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 -