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.
2020
Authors
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Karina Petersen S. Jannicke MoeAbstract
No abstract has been registered
Authors
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Karina Petersen S. Jannicke MoeAbstract
No abstract has been registered
Authors
Sophie Mentzel Merete Grung Knut-Erik Tollefsen Marianne Stenrød Roger Holten S. Jannicke MoeAbstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Andreas Hagenbo Yasmine Piñuela Carles Castano Juan Martınez de Aragon Sergio de-Miguel Josu G. Alday Jose Antonio BonetAbstract
* In forests, ectomycorrhizal mycelium is pivotal for driving soil carbon and nutrient cycles, but how ectomycorrhizal mycelial dynamics vary in ecosystems with drought periods is unknown. We quantified the production and turnover of mycorrhizal mycelium in Mediterranean Pinus pinaster, Pinus sylvestris and Quercus ilex forests and related the estimates to standardised precipitation index (SPI), to study how mycelial dynamics relates to tree species and drought‐moisture conditions. * Production and turnover of mycelium was estimated between July and February, by quantifying the fungal biomass (ergosterol) in ingrowth mesh bags and using statistical modelling. SPI for time scales of 1–3 months was calculated from precipitation records and precipitation data over the study period. * Forests dominated by Pinus trees displayed higher biomass but were seasonally more variable, as opposed to Q. ilex forests where the mycelial biomass remained lower and stable over the season. Production and turnover, respectively, varied between 1.4–5.9 kg ha−1 d−1 and 7.2–9.9 times yr−1 over the different forest types and were positively correlated with 2‐month and 3‐month SPI over the study period. * Our results demonstrated that mycorrhizal mycelial biomass varied with season and tree species and we speculate that production and turnover are related to physiology and plant host performance during drought.
Abstract
No abstract has been registered
Abstract
No abstract has been registered
Authors
Alexander Solstad Ringheim Daniel Mushi Ephraim Mtengeti Ismail Saidi Selemani Magnus Åsli Lars Olav Eik Elikira Kimbita Leif Jarle AsheimAbstract
By 2050, global food consumption is expected to rise by 60% compared to the 2005–2007 level. In sub-Saharan Africa (SSA), the population increase may be as much as 250% by the same period. Hence, there is an urgent need to increase food production and introduce productivity-enhancing measures in SSA agriculture, including the livestock sector, which is the main focus of this article. The current productivity of the Tanzanian livestock sector is low due to seasonal variations in the availability and quality of pasture and other feeds. The cattle gain weight during the rainy season and lose weight in the subsequent dry season. Additionally, pastoralists face challenges due to the conversion of grazing areas into cropland, overgrazing, and the increasingly frequent droughts. Although the optimum age for slaughter is 3.5–4.5 years, farmers in Tanzania slaughter their cows at 5–6 years. This article argues that this may be an unhelpful economical management practice. To study the effects of improved feeding on economic performance, we collected data on on-farm supplementation experiments with indigenous Zebu cattle, in collaboration with pastoral communities and a large-scale commercial wheat farm in Hanang, Tanzania. The study compared the income and costs associated with traditional cattle keeping (TS) for 6 years at slaughter, with that of two levels of concentrate supplementation, low (LSS) and medium (MSS), allowing for slaughtering at 4.5 and 3.5 years, respectively. Adjusted net margins for the three systems were 199, 911 and 978 USD, respectively. Our results strongly suggest that farmers should supplement the feeding of their young stock regularly, in times when the animals cannot sustain themselves on grazing alone. The primary explanations for the recommendation were that supplementation would lead to increased production of meat and reduced variable costs, that is, feeds and drugs. Our study was limited to steers. Future studies should include supplementation of cows to obtain annual calving and use of crop by-products instead of concentrates.
Abstract
The triploid pear cultivar ‘Ingeborg’ is currently the main commercial pear cultivar grown in Norway. However, fruit set and subsequent yields of this cultivar have proven to be variable and overall rather low. In order to promote the fruit set, different bioregulators were applied during and after bloom and compared with an untreated control. Investigations were done during the period 2017-2018, at NIBIO Ullensvang, western Norway. Different dosages of both gibberellins (GA3, trade name GIBB 3, 10% active ingredient (a.i.) and GA4/7, trade name Novagib®, 1% a.i.) were applied at full bloom and at petal fall. Additional applications of the growth retardant prohexadioneCa (trade name Regalis®, 10% a.i.) were applied twice, when bourse shoots had 3-5 leaves and after one month later. Ethephon (Cerone (480 g a.i. L-1)) was applied three times starting about 7 days after petal fall with ca. 7- to 10-day intervals. All gibberellin applications significantly increased fruit set compared to the untreated control. One single application with GA3 (3 g ha-1) almost tripled the fruit number per 100 flower clusters when compared with the control (136 and 46, respectively). The yield response was similar (16.8 to 9.6 kg tree-1, respectively). Similar results occurred with one application of GA4/7 (12 g ha-1) with the same crop load level, and the fruit weights were similar to the control (130 g). Prohexadione-Ca treatments significantly reduced shoot growth of the pear trees. Two treatments with 125 g ha-1 or one treatment of 250 g ha-1 reduced the growth by ~35% but had no significant effect on fruit set and yield. The multiple ethephon applications (275 mL ha-1 in total) had no effect on both set and shoot growth, and return bloom compared to the untreated or gibberellin treated trees.
Authors
Roar Linjordet Divina Gracia P. Rodriguez Mehreteab Tesfai Anne Prestvik Salome Modiselle Primrose Magama Mokhele MoeletsiAbstract
This chapter analyses the main challenges and opportunities to promote sustainable biogas technology adoption by smallholders through integrated food and energy systems (IFES), using a case study from Malonga village in the Limpopo Province of South Africa. Biogas has become attractive in recent years because of its multiple benefits and the contributions it can make to the UN SDGs. However, in Africa, its adoption remains low, due to several constraints, including: (1) water scarcity and lack of access to feedstocks; (2) high initial/upfront cost of installation and lack of investment; (3) lack of skilled labour for installation, operation and maintenance; (4) limited training facilities; (5) inadequate policy support and extension services; and (6) slow behavioural and social acceptance. Based on the information collected, integrated framework conditions that can encourage the adoption of smallholder biogas technology through IFES, were suggested. IFES will only succeed in delivering benefits, if the necessary framework conditions, such as adequate feedstock and water, training, policy support, stakeholder collaboration, credit and insurance and support services are provided. The implementation of the necessary framework conditions for biogas technology should be underpinned by conducting an integrated research study on using IFES type 2 in the context of smallholder farmers in Africa.