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.

During the industrial production of broiler chicken, a large amount of manure is produced, of which easily contained nitrogen content (without pre-treatment) is released into the atmosphere as an air pollutant. In our experiments, we aimed to prepare compost tea, also known as water extract of compost, from pre-treated poultry manure in order to create a product can be utilized as liquid nutrient supply. The poultry manure source was the Baromfi-Coop Ltd. located in Nyírjákó, Hungary, where it was treated by composting. As a result of this pre-treatment of the poultry manure, its nutrient parameters improve and nitrogen is present in a form that is better utilized for plants. Furthermore, this product is suitable for further utilization and also can be the base material for a brand-new product. For this reason the effects of compost/water ratio, incubation time, low oxygen level, and extraction time on the parameters of the resulted product were studied in the frame of developing new soil-life enhancing microbial product, so-called compost tea. Chemical parameters of the compost used as base material strongly determined the properties of the resulted compost tea, especially the ratio of the various nitrogen forms, their concentration and the salt content. It was found that adding water at a higher rate that means 1/40 and 1/50 mixing ratios results in more cost-effective production. In the experiment the compost tea were held under oxygen-poor conditions, therefore pH of the extractions decreased, which influenced the quality and quantity of their nutrient content.

Composting represents an efficient technology that enables the effective utilization of by-products and waste materials. Moreover, it proves to be highly suitable for processing raw materials and converting them into fertilizers that would not be recommended for direct application without undergoing pre-processing. This is particularly crucial in the case of poultry manure, which possesses potentially hazardous properties and necessitates pre-treatment. One increasingly prevalent form of compost is known as compost tea, which involves the immersion of compost in water. In this experiment, compost tea or compost solution were created using a product called composted and pelletized poultry litter (CPPL). Four compost:water ratio (CWR) (1/2.5, 1/5, 1/10, 1/20) were applied, along with three different extraction durations (24, 48, and 72 hours) and three distinct extraction temperatures (20 °C, 35 °C, and 50 °C). Since the 1/10 and 1/20 ratios were found to be the best for subsequent applicability and spreadability, their content parameters were measured further. After elimination of the experiment, the most important nutrients (nitrogen content (nitrate and ammonium), phosphorus and potassium) were determined. The results showed that the nutrient content was highest for all four parameters at the extraction temperature of 35 °C. For example, while at 20 and 50°C the NO3 – content ranged from 263 to 768 mg/l and from 210 to 534 mg/l, at 35 °C it ranged from 498.33 to 2636.67 mg/l, irrespective of the mixing ratio and extraction time. If the extraction temperature is not taken into account, the nutrient content increased with the increase of the extraction time, so that the highest values were measured at 72 hours extraction time obviously. The data measured in the present experiment will serve as a basis for subsequent experiments with different indicator plants, investigating the effect of compost when applied as a solution.

The treatment and utilization of plant and animal waste and by-products from agriculture is very diverse. Traditional environmental management practices for waste management have been retained through soil conservation and the applied of recycle degradable organic substances in soil. The management of by-products from agriculture (animal husbandry) is important because a closed loop can be created to utilize by-products (manure, feathers) from the production of the main product (eggs, meat, milk) and to form a raw material for a new product. It is important to treat the resulting by-products, especially deep-litter manure, as it has served as a basis for compost-treated manure to develop an organic-based, soil-conditioning product line. Poultry manure by itself is not suitable as a substrate for aerobic decomposition, so it has to be mixed with other substances (zeolite, bentonite, soil), because of its high nutrient capacity, it is an acidifying substance. The aim of this study was to compost the mixture of poultry manure and hen manure by the addition of zeolite and to monitor the composting process. It was also our aim to statistically determine the effect of the zeolite on parameters describing the composting process. The windrow composting experiments were set up in the composting area of the University of Debrecen, Institute of Water and Environmental Management. The composting experiment was 62 days long, during which the main parameters describing the composting process were continuously monitored: temperature (°C), moisture content (w/w%), electrical conductivity (mS/cm), organic matter content (w/w%), examination of nitrogen forms (w/w%). In this study, three factors were investigated: temperature, humidity, and pH. For statistical evaluation, R software and RStudio user interface were used. We developed a repeated measurement model, in which the fixed and random effects were determined for our parameters under study, and the resulting relationships were shown on interaction plots. Based on our results, the temperature of the prisms has become independent of the ambient temperature and the composting stages can be separated in both the control and the zeolite treated prisms. In the repeated measurement model, we proved that treatment, time and treatment: time interaction were significant at both temperature and pH.

Composting is one of the most popular recycling processes for organic waste. Composting plays an important role in waste and by-product management and is becoming increasingly important in both sustainable energy management and circular economy. Composting transforms organic matter to produce a safe and stable by-product (compost) that can be applied to arable land in a similar way to fertilizer. Physical, chemical and biological methods can be used to monitor the process and to determine the maturity of the compost, as spectrometric/spectroscopic methods play an important role in the analysis of different environmental samples. Our aim was to (1) non-destructively detect the effects of different additive ratios on the spectral properties of the composting process and the spectral data of different compost mixtures, (2) to find the wavelength ranges of the reflectance curve (inflection points) sensitive to compost maturity, (3) to determine the correlation between the inflection points and the chemical and physical parameters measured in compost by conventional methods. The mixture of broiler and hen manure and zeolite was composted 62 days in windrow composting. In the composting experiment, the moisture content and temperature (°C) were measured every three days and compost samples were taken and in 10% destillated aquaeous suspension were measured the pH and electrical conductivity (mS cm-1). Compost samples dried to mass stability were spectrally analyzed in the wavelength range 400–1000 nm with AvaSpec 2048 spectrometer. Based on the results, the reflectance of mature compost were smaller in the last days of composting than the reflectance values of day 0 samples, thus compost maturity can be detected spectral in the VIS-NIR wavelength range. For the tested compost prisms, the reflectance of each sampling day shows a constant slope, with a significant overlap of the reflectance curves up to 400–700 nm wavelength range, and there was a breakpoint in the 700–750 nm wavelength range which was proved by binary encoding.