FFL-JA-Forskningsmidlene for jordbruk og matindustri

Norway import large quantities of food and feed and have probably more nutrients circulating in blue and green sectors than what we can make use for in our agriculture. MAFIGOLD takes important steps to close recycling gaps in the two sectors. The main aim of the project is to develop efficient and sustainable methods to recycle nutrients and decrease geographic nutrient imbalances in the agricultural and aquacultural sectors hereby decreasing their environmental load. Goals include 1) the development and characterization of refined fertilizers from animal manure, fish sludge (a mixture of feed residues and fish feces), and food residues, 2) an evaluation of the impact of the effects of refined fertilizers on agronomic performance and soil nutrient characteristics, and 3) sustainability analyses including carbon footprint of nutrient refinement and recycling pathways. The priority is to find methods that can increase phosphorus (P) recirculation, and the production of commercial fertilizers and growing media. Separation and concentration of major plant nutrients in organic fertilizers as mineral compounds is a method to potentially increase plant availability of nutrients and decrease geographic imbalances. In MAFIGOLD we evaluate processes to separate P from animal manure as struvite that can be transported from regions with surplus to places with deficiencies. By first decreasing the pH in pig manure, dissolving P, and then separating manure into solid and wet phase, we were able to remove a large proportion of P from the dry phase. By precipitating P from the wet phase as struvite, concentrated P can be concentrated and easily transport to sites in need for his nutrient. Our results show that P in fish sludge needs considerably lower pH to be solved as compared to in pig manure. The process removes both P and nitrogen (N) from the manure. The results from experiments with agricultural productions will be used to give fertilizing recommendations aiming to avoid both surplus and deficiencies. Agronomic field and greenhouse trials in MAFIGOLD showed that only a small proportion of the total nitrogen and ammonium nitrogen in animal manure, fish sludge and food residues was taken up by barley plants, probably because the mineralization of nitrogen to plant available compounds was not synchronized with the plant nitrogen need. We aim to find out how different carbon/P ratios in separate phosphorus poor dry phase manure affect crop yield, phosphorus uptake and soil enzymes, which mediate soil phosphorus turnover. These studies also include soils that cover a range of phosphorus statuses representing animal dense regions in Norway. Knowledge from these studies can be used to evaluate to what extent the phosphorus can be removed from animal dense regions without negative effects on plant productivity and underlying soil mechanisms. Field experiments will show the extension services and farmers in Western and Eastern Norway how phosphorus poor and rich organic fertilizers affect yield and key soil functions for nutrient uptake. Granulated and pelleted compound fertilizers consisting of animal manure and fish sludge are being developed. Notably, Terramarine AS, a project business partner has, in cooperation with the project, produced 10 pelleted compound fertilizers from chicken manure, fish sludge and digestate (from anaerobic biogas production) with different concentrations of N, P and potassium (K). The effect of the 10 composite fertilizers on plant productivity and yield has been evaluated in greenhouse experiments. The results were used to improve the recipes of the fertilizers before new validation experiments on ley and cereals in Norway. Since the content of N and P were low in the first composite fertilizer prototypes, new prototype fertilizers were enriched with N (urea) and K (KCl) before experiments 2022 and 2023. Another task is to use the nutrient poor dry fraction manure as a substitute for peat, which is an important natural resource, to make growing media to plant nurseries and home gardens. Results from experiments showed that the solid fraction of manure has great potential as substitute for peat and can constitute a large proportion of the media. We mixed dry cattle manure with composted bark and biochar to improve the physical structure. Nursery production of shrubs and trees and herbs were grown (-22 and -23) to evaluate the growing media in comparison with available growing media used by the industry. Sustainability effects including carbon footprint from manure refining pathways including the production of 1) fish sludge, animal manure and food residue composite fertilizer, and the 2) separation of phosphorus as struvite from animal manure and animal manure based digestate are being evaluated in life cycle analyses (LCA).

This project addresses the whole value chain for improved nutrient recirculation in agriculture, with an emphasis on phosphorus. By using biomass more efficiently, soil quality may be improved and emission of greenhouse gasses from Norwegian agriculture decreased. We will firstly develop technical solutions for de-watering, de-salting, drying and logistics for fish sludge, manure and biogas digestate, before processing pellets or granules of fertilizers, as well as, refining methods to transform those organic fractions into fertilizers, soil amendments and growing media. Secondly, we will optimize crop management practices for improved nutrient efficient use of these products. Finally, we will calculate the net greenhouse gas emissions from processing, transport and utilisation chains of those products, applying life cycle assessment (LCA). By these components, we address a more efficient use of renewable biomass from the agricultural and marine sectors as plant fertilizers and soil amendments, new knowledge of fertilization strategies and their soil ecosystem responses, and definition of methods to take advantage of those organic materials, while reducing greenhouse gas emissions. The industrial partners will contribute with their knowledge and commercial interests in these topics, to ensure the sector-based relevance of the project. In total, this project offers advancements in the refinement of organic materials into plant fertilizer, including supply chains, to increase the efficiency of nitrogen and phosphorous recycling, expand sustainability and increase productivity and competitiveness in the agricultural sector in Norway.