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
Kris Van Looy Johan Bouma Michael Herbst John Koestel Budiman Minasny Umakant Mishra Carsten Montzka Attila Nemes Yakov A. Pachepsky José Padarian Marcel G. Schaap Brigitta Tóth Anne Verhoef Jan Vanderborght Martine J. van der Ploeg Lutz Weihermüller Steffen Zacharias Yonggen Zhang Harry VereeckenAbstract
Soil, through its various functions, plays a vital role in the Earth’s ecosystems and provides multiple ecosystem services to humanity. Pedotransfer functions (PTFs) are simple to complex knowledge rules that relate available soil information to soil properties and variables that are needed to parameterize soil processes. In this paper, we review the existing PTFs and document the new generation of PTFs developed in the different disciplines of Earth system science. To meet the methodological challenges for a successful application in Earth system modeling, we emphasize that PTF development has to go hand in hand with suitable extrapolation and upscaling techniques such that the PTFs correctly represent the spatial heterogeneity of soils. PTFs should encompass the variability of the estimated soil property or process, in such a way that the estimation of parameters allows for validation and can also confidently provide for extrapolation and upscaling purposes capturing the spatial variation in soils. Most actively pursued recent developments are related to parameterizations of solute transport, heat exchange, soil respiration, and organic carbon content, root density, and vegetation water uptake. Further challenges are to be addressed in parameterization of soil erosivity and land use change impacts at multiple scales. We argue that a comprehensive set of PTFs can be applied throughout a wide range of disciplines of Earth system science, with emphasis on land surface models. Novel sensing techniques provide a true breakthrough for this, yet further improvements are necessary for methods to deal with uncertainty and to validate applications at global scale.
Abstract
Red clover (Trifolium pratense L.) is normally a short-lived perennial with no vegetative propagation and the number of plants in the field declines rapidly. In organic farming, the amount of clover in the field is decisive for the N2 fixation and yield, the protein content and quality of the forage produced. In Nordland County (66.27°N), there is a farm with some red clover plants in more than 15 years old grassland. In the presented study we examined grassland botanical content and attempted to recognise age of red clover plants. Our hypotheses was 1) that extensive grassland management promotes self-seeding of red clover 2) self-seeding maintaining a desired content of red clover over time. In addition, we tested two harvesting regimes of the first cut for seed maturation and seed quality at two locations in Norway. Red clover plants in old swards showed very high age and a branched root system. Only very few seedlings were found in old sward suggesting that self-seeding was insignificant. Experiments with leaving the grassland after the first cut for seed production of clover failed due to poor seed maturation. Surface seeding of red clover in pure grass plots gave good results, especially with early spring seeding.
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.
Authors
Nesrin Colak Anja K. Primetta Kaisu R. Riihinen Laura Jaakola Jiři Grúz Miroslav Strnad Hülya Torun Faik Ahmet AyazAbstract
Bilberries and their products are popular worldwide and represent a very interesting source of dietary antioxidants. Berries of eight different-colored and non-pigmented bilberry (Vaccinium myrtillus L.) samples from Finland were evaluated in terms of antioxidant capacity and total phenolic compounds (range, 220.06 – 3715.21 mg/100 g dw) and total monomeric anthocyanin (range, 206.18 – 867.52 mg/100 g dw) contents. Delphinidin (range, 5915.93–18108.39 μg /g dw) was the major anthocyanin moiety, while sinapic acid was the major phenolic acid in the free form (range, 0.01 – 6.06 μg /g dw), and p-coumaric acid in the ester (range, 26.39 – 110.78 μg /g dw), glycoside (range, 15.83 – 57.73 μg /g dw) and ester-bound (range, 2.32 – 14.20 μg /g dw) forms. The white colored berry samples did not contain any anthocyanins, but the colored berries did contain them. Antioxidant capacity was much higher in colored (pink to blue/black) berry samples than in the white sample, and it was more related to the total phenolic concentration rather than to the anthocyanin concentration. This is the first time that these different-colored berry phenotypes of bilberry (V. myrtillus L.) have been analyzed within the same study.
Abstract
No abstract has been registered
Authors
Diego Faustolo Alves Bispo Marx Leandro Naves Silva Joao Jose Granate de Sa e Melo Marques Marianne Bechmann Pedro Velloso Gomes Batista Nilton CuriAbstract
Identifying and ranking nutrient loss risk areas are important steps towards integrated catchment management. This study aimed to apply the P index model at the Posses catchment, south of the state of Minas Gerais, Brazil. We applied the P index for the current land use at the Posses catchment and for two hypothetical scenarios: scenario 1, in which P fertilizer was applied to all land uses, except for native forests; and scenario 2, which considered the use of P fertilizer as in scenario 1, and that the Environmental Protection Areas referring to the riparian forests and springs were totally restored. Considering current land use, almost the whole catchment area (91.4%) displayed a low P loss risk. The highest P index was associated to croplands and eucalyptus plantations. Regarding scenario 1, areas under pasture fell into the low (15.1%), medium (45.5%), high (27.1%) and very high (12.3%) P index categories. Environmental Protection Areas on scenario 2 decreased the P loss risk from the scenario 1 in 37.6%. Hence, the model outputs indicate that the reforestation of buffer zones can decrease P loss risk in the case increasing use of P fertilizer. The P index model is a potential support tool to promote judicious use of fertilizers and conservation practices at the Posses catchment.
Authors
Bente Føreid Evengy A. Zarov Ilya M. Latysh Ilya V. Filippov Elena D. LapshinaAbstract
Exposure to sunshine is known to play a role in litter decomposition in some semi-arid areas. The aim of this study was to find out if it also plays a role in higher latitude environments in peat litter decomposition and could contribute to an explanation to the patchy nature of peat litter decomposition. Peat litter from 5 microenvironments (top of slope, bottom of slope, ridge, ryam and hollow) and put out and exposed to the sun or shaded over a summer in Western Siberia, 26 km west of the town of Khanty-Mansiysk. Afterwards the peat litter was incubated in the laboratory - at field capacity or submerged in peat water - and CO2 and methane emission measured. Chemical composition of exposed and control peat litter was also investigated using stepwise extraction. The results indicate that exposure to sunlight does increase subsequent decomposition rate in most peat litters when incubated at field capacity, but the difference between the treatments levelled off at the end of the 2 weeks incubation in most peat litter types. The total extra carbon loss was calculated to be up to about 2 mg C m− 2 over a season. When incubated submerged previous photo-exposure had less effect on CO2 evolution then when incubated at field capacity. No methane emission was recorded in any treatment. Some differences in chemical composition between exposed and shaded peat litters were found that could help explain the differences in subsequent decomposition rate. The results indicate that photodegradation could play a role in peat litter decomposition at higher latitudes when peat is disturbed and exposed to sunshine. However, the effect of photo-exposure in these areas is much smaller than observed in semi-arid areas at lower latitudes.
Authors
Jakob GeipelAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Jihong Liu Clarke Andre van Eerde Lisa Paruch Inger Heldal Hege Særvold Steen Yanliang Wang Astrid Sivertsen Sissel HaugslienAbstract
No abstract has been registered