This article presents the current state of biogas (biomethane) production technology—an example of the use of goat manure in terms of photofermentation efficiency. The theoretical and experimental potential of biomethane using biodegradability for anaerobic fermentation of goat manure was indicated. Goat manure was tested for its elemental composition to determine the suitability of this raw material for biogas production. The quality of biogas produced under atmospheric conditions from goat manure placed in a reactor (photodigester) was assessed. An attempt was made to determine the process conditions for immobilization on a goat manure bed (depending on the research material collected), which allows for demonstrating the activity of the fermentation bacterial flora, thus influencing the amount of biogas (biomethane) produced in the reactor. A mechanism for the photofermentation process involving the production of biomethane was developed. The novelty of this article is the development of the use of goat manure in an innovative way, pointing to the development of the biomethane industry. When comparing goat manure, active group (compact bed), it should be noted that K 3.132%, Na 0.266%, Ca 1.909% and Mg 0.993% are lower values compared to the material with values of K 3.397%, Na 0.284%, Ca 1.813% and Mg 0.990% which are higher. This is undoubtedly due to the presence of nutrients in the deposit that support the biomethane production process. The active group (compact bed) material A shows a dynamic increase in biomethane production with lower nutrient values. However, material B, having a higher percentage of ingredients, shows stabilization of biomethane production after the sixth month of the process. Technological trends and future prospects for the biomethane sector were initiated.

Effective nutrient management in grassland ecosystems is essential for maintaining soil nutrient balance and ensuring high forage productivity. A field experiment was conducted between 2022 and 2024 on a permanent dry meadow at the Experimental Station in Poznań-Strzeszyn, western Poland. The trial, established in autumn 2021, was carried out under production conditions on large plots (140 m² each). Plots were assigned to different fertilisation regimes, varying in both type and dosage. The treatments included an unfertilised control, three levels of annual mineral NPK fertilisation (NPK1, NPK2, NPK3), three levels of annually applied farmyard manure (FYM1, FYM2, FYM3), and three levels of mineral and organic fertilisers applied every two years (NPK1/FYM1, NPK2/FYM2, NPK3/FYM3). Throughout the study, botanical composition, annual dry matter yield (DMY), nitrogen (N), phosphorus (P), and potassium (K) content in the plant biomass were assessed. A simplified nutrient balance was calculated based on nutrient input from fertilisers and nutrient output with harvested yield. The average N balance across three years ranged from −12.17 kg N ha⁻¹ in control to +20.6 kg N ha⁻¹ in FYM3. For phosphorus, average balances ranged from −7.2 kg P ha⁻¹ in the control to +9.8 kg P ha⁻¹ in FYM3. In contrast, potassium balances were mostly negative: from −51.7 kg K ha⁻¹ in FYM1 to −7.4 kg K ha⁻¹ in NPK1. The most balanced nutrient budgets were observed under alternate NPK/FYM fertilisation, with moderate surpluses of N and P and a smaller K deficit compared to FYM applied alone. In contrast, inorganic and organic fertilisation applied separately resulted in greater nutrient surpluses or a pronounced potassium deficit. This study emphasises the importance of balanced nutrient management in permanent meadows, showing that moderate fertilisation strategies, such as alternating FYM and mineral NPK, can maintain productivity, and reduce environmental impacts. These findings provide a practical basis for developing sustainable grassland management practices under variable climatic conditions.

The increasing amount of waste generated by the agricultural industry, especially in the wine sector, poses environmental and economic challenges. This issue is particularly pressing as the global population is projected to reach 8.5 bln by 2030, which will further exacerbate solid waste management problems. Therefore, a study was conducted to investigate the possibility of using grapevine leaves as an alternative animal feed ingredient. The aim of the present study was to analyse the chemical composition of the leaves of four grape varieties, ‘Regent’, ‘Rondo’, ‘Seyval Blanc’ and ‘Solaris’, in the context of their potential use as animal feed. The results indicated that grapevine leaves are a valuable source of protein, fibre and micro- and macronutrients, with the content of these components differing significantly between varieties. The leaf yield per hectare ranged from 6.08 to 8.78 Mg, with ‘Solaris’ yielding significantly the highest biomass among the studied cultivars. The analysis also revealed significant differences in the content of amino acids such as cystine, glycine, valine, tryptophan and threonine, as well as in the content of minerals, starch and neutral detergent fibre. The results obtained highlight the variation in nutritional value of grapevine leaves between varieties, suggesting the possibility of selective use depending on the nutritional needs of the animals. Utilizing such by-products supports a circular economy model and reduces the negative environmental impact of wine production.

The use of agricultural and food industry by-products as alternative feed sources is gaining importance in the context of global environmental and economic challenges. The leaves and husks of hazelnuts (Corylus avellana) are rich in crude fibre and microelements, which may make them suitable for use in livestock feed. The aim of the study was to analyse and compare the chemical composition and nutritional value of the leaves and husks of four hazelnut varieties (‘Kataloński’, ‘Olbrzymi z Hale’, ‘Olga’, ‘Webba Cenny’) in terms of their potential use as feed components. Significant differences between biomass types and varieties were found in most of the analysed parameters. The leaves were characterised by higher nitrogen (up to 1.11%), phosphorus (up to 0.109%), calcium (up to 1.042%) and magnesium (up to 0.264%) content, which indicates their potential as a protein-mineral supplement. The husks showed higher potassium (up to 2.037%), sodium, iron (up to 3032.9 mg∙kg−1), manganese and zinc, suggesting their potential use as a source of fibre and trace elements. Both the leaves and husks of hazelnuts are characterised by a diverse chemical composition, indicating their potential use in livestock nutrition, especially in regions with a deficit of traditional feed sources. Further research on the digestibility and effect of these components on animal health and production parameters is needed to determine the full range of their practical usefulness in sustainable nutrition.

The nutritional value of green forage is a result of various pratotechnical practices, including fertilisation and harvest timing. Additionally, individual plant species present in natural grasslands may respond differently to those practices. The study aimed to investigate the effect of fertilisation type (farm yard manure (FYM) and NPK fertilisation) and the timing of the first regrowth harvest of meadow sward (ten harvest dates) on the lignin and structural carbohydrates of three dicotyledonous meadow plants: Taraxacum officinale F.H. Wigg., Achillea millefolium L. and Lotus corniculatus L. Plant material was harvested from 28 Apr until 26 Jun at 7-day intervals and analysed for cellulose (CL), hemicellulose (HCL), and acid detergent lignin (ADL). The levels of neutral detergent fibre (NDF), acid detergent fibre (ADF), and ADL were measured using near-infrared spectroscopy (NIRS) with a NIRFlex N-500 device. Cellulose was calculated as the difference between ADF and ADL, while HCL was calculated by subtracting ADF from NDF. T. officinale had the lowest HCL (average 65.5 g∙kg−1 DM) and ADL content (47.1 g∙kg−1 DM) while A. millefolium had the highest CL content (266.5 g∙kg−1 DM) and ADL (52.3 g∙kg−1 DM). In contrast, L. corniculatus accumulated the highest HCL (104.5 g∙kg−1 DM) and the lowest CL content (246.1 g∙kg−1 DM). An increase in all studied parameters content was observed with later harvest dates. On average, plants fertilised with FYM contained lower amounts of structural carbohydrates and ADL compared to those fertilised with NPK.