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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.

2022

Abstract

The objective of this report is to investigate the role of animal breeding in the partner European countries — in terms of (1) increase of the competitiveness of breeders’ association and (2) conservation of animal genetic resources including breeding programmes — to generate relevant lessons for African partner countries in addressing livestock and poultry productivity and quality challenges in Africa.

Abstract

Human urine contains essential nutrients (e.g., nitrogen and phosphorus) required for plant growth. Hence, urine can serve as a “free” and locally available nutrient source. Successful, low-cost urine-diverting toilets (UDTs) that separately collect urine have been developed in Scandinavia and in Europe and are being manufactured at large-scale in Africa. There exists many barriers to urine recycling at scale. The important initial steps for increased use of urine as a fertilizer (UBF) are to understand the technical, socio-cultural, economic, institutional and ecological aspects that affect large-scale adoption of UDTs, urine treatment technologies, and UBFs; provide evidence-based data that shows urine is safe in terms of heavy metals, pathogens, and organic micropollutants; and identify optimal combinations strategies to sustain adoption in the long term. FoodSecURe will be implemented and will utilize the already existing UDTs in communal public areas in Bahir-Dar, Ethiopia. Due to lack of technology and limited awareness of users, government and institutions, these UDTs were used inappropriately, and no UBF has been produced from the UDTs. The project will be conducted through 6 work packages (WPs): WP0 focuses on the project management. WPs 1-4 focus on identifying the barriers in the adoption of urine recycling based on technology (WP1), health (WP2), socio-culture and environment (WP3), and economic and institutions (WP4). The dissemination, exploitation and communication activities are in WP5. The various tasks are implemented through a multi-disciplinary and multi-actor approach by scientists specializing in social sciences, business management, agronomy, parasitology, environmental engineering, environmental science, and soil science. A Stakeholder Advisory Committee will be created to strengthen science-policy-stakeholder linkages and ensure that the technical and socio-economic solutions identified in the project match the stakeholders’ needs.

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Abstract

Digestate, a by-product from anaerobic digestion of organic materials such as animal manure, is considered a suitable plant fertilizer. However, due to its bulkiness and low economic value, it is costly to transport over long distances and store for long periods. Refinement processes to valorize digestate and facilitate its handling as a fertilizer include precipitation of phosphorus-rich mineral compounds, such as struvite and calcium phosphates, membrane filtration methods that concentrate plant nutrients in organic products, and carbonization processes. However, phosphorus retention efficiency in output products from these processes can vary considerably depending on technological settings and characteristics of the digestate feedstock. The effects of phosphorus in plant fertilizers (including those analogous or comparable to refined digestate products) on agronomic productivity have been evaluated in multiple experiments. In this review, we synthesized knowledge about different refinement methods for manure-based digestate as a means to produce phosphorus fertilizers, thereby providing the potential to increase phosphorus retention in the food production chain, by combining information about phosphorus flows in digestate refinement studies and agronomic fertilizer studies. It was also sought to identify the range, uncertainty, and potential retention efficiency by agricultural crops of the original phosphorus amount in manure-based digestate. Refinement chains with solid/wet phase separation followed by struvite or calcium phosphate precipitation or membrane filtration of the wet phase and carbonization treatments of the solid phase were included. Several methods with high potential to extract phosphorus from manure-based wet phase digestate in such a way that it could be used as an efficient plant fertilizer were identified, with struvite precipitation being the most promising method. Synthesis of results from digestate refinement studies and agronomic fertilizer experiments did not support the hypothesis that solid/wet separation followed by struvite precipitation, or any other refinement combination, results in higher phosphorus retention than found for unrefined digestate. Further studies are needed on the use of the phosphorus in the solid phase digestate, primarily on phosphorus-rich soils representative of animal-dense regions, to increase understanding of the role of digestate refinement (particularly struvite precipitation) in phosphorus recycling in agricultural systems.