Gerold, Gerhard

[["dc.bibliographiccitation.firstpage","168"],["dc.bibliographiccitation.journal","Geoderma"],["dc.bibliographiccitation.lastpage","175"],["dc.bibliographiccitation.volume","170"],["dc.contributor.author","Heitkamp, Felix"],["dc.contributor.author","Wendland, Matthias"],["dc.contributor.author","Offenberger, Konrad"],["dc.contributor.author","Gerold, Gerhard"],["dc.date.accessioned","2018-11-07T09:14:23Z"],["dc.date.available","2018-11-07T09:14:23Z"],["dc.date.issued","2012"],["dc.description.abstract","Effects of fertilisation and cropland management on soil organic carbon (SOC) dynamics can be assessed best in long-term experiments. Using data from the long-term fertilisation experiment in Puch, Germany (part of the series \"Internationale Organische Stickstoff Dauerversuche\", IOSDV), we tested the performance of the Rothamsted Carbon Model 26.3 (RothC). The objectives of this work were: (i) quantify the C-input and the efficiency of SOC stabilisation, (ii) test the performance of different input estimates on predictive power of the RothC and (iii) test implementations of residue quality and C-saturation on model predictions. The experiment is a full-factorial strip design, the factors being \"organic amendment\" and \"level of N-fertiliser\". Each treatment was replicated three times. The crop rotation is silage maize-winter wheat-winter barley. Five levels of the factor \"organic amendment\" were considered: (i) CON: no organic amendment; (ii) SLU: slurry application (on average 0.8 Mg C ha(-1) year(-1)); (iii) FYM: application of farmyard manure (30 to 40 Mg ha(-1) fresh mass every third year to maize, on average 1.0 Mg C ha(-1) year(-1)). (iv) STR: straw incorporation after harvest of wheat and barley (depending on straw yield on average 0.7 to 2.2 Mg C ha(-1) year(-1)): (v) STSL: slurry application plus straw incorporation (on average 1.1 to 2.4 Mg C ha(-1) year(-1)). All treatments (including CON) were combined with five different levels of N-fertilisation (N0 to N4), whereas N0 was nil N application and N4 averaged 177 kg N ha(-1) year(-1). N-rates increased gradually and differed depending on the crop. Starting values for SOC stocks (Mg hat) were measured in 1983 as a mean among N-rates for organic amendment treatments (CON: 42; SLU: 39.8; FYM: 40.5; STR 39.8; STSL: 40.5). SOC stocks (0-25 cm) in 2004 (35.5 to 46.6 Mg C ha(-1)) were in the order STSL> FYM = SLU > STR = CON (p <= 0.001). However, slightly different starting values indicated a higher loss of SOC after 21 years in the CON (11-14%) compared to the SIR treatments (1-10%). Effect of N-rate was not significant. The observed relation between change of SOC and C-input was quadratic (Y-O = -13.4 + 7.5x - 0.9x(2); R-2 = 0.74, p <= 0.001), which contrasted the linear relationship predicted by RothC (Y-P = -12.9 + 5.5x; R-2 = 0.97, p <= 0.0001). Serious deviation between observed and predicted relationship occurred above C-inputs of 2.5 Mg C ha(-1) year(-1). Mechanistic explanation (e.g. C-saturation or increased mineralisation by N-fertilisation) for the observation needs further exploration, but implication on regional estimates for C-accumulation for different cropland management scenarios is obvious: potential gain in SOC storage by increasing C-inputs may be overestimated, at least under conditions of the Puch site. Independent model predictions (i.e. no parameter adjustment and independent estimation and measurement of C-input) were successful for treatments without straw incorporation (CON, SLU, FYM). Using a regression between crop yields and crop residue input yielded better results than using a constant belowground-to-aboveground biomass ratio. SOC stocks of treatments STR and STSL were seriously overestimated by the model. Using a higher decomposability of crop residue improved result only marginally and required the change of a standard parameter. Using a simple implementation of C-saturtion improved predictions for STR and STSL but failed to simulate dynamics in all other treatments. Overall, our results showed that it is important to recognise that relation between SOC change and C-input is not necessarily linear. However, the RothC model predicted SOC dynamics well at lower input levels. Observation that a regression equation for input estimation is superior to a constant biomass ratio for modelling purposes has to be tested further. An implementation of residue quality or saturation capacity in the RothC model may be promising for a better mechanistic understanding of SOC dynamics. However, this requires careful calibration and will increase the number of parameters to be fitted. (C) 2011 Elsevier B.V. All rights reserved."],["dc.description.sponsorship","Bayrische Landesanstalt fur Landwirtschaft, state of Bavaria, Germany"],["dc.identifier.doi","10.1016/j.geoderma.2011.11.005"],["dc.identifier.isi","000300743100020"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/27394"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.publisher","Elsevier Science Bv"],["dc.relation.issn","0016-7061"],["dc.title","Implications of input estimation, residue quality and carbon saturation on the predictive power of the Rothamsted Carbon Model"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","194008291877108"],["dc.bibliographiccitation.journal","Tropical Conservation Science"],["dc.bibliographiccitation.volume","11"],["dc.contributor.author","Gómez-Díaz, Jorge Antonio"],["dc.contributor.author","Brast, Kristina"],["dc.contributor.author","Degener, Jan"],["dc.contributor.author","Krömer, Thorsten"],["dc.contributor.author","Ellis, Edward"],["dc.contributor.author","Heitkamp, Felix"],["dc.contributor.author","Gerold, Gerhard"],["dc.date.accessioned","2020-12-10T18:38:38Z"],["dc.date.available","2020-12-10T18:38:38Z"],["dc.date.issued","2018"],["dc.identifier.doi","10.1177/1940082918771089"],["dc.identifier.eissn","1940-0829"],["dc.identifier.issn","1940-0829"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/77394"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.title","Long-Term Changes in Forest Cover in Central Veracruz, Mexico (1993–2014)"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","408"],["dc.bibliographiccitation.issue","4"],["dc.bibliographiccitation.journal","Land Degradation and Development"],["dc.bibliographiccitation.lastpage","420"],["dc.bibliographiccitation.volume","19"],["dc.contributor.author","Heitkamp, Felix"],["dc.contributor.author","Glatzel, Stephan"],["dc.contributor.author","Michalzik, Beate"],["dc.contributor.author","Fischer, Elisabeth"],["dc.contributor.author","Gerold, Gerhard"],["dc.date.accessioned","2018-11-07T11:13:40Z"],["dc.date.available","2018-11-07T11:13:40Z"],["dc.date.issued","2008"],["dc.description.abstract","Decline of heathlands in Central Europe raises the question of successful restoration of degraded heathlands. We examined the impact of different restoration techniques oil soil microbial biomass carbon (C(mic)) and nitrogen (N(mic)) and enzyme activity on an abandoned military training site in the Luneburger Heaths. The aim was to determine which technique resulted in typical heathland soil conditions. The training site was ill use for about 50 years. Vegetation and soils were degraded in large areas. Restoration actions were: (1) spreading of heath plaggen (sods, containing the organic layer and a few centimetres mineral soil), (2) spreading of heath plaggen and grass seeds (Festuca filiformis Pourr.). (3) spreading of F. filiformis-seeds and (4) succession (episodical tree removal). Ten years after restoration. we measured pH, bulk density, abundance of roots, soil organic carbon (SOC), nitrogen (N(1)), phosphorus (P(1)) C(mic), N(mic) and acid phosphatase activity (AcP) in the first 10cm of the mineral soil. Four restoration treatments were compared with one reference site. The reference site is heathland located near the training site, where no military actions took place. At all disturbed sites, bulk density and pH proved to be higher than oil the reference site. Relative to the reference site, SOC storage reached from 37 to 91 per cent, regeneration of N(1) was slightly lower. In contrast to the advanced development of SOC and Nt, the regeneration of C(mic) and N(mic) was much lower (15-44 per cent). The succession site showed a low pool of SOC, Nt, C(mic) and N(mic), but microbial ratios indicated a less disturbed C- and N-cycle. AcP pronounced differences in nutrient demand between disturbed sites and reference. On this base, recommendations for restoration management were given. Copyright (C) 2008 John Wiley & Soils, Ltd."],["dc.identifier.doi","10.1002/ldr.848"],["dc.identifier.isi","000258557600005"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/53951"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1085-3278"],["dc.title","Soil microbiochemical properties as indicators for success of heathland restoration after military disturbance"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.status","published"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","1133"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Journal of Soils and Sediments"],["dc.bibliographiccitation.lastpage","1140"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Truong Xuan Vuong, Truong Xuan Vuong"],["dc.contributor.author","Heitkamp, Felix"],["dc.contributor.author","Jungkunst, Hermann F."],["dc.contributor.author","Reimer, Andreas"],["dc.contributor.author","Gerold, Gerhard"],["dc.date.accessioned","2018-11-07T09:21:58Z"],["dc.date.available","2018-11-07T09:21:58Z"],["dc.date.issued","2013"],["dc.description.abstract","The best method for determining soil organic carbon (SOC) in carbonate-containing samples is still open to debate. The objective of this work was to evaluate a thermal gradient method (ThG), which can determine simultaneously inorganic carbon (SIC) and SOC in a wide range of soil samples. The determination of SOC by ThG (SOCThG) was compared to the following widespread standard methods: (1) acidification (ACI) as pretreatment and subsequent dry combustion (SOCACI) and (2) volumetric quantification of SIC by a calcimeter (CALC) and subtraction of the total carbon content as determined by dry combustion (SOCCALC). Precision (F test) and bias (t test) were tested on a subset of seven samples (n = 3). Comparison of the ThG and CALC methods was performed by regression analysis (n = 76) on samples representing a wide range of SOC (5.5 to 212.0 g kg(-1)) and SIC (0 to 59.2 g kg(-1)) contents. Tests on the replicated subset showed that the precision of ThG was not significantly different from ACI or CALC (F values < 39, n = 3) for SOC and SIC measurements. However, SOCACI and SOCCALC contents were systematically and significantly lower compared to SOCThG contents. The positive bias for SOCThG relative to SOCCALC contents appeared also in the regression analysis (given numbers +/- standard errors) of the whole data set (y = (4.67 +/- 0.70) + (0.99 +/- 0.01)x, R (2) = 0.99, n = 76). When performing a regression with carbonate-free samples, the bias between the methods was negative (-2.90 +/- 0.63, n = 29) but was positive in the set with carbonate-containing samples (3.95 +/- 1.41, n = 47). This observation corroborated the suspicion that the use of acid for carbonate decomposition can lead to an underestimation of SOC. All methods were suitable for differentiation between SIC and SOC, but the use of acid resulted in lower estimates of SOC contents. When comparing soil samples with different carbonate concentrations, the use of the ThG method is more reliable."],["dc.identifier.doi","10.1007/s11368-013-0715-1"],["dc.identifier.isi","000322372200002"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/29229"],["dc.notes.status","zu prüfen"],["dc.notes.submitter","Najko"],["dc.relation.issn","1439-0108"],["dc.title","Simultaneous measurement of soil organic and inorganic carbon: evaluation of a thermal gradient analysis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dspace.entity.type","Publication"]]