Livestock farms often face a key challenge: the cost and complexity of transporting large volumes of slurry to distant fields, especially in areas with high livestock density and limited spreading capacity nearby.

The Slurry Concentrator addresses this by separating raw slurry into two liquid fractions:

The project focused on the implementation of precision farming tools with the objective of improving crop field management. This was done with the intention of reducing the environmental impact, increasing agricultural yield, and enhancing resource efficiency. The primary objective was to develop a management methodology that employed the use of soil conductivity sensors, GPS-equipped yield monitors, and satellite imagery to generate vegetation and harvest maps. Furthermore, the project aimed to devise strategies for reducing phosphorus (P) and potassium (K) levels in soil in accordance with local regulations, and to produce a practical guide for farmers and other stakeholders. Furthermore, an efficient strategy for the application of livestock manure using NIR+GPS technology was developed with the objective of optimising the application of nutrients on each field, thereby improving resource management.
The results demonstrated that the utilisation of soil conductivity sensors and satellite remote sensing for field mapping facilitates precision seeding, thereby enhancing crop management. Nevertheless, it was determined that subcontracting a company for conductivity measurement is not a financially viable option for smaller farms. This approach is economically viable for larger farms, particularly those exceeding 50 hectares, where it can result in significant gains in productivity and resource efficiency. Practitioners can utilize this knowledge to enhance the precision of their farming practices, reduce input costs, and comply with environmental regulations, ultimately increasing both yield and profitability while reducing environmental impact.

The project focused on the optimisation of agronomic management of pig slurry through the treatment and application of effluents, with the objective of adjusting the nutrient content to align with crop requirements while minimising environmental impact. The primary objective was to implement a nitrification-denitrification (NDN) system to treat slurry and produce effluents with nitrogen content that matched crop requirements, while keeping costs low and minimizing environmental impact. Moreover, the project sought to evaluate the impact of distinct effluent types, including the liquid fraction derived from solid-liquid separation, intensive NDN (Nitrification-Denitrification) treatment effluent, and effluent from a novel NDN-based treatment, on crop yield and quality. Furthermore, the project evaluated long-term alterations in the physical and chemical characteristics of soil following the repeated application of treated pig slurry effluents over multiple years.
The project was initiated in response to the challenge of nitrogen overproduction in the Osona region, with a view to developing a sustainable and economically viable approach to its management. The project yielded several outcomes, including field days for farmer education and micro-plot demonstrations where precision fertilisation was applied with controls. Additionally, the project continued with potassium recovery from struvite. For farmers, this project offers a practical solution for managing pig slurry effectively, improving crop quality and reducing environmental impact, while ensuring efficient nutrient use. This approach can help improve long-term soil health and potentially reduce fertiliser costs.

The project aimed to implement treatments to reduce ammonia emissions in pig farms, which are a source of both animal welfare issues and environmental concerns. Ammonia concentrations in the air at levels above the norm have been demonstrated to precipitate a variety of ailments in pigs, including dermatological, ocular, and pulmonary irritation, in addition to chronic respiratory disease. 
The primary objective was to reduce ammonia levels by applying acid or adsorbent materials, such as zeolites, to slats in pig housing. It was anticipated that this would serve to mitigate the negative effects of ammonia on pig health, improve air quality, and enhance the quality of the final product. Subsequently, further studies were conducted to evaluate the influence of ammonia reduction on overall productivity and product quality, thereby establishing a correlation between environmental practices and economic benefits for farms.
he findings indicated that the accumulation of slurry beneath the slats markedly elevated ammonia emissions, leading to a reduction in animal welfare despite the presence of adequate ventilation. As a consequence of the inefficacy of the control measures employed during the course of the trials, the results were inconclusive and the treatments are not yet in use on farms. As a subsequent measure, in accordance with Danish practices, it is recommended that outdoor slurry pits be acidified with sulfuric acid in order to further reduce emissions and improve air quality and animal welfare in pig farming systems.

The project concentrated on the development of technologies for the energy valorization of livestock manure through bio-drying, with the objective of reducing the energy and environmental impact in high-density livestock areas.
The primary objectives were to valorise surplus livestock manure that is unsuitable for use as fertiliser via an innovative bio-drying process; to produce a biofuel (2,500-3,500 kcal/kg) from manure that can be used in conventional biomass boilers; and to conduct a feasibility study at La Fageda's farm facilities, with results that could be applicable to other cattle and pig farming operations.
The results demonstrated that the bio-drying process is a highly complex one. The combustion of cattle manure is impeded due to its elevated straw content, which induces crystallisation. Moreover, the return on investment period is considerable, extending over 11 years, and requires the presence of pre-existing infrastructure, including a solid-liquid separator. Although the process is not currently operational, there is consideration of adapting it for use with pig slurry in future projects. This research provides an initial insight into the challenges and potential for the valorization of livestock manure as a renewable energy source.

The project was designed to assess the efficacy of strategies aimed at reducing nitrogen excretion in intensively reared beef calves by lowering the crude protein level in their diet. The objective of this approach is to reduce environmental pollution without any adverse effects on animal growth or feed conversion rates.
The primary objectives were to assess strategies for reducing nitrogen excretion in Friesian calves fed high-concentrate diets during the final fattening stage, to test three nutritional strategies to enhance nitrogen efficiency at the rumen level, and to evaluate the impact of these strategies on nitrogen excretion in manure and urine, ruminal fermentation and health, feed intake, growth, and carcass quality.
The results demonstrated that dietary changes and crude protein reduction effectively decreased nitrogen excretion, supporting environmental benefits without hindering growth. The return on investment is nearly immediate (within a year), and these practices are now implemented across the entire farm operation.
This knowledge offers farmers a practical, low-cost opportunity to reduce environmental impact while maintaining animal productivity, providing a model for sustainable, profitable beef production.

Bioferti+ aims to improve the management of animal manure and other organic waste by optimizing the composting process, transforming the waste into a tailor-made  bio-based fertilizer (TMF) in pelletized form. This product is designed to meet specific nutritional needs of target crops (vineyards and apple orchards), also considering the nutritional state of the soil. Moreover, this innovative solution optimizes the transportation of a more concentrated (and pelletised) fertilizer from areas with an intensive nutrient production to areas with high demand for organic matter and nutrients.
The TMFs provide a sustained release of nutrients that decomposes gradually, nourishing the crops over extended periods and favouring the optimization of nutrient use. Although the application costs of TMFs currently exceed those of conventional mineral fertilizers, the long-lasting pellets reduce the need for frequent applications and contributes to a more sustainable farming practices. It also provides organic carbon to the agricultural soils, an important practice towards the remediation of soil erosion. Additionally, the same machinery used for chemical fertilization can be utilized for TMFs, offering a significant practical advantage for farmers. 
This approach helps farmers transform cattle manure management into a business model rooted in circular economy principles, while the agricultural sector benefits from using organic fertilizers as a substitute for mineral ones.

The objective of the Operational Group Lettiera Stabilizzata was to evaluate the impact of stabilized litter obtained from the solid/liquid separation of dairy cow slurry subjected to a process of sanitation and stabilization in dairy farms operating in the Parmigiano-Reggiano district. The spread of the mechanical separation treatment in many dairy farms induced dairy farmers to consider the solid fraction not only as an organic fertilizer, but also a litter in cubicles for dairy cows, taking account of the relevant cost of the purchase and stocking of other litter material such as straw, wood chips or sawdust. The substrate on which the dairy cows lay down has an impact on their welfare conditions and their cleanliness, as well as on the hygiene and suitability of milk for cheese making.
The OG tested and evaluated the effectiveness of sanitization and stabilization of this material by using a prototype biocell/aerocell that exploits the increase in temperature due to the exothermic reactions of biological aerobic degradation of the organic matter.
The results derived from the monitoring activities have demonstrated that this technological solution can be successfully applied to the reality of Parmigiano Reggiano without adversely affecting the quality of housing and of the final milk product for Parmesane Cheese; based on the scenarios assumed, it can be economically viable for herds above 200 or 300 cows, depending on the business organization and structural equipment.

The introduction of biochar from gasification in the livestock effluent management chain is interesting for the valorisation of biochar in agriculture as a soil improver enriched in N, P and micronutrients, thanks to the interaction with pig slurry and as a means to sequester CO2 in the soil . The application of biochar to pig slurry contributes to reducing the carbon footprint only if the subsequent valorisation in the field is considered. Theses with biochar field application allow to sequester more CO2 in the soil than they emit in the analyzed process: -8352 kg CO2eq/ha (FiltChar), - 8597 kg CO2eq/ha (AeroChar), -15433 kg CO2eq/ha (MatChar) and +7830 kg CO2eq/ha for control.
The most suitable solution in reducing ammonia emissions is the covering  of the pig slurry storage by MatChar solution which reduces emissions by 32% compared to uncovered storage. The AeroChar N/DN biological treatment was effective in reducing methane and nitrous oxide emissions (-17% and -10% respectively) compared to the control. Slurry filtration by biochar (FiltChar) is less promising in mitigating emissions.
After interaction with pig slurry, biochar is more suitable for subsequent agronomic use for fertilizing purposes (pH, C/N and TOC) and the N and P content is significantly increased.
The critical point for large-scale development is the availability of biochar on the market and the high price due to the still undeveloped production chain. The economic sustainability of the biochar application could become positive if the procurement price fell to €80/t.

Aiming an improve manure management and its revalorization, the production of biogas in a flexible cover pond was studied in one of the partner farms of the OG FERTICOOP, with the benefit of better control in ammonia and GHG emissions, as methane, which is valued as biogas with a thermal use in boilers for heating the farm itself. 
During the project, there was tracking of non-treated slurry input, digested slurry output and the composition of the produced biogas,  thus evaluating the methanization potential of the fresh slurry. 
After an assessment of meteorological conditions, slurry characteristics and biogas characteristics, it has been concluded that:
 - Depending on the slurry origin, biogas conditions and digested slurry conditions can vary a lot. 
 - The storage system and the reactor of biogas production easily adapt to the temperature conditions and slurry characteristics.
 - It is necessary to have a good management of slurry inputs to maximize biogas production. 
 - Meterological conditions, temperature mainly, hugely affect biogas production and its quality in terms of its methane composition and other gases (such as hydrogen sulfide, which at can produce big damage to the boilers). 

In the OG FERTICOOP different manure management techniques and factors have been studied at livestock farming level. One of these factors has been the ammonia and GHG emissions, which were studied at pig farms and at storage systems (ponds) at the same farms. 
Pig farms have been assessed for methane (CH3), dinitrogen dioxide (N2O), carbon dioxide (CO2), hydrogen sulfide (H2S) and ammonia (NH3) in cattle sheds with different characteristics of pits and drains. Unfortunately results were not clear enough to make recommendations, it is necessary to study it over a longer period of time. 
Emissions at storage systems (ponds) at the farms
Emissions were assessed in two ponds with different characteristics, one pond with digested slurry and other pond assessed before and after implementation of an structure of floating pieces to cover it:
1. Evaluation of emissions in an uncovered pond with digested slurry
2. Evaluation of emissions in an uncovered pond with non-treated slurry     
3. Evaluation of emissions in a covered pond (floating pieces) with non-treated slurry
It was seen that emissions are strongly related to temperature and slurry pH. Comparing both uncovered ponds, non-treated slurry has lower emissions than digested slurry, being almost half of it.   
Last, once the non-treated slurry was covered with floating pieces, its emissions were reduced 52%  compared to being uncovered. 

Needs for manure management and the need to solve fertilization problems led the OG Manure management tools to study different tools and equipment to improve efficiency in the planning and application of manure: 
 - Use of conductimeters to determine the exact amount of nutrients in manure and soils to correctly plan the appropriate dose of manure to apply at the appropriate moment.
 - Use of brand spreaders for the application of manure since is a common practice in Catalonia. 
 - Use of hoses for the application which improves fertilization efficiency and allows the application of lower doses. 
  - Manure application during different phases of crop growth: (1) before sowing and (2) during first growth of crop. 
The study of these different tools and practices allowed to advise farmers about the best equipment and techniques for manure application on their crops, and it has generally been concluded that:   
 - Conductimeters allow an accurate estimation of needed and available nutrients and allow an application planning for the correct amount of slurry at the correct moment of crop growth. 
 - Use of hoses for the manure application allow nitrogen efficiency and achieve greater uniformity while reduces smells and ammonia volatilization. 
 - Application of manure during first growth of crop allows to add nutrients at the maximum extraction moment, increasing its efficiency. 

Biorefinery Glas, based in South-West Ireland, offers farmers an innovative way to increase resource use efficiency, boost sustainability and diversify income streams by converting grass into alternative animal feed.  Biorefinery technology provides farmers with the opportunity of moving up the bioeconomy value chain as processors and producers of products rather than biomass suppliers. This is done by capturing nutrients otherwise unused by traditional feeding practices while helping to address key environmental challenges in agriculture.
The biorefinery processes freshly harvested grass into two valuable alternative animal feed products: a high-fibre presscake feed for cattle and a protein-rich liquid concentrate for pigs. By using presscake silage to replace a portion of grass silage in dairy cows' diets, farmers can maintain milk yield and quality while reducing methane production in the rumen and improving nitrogen use efficiency (NUE). This feed also lowers nitrogen and phosphorus excretion, helping farmers comply with environmental regulations and reduced nutrient losses to the environment (N and P losses -25%)
For pig farmers, the protein-rich (33.9% Pr) concentrate offers a cost-effective replacement for imported soya, reducing feed costs and improving animal performance. The concentrate boosts daily feed intake and weight gain, reducing farmers reliance on expensive imports and lower transportation costs.
Producing alternative animal feeds will increase resource use efficiency, add value to the traditional grass crop and provide diversified income streams from the valorisation of grass. Also helping to close the nutrient cycle loop, reduce the carbon footprint of livestock and finite mineral use.
 

The Duncannon Blue Flag Farming & Communities Scheme brought together the local community, government, and farmers to reduce bacterial pollution in bathing waters and improve the ecological health of the area. A group of 35 farmers, including 8 arable crop and 27 livestock farmers, played a central role in managing over 975 hectares of land. Farmers were educated and provided with tools to assess and reduce water pollution risks. They used farm-specific Pollution Potential Zone (PPZ) maps, nutrient management plans, and soil tests to identify areas of concern and implement preventive measures.
One of the key actions was protecting 15.5 kilometres of watercourses by fencing them off from livestock, improving water quality and conserving water resources. Other measures included relocating water troughs 20m away from streams, creating natural buffer zones, creating native riparian zones, planting cover crops, and installing sediment traps to reduce soil erosion and nutrient runoff. These actions not only helped improve water quality but also enhanced farm productivity.
The project highlighted practical, cost-effective strategies for livestock farmers. By preventing water contamination and managing nutrients efficiently, farmers could reduce costs, keep livestock healthy, and boost productivity. In addition, a results-based reward scheme provided financial incentives for farmers who took steps to improve water quality, making environmental protection a profitable venture. By following these practices, farmers can protect water resources, enhance the sustainability of their farms, and potentially increase their earnings.
 

The Irish Organic Association conducted a project (2018-2021) with 11 organic horticulture growers to improve soil and nutrient management using green manures. 
Green manures are cover crops grown to enrich the soil. Different combinations of plant species including clover, ryegrass, cereals, phacelia, and buckwheat were used to create green manure seed mixtures for the trial over 3-years. Mixtures were sown for two months in summer and six months in winter, and then incorporated into the soil before planting cash crops. These green manure plots were then compared to control plots (no green manures were used).
Results from the use of green manures included; improved weed control, soil microbial activity was boosted, biodiversity was enhanced and beneficial insect numbers increased. Low-growing green manures attracted pollinators and predators of crop pests. High-biomass green manures, improved soil structure and increased soil organic matter. Benefits of using green manures included; Improved soil fertility, improved soil structure, increased soil water retention, less competition from weeds and reduced pest numbers. These combined for increased plant growth and yields. Healthier soils helped plants access nutrients.
Cash crops planted after green manures mature earlier providing farmers the opportunity to extend their growing season. Cost-benefit analysis revealed that farmers experienced financial gains from using green manures due to improved crop yields and reduced costs associated with weed control and pest management.
 

Biorefinery Glás focuses on the demonstration of a small-scale grass biorefinery with farmers to diversify farmer produce while addressing challenges in traditional agriculture. In the biorefinery, grass is crushed and separated into two parts, a solid high fibre presscake and a protein rich liquid. Presscake feed trial results (in comparison to grass silage) with dairy cows has shown benefits to include; milk quality, yield  and protein was not impacted, decreased rumen ammonia concentration, decreased N and P excretion and increased Nitrogen Use Efficiency (NUE).  Conversely, milk fat and milk solids content were lower and N (Urea) excreted in the milk increased.  
The liquid fraction is processed to produce a protein rich (33.9% Pr.) dried feed for pigs, which replaced up to 50% of the usual soya levels from the diet. Benefits show a higher-than-average daily intake and daily gain compared to the control group after 30 days. Thus reducing transport distances and import cost associated with soya. 
The remaining liquid is a bio-based fertiliser, called grass whey. Grass whey contains residual N,P,K. Nutrient values in Kg /M3 are N; 1.8 kg, P; 0.45kg and K; 4.05kg respectively. Grass whey is comparable to slurry in both nutrient value and grass yield when applied using low emission spreading systems.  
Biorefinery Glas allows farmers to increase resource efficiency while addressing key emissions challenges. The biorefinery model could allow farmers to continue to feed their cattle, while producing alternative animal feeds and a bio fertiliser. This while increasing NUE, increasing resource efficiency, providing new income streams and reducing emissions.

Biorefinery Glás focuses on the demonstration of a small-scale grass biorefinery with farmers  to diversify farmer produce while resolving significant challenges in traditional agriculture. In the biorefinery, grass is crushed and separated into two fractions, a solid presscake and a liquid protein rich fraction. Presscake feed trial results with dairy cows indicated that the dry matter intake was lower in the presscake fed group compared to grass silage.​ Milk quality and protein did not differ between the two groups, but milk fat and milk solids content were lower in presscake fed cows.  Rumen ammonia concentration in presscake fed cows decreased compared to grass silage.​ Nitrogen excreted in the milk increased but N & P excretion decreased in presscake fed compared to grass silage.​ The NUE increased in presscake compared to grass silage. Pigs fed the  protein rich dried feed were slow to adapt at first but adjusted within a week.​ They had a higher-than-average daily intake and higher than average daily gain compared to the control group after 30 days.​ Including dry protein concentrate in the pig's diet replaced up to 50% of the usual soya levels from the diet.​   Using this locally produced pig feed reduces transport distances and import  cost associated with soya. Currently, these types of small-scale biorefineries are being developed with built in automation, making this type of technology more accessible to farmers. It also allows farmers to increase resource efficiency while addressing key emissions challenges. The biorefinery model could allow farmers to continue to feed their cattle, with reduced emissions, while producing three co-products which can increase their overall farm efficiency and income.

Flemish Farmers have access to an abundance of roadside grass or low- quality grass that cannot be used as animal feed. Grass juice accounts for 40-60% of the total grass weight and research results have shown that it can be used for microalgae cultivation. Therefore, farmers can grow microalgae themselves to use as animal feed or supply the grass juice to algae growers who want to produce organic-certified algae, since grass juice can be considered an organic growing medium. The grass juice was separated from the fibre fractions by a sequence of sedimentation, coarse filtration and pH adjustments. The obtained grass juice has an intense green color and a high concentration of suspended solids, which means that light cannot penetrate efficiently. Therefore the grass juice was pretreated through a sequence of dilution to 10% and overnight sedimentation which resulted in a nutrient-rich clear supernatant with good light penetration properties. Further pH adjustment from the initial acidic pH of 4 to 8 was necessary to inhibit contaminants and ensure good algae growth. 
After proper treatment of the grass juice, green microalgae (Chlorella sorokiniana) and cyanobacteria (Arthorspira platensis) were successfully grown in this organic medium. The produced biomass had a 41% protein content, and most microorganisms complied with safety norms for feed production These findings offer new perspectives to sustainably manage plant waste and convert it to a protein source in a Green Biorefinery. Future studies are needed to further explore the potential of grass juice for microalgae cultivation at larger scales (e.g. pilot-scale).
 

The EU Joint Research Center proposed the RENURE criteria to allow the safe use of recovered nitrogen from manure as fertiliser substitutes, among the priority RENURE products are ammonium salts recovered through stripping and scrubbing process. The RENURE operational group aims to prepare the Flemish agriculture and horticulture sector for the practical use of recovered ammonium salts. Five field trials were set up in 2022 and one in 2023 to evaluate the ammonium nitrate recovered from animal manure through the stripping and scrubbing process. The results showed that ammonium nitrate recovered from animal manure performs as well as artificial fertilisers in terms of effectiveness and fertilising value.
Applying ammonium nitrate with a row tiller or with injection is preferred as a low-emission method over application with a spray boom. The main bottlenecks when using ammonium nitrate in practice are the lower nitrogen content as compared to synthetic fertilizer, and the legal status that it was still considered as animal manure. The lower nitrogen content (9-12%) means that larger volumes are required as compared to synthetic fertilizer, therefore the fertilizer machine has to be replenished more often and is especially an inconvenience if the storage is located far from the plot. Mixing ammonium salts with synthetic fertilizer can meet farmers' demand for a higher nitrogen content. Moreover, this can provide a bridge in a transition phase from fertiliser to recovered fertilizers, where the mixture combines the security of the known fertiliser with the cost savings of the ammonium salts. However, the status of animal manure in current legislation provides limited options for both the sole and mixed application of ammonium salts. 
 

In 2020, the EU Joint Research Centre proposed the RENURE criteria to allow the safe use of recovered nitrogen from manure as replacement for synthetic nitrogen fertilisers. Ammonium salts recovered from manure through stripping and scrubbing process are proposed as a priority of RENURE products. Depending on the counter acid (nitric acid or sulfuric acid), ammonium nitrate or ammonium sulphate is produced, respectively. The obtained ammonium salts are slightly acidic, containing 100% mineral N without organic particles. Ammonium nitrate only contains nitrogen (7.5-12% N) and at a higher concentration than ammonium sulphate which also contains a high concentration of sulphur. The storage of ammonium salts often has a higher price tag, because these are liquid products are with a lower nitrogen content compared to chemical fertilizers. The ammonium salts can be stored in a polyester tank or intermediate bulk container which makes it easily stackable.
Field tests in 2022 indicated a comparable performance of the recovered  ammonium nitrate as compared to synthetic fertilizers in terms of effectiveness and fertilising value. In some cases, the crops treated with ammonium nitrate resulted in higher yields than the synthetic reference (calcium ammonium nitrate), although this was partly due to the heterogeneity of growth induced by the dry growing season.  Fertilizing with ammonium nitrate in winter wheat or similar crops does offer possibilities, as the animal manure in those crops is often not filled in or is filled incompletely. However the current status of animal manure remain as a main bottleneck for applying ammonium nitrate in-field practice.
 

The Flemish agricultural sector finds itself in the paradoxical situation with an animal nutrient surplus and additional nutrients demand from synthetic fertilizers. To this end, the RENURE criteria have been introduced by the EU Joint Research Center to ensure the safe application of nitrogen recovered from manure as substitutes for synthetic fertilisers. Stripping-scrubbing is a technology that makes it possible to upgrade manure to RENURE fertilisers such as ammonium salts. A stripping-scrubbing installation consists of two compartments: firstly, air is blown into the stripping compartment to remove the gaseous ammonia that is released from the thin fraction of manure or digestate due to increased pH and/or temperature; in the successive compartment, the ammonia-rich air is sprayed with a strongly acidic solution, such as sulfuric acid or nitric acid, to form ammonium sulphate or nitrate, respectively. Since the process depends on temperature increase, it is usually coupled with an anaerobic digester to make use of the excess heat. The pH is increased by adding slaked lime (Ca(OH)2) or sodium hydroxide (NaOH). However, mixing CO2 from the input stream with Ca(OH)2 can also increase the pH and promote the formation of CaCO3 prevent precipitates in the stripper. 
The economic viability of implementing an ammonia stripper is highly dependent on the business type under study. The estimated price of the operational installation for pig farms is approximately €100-150/m3 (in June 2023). It requires an annual manure processing capacity of at least approximately 20,000 tons to achieve a desired economic viability.
 

During the project, an innovative technology was developed to remove ammonia from the air of pig housing. The EIP-AGRI Gas Loop Operational Group implemented and monitored for 2 years an air washing system which able to remove ammonia from pig housing and recover the nutrient in form of ammonium sulphate solution. In this way, the nitrogen (N) cycle ends, limiting the emissions into the atmosphere. Nitrogen is an essential nutrient which is often emitted into the atmosphere in the form of harmful ammonia. The proposed technology captures and reuses ammonia in the form of fertilizer. Air treatment is based on a chemical adsorption of ammonia by backwashing with an acid reagent in a tower. Usually, the acid reagent is sulfuric acid (H2SO4) which reacts with ammonia (NH3) to form a stable suspension of ammonium sulphate ((NH4)2SO4), accumulates in a tank at the base of the washing tower. Treatment was tested for 2 years in fattening cycles of pigs for the PDO Prosciutto di Parma supply chain. During this period, the process produced ammonium sulphate fertilizer which reduced GHG emissions by replacing N-based chemical fertilizers. In fact, the production of ammonium sulphate solution was 230 liters per ton of live weight in 1 year. The characterization of the liquid demonstrated a pH value of 4, a Total Kjeldahl Nitrogen of 64 kg per tons (99% as N-NH4+), and a Total Organic Carbon of 1% in weight. Ammonium sulphate solution produced nutrients N category PFC 1(C)(I)(b)(i). This allows a GHG reduction of 66 kg CO2eq per tons live weight in 1 year. This, linked to replacement of N-based chemical fertilizers. 

Gas Loop Operational Group has made a prototype system with a Technology Readiness Level (TRL) of 8-9, that is a real system, complete and ready for applicability. 
This device, made during the project, allowed ammonia-rich air to draw from the pig housing through suction ducts located below the slated floor. After, the collected air was purified by treatment based on chemical ammonia adsorption. The latter consisted of backwashing the air with an acid reagent sprayed from the top of a tower scrubbing with packing bodies. The process was carried out at pH of 4.5 and a sulfuric acid (H2SO4) solution is used. This reacts chemically with ammonia to form a stable solution of ammonium sulphate ((NH4)2SO4), collected in a tank at the base of the washing tower. This treatment cannot replace the existing ventilation system but complements it. 
Air scrubbing effectively removed ammonia from the airflow of pig housing was on average 86%. Moreover, air treatment improved indoor air quality, reducing the ammonia average percentage within the treatment (range 57-67%) compared to the untreated control.   

During the project SOS_Aquae an innovative system was developed to increase the use of liquid fraction of digestate by mixing with water in fertigation. This practice offers an interesting option in regions where crops require water. During the project, three innovative agrosystems were investigated. In particular, the agronomic techniques stand out from the comparison with traditional practices, including soil management, chemical fertilizers input, conventional application and sprinkler irrigation:
- no-tillage, based on spring-summer crops (i.e., sorghum and maize) alternating with autumn-winter cover crops, fertigated with ammonium sulphate derived from stripping treatment of digestate, injected through sub-surface drip irrigation;
- minimum tillage, based on double crops, the first for food and the second for biogas. Both of them fertigated with microfiltered digestate injected through subsurface drip irrigation;
- agricultural system based on conventional, for food and no-food but fertigated with microfiltered digestate spread through a Rainger.
Distributing the nutrients mixed with the irrigation water on growing crops reduces nitrogen leaching and ammonia emissions to almost zero. The efficient distribution of water in sub-irrigation avoids water saturation of the soil and the emission of nitrous oxide. These innovative techniques for applying digestate extend its spreading periods and avoids soil compaction due to the passage of the slurry tanker. The sub fertigation avoids ammonia and odor emissions compared to conventional digestate application.
 

Fertigation with digestate from biogas plants is a practice that significantly enhances nutrient use efficiency on growing crops but is not yet widespread because of chemical-physical characteristics of digestate cause problems of clogging of the nozzles of the fertigation line.
SOS_Aquae Operational Group has tested and promoted an innovative integrated system to valorize the liquid fraction of digestate in fertigation, in order to maximize efficiency of the reuse of nutrients and the reduction of mineral fertilizers. Optimizing the efficiency of nutrients use allows to reduce the mineral fertilizers apply (both nitrogen and phosphorous) and at the same time avoid pollution caused by agricultural activities and therefore improve the water quality.
Digestate undergoes a preliminary solid-liquid separation, resulting in a solid fraction and a clarified liquid fraction. The latter is then microfiltered at 50 μm. This process produced microfiltered digestate, which is transferred to the field and mixed with water for fertigation on growing crops and injected into a Subsurface Drip Irrigation system with drip lines buried at a depth of 25-30 cm.
Project demonstrated that it is possible to use conservation tillage up to no-tillage in combination with continuous soil cover with two crops per year and innovative techniques for fertigation with renewable fertilizers (liquid fraction of digestate). All with a view to a more rational use of inputs, which are expensive, non-renewable and often have a strong environmental impact. The main effects for farms consist in the identification and application of agro-technological technics that allow to increase both productivity and environmental sustainability.

Management of agricultural digestates could contribute to the reduction of greenhouse gas (GHG) emissions. Digestate treatment, also aimed at nutrient recovery, could facilitate the relocation of surplus nitrogen (N) and phosphorous (P) from high livestock areas. In fact, nutrient content in digestates could meet the demand for fertilizers, thus reducing the use of chemical fertilizers. In this regard, the aim of the project is to reduce the content of N and P in livestock manure and digestates to reduce atmospheric emissions of ammonia, methane and nitrous oxide from both the storage and field use of livestock manure and digestate. N and P were recovered to produce a slow-release renewable fertilizer: Struvite (Magnesium Ammonium Phosphate Hexahydrate, MgNH4PO4·6H2O). About this, a real-scale prototype was designed and implemented to recover struvite from digestate. N and P were recovered from digestate in a small volume of stable product. Consequently, the remaining liquid fraction obtained had a reduced nutrient and organic matter content than the raw digestate.
The study highlights how methane and ammonia emissions from the treated fraction storage were much lower than the raw digestate, 86% and 42% respectively. Field application of the treated digestate led to a reduction in N emissions of 19% compared to raw digestate. Furthermore, reduction of N, P and dry matter contents in agricultural digestates has made possible to reduce GHG emissions during storage and field application of liquid fraction.
 

The aim of the project was decreasing nitrogen (N) and phosphorous (P) content in agricultural digestates to reduce ammonia, methane and nitrous oxide emissions from both storage and field use compared to the use of raw digestate. Therefore, a real-scale prototype has been designed, implemented and installed to recovering N and P from digestate and produce a renewable fertilizer: Struvite (Magnesium Ammonium Phosphate Hexahydrate, MgNH4PO4·6H2O).
Digestate treatment consisted in a solid-liquid separation by screw-press, follow by acidification of the liquid fraction up to pH of 7.5 using sulfuric acid (H2SO4 50% v/v). The processing was carried out in order to mineralize the organic phosphorous. After the liquid is microfiltered at 40 microns to partially remove the suspended solids and the organic matter. Because the latter hinders the struvite formation. Finally, in a crystallization and precipitation reactor, magnesium chloride (MgCl2 15% v/v) and sodium hydroxide (NaOH 30% v/v) are added to promote production of struvite crystals and allows an efficient recovery of N and P from digestates. Air blowing was also provided in the crystallization reactor to support the pH increasing due to carbon dioxide stripping.
Results showed a significant depletion of N (- 20%) and P (- 73%) than the input digestate. Moreover, a reduction in the percentage of orthophosphoric in the precipitate was highlighted in contrast of the raw digestate, 8% and 36% respectively. Together, an increase of total phosphorous concentration in the precipitate compared to raw digestate was also observed (2.247 mg/kg and 725 mg/kg, respectively).

Elevated bacteria levels in bathing water quality at Duncannon Beach, Ireland, together with the loss of its ‘Blue Flag’ status of environmental excellence in 2007 had a major impact on tourism in the area. Overall, 35 farmers from 4 dairy, 8 tillage and 23 dry stock farms, covering a catchment area over 975 hectares, came together to contribute to the recovery and long-term retention of the Blue Flag status. With guidance from a dedicated sustainability manager, farmers developed results-based rewards scheme to assess the pollution risks on farms and formed Pollution Potential Zone (PPZ) maps. To improve their PPZ scores, participating farmers implemented water protection improvement works on their farms and the catchment area. Overall, 15.5km of watercourses were fenced off, water troughs were moved 20m from waterways and sediment traps were installed to trap and filter run-off. Soil sampling was conducted, farm roadways were improved and nutrient management plans were developed for all farms. Participating farmers were encouraged to implement native riparian zones, plant native hedgerows and sow winter cover crops.  At a farm level, the catchment farms became more efficient, the number of septic tank failures reduced and compliance above the Nitrates Directives was observed.  At a local level, a reduction in bacterial pollution at Duncannon Beach was recorded and   an improvement in ecological quality was observed. At a community level, the participants reported a sense of ownership and appreciation for the local water environment. A combination of implementing these water protection improvement works on farms, having access to a sustainability manager and having a nutrient management plan drawn up increased the success of this project.
 

The Slurry Concentrator addresses the challenge of nutrient imbalance in high-density livestock regions by efficiently separating slurry into two phases: a nutrient-rich semi-liquid phase and a low-nutrient liquid phase. This separation directly reduces transport costs by significantly decreasing the volume of material needing transport. The concentrated phase retains the majority of nutrients, making it efficient for long-distance transport.
Benefits and opportunities for farmers:
• Cost Savings: By reducing the total volume of manure that needs to be transported, the Slurry Concentrator decreases transport costs. Farmers can move less material while transporting the same amount of nutrients. For breeding farms, savings start at 350 m³ of treated slurry, while for fattening farms, benefits begin at 500 m³. 
• Flexibility: The concentrated fraction is ideal for transporting to distant fields where nutrients are needed, while the diluted fraction, with its higher volume but lower nutrient concentration, can be applied to nearby fields.
• Environmental Impact: Reduced transport frequency lowers fuel consumption and emissions, contributing to more sustainable farming practices.
Implementation: The Slurry Concentrator is easy to set up with no major infrastructure changes. It requires a slurry pond for initial processing and an additional pond for the diluted fraction. Its mobile design allows it to be shared among multiple farms, further reducing individual costs and maximising efficiency.

• Nutrient concentration as a viable technology for slurry management

Currently, both organic and synthetic fertilizers are used to supplement nutrients in the soil. This allows farmers to grow their crops optimally. However, improperly managed nutrients can become pollutants that harm the environment. Therefore sustainable nutrient management is essential. Pocket digestion can play an important role in this sustainable story. 
Through pocket digestion (farm-scale anaerobic digestion), renewable energy is produced from on-farm biomass. It mainly concerns digestion of only one type of input stream (mono-digestion), in most cases dairy manure. The produced biogas is valorised in a combined heat and power (CHP) unit (<200 kW electrical power), of which the generated electricity and heat can be used to meet the farmers’ energy demand, thereby (partly) replacing fossil fuels and reducing greenhouse gas emissions. The environmental benefits of pocket digesters are not limited to the production of renewable energy. Since storage is minimized, (methane) emissions can be significantly reduced and environmental nuisance is limited. In addition, the digestate can be used as an organic fertilizer (with a higher fertilization efficiency than raw manure).
The OG Pocketboer 2 aims to find solutions for persistent and common problems with pocket digesters. It encourages implementation of solutions at many existing and future plants to improve the digester performance and efficiency.
By tackling these challenges, demonstrating the positive environmental impact and highlighting the sustainability aspect of pocket digestion, the technology and the interest to invest will improve. Nevertheless, ongoing efforts are needed to create more awareness on farm-scale digestion.

The Slurry Concentrator separates livestock slurry into two phases: a semi-liquid phase rich in organic matter and nutrients and a liquid phase with low organic nutrient concentration. Outcomes:
•Reduction of slurry volume by 20-30%, making transport more efficient.
•Concentrated fraction retains 85-95% of total solids, 45-55% of total nitrogen, and 85-95% of phosphorus.
•Low energy consumption with costs as low as € 0,0351 per m³.
•Technological and economic viability confirmed in joint analysis and pilot-scale operations.
Practical recommendations and opportunities for farmers:
•Cost Savings: Using the same tractor and slurry tanker for both fractions cuts investment and operational costs, and reduces management time.
•Enhanced Monitoring: Integrated online devices track nutrient content in real-time, facilitating precision fertilization, minimizing nutrient losses, and reducing emissions.
•Efficiency: The system simplifies nutrient application by providing easy-to-handle liquid fractions, optimising soil health and productivity.
•Shared use: The mobile design allows for shared use between farmers or within cooperatives, spreading the costs of investment and maintenance.
•Versatility: Suitable for different farm sizes and regions, it operates effectively regardless of climate, providing a practical solution for any farm producing livestock slurry.
Implementation: Place the concentrator in a slurry pond with floats. An additional pond is required to collect the diluted fraction. Use the concentrated fraction for distant fields and the diluted fraction for nearby fields, ensuring efficient nutrient distribution and reducing transport costs.