TY  - JOUR
AB  - Mountainous grassland soils are considered one of the most unique biological hotspots, rich in organic carbon (OC). At the same time, they are exposed to great threats, as climate warming is more pronounced in mountainous regions than in lowland areas. In this study, we assessed the effect of simulated warming (+1K, +2K, and + 3 K) on OC stocks and soil structure in grassland soils of the Northern Limestone Alps in Germany by translocating plant-soil mesocosms from high- (1260 m a.s.l., Rendzic Phaeozem) and mid- (860 m a. s. l., Haplic Cambisol) to low-elevation (600 m a.s.l). Plant-soil mesocosms were exposed to both extensive and intensive grassland management practices. Four years after translocation, we observed a rapid decrease of topsoil SOC stocks under intensive (−1.0 t C ha yr−1) and extensive management (-2.2 t C ha yr−1), under the highest temperature increase. Intensive management with about 1 t C ha−1 yr−1 higher manure C return than extensive management (1.6 vs. 0.8 t C ha−1 yr−1 intensive and extensive, respectively) may explain the difference in SOC losses between different management treatments. Under both management practices, the loss of SOC was mainly associated with a decrease of large macroaggregates, at both management practices. In addition, different aggregate specific OC loss rates resulted in an altered distribution of OC among the aggregate size classes. Our study provides evidence that simulated climate change induced a rapid and substantial decline of SOC in mountainous, OC-rich grassland soils, which may be attributed to decreased physical OC protection within large macroaggregates. Optimized grassland management in form of increased application of organic fertilizers could only partially offset the SOC loss by improved formation of small macroaggregates.
AU  - Garcia-Franco, N.*
AU  - Wiesmeier, M.*
AU  - Buness, V.*
AU  - Berauer, B.J.*
AU  - Schuchardt, M.A.*
AU  - Jentsch, A.*
AU  - Schlingmann, M.*
AU  - Andrade Linares, D.R.
AU  - Wolf, B.*
AU  - Kiese, R.*
AU  - Dannenmann, M.*
AU  - Kögel-Knabner, I.*
C1  - 70013
C2  - 55361
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Rapid loss of organic carbon and soil structure in mountainous grassland topsoils induced by simulated climate change.
JO  - Geoderma
VL  - 442
PB  - Elsevier
PY  - 2024
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Net rhizodeposition corresponds to the portion of living root carbon (C) that remains in the soil after microbial processing and partial decomposition. Although it is assumed that this C input exerts an important role in the formation of soil organic matter (SOM), its contribution to distinct SOM pools is still not fully understood. In this study, we aimed to (i) quantify the retention of net rhizodeposition C in the different SOM fractions and in reactive Al and Fe mineral phases and (ii) investigate how rhizodeposition drives the spatial distribution of microbial communities in the rhizosphere. To track the transfer of net rhizodeposition into the soil, we used artificially labeled eucalypt (Eucalyptus spp.) seedlings under a 13C-CO2 atmosphere (multiple-pulse labeling). Combining physical SOM fractionation and the chemical extraction of aluminum (Al) and iron (Fe) reactive phases, we studied the distribution of net rhizodeposition into different soil fractions. We also assessed the 13C incorporation into microbial phospholipid fatty acids (PLFAs) at different distances from the roots. Our results show that 76 % of the net rhizodeposition 13C was retained within the mineral-associated organic matter (MAOM) fraction. About 28 % of net rhizodeposition 13C within the MAOM fraction was retained within the Al and Fe reactive phases, indicating that this is a sizeable mechanism for the retention of net rhizodeposition in soil. Rhizodeposition increased the abundance of microbial PLFAs exclusively in the soil close to the roots (0–4 mm), with prominent incorporation of net rhizodeposition 13C into fungal biomarkers. Overall, our findings underscore the importance of mineral associations for the retention of net rhizodeposition in the soil. We also highlight the role of fungi in transferring the root-derived C beyond the root vicinity and promoting the formation of occluded SOM.
AU  - Teixeira, P.P.C.*
AU  - Vidal, A.*
AU  - Teixeira, A.P.M.*
AU  - Souza, I.F.*
AU  - Hurtarte, L.C.C.*
AU  - Silva, D.H.S.*
AU  - Almeida, L.F.J.*
AU  - Buegger, F.
AU  - Hammer, E.C.*
AU  - Jansa, J.*
AU  - Mueller, C.W.*
AU  - Silva, I.R.*
C1  - 70288
C2  - 55488
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Decoding the rhizodeposit-derived carbon's journey into soil organic matter.
JO  - Geoderma
VL  - 443
PB  - Elsevier
PY  - 2024
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - It is crucial to promote soil carbon sequestration while reducing CO2 emissions to mitigate climate change. However, the extent of increasing actual soil carbon storage depends on the amount and composition of organic matter input, including its fate during decomposition and soil organic matter (SOM) formation via microbial transformation. With respect to the need to increase carbon sequestration in soil and sustain soil fertility, it is of great interest to better understand how soils with different organic matter content react to amendment with fresh organic matter. Here, we incubated three agricultural soils representing a gradient in C content, adding two different 13C labeled plant residues varying in carbon-to-nitrogen ratio. Carbon mineralization was monitored together with the analysis of the 13CO2 signatures. After the incubation, 13C compound-specific PLFAs, microbial necromass, and enzyme activities were analyzed. This study demonstrates that the carbon return on investment, thus the amount of retained fresh carbon in relation to the amount of added organic matter, clearly depends on the amount of native soil carbon. Notably, the addition of fresh organic matter to carbon-deficient soils leads to a higher specific CO2 release compared to soils with high carbon loading, which can be attributed to the differences in the soil microorganisms' response. The CO2 release of the soil with the lowest C-content was 2.1 and 2.0 mg g−1 soil for treatment with oat and pea litter addition, respectively, whereas for the soil with the highest C-content, CO2 release was 1.7 mg g−1 soil for oat treatment and 1.6 mg g−1 soil for pea treatment. Thus, higher SOC contents sustain a higher ‘return on investment’ for the fresh carbon that is amended to soils. With plant litter amendments the microbial community shifted towards a higher fungi-to-bacteria ratio (F/B). This shift in the microbial community was more pronounced (F/B ranging from 0.04 to 0.11) with the addition of oat litter (low quality) compared to pea litter (high quality). Hence, it is important to consider the fate of organic amendments with different N availability when aiming to rebuild soil carbon stocks in degraded soils. Soil management should focus on sustaining soil carbon in balance with current carbon stocks to avoid the vicious circle of soils losing carbon in conjunction with increased greenhouse gas release.
AU  - Wu, T.*
AU  - Wichern, F.*
AU  - Wiesmeier, M.*
AU  - Buegger, F.
AU  - Shi, L.*
AU  - Dippold, M.A.*
AU  - Höschen, C.*
AU  - Mueller, C.W.*
C1  - 70162
C2  - 55433
CY  - Radarweg 29, 1043 Nx Amsterdam, Netherlands
TI  - Organic carbon loading of soils determines the fate of added fresh plant-derived organic matter.
JO  - Geoderma
VL  - 443
PB  - Elsevier
PY  - 2024
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Arctic tundra fires have been increasing in extent, frequency and intensity and are likely impacting both soil nitrogen (N) and phosphorus (P) cycling and, thus, permafrost ecosystem functioning. However, little is known on the underlying microbial mechanisms, and different fire intensities were neglected so far. To better understand immediate influences of different fire intensities on the soil microbiome involved in nutrient cycling in permafrost-affected soil, we deployed experimental fires with low and high intensity on an Arctic tundra soil on Disko Island, Greenland. Soil sampling took place three days postfire and included an unburned control. Using quantitative real-time PCR, copy numbers of 16S and ITS as well as of 17 genes coding for functional microbial groups catalyzing major steps of N and P turnover were assessed. We show that fires change the abundance of microbial groups already after three days with fire intensity as key mediating factor. Specifically, low-intensity fire significantly enhanced the abundance of chiA mineralizers and ammonia-oxidizing archaea, while other groups were not affected. On the contrary, high-intensity fire decreased the abundance of chiA mineralizers and of microbes that fix dinitrogen, indicating a dampening effect on N cycling. Only high-intensity fires enhanced ammonium concentrations (by an order of magnitude). This can be explained by burned plant material and the absence of plant uptake, together with impaired further N processing. Fire with high intensity also decreased nirK-type denitrifiers. In contrast, after fire with low intensity there was a trend for a decreased nosZ: (nirK+nirS) ratio, indicating – together with increased nitrate concentrations – an enhanced potential for nitric oxide and nitrous oxide emissions. Concerning P transformation, only gcd was affected in the short term which is important for P solubilization. Changes in gene numbers consistently showed the same contrasting pattern of elevated abundance with low fire intensity and decreased abundance with high fire intensity. Differentiating fire intensities is therefore crucial for further, longer-term studies of fire-induced changes in N and P transformations and potential nutrient-climate feedbacks of permafrost-affected soils.
AU  - Ramm, E.*
AU  - Ambus, P.L.*
AU  - Gschwendtner, S.
AU  - Liu, C.*
AU  - Schloter, M.
AU  - Dannenmann, M.*
C1  - 68332
C2  - 53629
TI  - Fire intensity regulates the short-term postfire response of the microbiome in Arctic tundra soil.
JO  - Geoderma
VL  - 438
PY  - 2023
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Although the association of minerals and organic matter (OM) in soil plays an important role in the sequestration of C, the factors driving the initial formation of mineral-associated OM (MAOM), and thus the retention of new C input in soils are not yet fully understood. In this study, we investigated how the soil C loading and the differences in the N content of low-molecular-weight organic compound (LMWOC) input foster the rapid C retention in the soil's fine mineral fractions (clay and fine silt-sized fraction). Two topsoils (0–10 cm) with different C loading due to different long-term management (direct seeding vs. bare fallow) derived from an agricultural research trial were used for the short-term incubation experiment. In a 24-hour incubation experiment, we used two labeled substrates (without N, glucose, > 99% 13C and with N, amino acid mixture, > 98% 13C, > 98% 15N) to investigate how the different N content delivered by the LMWOC input determine the fate of newly formed OM in the MAOM pool. Our results show that the soil with low C loading and thus a low C saturation level retained more freshly added LMWOC in the fine MAOM pool compared to the high C-loading soil, demonstrating that the soil C loading is a major factor controlling the retention of freshly added OM at the early stage of MAOM formation. The LMW OM containing N significantly enhanced the recovery of freshly added LMWOC in the low C-loading soil but not in the high C-loading soil. This points to the great importance of the N availability for the retention of freshly added OM in soils. Our study showed that the level of the native OM content affects the fast retention of freshly added OM in the clay-sized fraction to a greater extent than the N availability of the OM substrate.
AU  - Wu, T.*
AU  - Ost, A.D.*
AU  - Audinot, J.N.*
AU  - Wiesmeier, M.*
AU  - Wirtz, T.*
AU  - Buegger, F.
AU  - Häusler, W.*
AU  - Höschen, C.*
AU  - Mueller, C.W.*
C1  - 63843
C2  - 51772
TI  - Association of fresh low-molecular-weight organic compounds with clay-sized mineral fraction in soils of different organic carbon loading.
JO  - Geoderma
VL  - 409
PY  - 2022
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Saturated acid sulfate soils with hypersulfidic material are productive wetland soils, but when they dry, they generate large amounts of sulfuric acid due to oxidation of pyrite to form sulfuric material (pH <4) and consequently sulfuric soils. After re-saturation of sulfuric soils and thus the re-establishment of reduced conditions, activity of sulfate reducing bacteria (SRB) can lead to a renewed formation of Fe sulfides and pH increase. Many SRB are heterotrophic and require sufficient available organic matter; however, little is known about OC consumption and changes of the composition of organic substrates during the amelioration process. To investigate remediation of a sandy, OC-poor sulfuric soil (initial pH = 2.5), short-term anoxic incubation experiments over a period of approx. 10 weeks were conducted after re-submerging under controlled laboratory conditions. We tested different organic matter quantities between 10% up to 200% of the native soil OC content. Besides wheat straw, we used lactate additions to test if this selectively promotes the activity of SRB, and thus, accelerates sulfate reduction and pH neutralization. The results showed that OC additions of ≥50% of native soil OC content and pre-adjustment of pH to values ≥5.0 were necessary to subsequently enable microbial reduction reactions to occur, which increased the pH to values ≥5.5. OC additions of ≥100% instead of 50% of native soil OC as wheat straw led to quicker changes of redox and pH values, to slightly higher microbial activity as indicated by CO 2 release, and to higher proportions of newly-formed mineral-associated OC. The addition of OC as lactate solution to promote specifically SRB was only successful in combination with wheat straw addition. Here, the presence of lactate led to the quickest changes of pH and redox values and resulted in pH ≥7 and redox values ≤ −300 mV due to an active microbial population. Our results indicate that a diverse microbial community is more important for successful remediation than a selective promotion of SRB.
AU  - Kölbl, A.*
AU  - Bucka, F.*
AU  - Marschner, P.*
AU  - Mosley, L.*
AU  - Fitzpatrick, R.*
AU  - Schulz, S.
AU  - Lueders, T.
AU  - Kögel-Knabner, I.*
C1  - 55891
C2  - 46629
SP  - 220-232
TI  - Consumption and alteration of different organic matter sources during remediation of a sandy sulfuric soil.
JO  - Geoderma
VL  - 347
PY  - 2019
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Organic farming and agroforestry both have the potential to develop sustainable and environmental-friendly agroecosystems and to sequester more soil organic C (SOC). In a long-term field trial, we evaluated the effect of 21-year organic farming and 4-year agroforestry (Robinia and Poplar-based alley cropping system) on water extractable organic matter (WEOM). The technique combining excitation emission matrix (EEM) spectra with parallel factor analysis (PARAFAC) was used to reveal the components of WEOM. In addition, WEOM was characterized by UV absorbance and fluorescence spectra. Organic farming generally increased SOC and total N contents but decreased the WEOM content as well as the WEOM components indicated by the maximum fluorescence intensity (Fmax). Specific UV absorbance (SUVA) and humification index (HIX) of WEOM in organic farming implied WEOM in the organic farming had more components with aromatic structure but less humified. Higher fluorescence (FI) and freshness indices (BIX) of WEOM in organic farming system indicated that a higher percentage of WEOM was microbial-derived in the organic than in the integrated farming system. Robinia showed positive effect on SOC and total N contents in comparison with poplar and had stronger effects on the WEOM components, although the WEOM content did not differ between the two tree species. The significant farming × trees interactions on SOC and water extractable organic carbon (WEOC) indicated that the robinia effects were more pronounced in the organic farming system. Thus, the change of SOC was the result of interactive effect of farming and hedgerow trees in an agroforestry system. The low-input organic farming and robinia tended to result in change of quality of WEOM and led to enrichment of substances of high stability in WEOM. From above, the combination of organic farming and robinia trees is an important means for developing sustainable agricultural systems and soil carbon sequestration.
AU  - Sun, H.
AU  - Koal, P.
AU  - Gerl, G.
AU  - Schroll, R.
AU  - Joergensen, R.G.*
AU  - Munch, J.C.*
C1  - 50253
C2  - 42397
CY  - Amsterdam
SP  - 83-90
TI  - Response of water extractable organic matter and its fluorescence fractions to organic farming and tree species in poplar and robinia-based alley cropping agroforestry systems.
JO  - Geoderma
VL  - 290
PB  - Elsevier Science Bv
PY  - 2017
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Inundation of paddy soils for submerged rice production strongly impacts soil formation. Here we used chronosequences with up to 2000 years of cultivation history to compare soil formation in non-inundated (non-paddy) cropping systems with the formation of soils used for paddy rice production. This approach allowed us to identify the influence of agricultural management at different stages of pedogenesis. Soil samples were taken from two chronosequences derived from uniform parent material in the coastal region of the Zhejiang Province (P.R. China). One chronosequence consisted of paddy soils of different ages (50-2000 years), characterized by a yearly cropping sequence of rice cultivation under flooded conditions alternated with a non-inundated crop. The adjacent non-inundated (non-paddy) chronosequence was exclusively used for non-inundated crop production for 50-700 years. Lipid biomarkers revealed origin and homogeneity of the original coastal sediments and enabled the reconstruction of a consistent land use history for both chronosequences. The chronological development of soil properties and horizons suggested that the formation of paddy soils can be subdivided into three phases. The initial phase of paddy soil development takes only a few decades and is dominated by desalinization and formation of a compacted plow pan, leading from Fluvisols to Anthraquic Cambisols. During the next centuries (second phase), the differentiation between paddy and non-paddy management becomes increasingly obvious in terms of accelerated carbonate losses and constantly increasing organic carbon concentrations in paddy topsoils. In the third stage of paddy soil development (≥ 700 years), a (trans-)formation and redistribution of oxides is accompanied by clearly visible hydromorphic patterns in paddy subsoils, thus promoting further development from Cambisols to Hydragric Anthrosols. To account for the underlying processes we suggest modifying the depth and mottling criteria for the definitions of anthraquic and hydragric soil horizons in the classification of the World Reference Base for Soil Resources. The non-paddy chronosequence was characterized by a low degree of soil development in which decalcification-related processes dominated throughout 700 years of soil formation. Hence, soil formation under paddy management was accelerated relative to that under dryland cropping, even though the 2000-year-old paddy soils lacked evidence of an advanced stage of silicate weathering, formation of pedogenic clay minerals, or clay migration.
AU  - Kölbl, A.*
AU  - Schad, P.*
AU  - Jahn, R.*
AU  - Amelung, W.*
AU  - Bannert, A.
AU  - Cao, Z.H.*
AU  - Fiedler, S.*
AU  - Kalbitz, K.*
AU  - Lehndorff, E.*
AU  - Müller-Niggemann, C.*
AU  - Schloter, M.
AU  - Schwark, L.*
AU  - Vogelsang, V.*
AU  - Wissing, L.*
AU  - Kögel-Knaber, I.*
C1  - 27827
C2  - 32830
CY  - Amsterdam
SP  - 67-89
TI  - Accelerated soil formation due to paddy management on marshlands (Zhejiang Province, China).
JO  - Geoderma
VL  - 228-229
PB  - Elsevier Science
PY  - 2014
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Paddy soils make up the largest anthropogenic wetlands on earth. They may originate from any type of soil in pedological terms, but are highly modified by anthropogenic activities. The formation of these Anthrosols is induced by tilling the wet soil (puddling), and the flooding and drainage regime associated with the development of a plough pan and specific redoximorphic features. Redox potential oscillations due to paddy management control microbial community structure and function and thus short-term biogeochemical processes. After flooding, microbial reduction processes sequentially use NO3−, Mn4+, Fe3+, SO42− as electron acceptors, accompanied by the emission of the trace gases N2O, N2, H2S, CH4 and - due to reduction-induced increasing pH - NH3. This results in N losses and low N fertilizer use efficiency. However, transport of atmospheric O2 to the roots via the rice plant's aerenchyma modifies conditions in the rhizosphere, leading to nitrification and methane oxidation, and precipitation of Mn and Fe oxides. High concentrations and fluxes of dissolved organic matter (DOM) in paddy soils from plant debris trigger microbial activity and thus the emission of greenhouse gases. Retention of DOM by soil minerals and its subsequent stabilisation against microbial decay depend on the redox state (e.g. DOM precipitation by Fe2+ under anaerobic conditions). Oscillation in redox conditions may enhance retention and stabilisation of DOM by Fe oxyhydroxides. Induced by the periodic short-term redox cycles, paddy management over long periods has strong effects on long-term biogeochemical processes. Frequent irrigation intensifies mineral weathering and leaching processes. High concentrations of DOM during flooding seasons enhance the changes and the release of structural iron in clay minerals, and support the formation of ferrihydrite. Repeated redox alternations lead to a translocation of iron in various directions, and particularly increase the crystallinity of iron oxides. This results also in higher total iron oxide contents in paddy compared to non-paddy soils. The large accumulation of soil organic matter (SOM) observed in some, but not all paddy soils, is considered to be due to high input of plant residues and charred material associated with retarded decomposition under anaerobic conditions. There is also evidence of SOM stabilisation via occlusion into aggregates and phytoliths as well as interactions with clay minerals and iron oxides. SOM accumulation in paddy subsoils can be explained by downward movement of DOM and its stabilisation by interaction with iron oxides. A specific feature of paddy soils is the coupling of organic matter turnover with mineral transformations and fluxes, which seem to be intensified by the alternating redox conditions with increasing age of paddy soil development. Bioavailability of soil organic N is strongly coupled to SOM cycling and is a crucial parameter determining crop yield. Anaerobic conditions inhibit N mineralization, with a high risk of gaseous N losses. In paddy soils the management-induced, microbially mediated redox processes control the dynamics of soil minerals and soil organic matter, which are strongly related to the microbial accessibility of C and N, but also of Fe.
AU  - Kögel-Knabner, I.*
AU  - Amelung, W.*
AU  - Cao, Z.*
AU  - Fiedler, S.*
AU  - Frenzel, P.*
AU  - Jahn, R.*
AU  - Kalbitz, K.*
AU  - Kölbl, A.*
AU  - Schloter, M.
C1  - 2219
C2  - 27169
SP  - 1-14
TI  - Biogeochemistry of paddy soils.
JO  - Geoderma
VL  - 157
IS  - 1-2
PB  - Elsevier
PY  - 2010
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - To control soil erosion and associated land degradation worldwide there is a need to assess the impact of major land use and the effectiveness of specific soil conservation technologies using various approaches. This study was conducted in an agricultural field at Mistelbach, Austria to assess the magnitude of deposition rates using Fallout RadioNuclides 'FRNs' (Cs-137 and Pb-210(ex)) and the mid-term (13 years) erosion rates using conventional runoff plot measurements in a small agricultural watershed under conventional and conservation tillage/cropping practices. Long-term erosion measurements (1994-2006) from runoff plots located in the upper part of an agricultural field just up-slope from a deposition area reached 29.4 t ha(-1) yr(-1) from the conventional tilled plot, 4.2 t ha(-1) yr(-1) from the conservation tillage plot and 2.7 t ha(-1) yr(-1) from the direct seeding treatment. Soil losses were reduced significantly by a factor of 10 using no tillage, direct seeding treatment. Using Cs-137 data that integrate the 1954-2007 period, the sedimentation rates down slope of the field containing the runoff plots were estimated to be 26.1 t-1 ha(-1) yr(-1) using the Cs-137 depth distribution profile and at 20.3 t-1 ha(-1) yr(-1) using the Mass Balance Model 2 (MBM 2). ne erosion rates under conventional tillage are in agreement with the sedimentation rates estimated down slope of the field by the Cs-137 depth distribution profile and MBM 2. In the lowest part of the watershed sedimentation rates of up to 50.5 t-1 ha(-1) yr(-1) were estimated through the Cs-137 depth distribution profile. These rates were greater than the average erosion rates measured by the erosion plots because this area is more representative of sedimentation processes occurring in the study area due to its topographical position and the basin geomorphology. The Pb-210 data obtained did not fulfil the requirements for the successful application of the methodology under the experimental conditions. This study demonstrates the complementarities of both methodologies (Cs-137 and runoff plots) to assessing erosion and sedimentation processes in an agricultural landscape.
AU  - Mabit, L.*
AU  - Klik, A.*
AU  - Benmansour, M.*
AU  - Toloza, A.*
AU  - Geisler, A.
AU  - Gerstmann, U.C.
C1  - 884
C2  - 26197
SP  - 231-239
TI  - Assessment of erosion and deposition rates within an Austrian agricultural watershed by combining ¹³⁷Cs, ²¹⁰Pbex and conventional measurements.
JO  - Geoderma
VL  - 150
IS  - 3-4
PB  - Elsevier Science
PY  - 2009
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - The concept of soil quality gives rise to more controversy than that of water or air quality. However, despite the difficulty in providing a definition, the maintenance of soil quality is critical for ensuring the sustainability of the environment and the biosphere. Literature exhibit a great number of soil quality indices for both agro-ecosystems and natural or contaminated soils. The objective of this work was to make a review of some of the soil quality indices established up to date as well as of the parameters that make up them, and to offer a reflection on the lack of consensus concerning the use of these indices. We will focus in those indices including biological parameters. The most straightforward index used in the literature is the metabolic quotient (qCO2) (respiration to microbial biomass ratio), widely used to evaluate ecosystem development, disturbance or system maturity. However, qCO2 and other indices integrating only two parameters provide insufficient information about soil quality or degradation. For this, lately there has been a wide development of multiparametric indices that clearly establish differences between management systems, soil contamination or density and type of vegetation. These indices integrate different parameters, among which the most important are the biological and chemical ones, such as pH, organic matter, microbial biomass C, respiration or enzyme activities. The major part of multiparametric indices has been established on the basis of either, expert opinion (subjective), or using mathematical–statistics methods (objective). Molecular indicators have not yet been used for soil quality indices establishment. However, the development of genomic, transcriptomic or proteomic methodologies could have importance in the evaluation of soil quality, not only in a diversity sense but also in a functional way. These methods can provide information about what is the role of specific microorganisms and their enzymes in key processes related to soil functionality. Despite of the great diversity of indices, they have never been used on larger scales, nor even in similar climatological or agronomic conditions. The lack of applicability of soil quality indices resides on: i) poor standardization of some methodologies; ii) some methods are out of reach in some parts of the world; iii) spatial scale problems (soil heterogeneity); iv) poor definition of soil natural conditions (climate and vegetation); and v) poor definition of soil function to be tested for soil quality.
AU  - Bastida, F.*
AU  - Zsolnay, A.
AU  - Hernandez, T.
AU  - Garcia, C.*
C1  - 3145
C2  - 25719
SP  - 159-171
TI  - Past, present and future of soil quality indices: A biological perspective.
JO  - Geoderma
VL  - 147
IS  - 3-4
PB  - Elsevier
PY  - 2008
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Data on the dynamics of dissolved or water extractable organic matter (DOM, WEOM) in soils are often contradicting, which is especially true for arable soils. Since a complex set of soil inherent and environmental factors affects these dynamics, there is still a great need for additional data. Especially DOM results from (arable) field studies and long-term trials are scarce. We sampled the WEOM of the soils under three fertilization treatments in a Haplic Chernozem differing in fertilization intensity for over 90 years: (i) no fertilization (Control), (ii) mineral fertilization (NPK), and (iii) mineral plus additional farmyard manure fertilization (NPK + FYM). We sampled the WEOM from 0–40 cm at 10 cm intervals over a three year period during three seasons (spring, summer, and fall). We measured WEOM quantity (WEOC and WEON concentrations) and investigated the quality of WEOM with UV (absorptivity) and fluorescence (humification index, HIX) as well as biodegradability (BWEOC). The total soil organic carbon (SOC) and nitrogen (TN) were also quantified. The overall results indicated that NPK did not affect SOC and TN but did increase WEOC and WEON even though NPK does not contain organic matter, implying that fertilization affected WEOM via the biomass. The more aromatic and condensed compound of WEOM were especially increased. The NPK + FYM treatment also increased SOC and TN and had a stronger effect on WEOM than NPK alone. However, BWEOC was not significantly affected by fertilization practices. The three sampled years varied strongly in total precipitation and in crop type. Nevertheless, with the exception of WEON and HIX, no significant overall annual fluctuations could be detected. A seasonal pattern was found in WEOM concentration and quality but, except for WEON and HIX, fertilization treatments did not influence this seasonal pattern. The effects of fertilization did not vary as a function of depth for the parameters WEOC, WEON, and BWEOC, presumably because of their mobile nature. For the immobile SOC and TN depth had an effect. The values in the plough layer (0–30 cm) were significantly higher than in the region below it (30–40 cm). Absorptivity and HIX also showed such a pattern, indicating that more aromatic and condensed compounds are either preferentially retained or not as well metabolized in the plough layer.
AU  - Embacher, A.
AU  - Zsolnay, A.
AU  - Gattinger, A.
AU  - Munch, J.-C.
C1  - 1982
C2  - 25720
SP  - 63-69
TI  - The dynamics of water extractable organic matter (WEOM) in common arable topsoils: II. Influence of mineral and combined mineral and manure fertilization in a Haplic Chernozem.
JO  - Geoderma
VL  - 148
IS  - 1
PB  - Elsevier
PY  - 2008
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Compared to total soil organic matter (SOM) the concentrations of water extractable organic matter (WEOM) are very small. Nevertheless, it is linked to many important soil functions. Numerous factors affect WEOM dynamics, most of them interacting in the same or in different directions. Therefore, there are still marked gaps in knowledge about WEOM. The majority of field studies have been done in forest ecosystems, and results on arable soils are scarce, contradictory and often do not fit to laboratory studies. Our purpose was to elucidate WEOM parameters in arable soils.
AU  - Embacher, A.
AU  - Zsolnay, A.
AU  - Gattinger, A.
AU  - Munch, J.-C.
C1  - 4553
C2  - 24336
SP  - 11-22
TI  - The dynamics of water extractable organic matter (WEOM) in common arable topsoils: I. Quantity, quality and function over a three year period.
JO  - Geoderma
VL  - 139
IS  - 1-2
PB  - Elsevier
PY  - 2007
SN  - 0016-7061
ER  - 

TY  - JOUR
AU  - Sommer, A.
AU  - Wehrhan, M.
AU  - Zipprich, M.
AU  - Weller, U.
AU  - zu Castell, W.
AU  - Ehrich, S.
AU  - Tandler, B.
AU  - Selige, T.*
C1  - 22327
C2  - 21159
SP  - 179-196
TI  - Hierarchical data fusion for mapping soil units at field scale.
JO  - Geoderma
VL  - 112
PY  - 2003
SN  - 0016-7061
ER  - 

TY  - JOUR
AU  - Zsolnay, A.
C1  - 10153
C2  - 20985
SP  - 187-209
TI  - Dissolved organic matter : Artefacts, definitions and functions. 
JO  - Geoderma
VL  - 113
PY  - 2003
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Sampling and analytical methods were developed to examine the input of various pesticides on noncultivated areas of the FAM (Research Network on Agroecosystems) Research Station Scheyern. Off-target drift from pesticide application on nearby cultivated land, as well as input due to long-range atmospheric transport, were measured. The wet deposition was determined by a cooled wet-only sampler. Bulk samplers and specially designed samplers with glass-fiber surface were used for total deposition measurements. Analysis of pesticides was carried out using liquid/liquid or solid-phase extraction and high performance liquid chromatography-UV (HPLC-UV) or gas chromatography-nitrogen/phosphorus-sensitive detector/MS (GC-NPD/MS) detection. Obtained results demonstrated that for several compounds, total deposition, i.e. the sum of wet and dry deposition, was marginally higher than wet deposition alone. In contrast, total deposition data of pesticides having been applied near the sampling site exceeded wet deposition values by orders of magnitude. In addition to direct drift, determined as droplets depositing near pesticide application areas, an indirect drift represented by particle-associated or gaseous transport was observed, both of which contributed considerably to total deposition. Therefore, to determine the input of pesticides to nontarget areas in the close vicinity of pesticide application, direct and indirect drift, and background deposition must be considered.
AU  - Epple, J.
AU  - Maguhn, J.
AU  - Spitzauer, P.
AU  - Kettrup, A.
C1  - 10147
C2  - 19984
SP  - 327-349
TI  - Input of pesticides by atmospheric deposition.
JO  - Geoderma
VL  - 105 
IS  - 3-4
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - An arable landscape (150 ha) comprising a broad variety of soil types had been cultivated conventionally for many years. A small section had been intensively managed (hops), while another had been used as grassland. For 2 years at the beginning of our study, all arable land was cultivated with cereals only. After that, management was changed to integrated or organic farming, grassland or fallow land. Within a group of sites representing the variety of soil types and management systems, the development of soil microorganisms and Collembola was monitored every spring during an 8-year period. The microbial biomass compared to initial conditions under uniform management increased, particularly in land that had been set aside. General Collembola abundance slightly decreased, except for areas that had been converted to integrated farming. Protaphorura armata and Lepidocyrtus cyaneus decreased over the entire area, whereas the Isotoma viridis group was positively affected by conversion to integrated farming. Although recorded only once per year, the main results were comparable to data recorded in this area at higher temporal or spatial resolution. Nevertheless, site conditions may influence the reactions of soil organisms to land use change, and should be taken into account for evaluation. Biota resident in the upper 0–10 cm of the soil reflected current management practice, whereas those at greater soil depth reflected instead management history and soil properties. The microbial biomass and abundance of selected Collembola taxa were modeled using artificial intelligence methods (regression trees). Land management type was the most important factor determining soil biota performance. The variation of Collembola abundance depended additionally on microbial biomass. When supported by a sufficiently large data set, regression trees are powerful tools for explaining complex non-linear relationships. Finally, suggestions for the sampling design in future long-term studies at the landscape scale are given.
AU  - Filser, J.*
AU  - Mebes, K.-H.*
AU  - Winter, K.
AU  - Lang, A.*
AU  - Kampichler, C.
C1  - 10148
C2  - 20057
SP  - 201-221
TI  - Long-term dynamics and interrelationships of soil Collembola and microorganisms in an arable landscape following land use change.
JO  - Geoderma
VL  - 105 
IS  - 3-4
PB  - Elsevier
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - The large temporal variation in nitrous oxide (N2O). methane (CH4) and carbon dioxide (CO2) flux rates is a major source of error when estimating cumulative fluxes of these radiative active trace gases. We developed an automated system for near-continuous, long-term measurements of N2O, CH4 and CO2 fluxes from cropland soils and used it to study the temporal variation of N2O and CH4 fluxes from potato (Solanum tuberosum L.) fields during the crop periods of 1997 and 1998, and also to determine the effects of management practices and weather. Additionally, we evaluated the error of other common methods, namely, weekly or monthly measurements, used for estimating cumulative fluxes. ne fluxes were quantified separately for the ridges, uncompacted interrows and tractor-compacted interrows. Total N2O-N emission from the potato field during the growing period (end of May to September) was 1.6 kg ha(-1) in 1997 and 2.0 kg ha(-1) in 1998; emissions were highest for the tractor-compacted soil. Periods of increased N2O losses were induced by heavy precipitation (in particular in compacted soil) and by the killing of potato tops (on the ridges) by herbicide application. The total CH4-C uptake in the potato field during the growing period was 295 g ha(-1) in 1997 and 317 g ha(-1) in 1998. The major fraction of the total CH, uptake (approximate to 86%) occurred on the ridges. Weekly measurements of N2O fluxes complemented by additional event-related flux determinations provided accurate estimates of total emissions. The monthly flux determination was not adequate for determining the temporal variation of the N2O emission rates. Weekly measurements were sufficient to provide reliable estimates of the cumulative CH4 uptake.
AU  - Flessa, H.*
AU  - Ruser, R.
AU  - Schilling, R.
AU  - Loftfield, N.*
AU  - Munch, J.-C.
AU  - Kaiser, E.
AU  - Beese, F.*
C1  - 50725
C2  - 42523
CY  - Amsterdam
SP  - 307-325
TI  - N2O and CH4 fluxes in potato fields: Automated measurement, management effects and temporal variation.
JO  - Geoderma
VL  - 105
IS  - 3-4
PB  - Elsevier Science Bv
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Using the modeling tool Expert-N, daily fluxes of water, carbon and nitrogen in potato fields were simulated in this study. The crop growth model Soil-Plant-Atmosphere System Simulation (SPASS) was integrated in Expert-N and adapted for the simulation of potato growth. The aim of the study was to investigate the extent to which the SPASS model, tested thus far only for winter wheat, is suitable for the simulation of potato crops. In addition to re-parameterization of the model, minor modifications, such as description of phenological development, assimilate partitioning, nitrogen uptake and leaf senescence were carried out without changing the overall structure of the model. The SPASS model was calibrated using data from a potato field experiment carried out in 1996 at the Research Station Scheyern, which examined the effects of various fertilization applications on the growth and yield of two potato varieties, Christa" and "Agria", representing early and late maturity classes, respectively. Distinctions between "Christa" and "Agria" were realized by variable parameter values concerning phenological development, assimilate partitioning and nitrogen concentration in tubers. The model's ability to predict potato yields and nitrogen uptake was compared with actual values obtained in different years at other fields of the Research Station (only "Agria"). Simulation results show that the SPASS model was able to describe the effect of different N fertilizer applications on potato growth and nitrogen uptake. Differences between the two potato varieties could be adequately predicted, and tuber yields and nitrogen uptake well predicted. However, estimated modeling efficiencies suggest that further improvements are due. Crucial components of the model are the control of root nitrogen uptake and the regulation of the distribution of assimilates to different plant organs. To obtain a broader basis for the verification of the corresponding simulation modules, further experiments addressing optimal nitrogen concentrations in plant organs are necessary. Efforts to refine the SPASS model should be concentrated on a dynamical description of the partitioning pattern of assimilates, including a direct response of the partitioning pattern to changing environmental conditions.
AU  - Gayler, S.
AU  - Wang, E.*
AU  - Priesack, E.
AU  - Schaaf, T.*
AU  - Maidl, F.-X.*
C1  - 10150
C2  - 20333
SP  - 367-383
TI  - Modeling biomass growth, N-uptake and phenological development of potato crop.
JO  - Geoderma
VL  - 105
PB  - Elsevier
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Modern agricultural production systems need to reduce their environmental contamination potential. Within the test site of the FAM Research Network on Agroecosystems, the existing agricultural system was modified from intensive to sustainable land use practices. The aim of this study was to quantify the long-term effects of these new practices on the surface and subsurface water quality at the Research Station Scheyern in Bavaria, Germany. Nutrient concentrations in soil water and ground water were monitored by soil hydrological stations and in multilevel wells. Water and material fluxes were observed in a brook and in the tile drain system over a 4-year period.
      
      	Nitrate concentrations in soil water were affected by soil types, relief position and fertilization (farming system). Highest concentrations were found in soils under potatoes and integrated crop production (ICP), lowest under organic farming (OF). Since monitoring began in 1994, nitrate concentrations below the root zone decreased continuously from 25–50 to 5–30 mg NO3− l−1. Temporal variable concentrations within the root zone were stabilized by plant uptake and lateral subsurface flow in deeper soil horizons. Lower material inputs to soils were confirmed by decreasing nitrate and chloride concentrations in drain water and diffuse lateral input to the Brook West. Nitrogen loading into the brook decreased up to 50% whereas in the upper regional ground water, values greater than 50 mg NO3− l−1 still reflect former nutrient loads. Surface water phosphorous load was also strongly affected by agricultural practice. The lateral inputs area into the brook from the farm showed that phosphate loading decreased up to 25% (from 0.37 to 0.09 kg P ha−1 a−1). However, concentrations of dissolved reactive ortho-phosphate (DRP) remained high, due to remobilization from the brook's sediment. Our results have shown that adapted land use practice can reduce groundwater and surface water loads effectively. The anti-erosion program (mulching, minimum tillage, fallow strips and others) minimized lateral loads to the surface water and optimized fertilization and intercropping, whereas ecofarming mainly reduced the leakage potential of soils. The slow response in the groundwater is strongly affected by the mean transit time, whereas lateral subsurface flow and buffering effects of soils and sediments determine the dynamics within brooks and ponds.
AU  - Honisch, M.*
AU  - Hellmeier, C.
AU  - Weiss, K.
C1  - 22049
C2  - 20663
SP  - 277-298
TI  - Response of surface and subsurface water quality to land use changes.
JO  - Geoderma
VL  - 105
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - In spite of the known below-ground biomass production of plant roots that concurrently introduce significant amounts of carbon and nitrogen into the soil, the effects of these inputs on N cycling in the soil-plant system are seldom considered. Here, we report on two field experiments carried out between 1995 and 1997 at the FAM Research Station Scheyern: (1) a N-turnover experiment to determine the N fluxes derived from N-15-labeled clover residues incorporated into the plough layer of defined plots, and (2) a root production experiment to assess the above (shoot) and below ground (gross and net root) biomass production of winter wheat in different fields, but nearby the N-15 plots. An initial 50% decrease in soil organic N-15 at 0-20-cm soil depth was recorded between fall, 1996 (incorporation of clover straw) and spring, 1997 (138 days after incorporation), which was then followed by a period of stability in N-15 levels in the soil organic N until the harvest of winter wheat (286 days after incorporation). This stability may be explained in two ways: (a) actual stability of clover-derived N-15 remaining in the second phase, e.g., due to recalcitrant compounds or microbial immobilization; or (b) apparent stability, e.g., because the actual mineralization of clover-derived N-15 in the soil was compensated by secondary inputs of organic 1 5 N (recycling). Further results showed that the first explanation was unlikely, as (1) between 138 and 286 days after clover incorporation, the mean N-15 signature in soil mineral N was 2.1 at.%, indicating a persistent mineralization of clover residues; and (2) a decrease in soil microbial biomass N-15 occurred in the second phase, indicating a continued N turnover in the soil, The amount of clover-derived N-15 accumulated below the plough layer at 20-110-cm soil depth (11.5%) between early spring and the harvest of wheat also corroborated the return of mineralized N-15 into the soil being due to the root N inputs by winter wheat. Based on the depth distribution of winter wheat net root biomass (root production experiment) and on soil organic N-15 depth distribution (1 5 N-turnover experiment), the root N input into soil was estimated to be 282 kg ha(-1), equivalent to 54% of total net N assimilation of winter wheat. Thus, the results of this study give substantial evidence for a N loop between soil and growing plants, whereby a part of the net mineralized N taken up by plants is continuously returned into the soil by their roots. The implications of this N loop for the interpretation of N-15 experiments and for plant nutrition are discussed.
AU  - Jimenez, M.A.
AU  - Schmid, H.*
AU  - von Lützow, M.
AU  - Gutser, R.*
AU  - Munch, J.-C.
C1  - 24301
C2  - 32751
SP  - 223-241
TI  - Evidence for recycling of N from plants to soil during the growing season.
JO  - Geoderma
VL  - 105
IS  - 3-4
PB  - Elsevier Science
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Improving information about agroecosystems, developing future strategies for environmentally compatible land use, and achieving agricultural productivity and sustainability under one umbrella are the main goals of the FAM Research Network on Agroecosystems. Scientists of various disciplines study these topics on a 150 ha research farm. The Research Station Scheyern (Bavaria, Germany) has been leased for 15 years, and is divided into two farming programs: an organic and an integrated crop production. The researchers record, evaluate and forecast management-induced changes of this agrarian ecosystem and its environment. They seek indicators for sustainable land use and model processes at the field level, the farm level and, whenever possible, at the landscape level.
AU  - Schröder, P.
AU  - Huber, B.*
AU  - Olazabal, U.*
AU  - Kämmerer, A.*
AU  - Munch, J.-C.
C1  - 10151
C2  - 20355
SP  - 155-166
TI  - Land use and sustainability : FAM Research Network on Agroecosystems.
JO  - Geoderma
VL  - 105
PB  - Elsevier
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - SER
AB  - Improving information about agroecosystems, developing future strategies for environmentally compatible land use, and achieving agricultural productivity and sustainability under one umbrella are the main goals of the FAM Research Network on Agroecosystems. Scientists of various disciplines study these topics on a 150 ha research farm. The Research Station Scheyern (Bavaria, Germany) has been leased for 15 years, and is divided into two farming programs: an organic and an integrated crop production. The researchers record, evaluate and forecast management-induced changes of this agrarian ecosystem and its environment. They seek indicators for sustainable land use and model processes at the field level, the farm level and, whenever possible, at the landscape level.
AU  - Schröder, P.
AU  - Munch, J.-C.
AU  - Huber, B.*
C1  - 10152
C2  - 20356
SP  - 386 S.
TI  - Land use and sustainability : FAM Research Network on Agroecosystems.
JO  - Geoderma
VL  - 105
PB  - Elsevier
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AU  - Seiler, K.-P.
AU  - von Loewenstern, S.
AU  - Schneider, S.
C1  - 22048
C2  - 20662
SP  - 299-306
TI  - Matrix and bypass-flow in quaternary and tertiary sediments of agricultural areas in south Germany.
JO  - Geoderma
VL  - 105
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Neglecting the spatial variation in soil nutrient status may result in unused yield potential and in environmental damage. Site-specific management has been suggested to reduce inappropriate fertilization that can adversely affect soil, ground and surface water. Decision criteria for determining variable-rate nitrogen fertilization are, however, lacking. This paper analyses the spatial variation of nitrate nitrogen (NO3-N) and soil properties related to the N cycle at the plot-scale, Three 50 X 50 in plots were sampled in nested sampling designs of varying complexities. Classical statistics revealed a characteristic ranking in the variability of soil properties. Geostatistical analysis of the NO3-N data from two plots showed that the small-scale variation found in one small subgrid was not typical for the small-scale variation in the entire plot, indicating bias in the sampling design. A trend component was found in the NO3-N data and, consequently, the minimal requirement for the regionalized variable theory was not fulfilled. Problems due to design were overcome with a more complex nested sampling at the third plot. However, the spherical model fitted to the NO3-N data of the first year explained only 21% of the total variance, whereas a pure nugget effect was observed in the second year. The water content data also showed a low structural variance, which was different in the two years, In contrast, two thirds of the variance of total carbon (C) and total nitrogen (N) could be explained by the fitted models. Seasonal variations, such as varying duration of snow cover, and extrinsic management effects, such as growing of a cover crop, may have contributed to the observed differences in variability between the years. Due to the low proportion of structural variance and the observation that spatial distribution was not stable with time, geostatistical analysis of NO3-N and water contents data added only little information to classical statistical analysis. However, geostatistical analysis of total C and N contents provided a useful means to calculate spatial distribution patterns of these properties.
AU  - Stenger, R.
AU  - Priesack, E.
AU  - Beese, F.*
C1  - 10149
C2  - 20332
SP  - 259-275
TI  - Spatial variation of nitrate-N and related soil properties at the plot-scale.
JO  - Geoderma
VL  - 105
PB  - Elsevier
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - Changes in management practice are reflected by soil carbon and nitrogen status, in particular by the proportion of soil organic matter (SOM) being easily transformed (active SOM). We describe SOM quality for three management practices, Organic Farming system (OF), Integrated Crop Production (ICP) and pasture sites (G), which intend to achieve sustainable management practice. The experimental sites were conventionally farmed until 1992. SOM quality was examined by describing active SOM pools, such as the decomposed 'young soil organic matter' (YSOM), ratio of microbial biomass carbon (C-mic) to organic carbon (C-org), ecophysiological status of the microbial biomasss (qCO(2)), and the ratio of light particulate organic matter (POM-LF) to C-org. Ratios of soil microbial biomass (C-mic/C-org) and POM-LF (POM-LF/C-org) and the amount of decomposed YSOM were relatively similar to each other, despite differences in management practice and soil texture. Soil microbial parameters (C-mic, C-mic/C-org and qCO(2)) were significantly (p < 0.05) affected by the amount of decomposed YSOM and the silt content in the OF. In the ICP, soil microbial parameters depended only on the amount of decomposed YSOM, which was considered to be a consequence of the more heterogeneous texture at the OF-sites. Management effects were detectable for no-tillage in the ICP leading to an accumulation of active SOM in the surface soil (0-10 cm). The ratio POM-LF/C-org showed no difference between G and OF despite markedly higher C-org-contents at the G-sites. Conclusively, all methods used indicate comparable SOM qualities for the three management systems, despite differences in soil texture and soil management during 7 years. Management practices seem to be well adapted to the site conditions.
AU  - von Lützow, M.
AU  - Leifeld, J.*
AU  - Kainz, M.*
AU  - Kögel-Knabner, I.*
AU  - Munch, J.-C.
C1  - 24299
C2  - 32752
SP  - 243-258
TI  - Indications for soil organic matter quality in soils under different management.
JO  - Geoderma
VL  - 105
IS  - 3-4
PB  - Elsevier Science
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AU  - von Wiren-Lehr, S.
AU  - Scheunert, I.
AU  - Dörfler, U.
C1  - 21978
C2  - 20503
SP  - 351-366
TI  - Mineralization of plant-incorporated residues of 14C-isoproturon in arable soils originating from different farming systems.
JO  - Geoderma
VL  - 105
PY  - 2002
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - A sandstone catchment of the cool, perhumid Black Forest, Germany, was studied with respect to podzolization processes on a landscape scale. Soil mapping along a steep slope (25%) revealed Spodosols with thick E-horizons combined with thin spodic horizons in the upper catchment area. Lowermost parts of the landscape showed thinnest E- and thickest Bhs-horizons. This catenary trend was quantified by a non-linear increase of the “illuviation–eluviation ratio of podzolization” (IERpodzol). Soil texture, pedogenic oxides (Feo, Fed, Alo, Mnd), pH (CaCl2), Corg, and mineralogical composition of the clay and medium sand fraction were determined in six representative pedons. Chemical analysis matched morphology in that very low contents and mass densities of Feo, Fed, Alo, and Mnd were found in upslope soils. The distal pedons were 2–5-fold higher in these elements. The catenary trends corresponded to a downslope increase in pH as well as organic carbon in mineral soils. Mineralogical analysis showed a decrease in feldspar weathering and an increase in hydroxy-interlayered vermiculites towards the downslope soils. The morphological, chemical, and mineralogical results led to the conclusion of a process sequence of (i) an upslope mobilization and depletion of iron, manganese and aluminum (“E-Spodosols”), (ii) a lateral translocation (≈30% of catchment discharge occurred as interflow), and (iii) a downslope immobilization resulting in a (relative or absolute) accumulation of the translocated soil compounds (“Bs-Spodosols”). The immobilization probably was controlled by an admixture of Fe- and base-richer rocks into the parent material downslope. The concept of lateral podzolization developed in a granite landscape was confirmed in the sandstone area studied.
AU  - Sommer, M.
AU  - Halm, D.*
AU  - Geisinger, C.*
AU  - Andruschkewitsch, I.
AU  - Zarei, M.*
AU  - Stahr, K.*
C1  - 10154
C2  - 21848
SP  - 231-247
TI  - Lateral podzolization in a sandstone catchment.
JO  - Geoderma
VL  - 103
PY  - 2001
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - The aim of the FAM research network (Forschungsverbund Agrarökosysteme München) is to investigate the ecological effects resulting from two different agricultural cultivation systems. This long-term experiment takes place on a landscape scale of a 143 ha farm which is situated in a hilly landscape derived from tertiary sediments. In April 1991 405 soil samples were taken along a 50 m by 50 m grid. One approach taken was to use geostastistical methods. Semivariograms were calculated, punctual kriging was performed and maps of the spatial distribution of the microbial biomass, soil carbon content and the Collembola were drawn. It was shown that management practice and type of cultivation had more influence on soil biota than different soil types. The higher amounts of organic matter in the top soil of grassland areas were reflected both in higher microbial biomass and in larger individual numbers of Collembola. On the whole experimental farm a high correlation (r = 0.79) was found between carbon content (Ct) and microbial biomass, whereas a value of r of 0.36 was found between Collembola and Ct.
AU  - Fromm, H.
AU  - Winter, K.
AU  - Filser, J.G.
AU  - Hantschel, R.E.
AU  - Beese, F.O.
C1  - 40358
C2  - 38001
SP  - 109-118
TI  - The influence of soil type and cultivation system on the spatial distributions of the soil fauna and microorganisms and their interactions.
JO  - Geoderma
VL  - 60
IS  - 1-4
PY  - 1993
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - A deterministic model was developed to simulate the microbial utilization and diffusion of finite amounts of substrate from the surface of a model aggregate into the intra-aggregate pore spaces. Experiments were performed for comparison with the simulation results and to estimate the effective intra-aggregate diffusion coefficient for glucose. Glucose was applied to the surfaces of sterilized and nonsterilized aggregates and the induced 13CO2-respiration and radial glucose distribution were measured. ATP measurements show a developing radial gradient of microbial activity decreasing from the outer to the inner part of the aggregate.
AU  - Priesack, E.
AU  - Kisser-Priesack, G.M.
C1  - 19969
C2  - 13137
SP  - 561-573
TI  - Modelling Diffusion and Degradation of 13C-Glucose in Soil Aggregates.
JO  - Geoderma
VL  - 56
PY  - 1993
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - A deterministic model was developed to simulate the microbial utilization and diffusion of finite amounts of substrate from the surface of a model aggregate into the intra-aggregate pore spaces. Experiments were performed for comparison with the simulation results and to estimate the effective intra-aggregate diffusion coefficient for glucose. Glucose was applied to the surfaces of sterilized and nonsterilized aggregates and the induced 13CO2-respiration and radial glucose distribution were measured. ATP measurements show a developing radial gradient of microbial activity decreasing from the outer to the inner part of the aggregate.
AU  - Priesack, E.
AU  - Kisser-Priesack, G.M.
C1  - 40391
C2  - 40065
SP  - 561-573
TI  - Modelling diffusion and microbial uptake of 13C-glucose in soil aggregates.
JO  - Geoderma
VL  - 56
IS  - 1-4
PY  - 1993
SN  - 0016-7061
ER  - 

TY  - JOUR
AB  - The chemical composition of saturation extracts (equilibrium soil solutions) from bulk samples (sieved and mixed) were compared with that of solutions obtained by percolating water through undisturbed cores of A horizons of five profiles and of B and C horizons of one profile in northeastern Bavaria. Solutions obtained by percolation contained larger amounts of protons and acidic cations (H+, Al3+, Fe2+) and smaller amounts of base cations (Ca2+, Mg2+, K+, Na+) than the saturation extracts. Differences were large enough to be statistically significant. These differences are attributed to distinctions in surfaces exposed to the extracting solutions, in exchange processes and in fluxes of elements out of aggregates. Because it works with undisturbed soil samples the percolation method is proposed as more realistic for identification of the chemical composition of soil solutions than the saturation extracts. The information thus obtained should provide better indications of conditions affecting root growth, nutrient uptake and seepage composition in soil horizons.
AU  - Hantschel, R.E.
AU  - Kaupenjohann, M.
AU  - Horn, R.
AU  - Gradl, J.
AU  - Zech, W.
C1  - 17604
C2  - 10855
SP  - 213-227
TI  - Ecologically Important Differences between Equilibrium and Percolation Soil Extracts, Bavaria.
JO  - Geoderma
VL  - 43
IS  - 2-3
PY  - 1988
SN  - 0016-7061
ER  -