Publications
NIBIOs employees contribute to several hundred scientific articles and research reports every year. You can browse or search in our collection which contains references and links to these publications as well as other research and dissemination activities. The collection is continously updated with new and historical material.
2017
Authors
Frans-Jan W. Parmentier Daniel Rasse Magnus Lund Jarle W. Bjerke Bert G. Drake Simon Weldon Hans Tømmervik Georg Heinrich Hansen Lennart Nilsen Elisabeth J. CooperAbstract
No abstract has been registered
Authors
Frans-Jan W. Parmentier Daniel Rasse Magnus Lund Jarle W. Bjerke Bert G. Drake Simon Weldon Hans Tømmervik Georg Heinrich HansenAbstract
No abstract has been registered
Authors
Frans-Jan W. Parmentier Daniel Rasse Magnus Lund Jarle W. Bjerke Bert G. Drake Simon Weldon Hans Tømmervik Georg Heinrich Hansen Lennart Nilsen Elisabeth J. CooperAbstract
No abstract has been registered
Authors
Alice Budai Lucia Calucci Daniel Rasse Line Tau Strand Annelene Pengerud Daniel Wiedemeier Samuel Abiven Claudia ForteAbstract
Infrared and 13C solid state nuclear magnetic resonance spectroscopies and benzene polycarboxylic acids (BPCA) analysis were used to characterize the structural changes occurring during slow pyrolysis of corncob and Miscanthus at different temperatures from 235 °C to 800 °C. In the case of corncob, a char sample obtained from flash carbonization was also investigated. Spectroscopic techniques gave detailed information on the transformations of the different biomass components, whereas BPCA analysis allowed the amount of aromatic structures present in the different chars and the degree of aromatic condensation to be determined. The results showed that above 500 °C both corncob and Miscanthus give polyaromatic solid residues with similar degree of aromatic condensation but with differences in the structure. On the other hand, at lower temperatures, char composition was observed to depend on the different cellulose/hemicellulose/lignin ratios in the feedstocks. Flash carbonization was found to mainly affect the degree of aromatic condensation.
Abstract
Evaluating biochars for their persistence in soil under field conditions is an important step towards their implementation for carbon sequestration. Current evaluations might be biased because the vast majority of studies are short-term laboratory incubations of biochars produced in laboratory-scale pyrolyzers. Here our objective was to investigate the stability of a biochar produced with a medium-scale pyrolyzer, first through laboratory characterization and stability tests and then through field experiment. We also aimed at relating properties of this medium-scale biochar to that of a laboratory-made biochar with the same feedstock. Biochars were made of Miscanthus biomass for isotopic C-tracing purposes and produced at temperatures between 600 and 700°C. The aromaticity and degree of condensation of aromatic rings of the medium-scale biochar was high, as was its resistance to chemical oxidation. In a 90-day laboratory incubation, cumulative mineralization was 0.1% for the medium-scale biochar vs. 45% for the Miscanthus feedstock, pointing to the absence of labile C pool in the biochar. These stability results were very close to those obtained for biochar produced at laboratory-scale, suggesting that upscaling from laboratory to medium-scale pyrolyzers had little effect on biochar stability. In the field, the medium-scale biochar applied at up to 25 t C ha-1 decomposed at an estimated 0.8% per year. In conclusion, our biochar scored high on stability indices in the laboratory and displayed a mean residence time > 100 years in the field, which is the threshold for permanent removal in C sequestration projects.
Abstract
No abstract has been registered
Abstract
Phosphorus (P) is one of the main limiting factors for crop productivity while rhizosphere organic anions have been hypothesized to play an important role in P acquisition. Sampling in a long-term field experiment was carried out in order to understand the impact of long-term differences in P fertilization on secretion of organic anions under field conditions. Rhizosphere organic anions were extracted and analyzed every week from three leaves stage to completed flowering stage of wheat (Triticum aestivum) grown on plots that have received 0 (P0) or 48 (P48) kg P ha−1 year−1 since 1966. The study showed that it is possible to extract and quantify rhizosphere organic anions from field plots. In P48 plots, root P concentrations decreased around 40 % at the early stages (before heading), compared with the first sampling, and then increased slightly, while plants grown in P0 plots showed the opposite trend. Malate was the main organic anion secreted throughout all the wheat growth stages. Rhizosphere citrate and malate showed negative and positive correlations (P < 0.05) respectively with root P concentrations at 29 and 42 days after emergence (DAE). Rhizosphere organic anion concentrations were quite low until 29 DAE and then increased up to 4–10-fold until 42 DAE; these concentrations declined at later stages, indicating that root-released organic anions may have been affected by developmental stage and root P concentration. The present study provides valuable information about the relationship between rhizosphere organic anions and various P concentrations of wheat grown in the field.
Authors
Alice BudaiAbstract
No abstract has been registered
Authors
Claudia Kammann Jim Ippolito Nikolas Hagemann Nils Borchard Maria Luz Cayuela José M. Estavillo Teresa Fuertes-Mendizabal Simon Jeffery Jürgen Kern Jeff Novak Daniel Rasse Sanna Saarnio Hans-Peter Schmidt Kurt Spokas Nicole Wrage-MönnigAbstract
Agriculture and land use change has significantly increased atmospheric emissions of the non-CO2 green-house gases (GHG) nitrous oxide (N2O) and methane (CH4). Since human nutritional and bioenergy needs continue to increase, at a shrinking global land area for production, novel land management strategies are required that reduce the GHG footprint per unit of yield. Here we review the potential of biochar to reduce N2O and CH4 emissions from agricultural practices including potential mechanisms behind observed effects. Furthermore, we investigate alternative uses of biochar in agricultural land management that may significantly reduce the GHG-emissions-per-unit-of-product footprint, such as (i) pyrolysis of manures as hygienic alternative to direct soil application, (ii) using biochar as fertilizer carrier matrix for underfoot fertilization, biochar use (iii) as composting additive or (iv) as feed additive in animal husbandry or for manure treatment. We conclude that the largest future research needs lay in conducting life-cycle GHG assessments when using biochar as an on-farm management tool for nutrient-rich biomass waste streams.
Authors
Daniel RasseAbstract
No abstract has been registered