TY - GEN A1 - Veste, Maik A1 - Littmann, Thomas A1 - Kunneke, Anton A1 - Du Toit, Ben A1 - Seifert, Thomas T1 - Windbreaks as part of climate-smart landscapes reduce evapotranspiration in vineyards, Western Cape Province, South Africa T2 - Plant, Soil and Environment N2 - Under the conditions of climate change in South Africa, ecological and technical measures are needed to reduce the water consumption of irrigated crops. Windbreak hedges are long-rated systems in agriculture that significantly reduce wind speed. Their possibilities to reduce evapotranspiration and water demand are being investigated at a vineyard in the Western Cape Province, South Africa. Detailed measurements of meteorological parameters relevant for the computation of reference and crop-specific evapotranspiration following the FAO 56 approaches within a vineyard in the Western Cape Province of South Africa have shown the beneficial effect of an existing hedgerow consisting of 6 m high poplars (Populus simonii (Carrière) Wesm.). With reference to a control station in the open field, the mean wind speed in a position about 18 m from the hedgerow at canopy level (2 m) was reduced by 27.6% over the entire year and by 39.2% over the summer growing season. This effect leads to a parallel reduction of reference evapotranspiration of 15.5% during the whole year and of 18.4% over the growing season. When applying empirical crop-specific Kc values for well-irrigated grapes, the reduction of evapotranspiration is 18.8% over the summer growth period. The introduced tree shelterbelts are a suitable eco-engineering approach to reduce water consumption and to enhance water saving in vineyards. KW - dry areas KW - viticulture KW - climate change KW - agroforestry Y1 - 2020 UR - https://www.agriculturejournals.cz/web/pse.htm?type=article&id=616_2019-PSE U6 - https://doi.org/10.17221/616/2019-PSE SN - 1214-1178 SN - 1805-9368 VL - 66 IS - 3 SP - 119 EP - 127 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 - Nsiah, Paul Kofi A1 - Schaaf, Wolfgang T1 - Subsoil Amendment With Poultry Manure as Topsoil Substitute for Promoting Successful Reclamation of Degraded Mine Sites in Ghana T2 - Journal of Natural Resources and Development N2 - Background: Despite the key role topsoil plays in reclamation, there are situations where topsoil is in deficit or unavailable, especially at degraded and abandoned mine sites in Ghana. The sites pose serious ecological and safety risks, underscoring the urgent need to finding alternative substrate for restoration. This study investigated the feasibility of using amended-subsoil as topsoil substitute for reclamation. The hypothesis was that amendment of stockpiled-subsoil with poultry manure positively influences tree growth and ground vegetation cover (GVC), which promote better soil stabilization at degraded mine sites. A graded waste-rock dump was covered with a 70 cm layer of the stockpiled subsoil at Newmont Ghana Gold Limited. Two experimental plots (24 × 15 m) were established with the treatments poultry manure (PLM 23 t ha-1) and control (no PLM), followed by seeding of Cowpea (Vigna unguiculata) and planting of potted-seedlings of five forest tree species. The Laser-point-quadrat method was used to estimate GVC, whereas erosion was visually observed. Diameter and height data of planted trees and surviving numbers were collected. Results: There was significant increase in tree growth and in GVC for the poultry manure treatment compared to the control. The manure provided sufficient nitrogen to overcome nitrogen deficiency and facilitated quicker and stronger vegetation growth that yielded superior soil stabilization. Conclusions: The findings demonstrate the potential of manure application in promoting successful restoration of the many degraded and abandoned mine sites in Ghana to productive uses. Y1 - 2020 SN - 0719-2452 VL - 10 SP - 1 EP - 12 ER - TY - GEN A1 - Oprei, Anna A1 - Schreckinger, José A1 - Kholiavko, Tatiana A1 - Frossard, Aline A1 - Mutz, Michael T1 - Functional and structural recovery of stream biofilms at the habitat scale is based on the individual disturbance history T2 - Ergebnisse der Jahrestagung 2019 in Münster KW - metabolic activity Y1 - 2020 UR - https://www.dgl-ev.de/cms/upload/dokumente/Publikationen/2020__DGL_Ergebnisse_Muenster_2019_web.pdf SN - 978-3-9818302-4-8 SP - 216 PB - Eigenverlag der DGL CY - Essen ER - TY - GEN A1 - Gypser, Stella A1 - Freese, Dirk T1 - Mobilization of P from crystalline and amorphous Fe- and Al-hydroxides T2 - EGU General Assembly 2020 KW - Phosphorus KW - Sorption KW - Hydroxides Y1 - 2020 U6 - https://doi.org/10.5194/egusphere-egu2020-2871 ER - TY - GEN A1 - Gerwin, Werner A1 - Schaaf, Wolfgang T1 - Abiotic and biotic drivers of ecosystem development – results from Chicken Creek Catchment T2 - EGU General Assembly 2020, Online, 4–8 May 2020 Y1 - 2020 U6 - https://doi.org/10.5194/egusphere-egu2020-7216 ER - TY - GEN A1 - Schaaf, Wolfgang T1 - The role of geodiversity in ecosystem development T2 - EGU General Assembly 2020, Online, 4–8 May 2020 Y1 - 2020 U6 - https://doi.org/10.5194/egusphere-egu2020-1415 ER - TY - GEN A1 - Sheppard, Jonathan P. A1 - Bohn Reckziegel, Rafael A1 - Borrass, Lars A1 - Chirwa, Paxie W. A1 - Cuaranhua, Claudio J. A1 - Hassler, Sibylle K A1 - Hoffmeister, Svenja A1 - Kestel, Florian A1 - Maier, Rebekka A1 - Mälicke, Mirko A1 - Morhart, Christopher A1 - Ndlovu, Nicholas P. A1 - Veste, Maik A1 - Funk, Roger A1 - Lang, Friedericke A1 - Seifert, Thomas A1 - du Toit, Ben A1 - Kahle, Hans-Peter T1 - Agroforestry: An Appropriate and Sustainable Response to a Changing Climate in Southern Africa? T2 - Sustainability N2 - Agroforestry is often discussed as a strategy that can be used both for the adaptation to and the mitigation of climate change effects. The climate of southern Africa is predicted to be severely affected by such changes. With agriculture noted as the continent’s largest economic sector, issues such as food security and land degradation are in the forefront. In the light of such concerns we review the current literature to investigate if agroforestry systems (AFS) are a suitable response to the challenges besetting traditional agricultural caused by a changing climate. The benefits bestowed by AFS are multiple, offering ecosystem services, influence over crop production and positive impacts on rural livelihoods through provisioning and income generation. Nevertheless, knowledge gaps remain. We identify outstanding questions requiring further investigation such as the interplay between trees and crops and their combination, with a discussion of potential benefits. Furthermore, we identify deficiencies in the institutional and policy frameworks that underlie the adoption and stimulus of AFS in the southern African region. We uphold the concept that AFS remains an appropriate and sustainable response for an increased resilience against a changing climate in southern Africa for the benefit of livelihoods and multiple environmental values KW - agroforestry KW - Southern Africa Y1 - 2020 UR - https://www.mdpi.com/2071-1050/12/17/6796 U6 - https://doi.org/10.3390/su12176796 VL - 12 IS - 17 ER - TY - GEN A1 - Boldt-Burisch, Katja A1 - Schillem, Steffi A1 - Schneider, Bernd Uwe A1 - Hüttl, Reinhard F. T1 - The effect of nitrogen-modified lignite granules on mycorrhization and root and shoot growth of Secale cereale (winter rye) in a nutrient-deficient, sandy soil T2 - Archives of Agronomy and Soil Science N2 - Organic soil amendments such as modified lignite and biostimulants like arbuscular mycorrhizal fungi (AMF) may have the potential to improve soil biological conditions of agricultural soils. The aim of the study was to test if nitrogen-modified lignite granules (NH) are beneficial for mycorrhization, root and shoot development compared to common mineral nitrogen (Nmin) in a nitrogen and phosphorus limited soil. A greenhouse experiment with Secale cereale L. was carried out using non-sterilized and sterilized sand substrate treated with NH, AMF or Nmin and AMF+NH and AMF+Nmin and was compared to an untreated substrate (control). 7.5 t ha-1 NH and 120 kg Nmin ha−1 led to a similar increase of AMF colonization compared to the control; however, Nmin had a more positive influence on biomass development. Significantly highest mycorrhizal colonization intensity was found for AMF+NH. The co-application of AMF+NH revealed that shoot and root development and shoot nutrient concentrations were significantly higher or were among the significantly highest values, when compared to the other treatments. AMF+NH may be a suitable soil amendment for nutrient-limited soils and may be more sustainable than Nmin due to a combined increase of nitrogen, AMF and carbon/humic acids in the soil that comes with the NH. Y1 - 2020 U6 - https://doi.org/10.1080/03650340.2020.1869724 SN - 1476-3567 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 - 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 - 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 -