TY - CHAP A1 - Böhm, Christian A1 - Bärwolff, Manuela A1 - Quinkenstein, Ansgar A1 - Freese, Dirk ED - Nelles, Michael T1 - Bereitstellung von holzartigen Bioenergieträgern durch Agroforstsysteme T2 - Tagungsband, 5. Rostocker Bioenergieforum, am 2. und 3. November 2011 an der Universität Rostock, Y1 - 2011 SN - 978-3-940364-20-3 SP - 57 EP - 68 PB - Univ. CY - Rostock ER - TY - GEN A1 - Gypser, Stella A1 - Schütze, Elisabeth A1 - Freese, Dirk T1 - Crystallization of single and binary iron- and aluminum hydroxides affect phosporus desorption T2 - Journal of Plant Nutrition and Soil Science N2 - In acidic soils, phosphorus availability is affected by its strong affinity for mineral surfaces, especially Fe- and Al-hydroxides. Plant roots have developed adaptive strategies to enhance the availability of phosphorus, including producing and exuding low molecular weight organic acids with a high affinity for phosphorus that competes with high molecular weight organic ligands formed during humification and mineralization. The aim of this study was to characterize the kinetics and mechanism of phosphorus desorption from Fe- and Al-hydroxides of variable crystallinity, as well as binary Fe:Al-hydroxide mixtures. Long-term desorption experiments (56 days) were conducted with CaCl₂, CaSO₄, citric acid, and humic acid as competitive sorptives. CaCl₂ and CaSO₄ were selected as general inorganic sorptives and citric and humic acids were selected as organic ligands produced by organisms in the rhizosphere or following humification. The cumulative phosphorus desorption increased following the order CaCl₂< CaSO₄< humic acid < citric acid. Amorphous ferrihydrite and Fe-rich Fe:Al-hydroxides exhibited much less desorption when exposed to inorganic solutions than the crystalline and Al-rich Fe:Al-hydroxide mixtures. Models of the desorption data suggest phosphorus desorption with citric acid is diffusion- controlled for ferrihydrite and Fe-rich amorphous Fe:Al-hydroxides. When humic acid was the sorptive, metal-organic complexes accumulated in the solution. The results suggest organic compounds, especially citric acid, are more important for liberating phosphorus from Fe- and Al-minerals than inorganic ions present in the soil solution. Y1 - 2019 U6 - https://doi.org/10.1002/jpln.201700543 SN - 1522-2624 VL - 182 IS - 5 SP - 741 EP - 750 ER - TY - CHAP A1 - Tsonkova, Penka A1 - Freese, Dirk A1 - Böhm, Christian A1 - Quinkenstein, Ansgar A1 - Schaller, Eberhard ED - Freese, Dirk ED - Pittruff, N. ED - Quinkenstein, Ansgar ED - Böhm, Christian T1 - Benefits provided by silvoarable agroforestry systems in the temperate region: a review T2 - Proceedings of the International Workshop on Agroforestry - Ecological Benefits of Agroforestry, 15-17 June 2011, Cottbus, Germany Y1 - 2011 UR - http://www-docs.tu-cottbus.de/multiland/public/FreeseEtAl2011_Proceedings_of_the_International_Workshop_on_Agroforestry.pdf SP - S. 29 ER - TY - GEN A1 - Freese, Dirk A1 - Böhm, Christian A1 - Kwasnicka, Kamila A1 - Quinkenstein, Ansgar A1 - Uckert, Götz T1 - Kostensparend und ökologisch. Ökonomie und rechtlicher Rahmen für Agroforstsysteme T2 - Neue Landwirtschaft Y1 - 2011 SN - 0863-2847 IS - 1 SP - 91 EP - 94 ER - TY - CHAP A1 - Schaaf, Wolfgang A1 - Gerwin, Werner A1 - Freese, Dirk A1 - Böhm, Christian A1 - Krümmelbein, Julia T1 - Initiale Ökosystementwicklung, Rekultivierung und alternative Landnutzung in der Niederlausitzer Bergbaufolgelandschaft T2 - Böden verstehen, Böden nutzen, Böden fit machen, Jahrestagung der Deutschen Bodenkundlichen Gesellschaft, 3. - 9. September 2011 Y1 - 2011 SP - 22 EP - 27 PB - Dt. Bodenkundliche Gesellschaft CY - Oldenburg ER - TY - CHAP A1 - Gypser, Stella A1 - Freese, Dirk ED - Krämer, Inga ED - Häberle, Stephanie T1 - Mechanisms of adsorption and desorption of phosphorus on crystalline iron, aluminum, manganese (hydr)oxides as well as iron and calcium phosphates in comparison to amorphous iron-aluminum compounds T2 - 8th International Phosphorus Workshop IPW8, Rostock, Germany, September 12-16, 2016 N2 - Inorganic phosphorus (P) plays an important role as plant nutrient in fertilizers, but also as a major pollutant to aquatic ecosystems by leaching from arable land. The mobility and bioavailability of P depends on adsorption, desorption and precipitation processes at soil mineral surfaces. In the soil matrix, P can be found in the forms of iron, aluminum or calcium complexes, adsorbed on mineral surfaces. P reactions in soil, especially the fixation on iron and aluminum (hydr) oxides, have been thoroughly studied. But the much slower process of P release has to be attended as well regarding the prospective supply of fertilizers and the use of plant available P pools in arable soils. The P adsorption ability of pedogenic oxides depends on their crystallinity, while soils contain both crystalline minerals such as goethite or ferrihydrite, as well as amorphous iron and aluminum compounds. In this study, long-term adsorption and desorption experiments were carried out to investigate the P binding mechanism during the sorption processes at certain time steps. For adsorption experiments, various experimental conditions such as pH, P ionic strength, competitive ions such as SO4 2- and Ca2+ as well as time will be considered. For desorption experiments, a Flow-Through-Reactor-Technique will be applied to investigate desorption kinetics and processes under nearly natural conditions without disturbance of the mineral-solution interface. Additionally, the release of P from the iron and calcium phosphates vivianite and hydroxyapatite, a main supplier of inorganic P and model substance for bone char, will be investigated. By using Fourier-Transformation-Infrared-Spectroscopy, changes of P binding mechanisms during ad- and desorption processes and easily as well heavily purgeable P can be detected. Aim is to identify fundamental processes of P fixation and mobilization as well as to specify similarities and differences of P binding on crystalline and amorphous reactive surfaces of pedogenic oxides. Y1 - 2016 U6 - https://doi.org/10.12754/procs-2016-ipw8 SP - S. 73 CY - Rostock ER - TY - GEN A1 - Quinkenstein, Ansgar A1 - Böhm, Christian A1 - Freese, Dirk A1 - Wöllecke, Jens A1 - Grünewald, Holger A1 - Schneider, Bernd Uwe A1 - Hüttl, Reinhard F. T1 - Alley-Cropping - Ein klima-adaptierbares Landnutzungssystem zur nachhaltigen Biomasseproduktion T2 - Forum der Forschung Y1 - 2008 SN - 0947-6989 VL - 12 IS - 21 SP - 131 EP - 138 ER - TY - GEN A1 - Gypser, Stella A1 - Freese, Dirk T1 - Phosphorus release from vivianite and hydroxyapatite by organic and inorganic compounds T2 - Pedosphere N2 - Based on recent mining rates and the exhaustion of global phosphorus (P) reserves, there is a need to mobilize P already stored in soils, and its recovery from secondary resources such as Ca- and Fe-phosphates is important. The Ca-phosphate hydroxyapatite forms a good fertilizer source, while vivianite is formed in waterlogged soils and sediments. During sludge treatment, the formation of vivianite has been identified, being mainly Fe-phosphate. Long-term P release from both hydroxyapatite and vivianite was studied using different inorganic (CaCl2 and CaSO4) and organic (citric and humic acid) reagents during batch experiments. Reagents CaCl2 and CaSO4 represent the soil solution, while citric and humic acids as organic constituents affect P availability in the rhizosphere and during the process of humification. Additionally, the flow-through reactor (FTR) technique with an infinite sink was used to study the long-term P release kinetics. The cumulative P release was higher by organic acids than by inorganic compounds. The cumulative P release rates were higher in the FTR with CaCl2 as compared to the batch technique. The infinite sink application caused a continuously high concentration gradient between the solid and liquid phases, leading to higher desorption rates as compared to the batch technique. The predominant amount of the total P released over time was available for a short term. While inorganic anion exchange occurred at easily available binding sites, organic acids affected the more heavily available binding sites, which could be embedded within the mineral structure. The results showed that organic compounds, especially citric acid, play a superior role as compared to the inorganic constituents of the soil solution during the recovery of already stored P from the tertiary phosphates vivianite and hydroxyapatite. Y1 - 2020 U6 - https://doi.org/10.1016/S1002-0160(20)60004-2 SN - 1002-0160 VL - 30 IS - 2 SP - 190 EP - 200 ER - TY - CHAP A1 - Repmann, Frank A1 - Gerwin, Werner A1 - Freese, Dirk ED - Böhm, Christian T1 - Nachhaltige Biomasserzeugung zur energetischen Verwertung auf marginalen Standorten in Europa - Bewertung der Standortqualität T2 - Bäume in der Land(wirt)schaft - von der Theorie in die Praxis, Tagungsband mit Beiträgen des 5. Forums Agroforstsysteme 30.11. bis 01.12.2016 in Senftenberg (OT Brieske) N2 - Der Lehrstuhl Bodenschutz und Rekultivierung der Brandenburgischen Technischen Universität Cottbus-Senftenberg (BTU CS) ist Projektpartner in dem von der Europäischen Union im Rahmen des Programms Horizon 2020 geförderten Forschungsprojekts SEEMLA → „Sustainable exploitation of biomass for bioenergy from marginal lands in Europe“ → „Nachhaltige Nutzung von Biomasse für Bioenergie von marginalen Standorten in Europa“. Übergeordnetes Ziel des Projektes ist die Ermittlung des Biomassepotenzials, das auf marginalen Standorten innerhalb von Europa nachhaltig produziert und energetisch verwertet werden kann. Die BTU CS hat in diesem Kontext Untersuchungen zur Bewertung der Marginalität von potenziellen Biomasse-Produktionsstandorten in Deutschland, Griechenland und der Ukraine durchgeführt. Zu diesem Zweck wurde das Müncheberger Soil-Quality-Rating System (SQR) (Müller et al. 2007) eingesetzt. Y1 - 2017 UR - http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus4-41487 SN - 978-3-940471-27-7 SP - 189 EP - 195 PB - BTU CY - Cottbus ER - TY - GEN A1 - Gypser, Stella A1 - Hirsch, Florian A1 - Schleicher, Anja M. A1 - Freese, Dirk T1 - Impact of crystalline and amorphous iron- and aluminum hydroxides on mechanisms of phosphate adsorption and desorption T2 - Journal of Environmental Sciences Y1 - 2018 U6 - https://doi.org/10.1016/j.jes.2017.12.001 VL - 70 SP - 175 EP - 189 ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Raab, Thomas A1 - Freese, Dirk T1 - Uptake of ferrocyanide in willow and poplar trees in a long term greenhouse experiment T2 - Ecotoxicology N2 - Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg-1 for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l-1. The maximum cyanide content in willow and poplar leaves was 518 mg kg-1 fresh weight (FW) and 148 mg kg-1 FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l-1 and for willow after 8 weeks of exposure—768 mg l-1. Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides. Y1 - 2015 U6 - https://doi.org/10.1007/s10646-014-1398-0 SN - 1573-3017 VL - 24 IS - 3 SP - 510 ER - TY - GEN A1 - Kayatz, Benjamin A1 - Baroni, Gabriele A1 - Hillier, Jon A1 - Lüdtke, Stefan A1 - Freese, Dirk A1 - Wattenbach, Martin T1 - Supporting decision-making in agricultural water management under data scarcity using global datasets – chances, limits and potential improvements T2 - Agricultural Water Management N2 - Assessing alternative agricultural water management strategies requires long-term field trials or vast data collection for model calibration and simulation. This work aims to assess whether an uncalibrated agro-hydrological model using global input datasets for climate, soil and crop information can serve as a decision support tool for crop water management under data scarcity. This study employs the Cool Farm Tool Water (CFTW) at eight eddy covariance sites of the FLUXNET2015 dataset. CFTW is tested using global (CFTWglobal) and local (CFTWlocal) input datasets under current and alternative management scenarios. Results show that the use of global datasets for estimating daily evapotranspiration had little effect on the median Root Mean Square Error (RMSE) (CFTWglobal: 1.70 mm, CFTWlocal: 1.79 mm), while, however, the median model bias is much greater (CFTWglobal: 18.6%, CFTWlocal: 4.3%). Furthermore, the periods of water stress were little affected by the use of local or global data (median accuracy: 0.84), whereas the use of global data inputs led to a significant overestimation of irrigation water requirements (median difference: 110 mm). The model performance improves predominantly through the use of more representative local precipitation data, followed by local reference evapotranspiration and soil for some European growing seasons. We identify model outputs that can support decision-making when relying on global data, such as periods of water stress and the daily dynamics of water use. However, our findings also emphasize the difficulty of overcoming data scarcity in decision-making in agricultural water management. Furthermore, we provide recommendations for enhancing model performance and thus may increase the accessibility of reliable decision support tools in the future. Y1 - 2024 U6 - https://doi.org/10.1016/j.agwat.2024.108803 SN - 0378-3774 VL - 296 PB - Elsevier BV ER - TY - GEN A1 - Hashar, Mohammad Rafiul A1 - Nasrin, Shamima A1 - Freese, Dirk A1 - Veste, Maik T1 - Study of phosphorus status and sorption properties in reclaimed lignite mine soils under different age stands of Robinia pseudoacacia L. in Welzow, Germany T2 - Land Degradation & Development N2 - AbstractDue to the open‐cast mining activities, a large area in the Lusatian region in eastern Germany was left unproductive. Robinia pseudoacacia L. was planted within different ages in that large area as a short rotation coppice for woody biomass cultivation as well as to increase soil nutrients by increasing plant phosphorous (P) availability, accumulating organic matter input and biological nitrogen fixation. In this experiment, soil chemical analysis has been done to investigate the improvement and status of P in the mining soil depending on the ages of plantation (16, 17, 18, and 27 years old) of Robinia pseudoacacia L. The results show a higher P sorption in the oldest site, and the average P sorption capacity (PSC) obtained in the oldest site was 21.0 mmol Kg−1, which was 3–4 times higher than the youngest site. However, all the values were very low compared with the optimum plant growth level, and low P desorption indicates a low level of plant‐available P in the soil. The lower sorption properties with the small amount of oxalate iron (Feox) and oxalate aluminum (Alox) indicate the general P deficiency in the soil. However, a comparison from a previous study on the same experimental areas shows that not much improvement has occurred in soil P, and the change in soil P dynamics is very low. Nevertheless, the improvement of the values with increasing ages of Robinia pseudoacacia L. indicates that further improvement may be expected in soil nutrients with time. Y1 - 2024 U6 - https://doi.org/10.1002/ldr.5214 SN - 1085-3278 PB - Wiley ER - TY - GEN A1 - Mantovani, Dario A1 - Veste, Maik A1 - Boldt-Burisch, Katja A1 - Fritsch, Simone A1 - Koning, Laurie Anne A1 - Freese, Dirk T1 - Carbon allocation, nodulation, and biological nitrogen fixation of black locust (Robinia pseudoacacia L.) under soil water limitation T2 - Annals of Forest Research N2 - The pioneer tree black locust (Robinia pseudoacacia L.) is a drought-resistant tree and, in symbiosis with Rhizobium, able to fix dinitrogen from the atmosphere. It is, therefore, an interesting species for marginal lands where soil amelioration is sought in addition to economic gain. However, the interaction between soil water availability, carbon allocation and nitrogen fixation is important for a successful establishment of trees on marginal lands and has not yet been investigated for black locust. Twoyear-old trees were grown under various soil water conditions and drought cycles. The stable isotopic composition of C (δ 13C) and N (δ 15N) of the leaves was used to identify i) the effective drought condition of the treatments and ii) the portion N accrued from the atmosphere by the biological nitrogen fixation. Drought-stressed plants significantly reduced their total aboveground biomass production, which was linearly linked to tree transpiration. The shoot:root ratio values changed from 2.2 for the drought-stressed to 4.3 for the well-watered plants. Our investigation shows that drought stress increases the nodule biomass of black locust in order to maintain biological nitrogen fixation and to counteract the lower soil nitrogen availability. The biological nitrogen fixation of drought-stressed trees could be maintained at relatively higher values compared to the well-watered trees. The average leaf nitrogen content varied between 2.8% and 3.0% and was not influenced by the drought stress. Carbon fixation, carbon allocation, and biological nitrogen fixation are to some extent balanced at low irrigation and allow Robinia to cope with long-term water constraints. The combination of black locust’s ecophysiological and morphological plasticity make it interesting as a biomass source for bioenergy and timber production, even in nutrient-limited and drought-affected areas of Europe. Y1 - 2015 U6 - https://doi.org/10.15287/afr.2015.420 SN - 2065-2445 VL - 58 IS - 2 SP - 259 EP - 274 ER - TY - GEN A1 - Mantovani, Dario A1 - Veste, Maik A1 - Gypser, Stella A1 - Halke, Christian A1 - Koning, Laurie Anne A1 - Freese, Dirk A1 - Lebzien, Stefan T1 - Transpiration and biomass production of the bioenergy crop Giant Knotweed Igniscum under various supplies of water and nutrients T2 - Journal of Hydrology and Hydromechanics N2 - Soil water availability, nutrient supply and climatic conditions are key factors for plant production. For a sustainable integration of bioenergy plants into agricultural systems, detailed studies on their water uses and growth performances are needed. The new bioenergy plant Igniscum Candy is a cultivar of the Sakhalin Knotweed (Fallopia sachalinensis), which is characterized by a high annual biomass production. For the determination of transpiration-yield relations at the whole plant level we used wicked lysimeters at multiple irrigation levels associated with the soil water availability (25, 35, 70, 100%) and nitrogen fertilization (0, 50, 100, 150 kg N ha–1). Leaf transpiration and net photosynthesis were determined with a portable minicuvette system. The maximum mean transpiration rate was 10.6 mmol m–2 s–1 for well-watered plants, while the mean net photosynthesis was 9.1 μmol m–2 s–1. The cumulative transpiration of the plants during the growing seasons varied between 49 l (drought stressed) and 141 l (well-watered) per plant. The calculated transpiration coefficient for Fallopia over all of the treatments applied was 485.6 l kg–1. The transpiration-yield relation of Igniscum is comparable to rye and barley. Its growth performance making Fallopia a potentially good second generation bioenergy crop. Y1 - 2014 U6 - https://doi.org/10.2478/johh-2014-0028 SN - 0042-790X VL - 62 IS - 4 SP - 316 EP - 323 ER - TY - GEN A1 - Koning, Laurie Anne A1 - Veste, Maik A1 - Freese, Dirk A1 - Lebzien, Stefan T1 - Effects of nitrogen and phsphate fertilization on leaf nutrient content, photosythesis, and growth of the novel bioenergy crop Fallopia schalinensis vc. 'Igniscum Candy' T2 - Journal of Applied Botany and Food Quality N2 - The aim of the study was to determine the effects of nitrogen and phosphate fertilization on the growth performance of the novel bioenergy crop Fallopia sachalinensis cv. ‘Igniscum Candy’ (Polygonaceae). In a controlled pot experiment various nitrogen (0, 50, 150, 300 kg N ha-1) and phosphate (20, 40, 80 kg P ha-1) fertilizer amounts were applied to measure the effect on the biomass, plant height, leaf area, and leaf nutrient (N and P) content. Furthermore, the ecophysiological processes of chlorophyll content, chlorophyll fluorescence, and gas exchange were measured. The application of nitrogen correlated positively with biomass production, while phosphate fertilization did not show a significant effect on plant growth or ecophysiological parameters. The leaf nitrogen contents were significantly correlated with the nitrogen applications, while the leaf phosphate contents did not show a correlation with the P fertilizations, but increased with the leaf nitrogen contents. A significant linear correlation between N-Tester chlorophyll meter values and chlorophyll contents as well as with leaf nitrogen contents could be determined. Under the influence of the nitrogen fertilization, net photosynthesis increased from 3.7 to 6.6 μmol m-2 s-1. The results of this experiment demonstrated that nitrogen fertilization has an overall positive correlation with leaf nitrogen content, photosynthesis, and growth of the bioenergy crop Fallopia sachalinensis var. Igniscum Candy. Y1 - 2015 U6 - https://doi.org/10.5073/JABFQ.2015.088.005 SN - 1439-040X VL - 88 SP - 22 EP - 28 ER - TY - GEN A1 - Mantovani, Dario A1 - Veste, Maik A1 - Böhm, Christian A1 - Vignudelli, Marco A1 - Freese, Dirk T1 - Spatial and temporal variation of drought impact on black locust (Robinia pseudoacacia L.) water status and growth T2 - iForest Biogeosciences and Forestry N2 - Stimulated by the rising demand for bioenergy, forestry practices for energy production are of increasing importance worldwide. Black locust (Robinia pseudoacacia L.) is a suitable tree species for biomass production in shortrotation plantations in East Germany, especially on marginal land where insufficient water and nutrients are a limiting factor for tree growth. Our study aims to clarify the spatial and temporal variability of the black locust growth through the analysis of the plant water status, and to evaluate the effect of adverse edaphic conditions on growth performances, amplified by periods of summer drought. The study was carried out at two sites presenting comparable climatic but different edaphic conditions: (i) fertile agricultural soil; and (ii) heterogeneous unstructured soil from a reclaimed post-mining area. During the vegetation period, the growth rate decreased in both sites following the plant water status in terms of pre-dawn leaf water potential. Particularly in the post-mining area, due to the adverse edaphic conditions, below the critical pre-dawn water potential value of -0.5 MPa, the stem growth was drastically reduced during a period of summer drought. However, the trees could cope with the extreme soil and weather conditions in the post-mining site without perishing. Y1 - 2015 U6 - https://doi.org/10.3832/ifor1299-008 SN - 1971-7458 VL - 8 SP - 743 EP - 747 ER - TY - CHAP A1 - Quinkenstein, Ansgar A1 - Böhm, Christian A1 - Matos, Eduardo da Silva A1 - Freese, Dirk A1 - Hüttl, Reinhard F. ED - Kumar, B. Mohan ED - Ramachandran Nair, P. K. T1 - Assessing the carbon sequestration in short rotation coppice systems of Robinia pseudoacacia on marginal sites in NE-Germany T2 - Carbon Sequestration Potential of Agroforestry Systems Opportunities and Challenges Y1 - 2011 SN - 978-94-007-1629-2 SP - 201 EP - 216 PB - Springer CY - Dordrecht [u.a.] ER - TY - GEN A1 - Ferreiro-Domínguez, Nuria A1 - Nair, Vimala D. A1 - Freese, Dirk T1 - Phosphorus dynamics in poplar silvopastural systems fertilised with sewage sludge T2 - Agriculture, Ecosystems and Environment N2 - The use of sewage sludge as fertiliser is a common practice in Europe, where sewage sludge is usually applied on a plant-available N or total metal concentration basis; as a result, phosphorus (P) concentrations can be well above crop needs. The objective of the study was to evaluate the effect of three doses of sewage sludge (0, 200, and 400 kg total N ha⁻¹ year⁻¹) combined with lime (2.5 Mg CaCO3 ha⁻¹) or without lime on the P in soil and pasture, tree growth and pasture production in a silvopastoral system established with Populus canadensis Moench over seven consecutive years. The P availability varied with the soil pH (a result of lime and sewage sludge applications) throughout the study. In general, an increase of the soil acidity (pH 5.39) increased the amounts of Fe and Al in the soil solution, which form very strong bonds with P, thereby reducing the P availability (M3-P: 20.99 g kg⁻¹). The effect of lime on the P availability gradually declined in the years following its application. However, in the latter part of the study (2007–2008), due to the higher residual effect of the sewage sludge compared with lime, the doses of sewage sludge (200 and 400 kg N total ha⁻¹) increased the concentrations of P (200N: 37.31 g kg⁻¹ and 400N: 48.71 g kg⁻¹) and Fe (200N: 321.51 mg kg⁻¹ and 400N: 341.56 mg kg ⁻¹) in a Mehlich 3 solution, the concentration of P in the pasture (200N: 2.53 g kg⁻¹ and 400N: 2.81 g kg⁻¹) and the amount of P extracted by the pasture (200N: 8.78 kg ha⁻¹ and 400N: 10.34 kg ha⁻¹), resulting in possible reduction in environmental problems. Further, due to its agronomic benefits as a source of plant nutrients and organic matter, fertilisation with high quality sewage sludge could be recommended for silvopastoral systems under edaphoclimatic conditions similar to those in this study. Y1 - 2016 U6 - https://doi.org/10.1016/j.agee.2016.02.022 SN - 0167-8809 VL - 223 SP - 87 EP - 98 ER - TY - GEN A1 - Mantovani, Dario A1 - Veste, Maik A1 - Freese, Dirk T1 - Effects of Drought Frequency on Growth Performance and Transpiration of Young Black Locust (Robinia pseudoacacia L.) T2 - International Journal of Forestry Research N2 - Black locust (Robinia pseudoacacia L.) is a drought-tolerant fast growing tree, which could be an alternative to the more common tree species used in short-rotation coppice on marginal land. The plasticity of black locust in the form of ecophysiological and morphological adaptations to drought is an important precondition for its successful growth in such areas. However, adaptation to drought stress is detrimental to primary production. Furthermore, the soil water availability condition of the initial stage of development may have an impact on the tree resilience. We aimed to investigate the effect of drought stress applied during the resprouting on the drought tolerance of the plant, by examining the black locust growth patterns. We exposed young trees in lysimeters to different cycles of drought. The drought memory affected the plant growth performance and its drought tolerance: the plants resprouting under drought conditions were more drought tolerant than the well-watered ones. Black locust tolerates drastic soil water availability variations without altering its water use efficiency (2.57 g L−1), evaluated under drought stress. Due to its constant water use efficiency and the high phenotypic plasticity, black locust could become an important species to be cultivated on marginal land. Y1 - 2014 U6 - https://doi.org/10.1155/2014/821891 SN - 1687-9376 N1 - Article ID 821891 ER - TY - GEN A1 - Mantovani, Dario A1 - Veste, Maik A1 - Freese, Dirk T1 - Black locust (Robina pseudoacacia L.) ecopysiological and morphological adaptations to drought and their consequence on biomass production and water-use efficiency T2 - New Zealand Journal of Forestry Science N2 - Background: Successful plantation efforts growing Robinia pseudoacacia L. (black locust) in the drier regions of Hungary and East Germany (Brandenburg), have demonstrated the potential of black locust as an alternative tree species for short-rotation biomass energy plantations. Methods: The response of black locust to water limitation was investigated in a lysimeter experiment. Plants were grown under three different soil moisture regimes, with values set at 35%, 70%, and 100% of the soil water availability, namely WA35, WA70, and WA100. Their morphological adaptation and productivity response to water constraint were assessed together with their water-use efficiency. Furthermore, the ecophysiological adaptation at the leaf level was assessed in terms of net photosynthesis and leaf transpiration. Results: During the growing season, plants in the WA35, WA70, and WA100 treatments transpired 239, 386, and 589 litres of water respectively. The plants subjected to the WA35 and WA70 treatments developed smaller leaves compared with the plants subjected to the WA100 treatment (66% and 36% respectively), which contributed to the total leaf area reduction from 8.03 m2 (WA100) to 3.25 m2 (WA35). The total above-ground biomass produced in the WA35 (646 g) and WA70 (675 g) treatments reached only 46% and 48% of the biomass yield obtained in the WA100 (1415 g). The water-use efficiency across all treatments was 2.31 g L−1. At vapour pressure deficit (VPD) values <1.4 kPa trees growing under the WA35 soil moisture regime showed a stomatal down-regulation of transpiration to 5.3 mmol m−2 s−1, whereas the trees growing under the WA100 regime did not regulate their stomatal conductance and transpiration was 11.7 mmol m−2 s−1, even at VPD values >2 kPa. Conclusions: Black locust plants can adapt to prolonged drought conditions by reducing water loss through both reduced transpiration and leaf size. However, under well-watered conditions it does not regulate its transpiration, and therefore it cannot be considered a water-saving tree species. Y1 - 2014 UR - http://www.nzjforestryscience.com/content/44/1/29 U6 - https://doi.org/10.1186/s40490-014-0029-0 VL - 44 IS - 1 ER - TY - GEN A1 - Kanzler, Michael A1 - Böhm, Christian A1 - Freese, Dirk T1 - Impact of P fertilisation on the growth performance of black locust (Robinia pseudoacacia L.) in a lignite post-mining area in Germany T2 - Annals of Forest Research N2 - Due to its ability to grow on marginal sites black locust (Robinia pseudoacacia L.) has been widely planted as a short rotation coppice (SRC) system that produce a renewable biomass feedstock in several post-mining areas of East Germany. However, as most of these sites are still in an initial stage of reclamation with low humus and nutrient contents, phosphorous can play a significant role as a plant limiting factor, because legumes require more P than other plants for their development. In April 2011, two experiments were conducted to evaluate the influence of higher rates and different applications of phosphorus fertiliser on the nutrition, survival, and biomass production of two different-aged black locust SRC plantations on the post lignite-mining site “Welzow-Süd”, situated in NE Germany. Treatments were applied as triple superphosphate (30, 60 and 120 kg P ha-1) and PK fertiliser (60 kg P ha-1) through broadcasting or banding on recently harvested or planted trees, respectively. Soil, leaf and woody biomass data were analysed utilising the Mann-Whitney U test and the Spearman correlation coefficient (rS). Following two growing seasons, it was observed that the total dry weight yields of the black locust seedlings were increased strongly by up to 8 times when compared to the control group, particularly when TSP was applied through banding. P fertilisation, however, did not affect the biomass yield of six-year-old black locust trees, but P concentration in leaves among treatments of both sites was still significantly increased and sufficient from a quantity upwards of 60 kg P ha-1. Taken together, a comparably moderate amount of P fertiliser (60 kg ha-1) had a strong impact on P uptake and growth performance in the examined black locust seedlings, which reveals a high potential to improve the current fertilisation practices for SRC black locust plantations grown on our research site. Y1 - 2015 U6 - https://doi.org/10.15287/afr.2015.303 VL - 58 IS - 1 SP - 39 EP - 54 ER - TY - GEN A1 - Tsonkova, Penka A1 - Böhm, Christian A1 - Quinkenstein, Ansgar A1 - Freese, Dirk T1 - Application of partial order ranking to identify enhancement potantials for the provision of selected ecosystem services by different land use strategies T2 - Agricultural Systems N2 - Conventional agricultural practices have often been associated with negative externalities, such as land degradation, pollution of soil and water resources, loss of biodiversity, and decreased provision of ecosystem services (ES). In response to these negative effects, the number of indicator-based attempts to assess ES provided by land use systems has increased. However, decisions regarding the importance of the different ES are usually made subjectively. Following an objective approach through the use of a partial order ranking method, this study aimed to assess several non-provisioning ES supplied by alley cropping system (ACS) in comparison with conventional agriculture (CA). The main objective of the study was to verify the applicability of partial order ranking to an ecologically-based assessment, focusing on soil, water, and biodiversity indicators. Results from 40 hypothetical scenarios representing various site conditions of agricultural fields in Germany were calculated using the Ecosystem Services Assessment Tool for Agroforestry (ESAT-A), a toolbox designed to assess selected ES of ACS following an empirical approach. The results were ranked using partial order and were visualized by a Hasse diagram. The findings depict partial order ranking as a promising technique to support decision making in order to find priority scenarios and indicators where the provision of ES can be enhanced by establishing ACS. The minimal scenarios under CA identified with simultaneously low values of all indicators were perceived as target scenarios for establishing ACS. The values of the indicators for the current land use system need to be taken into account in order to avoid scenarios where high tradeoff was suggested. Additionally, this approach can be extended and utilized at the field level to aid farmer decisions on which land use strategy is the most suitable alternative to increase the provision of ES. Y1 - 2015 U6 - https://doi.org/10.1016/j.agsy.2015.01.002 SN - 0308-521X VL - 135 SP - 112 EP - 121 ER - TY - GEN A1 - Medinski, Tanya V. A1 - Freese, Dirk A1 - Böhm, Christian T1 - Soil CO2 flux in an alley-cropping system composed of black locust and poplar trees, Germany T2 - Agroforestry Systems N2 - Understanding of soil carbon dynamics after establishment of alley-cropping systems is crucial for mitigation of greenhouse CO2 gas. This study investigates soil CO2 fluxes in an alley-cropping system composed of tree strips of black locust (Robinia pseudoacacia L.) and poplar (Populus nigra 9 P. maximowiczii, Max 1) trees and adjacent to them crop strips (Lupinus/Solarigol). Soil CO2 flux was measured monthly over a period from March to November 2012, using a LI-COR LI-8100A automated device. Concurrently with CO2 flux measurements, soil and air temperature, soil moisture, microbial C and hot water-extractable C were determined for the soils nearby soil collars. Root biomass was determined to a depth of 15 cm. In all sampling areas, soil CO2 flux increased from May to July, showing a significant positive correlation with air and soil temperature, which can be a reflection of increase in photosynthesis, and therefore supply of carbohydrates from leaves to rhizosphere, over the warm summer months. A positive correlation between CO2 flux and soil moisture over the warm period indicates an enhancing role of soil moisture on microbial mineralization and root respiration. Average CO2 flux values observed over March–November period did not differ significantly between sampling areas, showing 2.5, 3.2, and 2.9 lmol m-2 s-1 values for black locust, poplar and crops, respectively. Significantly higher CO2 flux values over the summer period in trees could be attributed to the higher photosynthetic activity and higher root density compared to crops. Y1 - 2015 U6 - https://doi.org/10.1007/s10457-014-9764-8 SN - 1572-9680 VL - 89 IS - 2 SP - 267 EP - 277 ER - TY - GEN A1 - Tsonkova, Penka A1 - Quinkenstein, Ansgar A1 - Böhm, Christian A1 - Freese, Dirk A1 - Schaller, Eberhard T1 - Ecosystem services assessment tool for agroforestry (ESAT-A): Anapproach to assess selected ecosystem services provided by alleycropping systems T2 - Ecological Indicators Y1 - 2014 U6 - https://doi.org/10.1016/j.ecolind.2014.04.024 IS - 45 SP - 285 EP - 299 ER - TY - GEN A1 - Slazak, Anna A1 - Freese, Dirk A1 - Matos, Eduardo da Silva A1 - Nii-Annang, Seth A1 - Hüttl, Reinhard F. T1 - Phosphorus pools in soil after land conversion from silvopasture to arable and grassland use T2 - Journal of Plant Nutrition and Soil Science N2 - Differences in soil P among silvopasture, grassland, and arable lands have been well established. Nevertheless, most of the reports compare soil properties under long-term sites. Thus, there exists little information on the effect of the conversion of silvopasture to arable or grassland use on soil P pools. The objective of the study was to determine the impact of converting silvopasture system (SP) into arable cropping and grassland system on the distribution of P pools and potential P bioavailability. We compared the following systems: SP system, SP converted to arable cropland (SP-AL), SP converted to grassland (SP-GL), and for comparative purposes, a long-term arable cropland (AL). The P fractionation was performed by a sequential extraction scheme, using acid and alkaline extractants on samples collected from the 0–10 and 10–20 cm soil layers. It was assumed that the large variations in soil-P fractionations are caused by the different management practices associated with land conversion. The results of P fractionation showed a dominance of calcium-bound P, HCl-extractable Pi constituted up to 36% of the soil total P (TP). However, the type of land use did not affect this P fraction. On the other hand, the reduction in labile-Pi and NaOH-Pi fractions observed at the SP-AL site may have led to the decline in readily available P. The soil total organic P (TPo) content was 8% and 17% lower at SP-AL compared to SP and SP-GL site, respectively. Labile organic-P (labile-Po) content was markedly higher at SP site compared to arable soils, and was ≈ 10% of TPo. The NaOH-Po constituted the highest fraction of the organic-P pool (55%–79% of TPo) across all the study systems, and was positively correlated with TPo (p < 0.01). The study indicates that conversion of SP system in temperate regions to arable cropping with conventional tillage seems to result in the reduction of P availability compared to SP, indicating SP as an important land-use practice. Y1 - 2014 U6 - https://doi.org/10.1002/jpln.201200334 SN - 1522-2624 VL - 177 IS - 2 SP - 159 EP - 167 ER - TY - GEN A1 - Medinski, Tanya V. A1 - Freese, Dirk A1 - Böhm, Christian A1 - Slazak, Anna T1 - Soil carbon fractions in short rotation poplar and black locust coppices, Germany T2 - Agroforestry Systems N2 - Short rotation coppice (SRC) is seen as a successful management system, which in addition to energy wood production may enhance soil carbon sequestration. The objective of this study was to investigate total, labile and stable soil carbon fractions at SRCs composed of poplar clones Max 1 (Populus nigra x P. maximowiczii), Muhle Larsen (Populus Trichocarpa), and black locust (Robinia pseudoacacia L.). Study was conducted at three SRC sites (Allendorf, Dornburg, and Forst) varying in age (1–4 years old), soil texture and climatic characteristics, in Germany. Composite soil samples collected at SRCs from 0 to 3; 0–10; 10–30; and 30–60 cm depth layers were compared with soils collected from adjacent crop strips. Samples were analysed for total organic carbon (TOC), hot-water extractable carbon (HWC), and organic carbon (OC) at 250–2,000; 53–250; and\53 lm soil-size aggregates. Total OC stocks in 0–60 cm soil layer were the highest at the site with the heaviest texture, Dornburg, followed by Forst and Allendorf, comprising 92–107; 59–74; and 53–64 Mg ha-1, respectively. Although no significant differences in the total OC stocks between SRCs and adjacent crops were found for the 0–60 cm layer, a significantly (p\0.05) higher TOC, HWC, OC at macroaggregates (250–2,000 lm), and the amount of macro-aggregates were found in the top 0–3 cm layer in all SRC sites (except the youngest poplar SRC in Forst) compared to adjacent crop strips. A greater macro-aggregate formation in SRCs related to the lower soil disturbance compared to the tilled crops, revealed a potential of SRC for C sequestration, as C occluded within soil aggregates has a slower decomposition rates and longer residence time. Y1 - 2014 U6 - https://doi.org/10.1007/s10457-014-9709-2 SN - 1572-9680 VL - 88 IS - 3 SP - 505 EP - 515 ER - TY - GEN A1 - Böhm, Christian A1 - Kanzler, Michael A1 - Freese, Dirk T1 - Wind speed reduction as influenced by woody hedgerows grown for biomass in short rotation alley cropping systems in Germany T2 - Agroforestry Systems N2 - The cultivation of fast growing trees on agricultural sites is an area undergoing a growth in interest due to the rising demand for woody biomass as a source of bioenergy. Short rotation alley cropping systems (SRACS) represent a promising possibility to combine annual crops for food, fodder or bioenergy with woody plants for biomass production, doing so through an integration of hedgerows of fast growing trees into conventional agricultural sites. Against such developments, the question has arisen as to what extent hedgerows in SRACS can act as an effective windbreak despite their management-related low height of only a few meters. On the basis of multiannual recorded wind velocity data in high resolution at two sites in Germany, it could be shown that the wind speed on crop alleys was reduced significantly by such hedgerows. At the central point of 24 m wide crop alleys, the wind speed decreased on an annual average basis by more than 50 % when compared to the wind speeds of open field. The overall amount of reduction was strongly dependent on the location within the crop alleys, the height of trees, the distance between two hedgerows, and their orientation. In reflection upon these results, it was concluded that the establishment of SRACS could lead to enhanced soil protection against wind erosion and thus to ecological and economic benefits for agricultural sites. Y1 - 2014 U6 - https://doi.org/10.1007/s10457-014-9700-y SN - 1572-9680 VL - 88 IS - 4 SP - 579 EP - 591 ER - TY - GEN A1 - Wang, Guan A1 - Zhu, Zihong A1 - Cao, Jianhua A1 - Zhu, Tongbin A1 - Zhou, Jinxing A1 - Müller, Christoph A1 - Li, Junran A1 - Freese, Dirk A1 - Le Roux, Xavier T1 - Agricultural cultivation duration affects soil inorganic N turnover and supply capacity : Evidence in subtropical karst regions T2 - Agriculture, Ecosystems & Environment N2 - The conversion of indigenous woodlands to agricultural lands has significantly altered nitrogen (N) cycling, impacting both ecosystem productivity and environmental health locally and globally. The relationship between cultivation duration and soil N availability and the mechanisms that drive these changes, however, remain unclear. In this study, we aimed to investigate how the duration of agricultural reclamation influences soil N cycling in the karst landscapes of southwestern China. We selected economic crops that have been cultivated for 1, 5, 15, and 30 years and conducted a regional survey using 15N labeling and molecular biology techniques to assess the effects of cultivation duration on soil N cycling. Our results show that short-term reclamation (< 5 years) caused minimal changes in soil N dynamics, with little effect on the net production rates of NH4+ and NO3–. However, as cultivation duration increased, we observed progressive declines in mineralization, nitrification, and microbial immobilization rates of NH4+ and NO3–. This led to a substantial reduction in soil inorganic N availability (–39 % for NH4+ and –70 % for NO3–) and a significant increase in the mean residence time of NH4+ and NO3–, indicating a slower N turnover. Long-term reclamation (30 years) resulted in the most pronounced effects, reducing the soil’s capacity to supply inorganic N by impairing soil organic matter input, degrading soil structure, and lowering soil pH. Key soil variables such as soil organic carbon content, pH, total N, and soil aggregate stability explained over 80 % of the variance in N turnover rates. Overall, our findings suggest that while shortterm reclamation has little impact, long-term agricultural practices significantly impair soil N cycling and availability. Sustainable agricultural practices that enhance soil organic matter content and promote soil aggregate stability could help preserve soil health and maintain productivity in karst and similar regions worldwide. Y1 - 2025 U6 - https://doi.org/10.1016/j.agee.2024.109462 SN - 0167-8809 VL - 381 PB - Elsevier BV ER - TY - GEN A1 - Kay, Sonja A1 - Rega, Carlo A1 - Moreno, Gerardo A1 - Herder, Michael den A1 - Palma, João H. N. A1 - Borek, Robert A1 - Crous-Duran, Josep A1 - Freese, Dirk A1 - Giannitsopoulos, Michail A1 - Graves, Anil A1 - Jäger, Mareike A1 - Lamersdorf, Norbert A1 - Memedemin, Daniyar A1 - Mosquera-Losada, R. A1 - Pantera, Anastasia A1 - Paracchini, Maria Luisa A1 - Paris, Pierluigi A1 - Roces-Díaz, José V. A1 - Rolo, Victor A1 - Rosati, Adolfo A1 - Sandor, Mignon A1 - Smith, Jo A1 - Szerencsits, Erich A1 - Varga, Anna A1 - Viaud, Valérie A1 - Wawer, Rafal A1 - Burgess, Paul J. A1 - Herzog, Felix T1 - Agroforestry creates carbon sinks whilst enhancing the environment in agricultural landscapes in Europe T2 - Land Use Policy N2 - Agroforestry, relative to conventional agriculture, contributes significantly to carbon sequestration, increases a range of regulating ecosystem services, and enhances biodiversity. Using a transdisciplinary approach, we combined scientific and technical knowledge to evaluate nine environmental pressures in terms of ecosystem services in European farmland and assessed the carbon storage potential of suitable agroforestry systems, proposed by regional experts. First, regions with potential environmental pressures were identified with respect to soil health (soil erosion by water and wind, low soil organic carbon), water quality (water pollution by nitrates, salinization by irrigation), areas affected by climate change (rising temperature), and by underprovision in biodiversity (pollination and pest control pressures, loss of soil biodiversity). The maps were overlaid to identify areas where several pressures accumulate. In total, 94.4% of farmlands suffer from at least one environmental pressure, pastures being less affected than arable lands. Regional hotspots were located in north-western France, Denmark, Central Spain, north and south-western Italy, Greece, and eastern Romania. The 10% of the area with the highest number of accumulated pressures were defined as Priority Areas, where the implementation of agroforestry could be particularly effective. In a second step, European agroforestry experts were asked to propose agroforestry practices suitable for the Priority Areas they were familiar with, and identified 64 different systems covering a wide range of practices. These ranged from hedgerows on field boundaries to fast growing coppices or scattered single tree systems. Third, for each proposed system, the carbon storage potential was assessed based on data from the literature and the results were scaled-up to the Priority Areas. As expected, given the wide range of agroforestry practices identified, the carbon sequestration potentials ranged between 0.09 and 7.29 t C ha −1 a −1 . Implementing agroforestry on the Priority Areas could lead to a sequestration of 2.1 to 63.9 million t C a −1 (7.78 and 234.85 million t CO 2eq a −1 ) depending on the type of agroforestry. This corresponds to between 1.4 and 43.4% of European agricultural greenhouse gas (GHG) emissions. Moreover, promoting agroforestry in the Priority Areas would contribute to mitigate the environmental pressures identified there. We conclude that the strategic and spatially targeted establishment of agroforestry systems could provide an effective means of meeting EU policy objectives on GHG emissions whilst providing a range of other important benefits. Y1 - 2019 U6 - https://doi.org/10.1016/j.landusepol.2019.02.025 SN - 0264-8377 VL - 83 SP - 581 EP - 593 ER - TY - GEN A1 - Adesipo, Adegbite Adeleke A1 - Akinbiola, Sehinde A1 - Awotoye, Olusegun O. A1 - Salami, Ayobami T. A1 - Freese, Dirk T1 - Impact of mining on the floristic association of gold mined sites in Southwest Nigeria T2 - BMC Ecology N2 - Background: Occurrences in land use, human activities and climate change have both direct and indirect influences on the environment. Of interest for this study is mining; a common activity in developing countries such as Nigeria which is endowed with over 34 solid minerals. The gold mining sites in the Southwest region of the country is predominantly by Artisanal and Small-Scale Mining (ASM). Though the benefits are known, its induced consequences are enormous. To understand its extent of floristic diversity, identification of functional plants and plant species surviving on the mined sites (despite its characterized mining and alteration level); this study compared the floristic composition of an abandoned mining site (Site 1), an active mining site (Site 2) and an undisturbed vegetation sites (Control) of similar vegetation zone. Results: A total of 54, 28 and 37 species belonging to 31, 20 and 23 families were found on Site 1, Site 2 and the control site, respectively. It shows that the floristic composition of all the sites has been altered due to its past intense agricultural colonization and human activities, but severe on Site 1 and 2 due to mining. Lots of the identified species are functional species and stand as ecological indicators. Species such as Acanthus montanus and Icacina richantha found on the Control sites are native and significance but species such as Capsicum frutescens and Crassocephalum crepidioides on Site 2 are due to human inference while most species on Site 1 shows both original and altered floristic composition (e.g. Adenia venenata and Grewia flavescens). Conclusions: Apart from the on-going farming activities, ASM activities such as pollution, deforestation and exposure of the forest soils to direct sunlight has greatly stressed and disturbed the floristic composition, species richness, life form patterns, of the mined sites as well as introduction of non-native plant species. It is therefore necessary to develop effective approaches and policies to curb these illegal ASM activities, empower the community (especially youths), stabilize the economy and establish sustainable development strategies with adequate reclamation measures. Y1 - 2020 U6 - https://doi.org/10.1186/s12898-020-00276-9 SN - 1472-6785 VL - 20 ER - TY - GEN A1 - Ahmed, Ashour A. A1 - Gypser, Stella A1 - Freese, Dirk A1 - Leinweber, Peter A1 - Kühn, Oliver T1 - Molecular level picture of the interplay between pH and phosphate binding at the goethite-water interface T2 - Physical Chemistry Chemical Physics N2 - The soil pH plays a substantial role in controlling phosphorus (P) adsorption and mobilization. These processes are strongly affected by the phosphate interaction strength with P-fixing soil minerals such as goethite. The target of the current contribution is to draw a molecular level picture of the interplay between pH and phosphate binding at the goethite–water interface via a joint experimental–theoretical approach. Periodic density functional theory (DFT) calculations were carried out to provide a molecular level understanding of the pH dependence of P adsorption. To validate the modeling approach, adsorption experiments of phosphate at goethite were performed in the pH range of 4–12. There was agreement between experiments and simulations in the description of the adsorption behavior by two pH-dependent successive stages. The adsorption increases along the pH change from 4 to 8. A further increase of pH leads to a decrease of adsorption. By comparing with literature data it is concluded that the first stage will be observed only if there is no significant change of the surface charge at low pH. Moreover, the molecular modeling results point to the abundance of the monodentate (M) binding motif at both extremely low and high pH ranges. Otherwise, the bidentate (B) one is predominant along the intermediate pH range. These observations could resolve the existing debate about the assignment of phosphate–goethite binding motifs. Furthermore, the results point to a decrease of pH upon phosphate sorption due to an induced acidification of soil solution. The present joint experimental–theoretical approach provides a better understanding and description of the existing phosphate sorption experiments and highlights new findings at the atomistic/molecular scale. KW - Phosphate KW - Goethite KW - Periodic density functional theory KW - Adsorption KW - pH Y1 - 2020 U6 - https://doi.org/10.1039/d0cp04698a SN - 1463-9084 VL - 22 IS - 45 SP - 26509 EP - 26524 ER - TY - GEN A1 - Kanzler, Michael A1 - Böhm, Christian A1 - Freese, Dirk T1 - The development of soil organic carbon under young black locust (Robinia pseudoacacia L.) trees at a post-mining landscape in eastern Germany T2 - New Forests N2 - The aim of this study was to evaluate the potential of short rotation alley cropping systems (SRACS) to improve the soil fertility of marginal post-mining sites in Brandenburg, Germany. Therefore, we annually investigated the crop alleys (AC) and black locust hedgerows (ABL) of a SRACS field trail under initial soil conditions to identify the short-term effects of tree planting on the storage of soil organic carbon (SOC) and its degree of stabilization by density fractionation. We detected a significant increase in SOC and hot-water-extractable organic C (HWEOC) at ABL, which was mainly restricted to the uppermost soil layer (0–10 cm). After 6 years, the SOC and HWEOC accumulation rates at ABL were 0.6 Mg and 46 kg ha−1 year−1, which were higher than those in the AC. In addition, comparatively high stocks of approximately 4.6 Mg OC and 182 kg HWEOC ha−1 were stored in the ABL litter layer. Density fractionation of the 0–3 cm soil layer at ABL revealed that the majority of the total SOC (47%) was stored in the free particulate organic matter fraction, which was more than twice that of the AC. At the same time, a higher and steadily increasing amount of SOC was stored in the occluded particulate organic matter fraction at ABL, which indicated a high efficiency for SOC stabilization. Overall, our findings support the suitability of black locust trees for increasing the soil fertility of the reclaimed mining substrate and, consequently, the high potential for SRACS to serve as an effective recultivation measure at marginal sites. KW - Marginal sites KW - SOC sequestration KW - Agroforestry KW - Density fractionation Y1 - 2020 U6 - https://doi.org/10.1007/s11056-020-09779-1 SN - 1573-5095 SN - 0169-4286 VL - 52 (2021) IS - 1 SP - 68 ER - TY - GEN A1 - Gypser, Stella A1 - Schütze, Elisabeth A1 - Freese, Dirk T1 - Single and binary Fe- and Al-hydroxides affect potential phosphorus mobilization and transfer from pools of different availability T2 - Soil Systems N2 - Phosphorus (P) fixation is a global problem for soil fertility and negatively impacts agricultural productivity. This study characterizes P desorption of already fixed P by using KCl, KNO3, histidine, and malic acid as inorganic and organic compounds, which are quite common in soil. Goethite, gibbsite, and ferrihydrite, as well as hydroxide mixtures with varying Fe- and Al-ratio were selected as model substances of crystalline and amorphous Fe- and Al-hydroxides. Especially twoand multi-component hydroxide systems are common in soils, but they have barely been included in desorption studies. Goethite showed the highest desorption in the range from 70.4 to 81.0%, followed by gibbsite with values in the range from 50.7 to 42.6%. Ferrihydrite had distinctive lower desorption in the range from 11.8 to 1.9%. Within the group of the amorphous Fe-Al-hydroxide mixtures, P desorption was lowest at the balanced mixture ratio for 1 Fe: 1 Al, increased either with increasing Fe or Al amount. Precipitation and steric effects were concluded to be important influencing factors. More P was released by crystalline Fe-hydroxides, and Al-hydroxides of varying crystallinity, but desorption using histidine and malic acid did not substantially influence P desorption compared to inorganic constituents. KW - phosphorus kinetics KW - desorption KW - Fe-Al-hydroxide mixtures KW - histidine KW - malic acid Y1 - 2021 U6 - https://doi.org/10.3390/soilsystems5020033 VL - 5 IS - 2 SP - 1 EP - 21 ER - TY - GEN A1 - Schütze, Elisabeth A1 - Gypser, Stella A1 - Freese, Dirk T1 - Kinetics of phosphorus release from vivianite, hydroxyapatite, and bone char influenced by organic and inorganic compounds T2 - Soil Systems N2 - The availability of P is often insuffcient and limited by accumulation in soils. This led to the necessity of solutions for the recovery as well as recycling of secondary P resources. Batch experiments were conducted with CaCl2 and citric acid to characterize P release kinetics from vivianite, hydroxyapatite, and bone char. While the P release during the CaCl2 treatment was so low that only vivianite and hydroxyapatite showed a slightly higher release with increasing CaCl2 concentration, the increase of dissolved P was more pronounced for citric acid. The application of citric acid resulted in a 32,190-fold higher P release for bone char. Fourier-transform infrared spectroscopic data suggested higher instability of hydroxyapatite than for bone char. The kinetic data showed that bone char, especially at a lower particle size, had a higher long-term P release than hydroxyapatite or vivianite. The suitability of hydroxyapatite and bone char as a poorly soluble, but sustainable P source is better than that of vivianite. However, the efficiency as a P fertilizer is also dependent on present soil P mobilization processes. The results underline the importance of the accessibility of fertilized or naturally bound P for plant roots to benefit from the excretion of organic acids. KW - bone char KW - hydroxyapatite KW - vivianite KW - phosphorus release KW - citric acid Y1 - 2020 U6 - https://doi.org/10.3390/soilsystems4010015 SN - 2571-8789 VL - 4 IS - 1 SP - 1 EP - 20 ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk T1 - Degradation of ferrocyanide by natural isolated bacteria T2 - International Journal of Phytoremediation N2 - This study aims at investigating the iron cyanide (CN) degradation potential of two natural bacterial isolates with the purpose of their application in iron CN phytoremediation. The strains were isolated from contaminated soil and incubated over 4 months with 50 mg L-1 CN (as ferrocyanide) as the sole iron and nitrogen source. Unlike previous reports, the study provides control for bacterial growth, biotic and abiotic CN losses. Bacterial growth, CN, ammonium, and nitrate concentrations were monitored regularly. Both strains grew less rapid with iron CN compared with the positive control. However, the growth was diauxic. The CN concentration in the media decreased with 20% and 25% respectively, while that in the sterile controls remained stable. Ammonium was detected in the media of both strains implying that a fraction of the initially applied ferrocyanide has been converted. The nitrogen lost from the system evened out with that in the cells at the end of the experiments. These results showed that the investigated strains were undoubtedly able to grow on iron CN as an alternative nitrogen source, but contrary to some previous findings, the iron CN utilization is much slower and takes place only after complete exhaustion of the cellular nitrogen reserves. KW - iron cyanide KW - detoxification KW - microorganisms Y1 - 2020 U6 - https://doi.org/doi:10.1080/15226514.2019.1633996 SN - 1522-6514 VL - Vol. 22 IS - 1 SP - 20 EP - 28 ER - TY - GEN A1 - Gerwin, Werner A1 - Repmann, Frank A1 - Galatsidas, Spyridon A1 - Vlachaki, Despoina A1 - Gounaris, Nikos A1 - Baumgarten, Wibke A1 - Volkmann, Christiane A1 - Keramitzis, Dimitrios A1 - Kiourtsis, Fotios A1 - Freese, Dirk T1 - Assessment and quantification of marginal lands for biomass production in Europe using soil-quality indicators T2 - SOIL N2 - The cultivation of bioenergy plants in fertile, arable lands increasingly results in new land use conflicts with food production and cannot be considered as sustainable. Marginal lands have been frequently considered as potential alternatives for producing bioenergy from biomass. However, clear definitions and assessment methods for selecting marginal lands and for calculating potentials are still widely missing. The project “SEEMLA” aims at triggering the exploitation of currently underused marginal lands for biomass production for energy purposes. Study sites have been selected in different European countries: Germany, Greece, and Ukraine. The selected sites represent a wide variety of different types of marginal lands. Based on a soil assessment set given by the Muencheberg Soil Quality Rating (SQR) system potentially “marginal” sites have been investigated. The SQR system allows for clearly distinguishing between soils of higher and lower quality. Soils with SQR scores below 40 are regarded as “marginal”. They can be classified into different groups with regard to the importance of soil hazard indicators as evaluated by the SQR approach. The calculated SQR scores correlate significantly with biomass yields of bioenergy plants. Further, the SQR method was adapted for use in a GIS study on marginal-land potentials in Europe. Thus, 46% of the investigated European area could be classified as “marginal” with SQR scores below 40. From that area 22.6% can be considered as potentially suitable for producing renewable resources after eliminating protected sites or other places not suitable for any kind of land use. Taking the ecological demands of selected bioenergy plants into account it is possible to give first preliminary recommendations for regional crop cultivation. It can be concluded that Europe offers a large potential for renewable resources from marginal sites. However, the implementation into practice is often impeded by missing or varying policies and regulations. A proper implementation needs clear regulations and also incentives for farmers at the European level. Y1 - 2018 U6 - https://doi.org/10.5194/soil-4-267-2018 SN - 2199-398X SN - 2199-3971 VL - 4 IS - 4 SP - 267 EP - 290 ER - TY - GEN A1 - Ahmed, Ashour A. A1 - Gypser, Stella A1 - Leinweber, Peter A1 - Freese, Dirk A1 - Kühn, Oliver T1 - Infrared Spectroscopic Characterization of Phosphate Binding at the Goethite-Water Interface T2 - Physical Chemistry Chemical Physics N2 - The interaction between phosphates and soil mineral surfaces, such as Fe- and Al-(oxyhydr)oxides, plays a crucial role in the P immobilization and thus its availability for plants. The reactions of phosphates with Fe-hydroxides and especially goethite have been studied extensively. But a molecular-level picture about 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 DFT calculations have been performed to explore the interaction mechanism as well as to calculate the IR spectra for monodentate (M) and bidentate (B) orthophosphate complexes 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. Y1 - 2019 U6 - https://doi.org/10.1039/C8CP07168C SN - 1463-9084 SN - 1463-9076 VL - 21 SP - 4421 EP - 4434 ER - TY - GEN A1 - Dimitrova, Tsvetelina A1 - Repmann, Frank A1 - Freese, Dirk T1 - Detoxification of ferrocyanide in a soil-plant system T2 - Journal of Environmental Sciences N2 - The detoxification of iron cyanide in a soil–plant system was investigated to assess the total cyanide extracted fromcontaminated soil and allocated in the leaf tissue ofwillowtrees (Salix caprea). They were grown in soil containing up to 1000 mg/kg dry weight (dw) of cyanide (CN), added as 15N-labeled potassium ferrocyanide and prepared with a new method for synthesis of labeled iron cyanides. CN content and 15N enrichment were monitored weekly over the exposure in leaf tissue of different age. The 15N enrichment in the young and old leaf tissue reached up to 15.197‰and 9063‰, respectively; it increased significantly over the exposure and with increasing exposure concentrations (p < 0.05). Although the CN accumulation in the old leaf tissue was higher, compared to the young leaf tissue (p < 0.05), the 15N enrichment in the two tissue types did not differ statistically. This indicates a non-uniform CN accumulation but a uniform 15N allocation throughout the leaf mass. Significant differences were detected between the measured CN content and the C15N content, calculated fromthe 15N enrichment (p < 0.05), revealing a significant CN fraction within the leaf tissue, which could not be detected as ionic CN. The application of labeled iron CN clearly shows that CN is detoxified during uptake by the willows. However, these results do not exclude other detoxification pathways, not related to the trees. Still, they are strongly indicative of the central role the trees played in CN removal and detoxification under the experimental conditions. Y1 - 2019 U6 - https://doi.org/10.1016/j.jes.2018.06.005 SN - 1001-0742 VL - 77 SP - 54 EP - 64 ER - TY - GEN A1 - Kayatz, Benjamin A1 - Baroni, Gabriele A1 - Hillier, Jon A1 - Lüdtke, Stefan A1 - Heathcote, Richard A1 - Malin, Daniella A1 - Tonder, Carl van A1 - Kuster, Benjamin A1 - Freese, Dirk A1 - Hüttl, Reinhard F. A1 - Wattenbach, Martin T1 - Cool Farm Tool Water: A global on-line tool to assess water use in crop production T2 - Journal of Cleaner Production N2 - The agricultural sector accounts for 70% of all water consumption and poses great pressure on ground water resources. Therefore, evaluating agricultural water consumption is highly important as it allows supply chain actors to identify practices which are associated with unsustainable water use, which risk depleting current water resources and impacting future production. However, these assessments are often not feasible for crop producers as data, models and experiments are required in order to conduct them. This work introduces a new on-line agricultural water use assessment tool that provides the water footprint and irrigation requirements at field scale based on an enhanced FAO56 approach combined with a global climate, crop and soil databases. This has been included in the Cool Farm Tool e an online tool which already provides metrics for greenhouse gas emissions and biodiversity impacts and therefore allows for a more holistic assessment of environmental sustainability in farming and agricultural supply chains. The model is tested against field scale and state level water footprint data providing good results. The tool provides a practical, reliable way to assess agricultural water use, and offers a means to engage growers and stakeholders in identifying efficient water management practices. Y1 - 2019 U6 - https://doi.org/10.1016/j.jclepro.2018.09.160 SN - 0959-6526 VL - 207 SP - 1163 EP - 1179 ER - TY - GEN A1 - Seserman, Diana-Maria A1 - Freese, Dirk A1 - Swieter, Anita A1 - Langhof, Maren A1 - Veste, Maik T1 - Trade-Off between Energy Wood and Grain Production in Temperate Alley-Cropping Systems: An Empirical and Simulation-Based Derivation of Land Equivalent Ratio T2 - Agriculture N2 - The alley-cropping systems (ACSs), which integrate parallel tree strips at varying distances on an agricultural field can result, complementarity of resource use, in an increased land-use efficiency. Practitioners’ concerns have been directed towards the productivity of such systems given a reduced area covered by agricultural crops. The land equivalent ratio (LER) serves as a valuable productivity indicator of yield performance and land-use efficiency in ACSs, as it compares the yields achieved in monocultures to those from ACSs. Consequently, the objective of this combined experimental and simulation study was to assess the tree- and crop-yields and to derive the LER and gross energy yield for two temperate ACSs in Germany under different design scenarios, i.e., tree arrangements (lee- or wind-ward) and ratios of tree area to crop area. Both LER and gross energy yields resulted in a convex curve where the maximum values were achieved when either the tree or crop component was dominant (>75% of the land area) and minimum when these components shared similar proportions of land area. The implications of several design scenarios have been discussed in order to improve the decision-making, optimization, and adaptation of the design of ACSs with respect to site-specific characteristics Y1 - 2019 U6 - https://doi.org/10.3390/agriculture9070147 SN - 2077-0472 VL - 9 IS - 7 ER - TY - GEN A1 - Medinski, Tetiana A1 - Freese, Dirk A1 - Reitz, Thomas T1 - Changes in soil phosphorus balance and phosphorus-use efficiency under long-term fertilization conducted on agriculturally used Chernozem in Germany T2 - Canadian Journal of Soil Science N2 - This study investigates changes in soil phosphorus (P) in different fertilization treatments applied since 1902 on Chernozem soil at a “Static Fertilization Experiment” in Germany. Total and plant-available soil P, and soil P balances were assessed at 0–30, 30–60, and 60–90 cm depth layers in unfertilized “Zero”, mineral “NK” and “NPK”, and combined mineral and organic “FYM + NK” (farmyard manure + NK) and “FYM + NPK” fertilization treatments. P-use efficiencies were determined for each crop in rotation (sugar beet, spring barley, potato, and winter wheat). The 110 yr of P fertilization at rates between 22 and 55 t ha−1 yr−1 resulted in a significant increase of available P contents. P stocks increased up to 60 cm depth. Total P accumulation comprised 1.4 t ha−1 for NPK, 1.3 t ha−1 for FYM + NK, and 3.1 t ha−1 for FYM + NPK. Crops cultivation without P fertilization in Zero and NK treatments resulted in negative P balances and reduction of available P below recommended levels. Reduction of mineral P application rates after 1981, along with crop variety-dependent yield increases, resulted in an improved P-use efficiency. An organic fertilization combined with mineral N and K fertilizers (FYM + NK) was found to be the most P-efficient treatment for Chernozem soils. Y1 - 2018 U6 - https://doi.org/10.1139/cjss-2018-0061 SN - 1918-1841 SN - 0008-4271 VL - 98 IS - 4 SP - 650 EP - 662 ER - TY - GEN A1 - Seserman, Diana-Maria A1 - Freese, Dirk T1 - Handling Data Gaps in Reported Field Measurements of Short Rotation Forestry T2 - Data N2 - Filling missing data in forest research is paramount for the analysis of primary data, forest statistics, land use strategies, as well as for the calibration/validation of forest growth models. Consequently, our main objective was to investigate several methods of filling missing data under a reduced sample size. From a complete dataset containing yearly first-rotation tree growth measurements over a period of eight years, we gradually retrieved two and then four years of measurements, hence operating on 72% and 43% of the original data. Secondly, 15 statistical models, five forest growth functions, and one biophysical, process-oriented, tree growth model were employed for filling these data gap representations accounting for 72% and 43% of the available data. Several models belonging to (i) regression analysis, (ii) statistical imputation, (iii) forest growth functions, and (iv) tree growth models were applied in order to retrieve information about the trees from existing yearly measurements. Subsequently, the findings of this study could lead to finding a handy tool for both researchers and practitioners dealing with incomplete datasets. Moreover, we underline the paramount demand for far-sighted, long-term research projects for the expansion and maintenance of a short rotation forestry (SRF) repository. KW - Yield-SAFE KW - Missing Data KW - Regression KW - Imputation Y1 - 2019 U6 - https://doi.org/10.3390/data4040132 SN - 2306-5729 VL - 4 IS - 4 ER - TY - GEN A1 - Seserman, Diana-Maria A1 - Pohle, Ina A1 - Veste, Maik A1 - Freese, Dirk T1 - Simulating Climate Change Impacts on Hybrid-Poplar and Black Locust Short Rotation Coppices T2 - Forestry N2 - In Brandenburg, north-eastern Germany, climate change is associated with increasing annual temperatures and decreasing summer precipitation. Appraising short rotation coppices (SRCs), given their long-time planning horizon demands for systematic assessments of woody biomass production under a considerable spectrum of climate change prospects. This paper investigates the prospective growth sensitivity of poplar and black locust SRCs, established in Brandenburg to a variety of weather conditions and long-term climate change, from 2015 to 2054, by a combined experimental and simulation study. The analysis employed (i) a biophysical, process-based model to simulate the daily tree growth and (ii) 100 realisations of the statistical regional climate model STAR 2K. In the last growing period, the simulations showed that the assumed climate change could lead to a decrease in the woody biomass of about 5 Mg ha -1 (18%) for poplar and a decrease of about 1.7 Mg ha -1 (11%) for black locust trees with respect to the median observed in the reference period. The findings corroborate the potential tree growth vulnerability to prospective climatic changes, particularly to changes in water availability and underline the importance of coping management strategies in SRCs for forthcoming risk assessments and adaptation scenarios. Y1 - 2018 U6 - https://doi.org/10.3390/f9070419 SN - 1464-3626 VL - 9 IS - 7 ER - TY - GEN A1 - Quinkenstein, Ansgar A1 - Wöllecke, Jens A1 - Böhm, Christian A1 - Grünewald, Holger A1 - Freese, Dirk A1 - Schneider, Bernd Uwe A1 - Hüttl, Reinhard F. T1 - Ecological benefits of the alley cropping agroforestry system in sensitive regions of Europe T2 - Environmental Science & Policy Y1 - 2009 U6 - https://doi.org/10.1016/j.envsci.2009.08.008 SN - 1462-9011 VL - 12 IS - 8 SP - 1112 EP - 1121 ER - TY - GEN A1 - Nii-Annang, Seth A1 - Grünewald, Holger A1 - Freese, Dirk A1 - Hüttl, Reinhard F. A1 - Dilly, Oliver T1 - Microbial activity, organic C accumulation and 13C abundance in soils under alley cropping systems after 9 years of recultivation of quaternary deposits T2 - Biology and Fertility of Soils Y1 - 2009 U6 - https://doi.org/10.1007/s00374-009-0360-4 SN - 1432-0789 VL - 45 IS - 5 SP - 531 EP - 538 ER - TY - GEN A1 - Matos, Eduardo da Silva A1 - Freese, Dirk A1 - Slazak, Anna A1 - Bachmann, Ute A1 - Veste, Maik A1 - Hüttl, Reinhard F. T1 - Organic-carbon and nitrogen stocks and organic-carbon fractions in soils under mixed pine and oak forest stands of different ages in NE Germany T2 - Journal of plant nutrition and soil science Y1 - 2010 SN - 1522-2624 VL - 173 IS - 5 SP - 654 EP - 661 ER - TY - GEN A1 - Slazak, Anna A1 - Freese, Dirk A1 - Matos, Eduardo da Silva A1 - Hüttl, Reinhard F. T1 - Soil organic phosphorus fraction in pine-oak forest stands in Northeastern Germany T2 - Geoderma Y1 - 2010 SN - 0016-7061 VL - 158 IS - 3-4 SP - 156 EP - 162 ER - TY - GEN A1 - Matos, Eduardo da Silva A1 - Freese, Dirk A1 - Mendonça, Eduardo S. A1 - Slazak, Anna A1 - Hüttl, Reinhard F. T1 - Carbon, nitrogen and organic C fractions in topsoil affected by conversion from silviopastoral to different land use systems T2 - Agroforestry Systems Y1 - 2011 SN - 1572-9680 VL - 81 IS - 3 SP - 203 EP - 211 ER - TY - GEN A1 - Matos, Eduardo da Silva A1 - Mendonca, Eduardo S. A1 - Cardoso, Irene Maria A1 - Lima, Paulo César de A1 - Freese, Dirk T1 - Decomposition and nutrient release of leguminous plants in coffee agrofrestry systems T2 - Revista Brasileira de Ciência do Solo Y1 - 2011 SN - 0100-0683 VL - 35 IS - 1 SP - 141 EP - 149 ER - TY - GEN A1 - Böhm, Christian A1 - Quinkenstein, Ansgar A1 - Freese, Dirk T1 - Yield prediction of young black locust (Robinia pseudoacacia L.) plantations for woody biomass production using allometric relations T2 - Annals of Forest Research Y1 - 2011 SN - 2065-2445 VL - 54 IS - 2 SP - 215 EP - 227 ER - TY - GEN A1 - Matos, Eduardo da Silva A1 - Freese, Dirk A1 - Böhm, Christian A1 - Quinkenstein, Ansgar A1 - Hüttl, Reinhard F. T1 - Organic Matter Dynamics in Reclaimed Lignite Mine Soils under Robinia pseudoacacia L. Plantations of Different Ages in Germany T2 - Communications in Soil Science and Plant Analysis Y1 - 2012 SN - 1532-2416 VL - 43 IS - 5 SP - 745 EP - 755 ER -