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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.

2023

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Abstract

Global warming necessitates urgent action to reduce carbon dioxide (CO2) emissions and remove CO2 from the atmosphere. Biochar, a type of carbonized biomass which can be produced from crop residues (CRs), offers a promising solution for carbon dioxide removal (CDR) when it is used to sequester photosynthetically fixed carbon that would otherwise have been returned to atmospheric CO2 through respiration or combustion. However, high-resolution spatially explicit maps of CR resources and their capacity for climate change mitigation through biochar production are currently lacking, with previous global studies relying on coarse (mostly country scale) aggregated statistics. By developing a comprehensive high spatial resolution global dataset of CR production, we show that, globally, CRs generate around 2.4 Pg C annually. If 100% of these residues were utilized, the maximum theoretical technical potential for biochar production from CRs amounts to 1.0 Pg C year−1 (3.7 Pg CO2e year−1). The permanence of biochar differs across regions, with the fraction of initial carbon that remains after 100 years ranging from 60% in warm climates to nearly 100% in cryosols. Assuming that biochar is sequestered in soils close to point of production, approximately 0.72 Pg C year−1 (2.6 Pg CO2e year−1) of the technical potential would remain sequestered after 100 years. However, when considering limitations on sustainable residue harvesting and competing livestock usage, the global biochar production potential decreases to 0.51 Pg C year−1 (1.9 Pg CO2e year−1), with 0.36 Pg C year−1 (1.3 Pg CO2e year−1) remaining sequestered after a century. Twelve countries have the technical potential to sequester over one fifth of their current emissions as biochar from CRs, with Bhutan (68%) and India (53%) having the largest ratios. The high-resolution maps of CR production and biochar sequestration potential provided here will provide valuable insights and support decision-making related to biochar production and investment in biochar production capacity.

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Abstract

The legume cavalcade, Centrosema pascuorum, is used extensively as a cover crop and as a component of conservation agriculture systems. It is also an attractive rotation or cover crop for the management of root-knot nematodes (RKN; Meloidogyne spp.) as it is a non-host. RKN are persistent pests that are well known to be difficult to control. However, the mechanisms governing the non-host status of cavalcade is unknown. The current study established that cavalcade leaves are toxic to RKN as either aqueous extracts or soil amendments. Bioassays conducted using Meloidogyne javanica showed that a 90% concentration of aqueous extract derived from 1-month-old cavalcade leaves (89 mg crude extract ml−1) suppressed nematode hatch (82.9%) and killed infective second-stage juveniles of M. javanica (85.3%). Soil amendments with 1% (w/w) of 1-month-old cavalcade leaves (0.99 mg crude extract g−1 soil) also provided effective control of M. javanica in the glasshouse on okra. One-month-old leaves appeared more effective than 2- or 3-month-old leaves. The soil amendments had no adverse phytotoxic effect on okra seed germination. Our study demonstrates the potential for using cavalcade leaves or extracts to manage RKN. This may be due to the nematicidal activity of the various compounds in the leaves, such as flavonoids, phenols and terpenoids, which should be further assessed.

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Abstract

Processing of 1000 kg of fresh Kappaphycus alvarezii yielded 25 kg salt. The optical microscopy revealed non-crystalline nature, absence of geometrical pattern; while squircle aggregates with ruffled surface were evident in SEM. Caenorhabditis elegans assay confirmed its non-toxicity; while absence of Salmonella and pesticides make it safe for human consumption. Among the macro elements, ‘K' content was highest (3792.74 ± 541.23 mg 100 g−1) and ‘Ca’ was lowest (7.01 ± 1.32 mg 100 g−1); whereas among micro element ‘Fe’ was highest (6.52 ± 1.40 mg 100 g−1) and ‘Ni’ lowest (0.14 ± 0.01 mg 100 g−1). Chromium (11.5 μg g−1) was lower than a permissible daily dose, while other heavy metals (Mo, Cu, Co, Zn, As, Cd, Hg, and Pb) were below detectable level. PXRD revealed that it has only KCl Form I. The study suggested potential economic utility of seaweed salt under the framework of waste to wealth.

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Abstract

Biowaste is becoming a significant category in the global energy mix to mitigate the negative impacts of burning fossil fuels. The aim of this review paper was to investigate the potential, conversion mechanisms, benefits, and policy gaps related to the utilization of solid biowaste resources as renewable, clean, and affordable energy sources. Thus, a systematic review approach was employed to undertake a comprehensive analysis of the studies that dealt with solid biowaste resources for energy recovery. This review paper was conducted from November 2022 to June 2023. The relevant literature was searched using databases from scholarly journal publishers, online search engines, and websites. A total of 82 studies were determined to be eligible from 659 records. Ethiopia has a huge potential for biowaste resources, with an annual generation potential of 18,446.4 MJ per year. The multifaceted advantages associated with biowaste-to-energy conversion such as clean energy production, waste management, forest conservation, greenhouse gas emission reduction, and maintaining soil fertility using the digestate left after anaerobic digestion were mentioned. This review highlights various conversion technologies for converting solid biowastes into valuable forms of energy, such as thermochemical, biochemical, and physico-mechanical techniques. It also investigated the value-added products of the Solid Biowastes-to-Energy (SBWtoE) process, including bio-oil, syngas, bioethanol, biodiesel, biomethane, bio-briquettes, and pellets, with applications ranging from transportation to power generation. Furthermore, this review addresses the multifaceted challenges associated with implementing a circular economy, emphasizing the need to overcome policy, technological, financial, and institutional barriers. These efforts are crucial for harnessing the growing biowaste resources in Ethiopia, ultimately promoting sustainable and cost-effective energy production while advancing the nation's environmental objectives.

Abstract

Sustainable forest management systems require operational measures to preserve the functional design of forest roads. Frequent road data collection and analysis are essential to support target-oriented and efficient maintenance planning and operations. This study demonstrates an automated solution for monitoring forest road surface deterioration using consumer-grade optical sensors. A YOLOv5 model with StrongSORT tracking was adapted and trained to detect and track potholes in the videos captured by vehicle-mounted cameras. For model training, datasets recorded in diverse geographical regions under different weather conditions were used. The model shows a detection and tracking performance of up to a precision and recall level of 0.79 and 0.58, respectively, with 0.70 mean average precision at an intersection over union (IoU) of at least 0.5. We applied the trained model to a forest road in southern Norway, recorded with a Global Navigation Satellite System (GNSS)−fitted dashcam. GNSS-delivered geographical coordinates at 10 Hz rate were used to geolocate the detected potholes. The geolocation performance over this exemple road stretch of 1 km exhibited a root mean square deviation of about 9.7 m compared to OpenStreetMap. Finally, an exemple road deterioration map was compiled, which can be used for scheduling road maintenance operations.

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Abstract

Forest damage caused by heavy wet snow accumulation in the canopy is the second most important abiotic forest disturbance agent in Nordic conifer stands after wind. The extent and frequency of snow damage in the future climate in the Nordic region is a major uncertainty. Few mechanistic models of snow damage risk to trees exist that could support forest management scenario analysis and decision making. We propose a snow damage risk model consisting of a numerical weather prediction-based snow accumulation model for forest canopies and a mechanistic critical snow load model. Snow damage probability predictions were validated on snow breakage data from the winters of 2016 and 2018 covering 3.5 million individual trees in south-eastern Norway derived from pre- and post-damage aerial laser scanning campaigns. The proposed model demonstrated satisfactory damage and no-damage class separation with an AUC of 0.72 and 0.77 in Norway spruce and Scots pine, respectively, and an F1 score of 0.7 in conifers taller than 10 m that suffered moderate stem breakage. The model achieved a classification accuracy that is comparable to that of statistical models but is simpler and requires fewer inputs.