Ludwig, Bernard

[["dc.bibliographiccitation.firstpage","634"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Journal of Plant Nutrition and Soil Science"],["dc.bibliographiccitation.lastpage","643"],["dc.bibliographiccitation.volume","174"],["dc.contributor.author","Jacobs, Anna"],["dc.contributor.author","Helfrich, Mirjam"],["dc.contributor.author","Dyckmans, Jens"],["dc.contributor.author","Rauber, Rolf"],["dc.contributor.author","Ludwig, Bernard"],["dc.date.accessioned","2018-11-07T08:53:25Z"],["dc.date.available","2018-11-07T08:53:25Z"],["dc.date.issued","2011"],["dc.description.abstract","Differences in the mechanisms of storage and decomposition of organic matter (OM) between minimum tillage (MT) and conventional tillage (CT) are generally attributed to differences in the physical impact through tillage, but less is known about the effects of residue location. We conducted an incubation experiment at a water content of 60% of the maximum water-holding capacity and 15 degrees C with soils from CT (0-25 cm tillage depth) and MT fields (0-5 cm tillage depth) with N-15-labeled maize straw incorporated to different depths (CT simulations: 0-15 cm; MT simulations: 0-5 cm) for 28 d in order to determine the effects of the tillage simulation on (1) mineralization of recently added residues, (2) the dynamics of macroaggregate formation and physical protection of OM, and (3) the partitioning of maize-derived C and N within soil OM fractions. The MT simulations showed lower relative C losses, and the amount of maize-C mineralized after 28 d of incubation was slightly but significantly lower in the MT simulations with maize added (MTmaize) than in the respective CT (CTmaize) simulations. The formation of new water-stable macroaggregates occurred during the phase of the highest microbial activity, with a maximum peak 8 d after the start of incubation. The newly formed macroaggregates were an important location for the short-term stabilization of C and N with a higher importance for MTmaize than for CTmaize simulations. In conclusion, our results suggest that a higher amount of OM in MT surface soils compared with CT surface soils may not only result from decreased macroaggregate destruction under reduced tillage but also from a higher efficiency of C retention due to a more concentrated residue input."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG-Research Training Group) [1397]"],["dc.identifier.doi","10.1002/jpln.201000208"],["dc.identifier.isi","000294665300013"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22404"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1436-8730"],["dc.title","Effects of residue location on soil organic matter turnover: results from an incubation experiment with N-15-maize"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","569"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE-ZEITSCHRIFT FUR PFLANZENERNAHRUNG UND BODENKUNDE"],["dc.bibliographiccitation.lastpage","575"],["dc.bibliographiccitation.volume","164"],["dc.contributor.author","Rumpf, S."],["dc.contributor.author","Ludwig, Bernard"],["dc.contributor.author","Mindrup, M."],["dc.date.accessioned","2018-11-07T08:36:32Z"],["dc.date.available","2018-11-07T08:36:32Z"],["dc.date.issued","2001"],["dc.description.abstract","Addition of wood ash to acid soils will affect the soil chemistry of forests in a number of ways which were assessed for a pine stand in northern Germany. A field experiment was carried out in a fifty-year old pine stand on a sandy Podzol at Fuhrberg (Luneburger Heide, Lower Saxony/Germany) which involved depositing wood ash (2.4 t ha(-1)) on the surface. Soil solution chemistry was investigated monthly at different depths for 24 months. Prior to and 19 months after the ash addition, exchangeable cations and amounts of heavy metals were determined at different depths. Two to four months after addition of wood ash, maximum mean concentrations in the soil solution of Ca were 240 mu mol l(-1) at 0 cm (surface of mineral soil) and 100 mu mol l(-1) at 100 cm and of K 980 mu mol l(-1) and 140 mu mol l(-1), respectively. The pH values in soil solutions dropped temporarily by 0.3 units at 0 and 10 cm depth. Nitrate concentrations increased at all depths and maximum mean concentration was 230 mu mol l(-1) at 100 cm. Concentrations of Pb and Cr in soil solution did not change significantly (p < 0.05) after ash addition. Concentrations of Cd and Zn increased significantly at some depths but stayed well below the legal limit for drinking water and below the limits given by the German recommendation for soil conservation. Nineteen months after ash addition, the cation exchange capacity (corrected for the release of cations from the ash) of the upper 6 cm of the organic layer was almost doubled and amounts of exchangeable Ca and Mg increased significantly in the upper 8 cm of the organic layer. Amounts of Zn were increased in the entire organic layer, but changes were significant only in the upper 4 cm. The results of is study suggest that ash from untreated wood (using modest additions) may be recommended for amelioration of forest soils."],["dc.identifier.doi","10.1002/1522-2624(200110)164:5<569::AID-JPLN569>3.0.CO;2-E"],["dc.identifier.isi","000171884800015"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/18336"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1436-8730"],["dc.title","Effect of wood ash on soil chemistry of a pine stand in Northern Germany"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","153"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE-ZEITSCHRIFT FUR PFLANZENERNAHRUNG UND BODENKUNDE"],["dc.bibliographiccitation.lastpage","159"],["dc.bibliographiccitation.volume","167"],["dc.contributor.author","Teepe, R."],["dc.contributor.author","Ludwig, Bernard"],["dc.date.accessioned","2018-11-07T10:50:00Z"],["dc.date.available","2018-11-07T10:50:00Z"],["dc.date.issued","2004"],["dc.description.abstract","The amounts of N2O released in periods of alternate freezing and thawing depend on site and freezing conditions, and contribute considerably to the annual N2O emissions. However, quantitative information on the N2O emission level of forest soils in freeze-thaw cycles is scarce, especially with regard to the direct and indirect effect of tree species and the duration of freezing. Our objectives were (i) to quantify the CO2 and N2O emissions of three soils under beech which differed in their texture, C and N contents, and humus types in freeze-thaw cycles, and (ii) to study the effects of the tree species (beech (Fagus sylvatica L.) and spruce (Picea abies (L.) Karst.)) for silty soils from two adjacent sites and the duration of freezing (three and eleven days) on the emissions. Soils were adjusted to a matric potential of -0.5 kPa, and emissions were measured in 3-hr intervals for 33 days. CO2 emissions of all soils were similar in the two freeze-thaw cycles, and followed the temperature course. In contrast, the N2O emissions during thawing differed considerably. Large N2O emissions were found on the loamy soil under beech (Loam-beech) with a maximum N2O emission of 1200 mug N m(-2) h(-1) and a cumulative emission of 0.15 g N m(-2) in the two thawing periods. However, the sandy soil under beech (Sand-beech) emitted only 1 mg N2O-N m(-2) in the two thawing periods probably because of a low water-filled pore space of 44%. The N2O emissions of the silty soil under beech (Silt-beech) were small (9 mg N m-2 in the two thawing periods) with a maximum emission of 150 mug N m(-2) h-1 while insignificant N2O emissions were found on the silty soil under spruce (0.2 mg N m(-2) in the two thawing periods). The cumulative N2O emissions of the short freeze-thaw cycles were 17% (Sand-beech) or 22% (Loam-beech, Silt-beech) less than those of the long freeze-thaw cycles, but the differences between the emissions of the two periods were not significant (P less than or equal to 0.05). The results of the study show that the amounts of N2O emitted in freeze-thaw cycles vary markedly among different forest soils and that the tree species influence the N2O thawing emissions in forests considerably due to direct and indirect impacts on soil physical and chemical properties, soil structure, and properties of the humus layer."],["dc.identifier.doi","10.1002/jpln.200321313"],["dc.identifier.isi","000221004400004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/48562"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1436-8730"],["dc.title","Variabilityof CO2 and N2O emissions during freeze-thaw cycles: results of model experiments on undisturbed forest-soil cores"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","671"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Biology and Fertility of Soils"],["dc.bibliographiccitation.lastpage","680"],["dc.bibliographiccitation.volume","46"],["dc.contributor.author","Jacobs, Anna"],["dc.contributor.author","Helfrich, Mirjam"],["dc.contributor.author","Hanisch, Susan"],["dc.contributor.author","Quendt, Ulrich"],["dc.contributor.author","Rauber, Rolf"],["dc.contributor.author","Ludwig, Bernard"],["dc.date.accessioned","2018-11-07T08:39:32Z"],["dc.date.available","2018-11-07T08:39:32Z"],["dc.date.issued","2010"],["dc.description.abstract","The objectives were to investigate (1) to which extent water-stable macro- and microaggregates sequester organic matter (OM) in a minimum tillage (MT) system compared to a conventional tillage (CT) system and (2) if the content of biochemically stabilized OM differs between both tillage systems, and (3) to study the temporal dynamics of the distribution of aggregate size classes and of storage of OM within aggregates in the field. Surface soils (0-5 cm) and subsoils (10-20 cm) were sampled after fallow (March 2007) and directly after tillage (November 2007) from a long-term experimental field near Gottingen, Germany. Macroaggregates (> 0.25 mm) were in general less abundant after fallow than directly after tillage. In March, only 21% (CT) and 45% (MT) of C(org) was stored within macroaggregates in the surface soil, whereas in November, the percentages increased to 58% and 73%, respectively. CT and MT soils of both depths were incubated as bulk soil (CT(bulk), MT(bulk)) and with macroaggregates disrupted (< 0.25 mm) (CT(md), MT(md)) for 28 days at 22A degrees C and water content of 50% of the maximum water holding capacity. For the MT(bulk) and MT(md) surface soils, C mineralization was significantly higher compared to the CT soils. Incubation of md soils did not generally result in a significantly higher C mineralization compared to the respective bulk soils, except for the MT(md) subsoil. Acid hydrolysis showed that the proportion of biochemically stabilized, nonhydrolysable, C(org) to total C(org) was lower in the MT than in the CT soils. Overall, the data indicate that the effect of physical stabilization of OM stored in the macroaggregates may not be a mechanism protecting very labile C with a turnover time of weeks, but that longer preservation likely occurs after macroaggregate transformation into microaggregates, and the surplus of OM found in the surface soil of MT does not only depend on the biochemically stabilized OM. Finally, our data suggest that the temporal variability of distribution of aggregate size classes in the field is large, but spatial and operator variability also contributed to the observed differences."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG)"],["dc.identifier.doi","10.1007/s00374-010-0472-x"],["dc.identifier.isi","000280783700002"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/6721"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/19020"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0178-2762"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Effect of conventional and minimum tillage on physical and biochemical stabilization of soil organic matter"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","158"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Soil and Tillage Research"],["dc.bibliographiccitation.lastpage","164"],["dc.bibliographiccitation.volume","102"],["dc.contributor.author","Jacobs, Anna"],["dc.contributor.author","Rauber, Rolf"],["dc.contributor.author","Ludwig, Bernard"],["dc.date.accessioned","2018-11-07T08:35:32Z"],["dc.date.available","2018-11-07T08:35:32Z"],["dc.date.issued","2009"],["dc.description.abstract","It is broadly accepted that reduced tillage increases soil organic carbon (C(org)) and total nitrogen (N) concentrations in arable soils. However, the underlying processes of sequestration are not completely understood. Thus, our objectives were to investigate the impact of a minimum tillage (MT) system (to 58 cm depth) on aggregates, on particulate organic matter (POM), and on storage of C(org) and N in two loamy Haplic Luvisols in contrast to conventional tillage (CT) (to 25 cm). Surface soils (0-5 cm) and subsoils (10-20 cm) of two experimental fields near Gottingen, Germany, were investigated. Each site (Garte-Sud and Hohes Feld) received both tillage treatments for 37 and 40 years, respectively. In the bulk soil of both sites C(org), N, microbial carbon (C(mic)), and microbial N (N(mic)) concentrations were elevated under MT in both depths. Likewise, water-stable macroaggregates (>0.25 mm) were on average 2.6 times more abundant under MT than under CT but differences in the subsoils were generally not significant. For surface soils under MT, all aggregate size classes <1 mm showed approx. 35% and 50% increased C(org) concentrations at Garte-Sud and Hohes Feld, respectively. For greater macroaggregates (1-2, 2-10 mm), however, differences were inconsistent. Elevations of N concentrations were regular over all size classes reaching 61% and 52%, respectively. Density fractionation of the surface soils revealed that tillage system affected neither the yields of free POM nor occluded POM nor their C(org) and N concentrations. Moreover, more C(org) and N (15-238%) was associated within the mineral fractions investigated under MT in contrast to CT. Overall. similar to no-tillage, a long-term MT treatment of soil enhanced the stability of macroaggregates and thus was able to physically protect and to store more organic matter (OM) in the surface soil. The increased storage of C(org) and N did not occur as POM, as reported for no-tillage, but as mineral-associated OM. (C) 2008 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG)"],["dc.identifier.doi","10.1016/j.still.2008.08.012"],["dc.identifier.isi","000262546800021"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/18094"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0167-1987"],["dc.title","Impact of reduced tillage on carbon and nitrogen storage of two Haplic Luvisols after 40 years"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","89"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Water Air & Soil Pollution"],["dc.bibliographiccitation.lastpage","105"],["dc.bibliographiccitation.volume","120"],["dc.contributor.author","Ludwig, B."],["dc.contributor.author","Deutschmann, G."],["dc.contributor.author","Xu, Y. Y."],["dc.date.accessioned","2018-11-07T10:56:28Z"],["dc.date.available","2018-11-07T10:56:28Z"],["dc.date.issued","2000"],["dc.description.abstract","The acidification of the soil and percolation water at soil depths from 150 to 500 cm was studied at the Solling spruce site from 1991 to 1996. NH4Cl exchangeable cations of the fine earth and bedrock fractions were obtained from different depths and the soil solution composition was monitored at 150, 200, 300, 400 and 500 cm depths using seven suction lysimeters at each depth. In the seepage water collected from 150 and 200 cm depth, pH values decreased in the period 1991 to 1996, but no significant changes were observed in solutions collected below 200 cm depth. Element budgets of Al and M-b (Na, K, Mg, Ca) cations indicated that buffering by exchange of Al with M-b cations occurred mainly in surface 200 cm soil depth. High variabilities in concentrations of SO4 (at 150 cm) and M-a (Al, Mn, H, Fe) cations (at 300 and 500 cm) were observed. High variabilities in M-a cations could be assigned to one of the lysimeters at each depth that extracted low pH solutions. The amount of exchangeable cations in the fine earth and the bedrock fractions indicated that the acidification front (exchangeable M-b cations < 80 equivalent percent) had occurred to soil depth of more than 360 cm, but the extent of acidification that might have occurred in the preindustrial period is not known. In both fine earth and bedrock fractions, depthwise changes of exchangeable M-a and M-b cations were quite similar, suggesting that rock fractions have contributed to proton buffering not only by silicate weathering but also by cation exchange."],["dc.identifier.doi","10.1023/A:1005281126507"],["dc.identifier.isi","000086533300006"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/50018"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0049-6979"],["dc.title","Acidification of solid and solution phases at greater depths (> 150 cm) at solling spruce site"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","183"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE-ZEITSCHRIFT FUR PFLANZENERNAHRUNG UND BODENKUNDE"],["dc.bibliographiccitation.lastpage","189"],["dc.bibliographiccitation.volume","163"],["dc.contributor.author","Deutschmann, G."],["dc.contributor.author","Ludwig, B."],["dc.date.accessioned","2018-11-07T11:18:24Z"],["dc.date.available","2018-11-07T11:18:24Z"],["dc.date.issued","2000"],["dc.description.abstract","Data on accumulated exchangeable H, Al, Fe and Mn (M-a) cations in rock fractions in German soil profiles are scarce. The objective of this study was to describe the sum of accumulated M-a cations of fine earth and rock fragments in 11 deep soil profiles of varying genesis. Soil profiles were laid out at the sites Selling, Eifel, Hart mountains and the Erzgebirge and the parent materials included sandstones, siltstones, quartzite, slate, greywacke, diabase, gneiss and quartz porphyry. Exchangeable cations in the fine earth and rock fragments were measured in depths down to 6 m. Additionally, effective porosity and specific surface of rock fragments were determined. The effective porosity of the different rock fragments ranged from 4 to 28% (v/v), indicating that the rocks were accessible to solutions. For most samples, the cation exchange capacities (CEC) of the fine earth fractions were larger than those of the rock fragments, and the CEC (fine earth)/CEC (rock) ratios decreased with depth. All 11 profiles had small (<40%) amounts of exchangeable Na, K, Mg and Ca (M-b) cations in the fine earth fraction. Exchangeable M-a and M-b cations in the rock fragments changed similarly with depth as in the fine earth fractions for all profiles. Cumulative (rock + fine earth) M-a cations from 0-200 cm ranged from 474 to 1592 kmol(c) ha(-1) The contribution of the rock fraction to the cumulative exchangeable M-a cations accounted for 13 to 85% of the total. The sum of exchangeable M-a cations was much higher than the cumulative acid deposition in western Germany since the beginning of industrialization, suggesting that carbonic acid and organic acids contributed largely to soil acidification. The rocks contribute significantly to buffering the acidity of the seepage water by silicate weathering and cation exchange. Therefore, acidification models which consider the fine earth fraction only, may lead to an overestimation of the rate of soil and groundwater acidification."],["dc.identifier.doi","10.1002/(SICI)1522-2624(200004)163:2<183::AID-JPLN183>3.0.CO;2-D"],["dc.identifier.isi","000086590600008"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55026"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1436-8730"],["dc.title","Exchangeable cations in rock fractions and fine earth in soil profiles of different genesis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","447"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Journal of plant nutrition and soil science"],["dc.bibliographiccitation.lastpage","454"],["dc.bibliographiccitation.volume","160"],["dc.contributor.author","Ludwig, Bernard"],["dc.contributor.author","Hölscher, Dirk"],["dc.contributor.author","Khanna, Partap"],["dc.contributor.author","Prenzel, Jürgen"],["dc.contributor.author","Fölster, Horst"],["dc.date.accessioned","2017-09-07T11:45:46Z"],["dc.date.available","2017-09-07T11:45:46Z"],["dc.date.issued","1997"],["dc.description.abstract","The results of physico-chemical investigations of an Ultisol subsoil under a 2-year old fallow in eastern Amazonia are presented. Subsoil chemistry was studied using 4 different approaches: i) concentrations of H, Na, K, Ca, Mg, Mn, Al, and Fe in seepage water were measured under field conditions, ii) the equilibrium soil chemistry was studied in sequential batch experiments where the soil was treated with different solutions, iii) results of batch experiments were simulated with a chemical equilibrium model, and iv) the seepage data were calculated using selectivity coefficients obtained by modelling the batch experiments. The model included multiple cation exchange, precipitation/dissolution of Al(OH)3 and inorganic complexation. Cation selectivity coefficients were pKx/Casel: X = Na: 0.3, K: 0.8, Mg: −0.1, and Al: 0.4. The amount of cations sorbed ranged from −0.2 to 2.0 (K), −0.7 to 2.3 (Mg), −1.6 to 1.8 (Ca), −4.8 to 3.6 (Al) and 0.0 to 8.5 (Na) mmolc kg−1. The model predictions were good with values lying within 0.3 pH units (for the pH range 3.7 to 7.2), and 3% of CEC for individual cations. The most important proton buffer reaction seemed to be the dissolution of gibbsite and a large release of Al into the soil solution. When selectivity coefficients obtained by the modelling procedure were used to predict the field data for cation concentrations in the seepage water, they decreased in the following order: Na > K > Ca > Mg > Al. These calculated values were similar to the measured order: Na > Ca > K ≈ Mg > Al. Thus the options for managing these soils should be carefully chosen to avoid soil acidification which may result from inappropriate use of fertilizer during the cropping period."],["dc.identifier.doi","10.1002/jpln.19971600403"],["dc.identifier.gro","3149090"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/5737"],["dc.language.iso","en"],["dc.notes.intern","Hoelscher Crossref import"],["dc.notes.status","final"],["dc.notes.submitter","chake"],["dc.relation.issn","0044-3263"],["dc.title","Modelling of sorption experiments and seepage data of an Amazonian Ultisol subsoil under cropping fallow"],["dc.type","journal_article"],["dc.type.internalPublication","unknown"],["dc.type.peerReviewed","no"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","87"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Journal of Geochemical Exploration"],["dc.bibliographiccitation.lastpage","95"],["dc.bibliographiccitation.volume","73"],["dc.contributor.author","Ludwig, B."],["dc.contributor.author","Prenzel, J."],["dc.contributor.author","Obermann, P."],["dc.date.accessioned","2018-11-07T08:36:05Z"],["dc.date.available","2018-11-07T08:36:05Z"],["dc.date.issued","2001"],["dc.description.abstract","Secondary reactions occurring in pyrite-containing sediments from open cut coal mines are complex and not fully understood. In this study, the changes in seepage water composition in a column experiment with a sediment containing pyrite (5.6 g kg(-1)) were evaluated using a chemical equilibrium model. A column experiment with artificial irrigation (730 mm water yr(-1)) was carried out for 2 yr with a sediment from the open pit mine Garzweiler, Germany, at the Institute of Applied Geology. Tracer (LiCl) was added to the sediment. Seepage water composition at 52 cm depth was sampled weekly. Redox potential and the water potential were also recorded weekly. Sulphate and Fe(II) were the dominant ions in the seepage water with concentration maxima of 500 and 350 mmol l(-1) after 50 days (0.7 pore volumes (PV)). Minimum pH values were around 0.8 after 100 days (1.4 PV), but increased subsequently and reached 2.4 after 700 days (9.5 PV). Ion activity product calculations indicated the intermediate formation of gypsum (19th-480th day of the experiment). Solutions were undersaturated with respect to alunite, jarosite, jurbanite, schwertmannite, melanterite, gibbsite and goethite during the whole experiment. The model of coupled equilibria which included inorganic complexation, precipitation/dissolution of gypsum and multiple cation exchange was tested. Pyrite oxidation and pH-dependent silicate weathering were considered using simple input functions. Transport was modelled using a field capacity cascade submodel. Model results showed satisfactory agreement with measured values for pH and concentrations of SO4, Fe, Mg, Ca and Al. Correlation coefficients lay between 0.7 and 0.9 and linear regression coefficients (modelled against measured) were 1.5 (Ca), 1.0 (Fe, SO4), 0.8 (Mg), 0.7 (pH) and 0.6 (Al). The results showed that the protons produced during pyrite oxidation (94 mmol(c) H+ kg(-1)) were mainly released into seepage water (as HSO4- and H+). Cation exchange reactions buffered 20 mmol, of H+ kg(-1) sediment, and Al released by silicate weathering accounted for 3.6 mmol, H+ kg(-1). Modelling was useful to further understand the significance of different pH buffer reactions. (C) 2001 Elsevier Science B.V. All rights reserved."],["dc.identifier.doi","10.1016/S0375-6742(01)00190-X"],["dc.identifier.isi","000171650900004"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/18227"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.publisher.place","Amsterdam"],["dc.relation.conference","International Symposium on the Ecology of Post-Mining Landscapes"],["dc.relation.eventlocation","BRANDENBURG UNIV TCHNOL, COTTBUS, GERMANY"],["dc.relation.issn","0375-6742"],["dc.title","Modelling ion composition in seepage water from a column experiment with an open cut coal mine sediment"],["dc.type","conference_paper"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","483"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Biology and Fertility of Soils"],["dc.bibliographiccitation.lastpage","494"],["dc.bibliographiccitation.volume","47"],["dc.contributor.author","Jaeger, Nadine"],["dc.contributor.author","Stange, Claus Florian"],["dc.contributor.author","Ludwig, Bernard"],["dc.contributor.author","Flessa, Heiner"],["dc.date.accessioned","2018-11-07T08:54:37Z"],["dc.date.available","2018-11-07T08:54:37Z"],["dc.date.issued","2011"],["dc.description.abstract","Increasing organic matter stocks in soils reduce atmospheric carbon dioxide (CO2), but they may also promote emissions of nitrous oxide (N2O) by providing substrates for nitrification and denitrification and by increasing microbial O-2 consumption. The objectives of this study were to determine the effects of fertilization history, which had resulted in different soil organic matter stocks on (1) the emission rates of N2O and CO2 at a constant soil moisture content of 60% water-holding capacity, (2) the short-term fluxes of N2O and CO2 following the application of different fertilizers (KNO3 vs. farmyard manure from cattle) and (3) the response to a simulated heavy rainfall event, which increased soil moisture to field capacity. Soil samples from different treatments of three long-term fertilization experiments in Germany (Methau, Sproda and Bad Lauchstadt) were incubated in a laboratory experiment with continuous determination of N2O and CO2 emissions and a monitoring of soil mineral N. The long-term fertilization treatments included application of mineral N (Methau and Sproda), farmyard manure + mineral N (Methau and Sproda), farmyard manure deposition in excess (Bad Lauchstadt) and nil fertilization (Bad Lauchstadt). Long-term addition of farmyard manure increased the soil organic C (SOC) content by 55% at Methau (silt loam), by 17% at Sproda (sandy loam) and by 88% at Bad Lauchstadt (silt loam; extreme treatment which does not represent common agricultural management). Increased soil organic matter stocks induced by long-term application of farmyard manure at Methau and Sproda resulted in slightly increased N2O emissions at a soil moisture content of 60% water-holding capacity. However, the effect of fertilization history and SOC content on N2O emissions was small compared to the short-term effects induced by the current fertilizer application. At Bad Lauchstadt, high N2O emissions from the treatment without fertilization for 25 years indicate the importance of a sustainable soil organic matter management to maintain soil structure and soil aeration. Emissions of N2O following the application of nitrate and farmyard manure differed because of their specific effects on soil nitrate availability and microbial oxygen consumption. At a soil moisture content of 60% waterholding capacity, fertilizer-induced emissions were higher for farmyard manure than for nitrate. At field capacity, nitrate application induced the highest emissions. Our results indicate that feedback mechanisms of soil C sequestration on N2O emissions have to be considered when discussing options to increase soil C stocks."],["dc.description.sponsorship","German Research Association (Deutsche Forschungsgemeinschaft, DFG)"],["dc.identifier.doi","10.1007/s00374-011-0553-5"],["dc.identifier.isi","000292972400001"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/6608"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22711"],["dc.notes.intern","Merged from goescholar"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0178-2762"],["dc.rights","Goescholar"],["dc.rights.uri","https://goescholar.uni-goettingen.de/licenses"],["dc.title","Emission rates of N2O and CO2 from soils with different organic matter content from three long-term fertilization experiments-a laboratory study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]