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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

Understanding the chemical composition of our planet's crust was one of the biggest questions of the 20th century. More than 100 years later, we are still far from understanding the global patterns in the bioavailability and spatial coupling of elements in topsoils worldwide, despite their importance for the productivity and functioning of terrestrial ecosystems. Here, we measured the bioavailability and coupling of thirteen macro- and micronutrients and phytotoxic elements in topsoils (3–8 cm) from a range of terrestrial ecosystems across all continents (∼10,000 observations) and in response to global change manipulations (∼5,000 observations). For this, we incubated between 1 and 4 pairs of anionic and cationic exchange membranes per site for a mean period of 53 days. The most bioavailable elements (Ca, Mg, and K) were also amongst the most abundant in the crust. Patterns of bioavailability were biome-dependent and controlled by soil properties such as pH, organic matter content and texture, plant cover, and climate. However, global change simulations resulted in important alterations in the bioavailability of elements. Elements were highly coupled, and coupling was predictable by the atomic properties of elements, particularly mass, mass to charge ratio, and second ionization energy. Deviations from the predictable coupling-atomic mass relationship were attributed to global change and agriculture. Our work illustrates the tight links between the bioavailability and coupling of topsoil elements and environmental context, human activities, and atomic properties of elements, thus deeply enhancing our integrated understanding of the biogeochemical connections that underlie the productivity and functioning of terrestrial ecosystems in a changing world.

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This report summarizes the status of biochar in forestry in the Nordic-Baltic countries today. Biochar is charred material formed by pyrolysis of organic materials. In addition to improving soil physical and chemical properties and plant growth, biochar is a promising negative emission technology for storing carbon (C) in soils. The report gives an overview of current and potential uses, production methods and facilities, legislation, current and future research as well as biochar properties and effects. Forests are both a source of feedstock for biochar production and a potential beneficiary for biochar use. Production is still limited in the Nordic-Baltic countries, but commercial production is on the rise and several enterprises are in the planning or start-up phase. In this report different biochar production technologies are described. As the (modern) use of biochar for agricultural and especially forestry purposes is relatively new, in many countries there are no specific legislation regulating its use. Sometimes the use of biochar is regulated through more general laws and regulations on e.g. fertilizers or soil amendment. However, both inside and outside EU several documents and standards exist, listing recommended physical and chemical limit values for biochar. So far, most biochar studies have been conducted on agricultural soils, though research in the forestry sector is starting to emerge. The first biochar field experiments in boreal forests support that wood biochar promotes tree growth. Also, studies on the use of biochar as an additive to the growing medium in tree nurseries show promising results. Because biochar C content is high, it is recalcitrant to decomposition, and application rates to soil can be high, biochar is a promising tool to enhance the C sequestration in boreal forests. However, available biomass and production costs may be barriers for the climate change mitigation potential of biochar. When it comes to effects on biodiversity, few field-based studies have been carried out. Some studies from the Nordic region show that biochar addition may affect microbial soil communities and vegetation, at least on a short time scale. There is clearly a need for more research on the effects of biochar in forestry in the Nordic-Baltic region. Long-term effects of biochar on e.g., forest growth, biodiversity, soil carbon and climate change mitigation potential should be studied in existing and new field experiments.

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Abstract

Biochar, derived from organic waste via pyrolysis, is proposed as a soil amendment in the early twenty-first century. In this chapter, we summarize the great potential of pure biochar application in food production, soil fertility improvement, plant disease suppression, climate change mitigation, and heavy metal contamination control, based on field experiments globally. However, large-scale pure biochar implementation is restricted by high cost in terms of high price and application rate. The difficulty of biochar application using machines further reduces the farmers’ willingness to use biochar. Based on the experience of biochar usage in China, we propose a framework for large-scale implementation of industrialized biochar. Biochar can be developed into three products including liquid fertilizer, biochar-based organic fertilizer, and inorganic fertilizer. The soluble components in biochar after water extraction or in the wood vinegar during biochar production can be used to develop liquid fertilizer and used in fruit and vegetable growing. For fertile soils, biochar-based inorganic fertilizer is recommended for use instead of pure biochar. For degraded soils, biochar-based organic fertilizer is recommended to improve soil structure and provide nutrients for crops. Pure biochar is recommended to apply to heavy metal contaminated soil to decrease their uptake by crops.

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Abstract

The mainstream public health community often treats the natural environment with ambivalence. On one side, there are infectious agents, extreme weather, and catastrophic events such as floods, landslides, wildfires, storms, and earthquakes that directly or indirectly sicken, injure, or kill people (Hartig et al. 2014). On the other hand, human health is positively connected with the characteristics and quality of nature near to where people live. This ambivalence becomes crucial in cities where the living environment has peculiar characteristics both for humans and other living organisms. Indeed, there are many ways in which the urban environment can affect human health, positively or negatively. BioCities develop as dynamic socio-ecological systems hosted by nature. Therefore, addressing the issue of health according to an integrated and holistic approach, which reduces the negative effects of the natural environment and optimises its positive aspects, is a primary pillar in the construction of BioCities.

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Abstract

Coffee is an important commodity for Kenya, where production is steadily declining, despite a global rise in demand. Of the various constraints affecting production, plant-parasitic nematodes are a significant, but often overlooked, threat. As a perennial crop, treating plantations once infected with nematodes becomes difficult. The current study evaluated the drenching application of two biocontrol agents, Trichoderma asperellum and Purpureocillium lilacinum, for their nematode control efficacy, as well as their impact on the soil nematode community structure on mature, established coffee trees in Kenya. Seven Arabica coffee field trials were conducted over two years on trees of various ages. All the fields were heavily infested with Meloidogyne hapla, the first report of the species on coffee in Kenya. Both fungal biocontrol agents were detected endophytically infecting roots and recovered from soil but not until six months after initial applications. The population densities of M. hapla had significantly declined in roots of treated trees 12 months after the initial application, although soil nematode density data were similar across treatments. Based upon the maturity index and the Shannon index, treatment with T. asperellum led to improved soil health conditions and enrichment of diversity in the microbial community. Application of P. lilacinum, in particular, led to an increased abundance of fungivorous nematodes, especially Aphelenchus spp., for which P. lilacinum would appear to be a preferred food source. The soils in the trials were all stressed and denuded, however, which likely delayed the impact of such treatments or detection of any differences between treatments using indices, such as the functional metabolic footprint, over the period of study. A longer period of study would therefore likely provide a better indication of treatment benefits. The current study positively demonstrates, however, the potential for using biologically based options for the environmentally and climate-smart management of nematode threats in a sustainable manner on established, mature coffee plantations.

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Abstract

Potato Cyst Nematodes (PCN) (Globodera rostochiensis and G. pallida Woll.) are quarantine pests of potato (Solanum tuberosum L.) worldwide capable of causing significant yield loss and difficult to manage with conventional methods. The study explored the diversity of antagonistic fungi associated with PCN obtained from soil samples collected in Nyandarua and Nakuru Counties in Kenya and their effect on PCN egg viability and hatching was also evaluated. Twelve fungal isolates from five genera were isolated and characterized using morphological and molecular techniques. The twelve isolates were Trichoderma asperellum (4), T. hamatum, T. breve, T. atrobruneum, Amanita basiorubra, Setophoma terrestris (2), Penicillium chrysogenum and Clonostachys rosea. The most abundant isolate was Trichoderma spp. with 58 % occurrence. The effect of seven of the isolates on PCN eggs showed that T. breve and P. chrysogenum reduced egg viability by 41 % and 34 %, respectively while T. asperellum and T. breve reduced their hatching by 50 % on average. Trichoderma atrobrunneum, T. hamatum, and A. basiorubra also reduced the PCN egg viability by 27 % on average. These fungal isolates could provide a potential tool for PCN management in potato production systems for improved yields. However, further studies are warranted to validate these findings under greenhouse and field conditions. A more comprehensive bioprospecting survey for PCN associated antagonistic fungi needs to be extended to other potato growing regions to explore further cyst pathogens.