Flessa, Heiner

[["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"]]

[["dc.bibliographiccitation.firstpage","114"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","Soil and Tillage Research"],["dc.bibliographiccitation.lastpage","121"],["dc.bibliographiccitation.volume","112"],["dc.contributor.author","Ludwig, B."],["dc.contributor.author","Bergstermann, Anja"],["dc.contributor.author","Priesack, Eckart"],["dc.contributor.author","Flessa, H."],["dc.date.accessioned","2018-11-07T08:57:45Z"],["dc.date.available","2018-11-07T08:57:45Z"],["dc.date.issued","2011"],["dc.description.abstract","The choice of tillage system affects crop growth and soil nitrogen dynamics. Models help us to better understand these systems and the interaction of the processes involved. Objectives were to test a calibration and validation scheme for applications of the denitrification-decomposition (DNDC) model to describe a long-term field experiment with conventional tillage (CT) and reduced tillage (RI) at two sites (G and silty Haplic Luvisols) near Gottingen, Germany (G-CT, G-RI, H-CT, H-RI). Crop growth of field bean (Vicia faba L) and winter wheat (Triticum aestivum L) as well as soil water dynamics and nitrous oxide (N2O) emissions were determined for two subsequent years. A model test was performed based on a model parameterization to best describe the case G-CT. This parameterization was then applied to the other cases as a retrospective simulation. Results of model variant vi (no parameter optimization) indicated that soil water contents were not accurately simulated using the DNDC default values for a silt loam. After successful calibration of the soil water flow model using modified water-filled pore spaces at field capacity and wilting point and a modified hydro-conductivity that led to a good fit of the measured water content data, grain yields were markedly underestimated and modelled N2O emissions were too large (v2). An optimization of the crop properties (maximum grain yield. N fixation index, thermal degree days, transpiration coefficient) was essential for a better match of measured yields (v3). Further adjustments in the model (v4) were required to better match cumulative N2O emissions: reducing the initial soil organic carbon content and mineralization rates. Predictions of crop yields and annual cumulative N2O emissions using model variant v4 were fairly accurate for the reduced tillage system G-RI and also for the second field experiment H-CT and H-RI, but annual distributions of N2O emissions were not. Overall our results indicate that site specific calibration was an essential requirement for the silty German sites, and that the pedotransfer functions and denitrification submodel of DNDC may need further improvement. (C) 2010 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft [1397]"],["dc.identifier.doi","10.1016/j.still.2010.12.005"],["dc.identifier.isi","000288689800002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23476"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0167-1987"],["dc.title","Modelling of crop yields and N2O emissions from silty arable soils with differing tillage in two long-term experiments"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","384"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE-ZEITSCHRIFT FUR PFLANZENERNAHRUNG UND BODENKUNDE"],["dc.bibliographiccitation.lastpage","391"],["dc.bibliographiccitation.volume","171"],["dc.contributor.author","Ludwig, Bernard"],["dc.contributor.author","Nitschke, Renate"],["dc.contributor.author","Terhoeven-Urselmans, Thomas"],["dc.contributor.author","Michel, Kerstin"],["dc.contributor.author","Flessa, Heiner"],["dc.date.accessioned","2018-11-07T11:14:47Z"],["dc.date.available","2018-11-07T11:14:47Z"],["dc.date.issued","2008"],["dc.description.abstract","Mid-infrared spectroscopy (MIRS) is assumed to be superior to near-infrared spectroscopy (NIRS) for the prediction of soil constituents, but its usefulness is still not sufficiently explored. The objective of this study was to evaluate the ability of MIRS to predict the chemical and biological properties of organic matter in soils and litter. Reflectance spectra of the mid-infrared region including part of the near-infrared region (7000-400 cm(-1)) were recorded for 56 soil and litter samples from agricultural and forest sites. Spectra were used to predict general and biological characteristics of the samples as well as the C composition which was measured by C-13 CPMAS-NMR spectroscopy. A partial least-square method and cross-validation were used to develop equations for the different constituents over selected spectra ranges after several mathematical treatments of the spectra. Mid-infrared spectroscopy predicted well the C : N ratio: the modeling efficiency EF was 0.95, the regression coefficient (a) of a linear regression (measured against predicted values) was 1.0, and the correlation coefficient (r) was 0.98. Satisfactorily (EF >= 0.70, 0.8 <= a <= 1.2, r >= 0.80) assessed were the contents of C, N, and lignin, the production of dissolved organic carbon, and the contents of carbonyl C, aromatic C, O-alkyl C, and alkyl C. However, the N mineralization rate, the microbial biomass and the alkyl-to-aromatic C ratio Were predicted less satisfactorily (EF < 0.70). Limiting the sample set to mineral soils did generally not result in improved predictions. The good and satisfactory predictions reported above indicate a marked usefulness of MIRS in the assessment of chemical characteristics of soils and litter, but the accuracies of the MIRS predictions in the diffuse-reflectance mode were generally not superior to those of NIRS."],["dc.identifier.doi","10.1002/jpln.200700022"],["dc.identifier.isi","000257172700010"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/54217"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1436-8730"],["dc.title","Use of mid-infrared spectroscopy in the diffuse-reflectance mode for the prediction of the composition of organic matter in soil and litter"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","3516"],["dc.bibliographiccitation.issue","12"],["dc.bibliographiccitation.journal","Soil Biology and Biochemistry"],["dc.bibliographiccitation.lastpage","3519"],["dc.bibliographiccitation.volume","38"],["dc.contributor.author","Ludwig, B."],["dc.contributor.author","Teepe, R."],["dc.contributor.author","de Gerenyu, Valentin Lopes"],["dc.contributor.author","Flessa, H."],["dc.date.accessioned","2018-11-07T08:56:11Z"],["dc.date.available","2018-11-07T08:56:11Z"],["dc.date.issued","2006"],["dc.description.abstract","Knowledge is scarce on mineralization of soil organic carbon (SOC) in and N2O emissions from tundra soils in periods of alternate freezing and thawing. Our objectives were to study the CO2 and N2O emissions from two silty gleyic soils formed in different climate zones (a gleyic Cryosol located in the Russian tundra, and a stagnic Gleysol located in an oak stand in central Germany) during freeze-thaw events. Soils were adjusted to a matric potential of -0.2kPa and emissions were measured in 3-h intervals during an incubation period of 50 days including three freeze-thaw cycles. CO2 emissions from the German oak forest soil were twofold higher than those of the tundra soil. The ratios of the mean CO2 production rate before the freezing to the mean CO2 production rate after thawing ranged from 0.63 to 0.73 for the forest soil and from 0.85 to 0.89 for the tundra soil. The specific CO2-C production rate (CO2-C/SOC) was 0.16 for the tundra soil and 0.57 for the forest soil. The results indicate that bioavailability of SOC was markedly smaller in the tundra soil than in the forest soil. Large N2O emissions were found for the German forest soil, but no N2O emissions were observed for the tundra soil. The main reason for the absence of N2O emissions was most likely the negligible availability of nitrate for denitrification. There was some indication that the initial increase in mineralization of SOC induced by freezing and thawing differs between soils from various climatic regions, probably mainly due to a differing bioavailability of the SOC and differing releases of nutrients after thawing. (c) 2006 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/j.soilbio.2006.06.006"],["dc.identifier.isi","000242007100022"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/23080"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.relation.issn","0038-0717"],["dc.title","CO2 and N2O emissions from gleyic soils in the Russian tundra and a German forest during freeze-thaw periods - a microcosm study"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","111"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE-ZEITSCHRIFT FUR PFLANZENERNAHRUNG UND BODENKUNDE"],["dc.bibliographiccitation.lastpage","124"],["dc.bibliographiccitation.volume","171"],["dc.contributor.author","von Lutzow, Margit"],["dc.contributor.author","Kogel-Knabner, Ingrid"],["dc.contributor.author","Ludwig, Bernard"],["dc.contributor.author","Matzner, Egbert"],["dc.contributor.author","Flessa, Heinz"],["dc.contributor.author","Ekschmitt, Klernens"],["dc.contributor.author","Guggenberger, Georg"],["dc.contributor.author","Marschner, Bernd"],["dc.contributor.author","Kalbitz, Karsten"],["dc.date.accessioned","2018-11-07T11:18:44Z"],["dc.date.available","2018-11-07T11:18:44Z"],["dc.date.issued","2008"],["dc.description.abstract","Based on recent findings in the literature, we developed a process-oriented conceptual model L that integrates all three process groups of organic matter (OM) stabilization in soils namely (1) selective preservation of recalcitrant compounds, (2) spatial inaccessibility to decomposer organisms, and (3) interactions of OM with minerals and metal ions. The model concept relates the diverse stabilization mechanisms to active, intermediate, and passive pools. The formation of the passive pool is regarded as hierarchical structured co-action of various processes that are active under specific pedogenetic conditions. To evaluate the model, we used data of pool sizes and turnover times of soil OM fractions from horizons of two acid forest and two agricultural soils. Selective preservation of recalcitrant compounds is relevant in the active pool and particularly in soil horizons with high C contents. Biogenic aggregation preserves OM in the intermediate pool and is limited to topsoil horizons. Spatial inaccessibility due to the occlusion of OM in clay microstructures and due to the formation of hydrophobic surfaces stabilizes OM in the passive pool. If present, charcoal contributes to the passive pool mainly in topsoil horizons. The importance of organo-mineral interactions for OM stabilization in the passive pool is well-known and increases with soil depth. Hydrophobicity is particularly relevant in acid soils and in soils with considerable inputs of charcoal. We conclude that the stabilization potentials of soils are site- and horizon-specific. Furthermore, management affects key stabilization mechanisms. Tillage increases the importance of organo-mineral interactions for OM stabilization, and in Ap horizons with high microbial activity and C turnover, organo-mineral interactions can contribute to OM stabilization in the intermediate pool. The application of our model showed that we need a better understanding of processes causing spatial inaccessibility of OM to decomposers in the passive pool."],["dc.identifier.doi","10.1002/jpln.200700047"],["dc.identifier.isi","000253431000009"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/55111"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","1436-8730"],["dc.title","Stabilization mechanisms of organic matter in four temperate soils: Development and application of a conceptual model"],["dc.type","review"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","315"],["dc.bibliographiccitation.issue","1-2"],["dc.bibliographiccitation.journal","Plant and Soil"],["dc.bibliographiccitation.lastpage","325"],["dc.bibliographiccitation.volume","278"],["dc.contributor.author","Ludwig, B."],["dc.contributor.author","Helfrich, Mirjam"],["dc.contributor.author","Flessa, Heiner"],["dc.date.accessioned","2018-11-07T10:54:01Z"],["dc.date.available","2018-11-07T10:54:01Z"],["dc.date.issued","2005"],["dc.description.abstract","Soil organic carbon (SOC) models have been widely used to predict SOC change with changing environmental and management conditions, but the accuracy of the prediction is often open to question. Objectives were (i) to quantify the amounts of C derived from maize in soil particle size fractions and at various depths in a long-term field experiment using C-13/C-12 analysis, (ii) to model changes in the organic C, and (iii) to compare measured and modelled pools of C. Maize was cultivated for 24 years on a silty Luvisol which resulted in a stock of 1.9 kg maize-derived C m(-2) (36% of the total organic C) in the Ap horizon. The storage of maize-derived C in particle size fractions of the Ap horizon decreased in the order clay (0.65 kg C m(-2)) > fine and medium silt (0.43) > coarse silt (0.33) > fine sand (0.13) > medium sand (0.12) > coarse sand (0.06) and the turnover times of C-3-derived C ranged from 26 (fine sand) to 77 years (clay). The turnover times increased with increasing soil depth. We used the Rothamsted Carbon Model to model the C dynamics and tested two model approaches: model A did not have any adjustable parameters, but included the Falloon equation for the estimation of the amount of inert organic matter (IOM) and independent estimations of C inputs into the soil. The model predicted well the changes in C-3-derived C with time but overestimated the changes in maize-derived C 1.6-fold. In model B, the amounts of IOM and C inputs were optimized to match the measured C-3- and C-4-derived SOC stocks after 24 years of continuous maize. This model described the experimental data well, but the modelled annual maize C inputs (0.41 kg C m(-2) a(-1)) were less than the independently estimated total input of maize litter C (0.63 kg C m(-2) a(-1)) and even less than the annual straw C incorporated into the soil (0.46 kg C m(-2) a(-1)). These results indicated that the prediction of the Rothamsted Carbon Model with independent parameterization served only as an approximation for this site. The total amount of organic C associated with the fraction 0-63 mu m agreed well with the sum of the pools 'microbial biomass', 'humified-organic matter' and IOM of the model B. However, the amount of maize-derived C in this fraction (3.4 g kg(-1)) agreed only satisfactorily with the sum of maize-derived C in the pools 'microbial biomass' and 'humified organic matter' (2.6 g kg(-1))."],["dc.identifier.doi","10.1007/s11104-005-8808-2"],["dc.identifier.isi","000233643000026"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/49473"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Springer"],["dc.relation.issn","0032-079X"],["dc.title","Modelling the long-term stabilization of carbon from maize in a silty soil"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","77"],["dc.bibliographiccitation.issue","2"],["dc.bibliographiccitation.journal","ACTA HYDROCHIMICA ET HYDROBIOLOGICA"],["dc.bibliographiccitation.lastpage","82"],["dc.bibliographiccitation.volume","28"],["dc.contributor.author","Ludwig, B."],["dc.contributor.author","Heil, B."],["dc.contributor.author","Flessa, H."],["dc.contributor.author","Beese, F."],["dc.date.accessioned","2018-11-07T10:04:32Z"],["dc.date.available","2018-11-07T10:04:32Z"],["dc.date.issued","2000"],["dc.description.abstract","Dissolved organic carbon (DOC) in seepage water can combine with organic pollutants, with Al and heavy metal ions and transport them through the soil profile with a potential to contaminate groundwater. We studied the production of DOC in aerobic decomposition experiments at 8 degrees C and moisture close to field capacity in soils from two sites with different microbial activities (spodic dystric Cambisols with moder (SLB) and mor-moder (SLS) layers) using C-13-depleted plants of differing decomposability (Epilobium angustifolium and Calamagrostis epigeios). Additionally, we investigated the DOC transformation during soil passage in decomposition experiments and in the field for the sites SLB and SLS. For SLS, decomposition of Epilobium resulted in a cumulative CO2 production of 14% of the added C within 128 days. Priming effects were negligible. CO2: production for the experiments using Calamagrostis was less with 11% for SLB and 10% for SLS. Cumulative DOC production was markedly high in the Epilobium decomposition experiment, being 25 g m(-2), out of which 11 g m(-2) were Epilobium-derived (2% of the added C). For the Calamagrostis experiments, cumulative productions of DOC and Calamagrostis-derived DOC (0.1% of the added C for SLS and SLB) were much less. During the soil passage, much of the DOC was removed by sorption or decomposition processes. Field studies at SLS and SLB using C-13 natural abundance showed that C-13 distribution of soil organic matter increased with depth, probably mainly due to a discrimination of C isotopes by decomposing microorganisms. DOG, however, showed a depletion of C-13 from -28 parts per thousand PDB to -29 parts per thousand (SLB at 40 cm) or --28 to -30 parts per thousand (SLS at 20 cm) with depth, owing to preferential decomposition of C-13-enriched substances or preferential adsorption. This study indicates that DOC production is strongly affected by litter composition and that significant changes in DOC composition may occur during its passage through a soil depth of 40 cm."],["dc.identifier.doi","10.1002/(SICI)1521-401X(20002)28:2<77::AID-AHEH77>3.0.CO;2-V"],["dc.identifier.isi","000087121600002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/38713"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-v C H Verlag Gmbh"],["dc.relation.issn","0323-4320"],["dc.title","Dissolved organic carbon in seepage water - Production and transformation during soil passage"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1193"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Soil Biology and Biochemistry"],["dc.bibliographiccitation.lastpage","1202"],["dc.bibliographiccitation.volume","35"],["dc.contributor.author","John, Bettina"],["dc.contributor.author","Ludwig, B."],["dc.contributor.author","Flessa, H."],["dc.date.accessioned","2018-11-07T10:36:50Z"],["dc.date.available","2018-11-07T10:36:50Z"],["dc.date.issued","2003"],["dc.description.abstract","Understanding carbon dynamics in soil is the key to managing soil organic matter. Our objective was to quantify the carbon dynamics in microcosm experiments with soils from long-term rye and maize monocultures using natural C-13 abundance. Microcosms with undisturbed soil columns from the surface soil (0-25 cm) and subsoil (25-50 cm) of plots cultivated with rye (C-3-plant) since 1878 and maize (C-4-plant) since 1961 with and without NPK fertilization from the long-term experiment 'Ewiger Roggen' in Halle, Germany, were incubated for 230 days at 8 degreesC and irrigated with 2 mm 10(-2) M CaCl2 per day. Younger, C-4-derived and older, C-3-derived percentages of soil organic carbon (SOC), dissolved organic carbon (DOC), microbial biomass (C-mic) and CO2 from heterothropic respiration were determined by natural C-13 abundance. The percentage of maize-derived carbon was highest in CO2 (42-79%), followed by C-mic (23-46%), DOC (5-30%) and SOC (5-14%) in the surface soils and subsoils of the maize plots. The percentage of maize-derived C was higher for the NPK plot than for the unfertilized plot and higher for the surface soils than for the subsoils. Specific production rates of DOC, CO2-C and C-mic from the maize-derived SOC were 0.06-0.08% for DOC, 1.6-2.6% for CO2-C and 1.9-2.7% for Cmic, respectively, and specific production rates from rye-derived SOC of the continuous maize plot were 0.03-0.05% for DOC, 0.1-0.2% for CO2-C and 0.3-0.5% for C-mic. NPK fertilization did not affect the specific production rates. Strong correlations were found between C-4-derived C-mic and C-4-derived SOC, DOC and CO2-C (r greater than or equal to 0.90), whereas the relationship between C-3-derived C-mic and C-3-derived SOC, DOC and CO2-C was not as pronounced (r less than or equal to 0.67). The results stress the different importance of former (older than 40 years) and recent (younger than 40 years) litter C inputs for the formation of different C pools in the soil. (C) 2003 Elsevier Ltd. All rights reserved."],["dc.identifier.doi","10.1016/S0038-0717(03)00180-9"],["dc.identifier.isi","000184666300005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/45421"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Pergamon-elsevier Science Ltd"],["dc.relation.issn","0038-0717"],["dc.title","Carbon dynamics determined by natural C-13 abundance in microcosm experiments with soils from long-term maize and rye monocultures"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","350"],["dc.bibliographiccitation.issue","3"],["dc.bibliographiccitation.journal","Journal of Plant Nutrition and Soil Science"],["dc.bibliographiccitation.lastpage","358"],["dc.bibliographiccitation.volume","174"],["dc.contributor.author","Ludwig, Bernard"],["dc.contributor.author","Jaeger, Nadine"],["dc.contributor.author","Priesack, Eckart"],["dc.contributor.author","Flessa, Heinz"],["dc.date.accessioned","2018-11-07T08:55:36Z"],["dc.date.available","2018-11-07T08:55:36Z"],["dc.date.issued","2011"],["dc.description.abstract","Modeling crop growth and soil N dynamics is difficult due to the complex nature of soil-plant systems. In several studies, the DNDC model has been claimed to be well-suited for this purpose whereas in other studies applications of the model were less successful. Objectives of this study were to test a calibration and validation scheme for DNDC-model applications to describe a field experiment with spring wheat on a sandy soil near Darmstadt (SW Germany) using different fertilizer types (either application of mineral fertilizer and straw-MSI; or application of farmyard manure-FYM) and rates (low-MSIL, FYML; and medium-MSIM, FYMM). The model test is based on a model parameterization to best describe the case MSIL and applies this parameterization for a retrospective simulation of the other cases (MSIM, FYML, FYMM) including crop growth and N2O emissions. Soil water contents were not accurately simulated using either the DNDC default values for a loamy sand or for the next finer texture class or using results from the pedotransfer function provided by ROSETTA. After successful calibration of the soil water flow model using a soil texture class that led to the best fit of the measured water content data, grain yield of spring wheat and cumulative N2O emission were slightly underestimated by DNDC and were between 91% and 86% of the measured data. A subsequent calibration of the yields and cumulative N2O emissions from soils of the MSIL treatment gave a good prediction of crop growth and N2O emissions in the MSIM treatment, but a marked underestimation of yields of the FYM treatments. Cumulative N2O emissions were predicted well for all MSI and FYM treatments, but seasonal dynamics were not. Overall, our results indicated that for the sandy soil in Germany, site-specific calibration was essentially required for the soil hydrology and that a calibration was useful for a subsequent prediction where greater amounts of the same fertilizer were used, but not useful for a prediction with a different fertilizer type."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [1397]"],["dc.identifier.doi","10.1002/jpln.201000040"],["dc.identifier.isi","000291361500002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/22943"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Wiley-blackwell"],["dc.relation.issn","1436-8730"],["dc.title","Application of the DNDC model to predict N2O emissions from sandy arable soils with differing fertilization in a long-term experiment"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","933"],["dc.bibliographiccitation.issue","9"],["dc.bibliographiccitation.journal","Archives of Agronomy and Soil Science"],["dc.bibliographiccitation.lastpage","944"],["dc.bibliographiccitation.volume","58"],["dc.contributor.author","Heitkamp, Felix"],["dc.contributor.author","Jaeger, Nadine"],["dc.contributor.author","Flessa, Heinz"],["dc.contributor.author","Raupp, Joachim"],["dc.contributor.author","Ludwig, Bernard"],["dc.date.accessioned","2018-11-07T09:15:04Z"],["dc.date.available","2018-11-07T09:15:04Z"],["dc.date.issued","2012"],["dc.description.abstract","Annual changes in stocks of soil organic carbon may be detected by measurement of heterotrophic respiration, but field studies of heterotrophic respiration in long-term fertilization experiments on sandy soils are scarce. Our objectives were to: (1) investigate the influence of fertilizer type on mineralization of soil organic carbon and crop residue, and (2) show how fertilization treatments affect the annual C balance (net ecosystem carbon balance, NECB; negative values indicate a CO2-source) in the sandy soil of the Darmstadt experiment. Treatments were long-term mineral fertilization with cereal straw incorporation (MSI) and application of rotted farmyard manure (FYM), both treatments receiving 14 g N m(-2) year(-1). This study used delta C-13 natural abundance after introduction of a C-4 crop to distinguish between different sources of respiration. Mineralization derived from C-3 sources was similar for MSI and FYM treatments (similar to 270 g C m(-2) year(-1)). The rate of residue mineralization in MSI treatments was higher, resulting in a mineralization of 49 and 37% of initial residue C in the soil of MSI and FYM treatments, respectively. The NECB (g C m(-2) year(-1)) indicated the MSI treatment (approximately - 190) as a stronger source compared with the FYM treatment (similar to-30)."],["dc.description.sponsorship","Deutsche Forschungsgemeinschaft (DFG) [GRK 1397/1]"],["dc.identifier.doi","10.1080/03650340.2011.555762"],["dc.identifier.isi","000307189400001"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/27586"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Taylor & Francis Ltd"],["dc.relation.issn","0365-0340"],["dc.title","Effect of fertilization on respiration from different sources in a sandy soil of an agricultural long-term experiment"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]