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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.

2021

To document

Abstract

Soil erosion is generally recognized as the dominant process of land degradation. The formation and expansion of gullies is often a highly significant process of soil erosion. However, our ability to assess and simulate gully erosion and its impacts remains very limited. This is especially so at regional to continental scales. As a result, gullying is often overlooked in policies and land and catchment management strategies. Nevertheless, significant progress has been made over the past decades. Based on a review of >590 scientific articles and policy documents, we provide a state-of-the-art on our ability to monitor, model and manage gully erosion at regional to continental scales. In this review we discuss the relevance and need of assessing gully erosion at regional to continental scales (Section 1); current methods to monitor gully erosion as well as pitfalls and opportunities to apply them at larger scales (section 2); field-based gully erosion research conducted in Europe and European Russia (section 3); model approaches to simulate gully erosion and its contribution to catchment sediment yields at large scales (section 4); data products that can be used for such simulations (section 5); and currently existing policy tools and needs to address the problem of gully erosion (section 6). Section 7 formulates a series of recommendations for further research and policy development, based on this review. While several of these sections have a strong focus on Europe, most of our findings and recommendations are of global significance.

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Abstract

Dollar spot, caused by at least five Clarireedia species (formerly Sclerotinia homoeocarpa F. T. Benn.), is one of the economically most important turfgrass diseases worldwide. The disease was detected for the first time in Scandinavia in 2013. There is no available information from Scandinavian variety trials on resistance to dollar spot in turfgrass species and cultivars (http://www.scanturf.org/). Our in vitro screening (in glass vials) of nine turfgrass species comprising a total of 20 cultivars showed that on average for ten Clarireedia isolates of different origin, the ranking for dollar spot resistance in turfgrass species commonly found on Scandinavian golf courses was as follows: perennial ryegrass = slender creeping red fescue > strong creeping red fescue > Kentucky bluegrass = velvet bentgrass > colonial bentgrass = Chewings fescue ≥ creeping bentgrass = annual bluegrass. Significant differences in aggressiveness among Clarireedia isolates of different origin were found in all turfgrass species except annual bluegrass (cv. Two Putt). The U.S. C. jacksonii isolate MB-01 and Canadian isolate SH44 were more aggressive than C. jacksonii isolates from Denmark and Sweden (14.10.DK, 14.15.SE, and 14.16.SE) in velvet bentgrass and creeping bentgrass. The Swedish isolate 14.112.SE was generally more aggressive than 14.12.NO despite the fact that they most likely belong to the same Clarireedia sp. The U.S. C. monteithiana isolate RB-19 had similar aggressiveness as the Scandinavian C. jacksonii isolates, but was less aggressive than two U.S. C. jacksonii isolates MB-01 and SH44. Thus, aggressiveness of Clarireedia isolates was more impacted by their geographic origin and less by species of the isolate and/or the host turfgrass species.

To document

Abstract

We synthesized 20 years of research to explain the interrelated processes that determine soil and plant responses to biochar. The properties of biochar and its effects within agricultural ecosystems largely depend on feedstock and pyrolysis conditions. We describe three stages of reactions of biochar in soil: dissolution (1–3 weeks); reactive surface development (1–6 months); and aging (beyond 6 months). As biochar ages, it is incorporated into soil aggregates, protecting the biochar carbon and promoting the stabilization of rhizodeposits and microbial products. Biochar carbon persists in soil for hundreds to thousands of years. By increasing pH, porosity, and water availability, biochars can create favorable conditions for root development and microbial functions. Biochars can catalyze biotic and abiotic reactions, particularly in the rhizosphere, that increase nutrient supply and uptake by plants, reduce phytotoxins, stimulate plant development, and increase resilience to disease and environmental stressors. Meta-analyses found that, on average, biochars increase P availability by a factor of 4.6; decrease plant tissue concentration of heavy metals by 17%–39%; build soil organic carbon through negative priming by 3.8% (range −21% to +20%); and reduce non-CO2 greenhouse gas emissions from soil by 12%–50%. Meta-analyses show average crop yield increases of 10%–42% with biochar addition, with greatest increases in low-nutrient P-sorbing acidic soils (common in the tropics), and in sandy soils in drylands due to increase in nutrient retention and water holding capacity. Studies report a wide range of plant responses to biochars due to the diversity of biochars and contexts in which biochars have been applied. Crop yields increase strongly if site-specific soil constraints and nutrient and water limitations are mitigated by appropriate biochar formulations. Biochars can be tailored to address site constraints through feedstock selection, by modifying pyrolysis conditions, through pre- or post-production treatments, or co-application with organic or mineral fertilizers. We demonstrate how, when used wisely, biochar mitigates climate change and supports food security and the circular economy.