Evolution of microbiome composition, antibiotic resistance gene loads, and nitrification during the on-farm composting of the solid fraction of pig slurry using two bulking agents.

Composting is a nature-based method used to stabilize organic matter and to transform nitrogen from animal farm manure or solid fraction of slurry (SFS). The use of composted material as source of nutrients for agriculture is limited by its potential to facilitate the propagation of biological hazards like pathogens and antibiotic-resistant bacteria and their associated antibiotic-resistance genes (ARG). We show here an experimental on-farm composting (one single batch) of pig SFS, performed under realistic conditions (under dry continental Mediterranean climate) for 280 days, and using two different bulking agents (maize straw and tree pruning residues) for the initial mixtures.

The use of recovered struvite and ammonium nitrate in fertigation in a horticultural rotation: agronomic and microbiological assessment.

Phosphorus and nitrogen recovery from wastewater as struvite and ammonium nitrate (AN) may be viable alternative fertilizers to boost circularity in horticulture. A 2-year fertigated crop rotation in soil under greenhouse conditions was evaluated to determine the efficiency of both recovered products as raw materials for a nutrient solution (NS) manufacture. The effects of these treatments versus synthetic fertilizers were compared in terms of crop performance, plant nutrient uptake, soil chemistry and microbiota.

An effective method of utilizing vegetable waste in the form of carriers for Trichoderma strains with phytosanitary properties.

It has been assumed that compost from savoy cabbage and rapeseed straw is a good substrate for discrimination of the reproduction potential of Trichoderma strains. This hypothesis was verified based on a two-stage incubation experiment. The prepared mixture was fermented in a bio-reactor for 11 weeks.

Nitrification within composting: A review.

Composting could be regarded as a process of processes because it entails a number of complex chemical and microbiological reactions and transformations. Nitrification is one of such processes that normally takes place during the curing phase. This process has been studied in detail for wastewater treatment, and it is becoming an extensively studied topic within composting.

Effectiveness of a full-scale horizontal slow sand filter for controlling phytopathogens in recirculating hydroponics: From microbial isolation to full microbiome assessment.

The microbial disinfestation efficiency of an innovative horizontal-flow slow sand filter (HSSF) for treating nutrient solution spent from an experimental closed-loop nursery was evaluated by means of a combination of culture-dependent and independent molecular techniques. A dense inoculum of the fungal plant pathogen Fusarium oxysporum f.sp.

Biochar to reduce ammonia emissions in gaseous and liquid phase during composting of poultry manure with wheat straw.

Composting of poultry manure which is high in N and dense in structure can cause several problems including significant N losses in the form of NH through volatilization. Biochar due to its recalcitrance and sorption properties can be used in composting as a bulking agent and/or amendment. The addition of a bulking agent to high moisture raw materials can assure optimal moisture content and enough air-filled porosity but not necessarily the C/N ratio.

Biochar amendment for integrated composting and vermicomposting of sewage sludge - The effect of biochar on the activity of Eisenia fetida and the obtained vermicompost.

Sewage sludge derived biochar (SSDB) was used as a supplementary material for municipal sewage sludge (SS) and wood chips mixtures (WC) treated by combined composting and vermicomposting. SSDB added to the mixture before composting resulted in significantly higher reproduction rate: on week 4 the number of cocoons increased by 213% when compared to the mixture with no biochar. On week 6 the average number of juveniles increased 11-fold in the mixture with biochar added before composting and 5-fold in the mixtures with biochar added after composting when compared to the mixture with no biochar.

Nitrification during extended co-composting of extreme mixtures of green waste and solid fraction of cattle slurry to obtain growing media.

Next generation of waste management systems should apply product-oriented bioconversion processes that produce composts or biofertilisers of desired quality that can be sold in high priced markets such as horticulture. Natural acidification linked to nitrification can be promoted during composting. If nitrification is enhanced, suitable compost in terms of pH can be obtained for use in horticultural substrates.

Co-composting of poultry manure mixtures amended with biochar - The effect of biochar on temperature and C-CO2 emission.

Biochar as an amendment could have an impact on composting dynamics. This study investigated the effect of the addition of biochar (B) to poultry manure (P) mixed with wheat straw (S) (i.e.

Nitrification of leachates from manure composting under field conditions and their use in horticulture.

This work aimed to demonstrate the feasibility of nitrification applied to the treatment of leachates formed during composting of cattle and pig manure in order to promote their further use as liquid fertilizer in horticulture. Nitrification trials were successfully conducted in summer and winter seasons under Mediterranean climate conditions. Subsequently, effect of using the nitrified effluents as nutritive solution in the fertigation of lettuce (Lactuca sativa L.

Evolution of process control parameters during extended co-composting of green waste and solid fraction of cattle slurry to obtain growing media.

This study aimed to monitor process parameters when two by-products (green waste - GW, and the solid fraction of cattle slurry - SFCS) were composted to obtain growing media. Using compost in growing medium mixtures involves prolonged composting processes that can last at least half a year. It is therefore crucial to study the parameters that affect compost stability as measured in the field in order to shorten the composting process at composting facilities.

Design and monitoring of horizontal subsurface-flow constructed wetlands for treating nursery leachates.

Nursery leachates usually contain high concentrations of nitrates, phosphorus and potassium, so discharging them into the environment often causes pollution. Single-stage or two-stage horizontal subsurface flow constructed wetlands (HSSCW) filled with different substrates were designed to evaluate the effect and evolution over time of the removal of nitrogen and other nutrients contained in nursery leachates. The addition of sodium acetate to achieve a C:NO(3)(-)-N ratio of 3:1 was sufficient to reach complete denitrification in all HSSCW.

Nutrient solution monitoring in greenhouse cultivation employing a potentiometric electronic tongue.

This work investigates the use of electronic tongues for monitoring nutrient solution compositions in closed soilless systems. This is a horticultural technique in which the nutrient solution is continuously recirculated and an automatic recomposition system maintains the concentration of the different ions in the optimum range for the plants. Electronic tongues used in this study comprised an array of potentiometric sensors and complex data processing by artificial neural networks.

Changes in the chemical and physicochemical properties of the solid fraction of cattle slurry during composting using different aeration strategies.

Replacement of peat as a growing medium by a renewable material, such as an organic waste, is an issue of concern since harvesting of peat has a considerable environmental impact and, actually, it is a non-renewable resource. Cattle manure is a readily available organic waste, which means that once it goes through the composting process, it can be used as an alternative to peat, specifically, the solid fraction obtained from mechanical liquid-solid separation of cattle slurry (SF). Studies have shown it to be suitable for such uses.