Rainer Georg Joergensen

Universität Kassel, Cassel, Hesse, Germany

Are you Rainer Georg Joergensen?

Claim your profile

Publications (198)533.98 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Middle infrared (MIR) spectroscopy (MIRS) has been used to characterize soil chemical and biological properties and to date, the accuracy for estimation of these properties has been variable. Objectives were (i) to study the usefulness of MIRS for the estimation of a series of chemical and biological properties for three different sets of soil samples using OPUS Quant 2 software, WinISI software (developed for vis-near infrared spectra) and ParLeS software and (ii) to analyse possible predictive mechanisms for the biological properties statistically. A data set of chemical and biological properties of 422 samples from three arable soils in Germany of different long-term experiments was used, and the reflectance spectra in the MIR region were recorded after shock-freezing followed by freeze-drying. Cross-validation was carried out for the entire soil sample set and for each soil sample set from the three sites. Accuracies of estimation for the chemical and biological properties depended markedly on the sample set. All three software packages tested reached similar accuracies (despite differences in the mathematical treatments), whereby WinISI and OPUS slightly outperformed ParLeS. Additionally, the treatment of outliers affected the results markedly and the coefficients of determination increased with an increasing removal of outliers. Multiple linear regressions indicated that, at least for microbial biomass C (Cmic) and N (Nmic), an estimation using pH and the contents of C, N, P, S, sand and clay was as accurate (entire set, Cmic: r2 = 0.77, Nmic: r2 = 0.72) as an estimation using MIR data (entire set, Cmic: r2 = 0.78, Nmic: r2 = 0.73). The general idea behind infrared spectroscopy is that only a part of a sample set needs to be investigated by laboratory methods and that after appropriate calibration then the determination of spectra may be sufficient for the remaining part of the sample set. This benefit of MIRS does obviously not apply for predicting soil biological properties in sample sets when multiple linear regressions using the contents of chemical and physical soil properties give estimates of similar accuracies (in the calibration and cross-validation, respectively). However, MIRS provides an effective tool to estimate spectrally active chemical and physical properties.
    Soil Biology and Biochemistry 07/2015; 86. DOI:10.1016/j.soilbio.2015.03.015 · 4.41 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Given high mineralization rates of soil organic matter addition of organic fertilizers such as compost and manure is a particularly important component of soil fertility management under irrigated subtropical conditions as in Oman. However, such applications are often accompanied by high leaching and volatilization losses of N. Two experiments were therefore conducted to quantify the effects of additions of activated charcoal and tannin either to compost in the field or directly to the soil. In the compost experiment, activated charcoal and tannins were added to compost made from goat manure and plant material at a rate of either 0.5 t activated charcoal ha−1, 0.8 t tannin extract ha−1, or 0.6 t activated charcoal and tannin ha−1 in a mixed application. Subsequently, emissions of CO2, N2O, and NH3 volatilization were determined for 69 d of composting. The results were verified in a 20-d soil incubation experiment in which C and N emissions from a soil amended with goat manure (equivalent to 135 kg N ha−1) and additional amendments of either 3 t activated charcoal ha−1, or 2 t tannin extract ha−1, or the sum of both additives were determined. While activated charcoal failed to affect the measured parameters, both experiments showed that peaks of gaseous CO2 and N emission were reduced and/or occurred at different times when tannin was applied to compost and soil. Application of tannins to compost reduced cumulative gaseous C emissions by 40% and of N by 36% compared with the non-amended compost. Tannins applied directly to the soil reduced emission of N2O by 17% and volatilization of NH3 by 51% compared to the control. However, emissions of all gases increased in compost amended with activated charcoal, and the organic C concentration of the activated charcoal amended soil increased significantly compared to the control. Based on these results, tannins appear to be a promising amendment to reduce gaseous emissions from composts, particularly under subtropical conditions.
    Journal of Plant Nutrition and Soil Science 02/2015; DOI:10.1002/jpln.201400233 · 1.66 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The aim was to quantify medium term litter type and litter mixture effects on the translocation and transformation dynamics of root and leaf litter C during decomposition. Partitioning of 13C-labeled root or leaf litter C (beech - Fagus sylvatica L., ash - Fraxinus excelsior L.) to CO2, water-extractable organic C (WEOC), microbial biomass C (CMB) and light (LF) and heavy soil fraction (HF) was determined in a laboratory decomposition experiment of 206 days. The proportions of C mineralized from ash leaf (34%) and root litter (29%) were higher than those from beech leaf (24%) and root litter (23%). In mixture with beech, the mineralization of ash leaf litter was enhanced. Mineralization was positively correlated with litter-derived WEOC until day 29. Water-extractable organic C declined with time, until <0.1% of litter C remained in this fraction. Litter-C recovery in CMB was higher for ash (0.7-1.0%) than for beech (0.2-0.4%). The litter C recovery in HF (4-12%) was positively correlated with that in WEOC (days 9 and 29) and CMB, but did not differ between treatments. Ash leaf litter mineralization showed different behavior in mixed treatments from pure treatments. Thus, the ability to transfer results from pure to mixed treatments is limited. The litter differed in chemical composition and in mineralization dynamics, but differences in partitioning to HF, WEOC and MB were finally of minor importance.
    Soil Biology and Biochemistry 02/2015; 83. DOI:10.1016/j.soilbio.2015.01.015 · 4.41 Impact Factor
  • Source
    Biosystems Engineering 11/2014; DOI:10.1016/j.biosystemseng.2014.11.007 · 1.37 Impact Factor
  • Sibylle Faust, Susan Hanisch, Andreas Buerkert, Rainer Georg Joergensen
    [Show abstract] [Hide abstract]
    ABSTRACT: The current study investigated how the presence of tamarinds and manure affect (1) soil chemical properties; (2) C and N mineralization; (3) microbial biomass indices (C, N, and fungal ergosterol); (4) microbial residues, that is, amino sugars; and (5) the germination of sorghum seeds in soils of the littoral zone in southwestern Madagascar. Soil pH was lower under than outside the tamarind canopy, whereas SOC, total N content, and the cation exchange capacity were roughly three times higher than in the uncovered situation. Under the tamarind canopy, basal respiration was increased nearly threefold, whereas net N mineralization remained unaffected. However, net N mineralization was increased by 74% in the manure treatment, especially under the tamarind canopy. Tamarind did not inhibit the germination of sorghum seeds. Contents of microbial biomass C and N, and especially fungal ergosterol, were also higher under the tamarind canopy. Muramic acid, galactosamine, and glucosamine were increased threefold under the tamarind canopy. The mean fungal C to bacterial C ratio was 0.67 and remained unaffected by any treatment. The presence of manure increased the contribution of microbial residue C to SOC from 28% to 41% and of microbial biomass N to total N from 3.5% to 5.6%, especially under the tamarind canopy.
    Arid Land Research and Management 11/2014; 29(2). DOI:10.1080/15324982.2014.944243 · 0.56 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Climate scenarios predict increasing temperatures and higher precipitation rates in late autumn to early spring, both of which holding the potential to change the dynamics of plant residue decomposition and overall microbial activity in soil. In company with consequences for nutrient release patterns influences on the survival of fungal plant pathogens and their phytopathogenicity can be expected. Both, litter decomposition and pathogen survival, was analyzed in a 70-day litterbag incubation experiment. Continuous +4 °C was compared to permanent frost (−3 °C) and different freeze-thaw cycles for the decomposition of maize residues and disease potential of soil-borne plant pathogens Fusarium culmorum, Fusarium graminearum, and Rhizoctonia solani. Frost generally reduced maize residue decomposition. On the lower levels of CO2 production in the permanent or occasionally frost treatments pathogen inoculation had large effects on microbial maize use, indicating high saprotrophic activity of pathogens even in cold winter scenarios. Pathogen inoculation led to higher amino sugar contents of maize residue dwelling microbial organisms. At constant 4 °C remarkable high amounts of glucosamine were detected, indicating higher substrate use efficiency without frost. Both, temperature treatments as well as intra- and interspecific competition directed the development of pathogens after inoculation. F. culmorum took large advantage from the non-frost scenario, while no significant increase was found under continuous frost. F. graminearum was also able to increase its abundance at +4 °C. But this was strongly reduced when F. graminearum was in competition to the other two pathogens. In summary, F. culmorum was found to be highly frost tolerant and competitive against F. graminearum, particularly under conditions of freeze-thaw cycles since F. culmorum was able to take a large share of saprotrophic litter residue use under the cold conditions. Biomass of R. solani was strongly decomposed in all treatments. We conclude that constant mild conditions during winter can increase biomass of F. culmorum and F. graminearum in crop residues, causing increased infection pressure in the next season. In contrast to that, frost and freeze-thaw events can lower the build-up of Fusarium biomass and thus diminish the risk of crop infection.
    Soil Biology and Biochemistry 10/2014; 77:141–149. DOI:10.1016/j.soilbio.2014.06.023 · 4.41 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Background and aims Species rich, semi-natural grassland systems provide several ecosystem functions. The goal was to assess how aboveground composition and evenness affects soil substrate utilization pattern and soil microbial functional evenness. Methods At five German NATURA 2000 grassland sites, the interactions of plant functional groups (graminoids, forbs and legumes) and belowground microbial functional evenness were investigated in relation to soil properties and sampling date. Functional evenness of soil microorganisms was measured with high spatial resolution by community level physiological profiling (CLPP) using multi-SIR (substrate-induced respiration) at three sampling dates during the vegetation period. Evenness indices were used to compare plant functional group diversity and soil microbial functional diversity. Results All sites differed in the consistently high soil microbial functional evenness, which was strongly predicted by soil pH, but not by plant functional groups or aboveground plant dry matter production. However, soil microbial functional evenness was particularly decreased by an increasing legume proportion and showed seasonal changes, probably driven by shifts in resource availability and soil water content. Conclusions Our results suggest that changes in soil chemical properties or in a single key plant functional group may have stronger effects on soil microbial functional evenness than changes in plant functional group evenness.
    Plant and Soil 10/2014; DOI:10.1007/s11104-014-2167-9 · 3.24 Impact Factor
  • Source
    Jannike Wichern, Florian Wichern, Rainer Georg Joergensen
  • André Sradnick, Meike Oltmanns, Joachim Raupp, Rainer Georg Joergensen
    [Show abstract] [Hide abstract]
    ABSTRACT: Long-term organic fertilization may control the accumulation of organic matter in subsoil. The objective of this study was to evaluate the effects of long-term farmyard manure application in comparison with mineral fertilization on the accumulation of amino sugars as indices for microbial residues down to 1 m depth at a sandy site that exhibits highly heterogeneous pH conditions. In relation to maximum values in topsoil at 90–100 cm depth, the SOC content decreased to roughly 24% and the total N content to 16% of the maximum values, leading to an increased soil C/N ratio from 11 to values around 16 in all treatments. The relative contribution of microbial residue C to SOC decreased with depth from 68% at 0–25 cm to 24% at 50–100 cm. In the subsoil, the stocks of microbial residue C were increased by manure in comparison with mineral fertilization, but not the stocks of SOC. This suggests that manure-induced priming effects increase the microbial turnover at 50–100 cm depth. Manure fertilization promoted the formation of bacterial residues in the topsoil at 0–25 cm depth, but not in the subsoil. Below the topsoil, the fungal C to bacterial C ratio decreased from 2.6 at 0–25 cm depth to 2.1 at 50–100 cm depth. Below the topsoil, the ratio of fungal to bacterial residues continuously decreased with depth from 2.7 to 1.7 at 90–100 cm depth, without fertilizer effects. Possible reasons for this decrease, such as effects of pH on the subsoil microbial community, a higher sensitivity of fungi to the absence of fresh organic matter or to an unfavourable composition of the subsoil atmosphere, need further investigations.
    Geoderma 08/2014; s 226–227:79–84. DOI:10.1016/j.geoderma.2014.03.005 · 2.51 Impact Factor
  • 18th Nitrogen Workshop, Lisbon, Portugal; 07/2014
  • 18th Nitrogen Workshop, Lisbon, Portugal; 07/2014
  • Source
  • Source
  • Source
  • Source
  • Source
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: C mineralization and aggregate stability directly depend upon organic matter and clay content, and both processes are influenced by the activity of microorganisms and soil fauna. However, quantitative data are scarce. To achieve a gradient in C and clay content, a topsoil was mixed with a subsoil. Single soils and the soil mixture were amended with 1.0 mg maize litter C g soil−1 with and without endogeic earthworms (Aporrectodea caliginosa). The differently treated soils were incubated for 49 days at 15 °C and 40% water holding capacity. Cumulative C mineralization, microbial biomass, ergosterol content and aggregate fractions were investigated and litter derived C in bulk soil and aggregates were determined using isotope analyses. Results from the soil mixture were compared with the calculated mean values of the two single soils. Mixing of soil horizons differing in carbon and clay content stimulated C mineralization of added maize residues as well as of soil organic matter. Mixing also increased contents of macro-aggregate C and decreased contents of micro-aggregate C. Although A. caliginosa had a stimulating effect on C mineralization in all soils, decomposition of added litter by A. caliginosa was higher in the subsoil, whereas A. caliginosa decreased litter decomposition in the soil mixture and the topsoil. Litter derived C in macro-aggregates was higher with A. caliginosa than with litter only. In the C poor subsoil amended with litter, A. caliginosa stimulated the microbial community as indicated by the increase in microbial biomass. Furthermore, the decrease of ergosterol in the earthworm treated soils showed the influence of A. caliginosa on the microbial community, by reducing saprotrophic fungi. Overall, our data suggest both a decrease of saprotrophic fungi by selective grazing, burrowing and casting activity as well as a stimulation of the microbial community by A. caliginosa.
    Pedobiologia 05/2014; 57(3). DOI:10.1016/j.pedobi.2014.03.001 · 1.67 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: In many arid and semi-arid regions, irrigated vegetable production leads to major carbon (C) and nitrogen (N) losses owing to high turnover rates. The goal of this experiment was therefore to test two amendments, activated charcoal and quebracho tannins, in their ability to stabilize soil organic carbon (SOC) from goat manure application in order to enhance nutrient and water retention. To this end, a 2-year field experiment was conducted on a sandy alluvial soil in Northern Oman investigating the effects of the two amendments either by mixing them with goat manure in the soil (MCmix and MTmix) or by applying manure from goats fed 2.5 % charcoal (MCfed) or 3.6 % tannin (MTfed) of their daily diet. Mineral fertilizer (NPK) and pure goat manure (M) served as controls. Application rates amounted to 335 kg N ha−1 year−1 and 6.4-8.2 t C ha−1 year−1 (depending on C and N concentrations) and 2.0 and 1.4 t activated charcoal ha−1 year−1 and 2.8 and 1.7 t quebracho tannin ha−1 year−1 (in 2010 and 2011, respectively). Goat manure applications, in general, increased SOC, total N, and basal respiration compared with mineral fertilizer. Mineral fertilizer reduced SOC by −25.5 % and total N by −20 %, whereas organic treatments increased SOC by up to 21 % and total N by 19 to 48 %. Basal respiration ranged between 4.1 and 8.5 μg CO2-C day−1 g−1 and was only affected by mineral fertilizer with an average reduction of 25 and 40 % in 2010 and 2011, respectively, compared with organic treatments. The metabolic quotient was not significantly altered by any of the treatments. Charcoal amendments increased SOC by 10.6 % when charcoal was fed to goats and by 21.3 % when charcoal was mixed with manure and reduced net C losses, whereas pure goat manure did not change it significantly. Tannins mixed with manure did not affect soil parameters, whereas tannins fed to goats showed opposite effects to the other goat manure treatments on pH and SOC.
    Biology and Fertility of Soils 04/2014; 51(3):1-11. DOI:10.1007/s00374-014-0982-z · 3.40 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The relationship between microbial biomass, residues and their contribution to microbial turnover is important to understand ecosystem C storage. The effects of permanent grassland (100 % ryegrass-PG), conversion to modified grassland (mixture of grass and clover-MG) or maize monoculture (MM) on the dynamics of soil organic C (SOC), microbial biomass, fungal ergosterol and microbial residues (bacterial muramic acid and fungal glucosamine) were investigated. Cattle slurry was applied to quantify the effects of fertilisation on microbial residues and functional diversity of microbial community across land use types. Slurry application significantly increased the stocks of microbial biomass C and S and especially led to a shift in microbial residues towards bacterial tissue. The MM treatment decreased the stocks of SOC, microbial biomass C, N and S and microbial residues compared with the PG and MG treatments at 0-40 cm depth. The MM treatment led to a greater accumulation of saprotrophic fungi, as indicated by the higher ergosterol-to-microbial biomass C ratio and lower microbial biomass C/S ratio compared with the grassland treatments. The absence of a white clover population in the PG treatment caused a greater accumulation of fungal residues (presumably arbuscular mycorrhizal fungi (AMF), which do not contain ergosterol but glucosamine), as indicated by the significantly higher fungal C-to-bacterial C ratio and lower ergosterol-to-microbial biomass C ratio compared with the MG treatment. In addition to these microbial biomass and residual indices, the community level physiological profiles (CLPP) demonstrated distinct differences between the PG and MG treatments, suggesting the potential of these measurements to act as an integrative indicator of soil functioning.
    Microbial Ecology 02/2014; 67(4). DOI:10.1007/s00248-014-0383-8 · 3.12 Impact Factor
  • Khair T. S. Al-Busaidi, Andreas Buerkert, Rainer Georg Joergensen
    [Show abstract] [Hide abstract]
    ABSTRACT: A 56-d incubation experiment at 30 °C was carried out to study how salinity affects C and N mineralization of composted dairy manure and date palm straw. A low- and a high-saline soil were amended with (1) manure, (2) manure + low straw, (3) manure + straw, and (4) sole straw. The microbial and fungal biomass contents are very low in Omani soil abandoned for at least 6 years. Straw application revealed a highly significant increase in microbial biomass C, but especially in ergosterol in the low-saline soil. In contrast, straw led only to an increase in ergosterol in the high-saline soil, where only the combined application of manure with straw had significant positive effects on microbial biomass C. In the high-saline soil, the sum of C mineralized reached only 55% of SOC-derived CO2–C, 65% of manure-derived CO2–C, and 75% of straw-derived CO2–C in comparison with the respective treatments of the low-saline soil. The application of straw led always to a net N immobilization, which was markedly stronger in the high- than in the low-saline soil. The increase in salinity by composted cattle manure should be considered if this fertilizer is applied to soils sensitive to changes in salinity.
    Journal of Arid Environments 01/2014; s 100–101:106–110. DOI:10.1016/j.jaridenv.2013.10.013 · 1.82 Impact Factor