydr)oxides. The reactions of phosphates with Fe-hydroxides and especially goethite have been studied extensively. But a molecular-level picture of the phosphate binding mechanism at the goethite-water interface is still lacking. Therefore, in the current contribution we have explored the molecular binding mechanism for the adsorbed phosphate at the goethite-water interface by performing sorption kinetics experiments for orthophosphate and characterizing the adsorbed species by FT-IR spectroscopy. In parallel, periodic quantum mechanical calculations, at the density functional theory (DFT) level, have been performed to explore the interaction mechanism as well as to calculate the IR spectra for monodentate (M) and bidentate (B) orthophosphate complexes with goethite at two different goethite surface planes (010 and 100) in the presence of water. In general, our interaction energy results give evidence that the mono-protonated B phosphate complex is more favored to be formed at the goethite-water interface although the M motif could exist as a minor fraction. Moreover, it was found that water plays an important role in controlling the phosphate adsorption process at the goethite surfaces. The interfacial water molecules form H-bonds (HBs) with the phosphate as well as with the goethite surface atoms. Further, some water molecules form covalent bonds with goethite Fe atoms while others dissociate at the surface to protons and hydroxyl groups. The present theoretical assignment of IR spectra introduces a benchmark for characterizing experimental IR data for the adsorbed KH2PO4 species at the goethite-water interface. In particular, IR spectra of the mono-protonated (2O+1Fe) B complex at the 010 goethite surface plane and the M complex at the 100 goethite surface plane were found to be consistent with the experimental data. In order to explore the role of different abundancies of surface planes and binding motifs, IR spectra obtained from weighted averages have been analyzed. Results confirmed the above conclusions drawn from interaction energy calculations. Moreover, the soil solution pH effect on the phosphate binding mechanism to goethite surface has been explored as well.}, language = {en} } @inproceedings{DimitrovaRepmannFreese, author = {Dimitrova, Tsvetelina and Repmann, Frank and Freese, Dirk}, title = {Remediation of cyanide-contaminated industrial sites through woody biomass production}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {Due to the unfavourable chemical and physical soil quality parameters and the potential presence of contaminants, former industrial sites can hardly be utilized as arable land and can thus be classified as marginal areas. Still, as far as possible, they can effectively be used for the production of alternative energy, including the cultivation of fast growing trees. Apart from being a source of bioenergy, trees might facilitate the stabilization, remedation, contaminant extraction and degradation and, not on the last place, to enhance soil quality improvement on former industrial areas. This process is known as phytoremediation and has successfully been applied on industrial sites of various organic and inorganic contamination. The former manufactured gas plant site (� 2500 m2) "ehemalige Leuchtgasanstalt" Cottbus, contaminated, among others, with iron cyanides undergoes phytoremediation with simultaneous biomass production since 2011. The project "Biomass-Remediation" is fully financed by the German Railways JSC. A dense (23700 stems/ha), mixed cover of willow (Salix caprea), poplar (Populus maximowicii Henry x Populus trichocarpa Torr. et Gray (Hybrid 275)) and black locust (Robinia pseudoaccacia) trees has been planted on the site. Throughout the five years of remediation, a successful long-term stabilization of the site has been achieved as a result of the nearly outright established tree stock and the dense planting. Annual monitoring of the cyanide levels in the leaf tissue of the trees on the site and results from greenhouse experiments indicate the ability of all tree species to extract and transport the cyanide from the soil. Additonally, the greenhouse experiments suggest that the willows might be able, although not to a full extent, to detoxify the contaminant by splitting the CN moiety. The contaminated biomass material might easily be dealt with through regular harvests and subsequent incineration. Phytoremediation with simultaneous biomass production for bioenergy offers an environmenatlly-friendly and a cost-effective solution of the problem with contaminated former industrial areas in the context of marginal land use options.}, language = {en} } @misc{MajauraBoehmFreese, author = {Majaura, Marie and B{\"o}hm, Christian and Freese, Dirk}, title = {Effects of agroforestry systems on microclimate and water availability as determinants for sustainable soil productivity}, series = {4th World Congress on Agroforestry : 20-22 May 2019, Le Corum, Montpellier, France, Book of Abstracts}, journal = {4th World Congress on Agroforestry : 20-22 May 2019, Le Corum, Montpellier, France, Book of Abstracts}, pages = {669}, abstract = {Recent studies have shown that hedgerows in short rotation alley cropping systems (SRACS) can improve the microclimate in adjacent crop alleys through, e.g., a reduction of daytime temperature, wind speed and evaporation (Kanzler et al. 2018). Improved microclimatic conditions may positively affect crop yields by increasing the availability of water for the crop. However, studies that examine the interdependencies between microclimate changes caused by hedgerows in SRACS, water availability and crop yields are rare. In a poplar SRACS, we investigate with high spatial and temporal resolution if changes in microclimate affect water availability for two crops and crop yields. For this purpose, we use stationary weather stations installed in a transect and mobile sensors in four strips running parallel to the stationary transect at different distances from tree strips (Fig. 1) and in a monoculture. At all measuring points air temperature, air humidity and Pich{\´e} evaporation will be continuously determined. In addition, wind speed, global radiation and precipitation will be measured at the stationary weather stations. Furthermore, transpiration of crops will be determined at different times close to all microclimate points. Subsequent crop yield sampling will then enable us to determine the degree to which tree strips in ACS influence microclimate and water availability for crops at different distances from tree strips and how these relate to small-scale changes in crop yield.}, language = {en} } @inproceedings{QuinkensteinCarreroBastosFreese, author = {Quinkenstein, Ansgar and Carrero Bastos, Lina Tatiana and Freese, Dirk}, title = {Root distribution of black locust trees in an alley cropping system}, series = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, booktitle = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, editor = {B{\"o}hm, Christian}, publisher = {BTU}, address = {Cottbus}, isbn = {978-3-940471-27-7}, pages = {163 -- 167}, abstract = {In a five-year old alley cropping system in Brandenburg, Germany, the extension of the root system of black locust (Robinia pseudoacacia L.) trees into the neighbouring agricultural field alleys was investigated. Along transects between the hedgerows and the middle of the neighbouring field alleys, samples were collected at distances of 1.30, 4.3 and 49.3 m to the hedgerow border and for the soil depths 0-15, 15-30, 30-45 and 45-60 cm by using an auger with a diameter of 8 cm. Roots were separated from the soil by means of washing and sieving. The root samples were then sorted and analysed for root length densities and dry masses. The results indicate a logarithmic decrease of root length densities and root masses of black locust with increasing distance to the trees, although, the number of positive samples was too small to conduct a substantiated statistical analysis. In result, the authors assume that the tree roots did not extend into the agricultural alley for the considered soil depths substantially, but, nevertheless, suggest a modified sampling method or/and the investigation of older tree stands for future studies.}, language = {en} } @inproceedings{VesteBoehmQuinkensteinetal., author = {Veste, Maik and B{\"o}hm, Christian and Quinkenstein, Ansgar and Freese, Dirk}, title = {Estimation of biological nitrogen fixation by black locust in short-rotation forests using natural 15N abundance method}, series = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, booktitle = {EGU General Assembly 2012, held 22-27 April, 2012 in Vienna}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {The importance of short rotation forests and agroforestry systems for woody biomass production for bioenergy will increase in Central Europe within the next decades. In this context, black locust (Robinia pseudoacacia) has a high growth potential especially at marginal, drought-susceptible sites such as occur in Brandenburg State (Eastern Germany). As a pioneer tree species black locust grows under a wide range of site conditions. The native range of black locust in Northern America is classified by a humid to sub-humid climate with a mean annual precipitation of 1020 to 1830 mm. In Central and Eastern Europe, this species is cultivated in a more continental climate with an annual precipitation often below 600 mm. Therefore, black locust is known to be relatively drought tolerant compared to other temperate, deciduous tree species. Because of its N2-fixation ability black locust plays generally an important role for the improvement of soil fertility. This effect is of particular interest at marginal sites in the post-mining landscapes. In order to estimate the N2-fixation potential of black locust at marginal sites leaf samples were taken from black locust trees in short rotation plantations planted between 1995 and 2007 in post-mining sites south of Cottbus (Brandenburg, NE Germany). The variation of the natural 15N abundance was measured to evaluate the biological nitrogen fixation. The nitrogen derived from the atmosphere can be calculated using a two-pool model from the quotient of the natural 15N abundances of the N2-fixing plant and the plant available soil N. Because representatively determining the plant available soil N is difficult, a non-N2-fixing reference plant growing at the same site with a similar root system and temporal N uptake pattern to the N2-fixing plant is often used. In our case we used red oak (Quercus rubra) as a reference. The average nitrogen content in the leaves of black locust ranged from 3.1\% (C/N 14.8) in 15 years old trees to 3.4\% (C/N 14.4) in 3 year-old trees, respectively. A higher content of nitrogen was found in leaves of re-sprouted trees with 4.3\% (C/N 11.5). The estimated percentage of nitrogen derived from the atmosphere (\% NdfA) in black locust was 63\% - 83\% compared to 56\% in seabuckthorn (Hippopha{\"e} rhamnoides) and 79\% in common broom (Genista scuparia). The annual leaf biomass production of black locust varied between 1325 (2 years old trees) and 2576 kg/ha a (4 years old trees). The estimated leaf nitrogen fixed by Robinia was approx. 30.5 - 59.2 kg/ha a. From the results, we can conclude that the biological nitrogen fixation by Robina is an important factor for the nitrogen balance of short-rotation plantations on nutrient poor-soils.}, language = {en} } @inproceedings{SesermanVesteFreeseetal., author = {Seserman, Diana-Maria and Veste, Maik and Freese, Dirk and Swieter, Anita and Langhof, Maren}, title = {Benefits of agroforestry systems for land equivalent ratio - case studies in Brandenburg and Lower Saxony, Germany}, series = {Proceedings of the 4th European Agroforestry Conference Agroforestry as Sustainable Land Use 28-30 May 2018, Nijmegen, The Netherlands}, booktitle = {Proceedings of the 4th European Agroforestry Conference Agroforestry as Sustainable Land Use 28-30 May 2018, Nijmegen, The Netherlands}, publisher = {University of Santiago de Compostela}, address = {Santiago de Compostela}, isbn = {978-84-09-02384-4}, pages = {26 -- 29}, abstract = {Transitioning towards agroforestry demands systematic productivity assessments of such systems under different climatic and edaphic conditions. In this regard, the Land Equivalent Ratio (LER) serves as a valuable productivity indicator of agroforestry since it evaluates yields from growing trees and crops together in comparison to yields from monocultures over the same period. Consequently, our objective was to evaluate the overall productivity of two agroforestry systems in Forst (Brandenburg) and Wendhausen (Lower Saxony) by means of LER. Our approach followed two assumptions: (i) the yields of trees and crops had equal economic importance and (ii) the economic importance was given solely by the annual crop, the yield of trees representing a supplementary profit. The resulted values for LER were consistently above their specific threshold, corroborating the greater efficiency of agroforestry systems rather than monoculture. Additionally, this study highlighted the importance of choosing the appropriate assumptions when calculating the LER.}, language = {en} } @inproceedings{SesermanPohleVesteetal., author = {Seserman, Diana-Maria and Pohle, Ina and Veste, Maik and Freese, Dirk}, title = {Variabilit{\"a}t der holzigen Biomasseproduktion von Pappel und Robinie als Folge des Klimawandels in einem Alley-Cropping System in der Lausitz}, series = {1. Erfurter Tagung "Schnellwachsende Baumarten - Etablierung, Management und Verwertung", vom 16.11.-17.11.2017}, booktitle = {1. Erfurter Tagung "Schnellwachsende Baumarten - Etablierung, Management und Verwertung", vom 16.11.-17.11.2017}, publisher = {Fachhochschule Erfurt}, address = {Erfurt}, pages = {88 -- 89}, language = {de} } @inproceedings{RepmannGerwinFreese, author = {Repmann, Frank and Gerwin, Werner and Freese, Dirk}, title = {Assessing soil quality and potential productivity - a basic approach to define and assess the marginality of land}, series = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, booktitle = {European Geosciences Union General Assembly 2017 Vienna, Austria, 23-28 April 2017}, publisher = {European Geophysical Society}, address = {Katlenburg-Lindau}, abstract = {An ever growing demand for energy and the widely proposed switch from fossil fuels to more sustainable energy sources puts the cultivation and use of bioenergy plants into focus. However, bioenergy production on regular and fertile agricultural soils might conflict with the worldwide growing demand for food. To mitigate or omit this potential conflict, the use of low quality or marginal land for cultivation of bioenergy plants becomes favorable. Against this background the definition and assessment of land marginality and, respectively, the evaluation whether and to which extent specific areas are marginal and thus convenient for sustainable bioenergy production, becomes highly relevant. Within the framework of the EU funded Horizon 2020 project SEEMLA, we attempted to asses land marginality of designated test sites in the Ukraine, Greece and Germany by direct field survey. For that purpose, soil and site properties were investigated and evaluated by applying the Muencheberg Soil Quality Rating (SQR) method, developed at the Leibniz Centre for Agricultural Landscape Research (ZALF). The method deploys a comprehensive set of biogeophysical and chemical indicators to describe and finally evaluate the quality of the soil and site by a score ranging from 1 to 100 points. Field survey data were supported by additional laboratory tests on a representative set of soil samples. Practical field work and analysis of field and lab data from the investigated sites proved the applicability of the SQR method within the SEEMLA context. The SQR indices calculated from the field and lab data ranged from 2 to < 40 and clearly demonstrated the marginality of the investigated sites in the Ukraine, Greece and Germany, which differed considerably in respect to their characteristics. Correlating the site quality index to yield data reflecting yield estimations for common bioenergy plants such as willow (Salix sp.), black locust (Robinia pseudoacacia) and poplar (Populus sp.) cultivated at the respective test sites, revealed that SQR might additionally reflect the potential yield of the investigated sites.}, language = {en} } @inproceedings{GerwinRepmannFreese, author = {Gerwin, Werner and Repmann, Frank and Freese, Dirk}, title = {B{\"o}den marginaler Standorte - eigenschaften, Limitierungen und Potentiale}, series = {Abstracts der DBG Jahrestagung 2017, 02.-07. Sept. 2017, G{\"o}ttingen}, booktitle = {Abstracts der DBG Jahrestagung 2017, 02.-07. Sept. 2017, G{\"o}ttingen}, pages = {V49}, abstract = {Eine zunehmende Knappheit ackerbaulicher Standorte und der zugleich steigende Bedarf an nachwachsenden Rohstoffen f{\"u}r die energetische und stoffliche Nutzung l{\"o}sen verst{\"a}rkt Konflikte zwischen der Nahrungsmittelproduktion und der Biomasseproduktion aus. Marginale Standorte kommen entsprechend immer st{\"a}rker in den Blickpunkt als m{\"o}gliche Erweiterungsfl{\"a}chen f{\"u}r die Biomasseproduktion. In der wissenschaftlichen Auseinandersetzung fehlt allerdings eine eindeutige Definition f{\"u}r derartige marginale Standorte. Gerade im Hinblick auf eine m{\"o}gliche Reduzierung von Nutzungskonflikten ist die Abgrenzung zu stillgelegten, aber agrarisch nutzbaren Standorten oder zu nat{\"u}rlichen Badlands, mit naturschutzfachlichen Potentialen oftmals schwierig. Das EU H2020-Projekt SEEMLA untersucht Potentiale und Verf{\"u}gbarkeit von marginalen Standorten europaweit. In Deutschland, Griechenland und der Ukraine wurden Pilotstandorte eingerichtet, auf denen der Anbau von Bioenergiepflanzen exemplarisch durchgef{\"u}hrt wird. F{\"u}r eine erste Bewertung der Standortspotentiale und auch der Ursachen der Marginalit{\"a}t der Standorte wurden Bodenuntersuchungen an allen Pilotstandorten nach den Vorgaben des Muencheberger Soil Quality Rating-Verfahrens (SQR) (1) durchgef{\"u}hrt und die Standorte klassifiziert. Das SQR-Verfahren bewertet ausgew{\"a}hlte Boden- und Standortseigenschaften und bezieht zus{\"a}tzlich m{\"o}gliche limitierende Faktoren (Hazard Indicators) wie Versauerung, Versalzung, Vern{\"a}ssung etc. mit ein, um eine Gesamtbewertungszahl zur Bodenfruchtbarkeit zu ermitteln. Dieser Beitrag stellt anhand der SEEMLA-Standorte exemplarisch B{\"o}den marginaler Standorte vor. Mit Hilfe der SQR Hazard Indicators werden charakteristische limitierende Faktoren vorgestellt. Es wird zudem versucht, die untersuchten Standorte in eine m{\"o}gliche Klassifikation marginaler Standorte einzupassen und ihre Eignung f{\"u}r die Biomasseproduktion einzusch{\"a}tzen.}, language = {de} } @inproceedings{GypserSlazakFreese, author = {Gypser, Stella and Slazak, Anna and Freese, Dirk}, title = {Impact of crystallization of iron and aluminium hydroxides on the mechanisms of phosphate binding}, series = {9th International Symposium on Ecosystem Behavior BIOGEOMON, Litomysl, Czech Republic, August 20-24, 2017}, booktitle = {9th International Symposium on Ecosystem Behavior BIOGEOMON, Litomysl, Czech Republic, August 20-24, 2017}, editor = {Nov{\´a}k, Martin and Kr{\´a}m, Pavel and Step{\´a}nov{\´a}, M.}, pages = {366 -- 367}, language = {en} } @inproceedings{QuinkensteinJanusFreese, author = {Quinkenstein, Ansgar and Janus, Tomasz and Freese, Dirk}, title = {Depth gradient of soil C, N and S contents in an alley cropping system for biomass production}, series = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, booktitle = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, editor = {B{\"o}hm, Christian}, address = {Cottbus}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-41487}, pages = {158 -- 162}, abstract = {In a six-year-old alley cropping system with fast growing trees for biomass production (ACS), the depth distribution of soil contents of carbon (C), nitrogen (N) and sulphur (S) under the trees (poplar) and under the neighbouring agricultural field was investigated. The measured soil contents were usual for agricultural sites and showed a significant decrease with increasing soil depth under the trees. These results might indicate that the introduction of trees into agricultural areas leads to an alteration of the soil distribution pattern of C, N, S from a pattern typical for agricultural soils (more or less constant values at least within the ploughing horizon from 0-30 cm) to a pattern more typical for forest ecosystems (comparatively higher values in the topsoil, lower values in the deeper soil). However, for more reliable results measurements should be repeated and preferably older stands should be investigated.}, language = {en} } @inproceedings{DimitrovaRepmannFreese, author = {Dimitrova, Tsvetelina and Repmann, Frank and Freese, Dirk}, title = {Phytoremediation und Biomasseerzeugung auf Industristandorten am Beispiel "ehemalige Leuchtgasanstalt" Cottbus}, series = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, booktitle = {B{\"a}ume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beitr{\"a}gen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske)}, editor = {B{\"o}hm, Christian}, publisher = {BTU}, address = {Cottbus}, isbn = {978-3-940471-27-7}, pages = {196 -- 201}, language = {de} }