Reducing the use of chemical fertilizers in agriculture is one of the EU Green Deal’s priorities. Since poultry production is increasing worldwide, stabilized poultry litter such as composted pelletized poultry litter (CPPL) is an alternative fertilizer option. On the contrary, compared to chemical fertilizers, the environmental impacts of composted products have not been adequately studied, and no data are currently available for CPPL produced by a closed composting system, such as the Hosoya system. The aim of this research was to assess the role of CPPL as a potential alternative for chemical fertilizer by evaluating the environmental impact of CPPL production via the Hosoya system using common chemical fertilizers. Based on life cycle assessment (LCA), the environmental impact (11 impact categories) was determined for the production of 1 kg of fertilizer, as well as for the production of 1 kg of active substances (nitrogen (N), phosphorus pentoxide (P2O5), and potassium chloride (K2O)) and the theoretical nutrient (NPK) supply of a 100 ha field with CPPL and several chemical fertilizer options. The production of CPPL per kilogram was smaller than that of the chemical fertilizers; however, the environmental impact of chemical fertilizer production per kilogram of active substance (N, P2O5, or K2O) was lower for most impact categories, because the active substance was available at higher concentrations in said chemical fertilizers. In contrast, the NPK supply of a 100 ha field by CPPL was found to possess a smaller environmental impact compared to several combinations of chemical fertilizers. In conclusion, CPPL demonstrated its suitability as an alternative to chemical fertilizers.

Due to the intensification of the poultry sector, poultry manure is being produced in increasing quantities, and its on-site management is becoming a critical problem. Animal health problems can be solved by stricter the veterinary and environmental standards. The off-site coupled industrial chicken manure recycling technology (Hosoya compost tea) fundamentally affects the agricultural value of new organic-based products. Due to the limited information available on manure recycling technology-related microbiological changes, this was examined in this study. A pot experiment with a pepper test plant was set up, using two different soils (Arenosol, slightly humous Arenosol) and two different doses (irrigation once a week with 40 mL of compost tea: dose 1, D1; irrigation twice a week with 40 mL of compost tea: dose 2, D2) of compost tea. Compost tea raw materials, compost tea, and compost tea treated soils were tested. The products (granulated manure, compost tea) and their effects were characterized by the following parameters: aerobic bacterial count (log CFU/g), fluorescein diacetate activity (3′,6′-diacetylfluorescein, FDA, µg Fl/g soil), glucosidase enzyme activity (GlA; PNP/µmol/g), and identification of microorganisms in compost tea with matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS). Furthermore, we aimed to investigate how the microbiological indicators tested, and the effect of compost tea on the tested plant, could be interpreted. Based on our results, the microbiological characteristics of the treated soils showed an increase in enzyme activity, in the case of FDA an increase +0.26 μg Fl/g soil at D1, while the GlA increased +1.28 PNP/µmol/g with slightly humous Arenosol soil and increased +2.44 PNP/µmol/g at D1; and the aerobic bacterial count increased +0.15 log CFU/g at D2, +0.35 log CFU/g with slightly humous Arenosol and +0.85 log CFU/g at W8. MALDI-TOF MS results showed that the dominant bacterial genera analyzed were Bacillus sp., Lysinibacillus sp., and Pseudomonas sp. Overall, the microbial inducers we investigated could be a good alternative for evaluating the effects of compost solutions in soil–plant systems. In both soil types, the total chlorophyll content of compost tea-treated pepper (Capsicum annuum L.) had increased as a result of compost tea. D1 is recommended for Arenosol and, D2 for slightly humous Arenosol soil.

Sunflower (Helianthus annuus L.) is one of the most important oil plants in Hungary, with a sown area of more than 627.000 ha in 2019. Sunflower cultivation is primarily important for use in the oil industry, but its role in feed and beekeeping cannot be neglected either. Sunflower adapts well to different production areas in terms of soil demand, yet, as important fact, it must be grown on soils with poorer conditions with intensive nutrient replenishment. From the agri-environmental point of view, in addition to the use of pelleted poultry manure products, which are also new to the consumer market, is of paramount importance. Their advantages include a wide range of nutrients as well as a soil structure improving effect. In our research, we investigated the starter effect of pelleted poultry manure products applied at different doses (200 kg ha-1 and 400 kg ha-1) on sandy soil with humus using a sunflower plant. The aim of our research to investigate the effect of using pelleted fertilizer products as starter fertilizers on sunflower plant germination, and investigate the effect of poultry manure products on soils. Based on our results, it can be stated that the pigment content (chlorophyll and carotenoid content) was positively influenced by the higher dose treatments (400 kg ha-1), thus increasing the photosynthetically active leaf area. Compared to the control, the carotenoid content in the test plants of the treatments increased, and the differences of this treatment proved to be significant (p<0.05). Our experiments supported the beneficial effect of pelleted poultry manure-based products in the soil-plant system.

Composting is an efficient technology for the utilisation of by-products and waste. It is also suitable for treating raw materials to convert fertilisers that are not recommended for application without pre-processing. Such is the case with poultry manure, which is very important to pre-treat due to its hazardous properties. An increasingly common form of compost is compost tea, which is made by soaking compost in water. In our experiment, we made compost tea from a composted and granulated poultry manure product. Three mixing ratios were used (1/5, 1/10, 1/10) and compost teas were set for three different extraction times (24–48–72 hours). After elimination of the experiment, the pH, EC, and nitrate and ammonium contents of the samples were measured. The aim of this study was to determine whether there is a difference between each mixing ratio and different extraction times. Based on our results, it can be said that the fluctuation of pH values during the experiment was low. Regardless of the mixing ratio and extraction time, the samples were in the slightly acidic range. The electrical conductivity, nitrate and ammonium content follow a similar trend, the values decrease significantly with the increase of the mixing ratio. Similar tendency was observed at the incubation time. The concentrations of both EC and nitrogen forms increase with increasing incubation time, in most cases significantly.

The management and recycling of organic manure, which is generated in increasing quantities in fastgrowing industries such as broiler chicken production, has become extremely significant. The European Union also encourages the application of organic fertilizers through the European Green Deal, which one of the aims to minimize chemical fertilizer use and increase the use of organic fertilizers. In the present study, the treatment and application of broiler chicken manure was investigated from an environmental standpoint, using the life cycle assessment methodology (ISO 14040:2006) and including three impact categories (global warming potential (GWP), acidification potential (AP), eutrophication potential (EP)). In the first scenario, the environmental impact of the production of a composted and pelleted poultry litter (CPPL) product from a so-called Hosoya composting plant was evaluated. The environmental impact of producing CPPL in the amount necessary to supply a 100 ha area with nutrients was analysed, compared to the environmental impact of producing NPK fertilizer combinations (AN, CAN, urea, TSP, MAP, KCl) with the same active ingredient content. In the second scenario, the environmental impact on maize production was assessed when nutrient replenishment was carried out with CPPL and NPK fertilizer combinations. Based on the results of the first scenario, the environmental impact of producing the CPPL is similar for GWP and higher for AP and EP than for the NPK fertilizer combinations. But need to considering that the same amount of NPK active substance requires a much larger amount of broiler chicken manure to be processed than the amount of chemical fertilizer to be produced. In contrast, in the second scenario a much lower environmental impact was already observed for GWP, AP and EP when the nutrient supplementation was done with CPPL in maize production. Overall, the results indicate that CPPL can be viable alternative to chemical fertilizers, not just from an environmental standpoint but from financially due to continuously rising fertilizer prices.