Search Results (178)

This study aims to evaluate eco-innovative solutions in the fertilizer industry that allow for waste valorization in the context of a resource-efficient circular economy. A comprehensive reuse strategy was developed for low-rank peat and post-cultivation horticultural mineral wool, involving the extraction of valuable humic substances from peat and residual nutrients from used mineral wool, followed by the use of both post-extraction residues to produce organic–mineral substrates. The resulting products/semifinished products were characterized in terms of their composition and properties, which met the requirements necessary to obtain the admission of this type of product to the market in accordance with the Regulation of the Minister for Agriculture and Rural Development of 18 June 2008 on the implementation of certain provisions of the Act on fertilizers and fertilization (Journal of Laws No 119, item 765). Elemental analysis, FTIR spectroscopy, and solid-state CP-MAS ¹³C NMR spectroscopy suggest that post-extraction peat has a relatively condensed structure with a high C content (47.4%) and a reduced O/C atomic ratio and is rich in alkyl-like matter (63.2%) but devoid of some functional groups in favor of extracted fulvic acids. Therefore, it remains a valuable organic biowaste, which, in combination with post-extraction waste mineral wool in a ratio of 60:40 and possibly the addition of mineral nutrients, allows us to obtain a completely new substrate with a bulk density of 264 g/m³, a salinity of 7.8 g/dm³ and a pH of 5.3, with an appropriate content of heavy metals and with no impurities, meeting the requirements of this type of product. A liquid fertilizer based on an extract containing previously recovered nutrients also meets the criteria in terms of quality and content of impurities and can potentially be used as a fertilizing product suitable for agricultural crops. This study demonstrates a feasible pathway for transforming specific waste streams into valuable agricultural inputs, contributing to environmental protection and sustainable production. The production of a new liquid fertilizer using nutrients recovered from post-cultivation mineral wool and the preparation of an organic–mineral substrate using post-extraction solid residue is a rational strategy for recycling hard-to-biodegrade end-of-life products. Full article

Agriculture is one of the most important sectors of the global economy, but it increasingly faces sustainability challenges in meeting rising food demands. The intensive use of mineral fertilizers not only improves yields, but also causes negative environmental impacts such as increasing greenhouse gas emissions, water eutrophication, and soil degradation. To develop more sustainable solutions, the focus is on organic fertilizers, which are produced using waste and biostimulants such as amino acids. The aim of this study was to develop and characterize liquid nitrogen–calcium–magnesium fertilizers produced by decomposing dolomite with nitric acid followed by further processing and to enrich them with a powdered amino acid concentrate Naturamin-WSP and liquid extracts from digestate, a by-product of biogas production. Nutrient-rich extracts were obtained using water and potassium hydroxide solutions, with the latter proving more effective by yielding a higher organic carbon content (4495 ± 0.52 mg/L) and humic substances, which can improve soil structure. The produced fertilizers demonstrated favourable physical properties, including appropriate viscosity and density, as well as low crystallization temperatures (eutectic points from –3 to –34 °C), which are essential for storage and application in cold climates. These properties were achieved by adjusting the content of nitrogenous compounds and bioactive extracts. The results of the study show that liquid fertilizers enriched with organic matter can be an effective and more environmentally friendly alternative to mineral fertilizers, contributing to the development of the circular economy and sustainable agriculture. Full article

Green energy is expected to play an increasingly important role in the energy sector, so the volume of biogas production and the formation of anaerobic digestates is likely to increase in the future. A wide range of biodegradable organic materials are used in anaerobic digesters to produce biogas. This review focuses on the properties of anaerobic digestates and their effects on physical, chemical and biological soil parameters discussing the benefits, limitations and potential risks. Due to the variety of technologies and raw materials used, anaerobic digestates have diverse properties. Therefore, their impact on specific soil parameters, such as bulk density, aggregate stability, pH, electrical conductivity (EC), soil organic matter (SOM) or microbial activity can vary in magnitude and direction. These effects are also influenced by the variety of soils. Although digestates usually have a significant macro- and micronutrient content, their potentially toxic components or high salt content may limit their use. Despite the limitations, the application of anaerobic digestates generally has more advantages than disadvantages. The use of good-quality anaerobic digestates can improve the physical and chemical properties of the soil, increase soil nutrient and SOM content, as well as soil microbial activity. Full article

The domestic cat is the primary reservoir host of three flea-borne Bartonella species, one of which (Bartonella henselae) causes reduced fertility and reproductive failure in experimentally infected cats. Vertical transmission of Bartonella has been documented only in B-cell deficient mice, but not immunocompetent animals. As many free-roaming cats are chronically infected with Bartonella and may be immunocompromised by environmental stress or coinfection, we attempted to isolate Bartonella from the fetal and placental tissues of pregnant queens spayed during trap–neuter–release. Four samples from each tissue (ovary, uterus, fetus, and placenta) were split for direct DNA extraction, liquid culture, and culture on a blood agar plate. Samples from infected queens were inoculated into liquid media and sampled weekly for three weeks for DNA extraction and plating. Bartonella DNA was sequenced directly from 28% (5/18) of the free-roaming queens. For these five queens, liquid enrichment culture was attempted in duplicate for fetal and placental samples. Bartonella clarridgeiae DNA was amplified using qPCR liquid enrichment cultures from the placentas of two cats. These findings suggest that viable Bartonella organisms are present in feline reproductive tissue. Additional studies are needed to assess the transplacental transmission of Bartonella spp. and Bartonella’s influence on fetal development. Full article

The application of soil organic amendments is a well-established approach to enhancing soil fertility; yet the effects of poultry feather hydrolysate (PFH) on temperate coarse-textured agricultural soils remain underexplored. A six-month microcosm experiment was conducted to determine the effects of PFH in different states (liquid or solid) and addition rates (none, low, or high; i.e., 0, 4, or 8 t dw ha⁻¹, respectively) on microbial activity, nutrient availability and retention, and organic matter (OM) stabilization in two coarse-textured soils (loamy sand or sandy loam). Sandy loam soil exhibited a stronger response to PFH application, supporting 20% higher microbial activity, 35% higher nutrient retention, and 89% higher OM content in soil aggregates compared to loamy sand soil, reflecting enhanced OM stabilization. Moreover, PFH in the liquid state demonstrated more prolonged microbial activity and more sustained release of nutrients compared to the solid state. Finally, at the end of incubation, the high addition rate of PFH significantly increased soil nutrient content by 106%, while the low addition rate limited the increase to 39%, both compared to the no addition rate. Overall, the results suggest that PFH, particularly in the liquid state and at the high addition rate, serves as an effective soil organic amendment, enhancing microbial activity and soil fertility while emphasizing the importance of soil texture in optimizing its application. Full article

Cucumber (Cucumis sativus) greenhouse cultivation offers higher yields and quality compared to open-field systems, but success depends on balanced fertilization. This study compared chemical and biol (liquid organic fertilizer) treatments on cucumber yield, fruit number, and size (Centauro 1 variety). Four treatments—Biol30 (3% biol), Biol70 (7% biol), Nitro (urea), and Comp (complete chemical fertilization)—were applied in a randomized design. Results indicated no statistically significant differences in yield among treatments (p = 0.094), yet Biol70 outperformed Nitro and Comp by 1.44× and 1.18×, respectively. Notably, Nitro produced the largest and heaviest fruits but the lowest fruit count, while organic treatments (Biol30 and Biol70) demonstrated comparable fruit quality and higher yields. The Biol70 treatment, in particular, highlighted the potential of biol as a sustainable alternative, achieving yields of 272.59 kg total production and 34.07 kg per bed, with fruit weights averaging 0.4309 kg and lengths of 26.511 cm. These findings underscore the viability of biol, especially at higher concentrations, as an eco-friendly substitute for chemical fertilizers, aligning with global efforts to promote sustainable agricultural practices. Full article

The content of bioavailable forms of phosphorus (P) and potassium (K) in soil is essential for the proper functioning of agroecosystems. This study aimed to determine the effects of pig slurry (PS) and NPK mineral fertilizers on soil phosphorus (P) and potassium (K) fractions, the relationship between these fractions and basic soil agrochemical properties, and crop yield. The research material was collected from a long-term experiment established in 1955 in Prague-Ruzyně, Czechia. The effect of two constant factors was analyzed: manure application (control, PS) and different doses of NPK fertilizers (N₀P₀K₀, N₁P₁K₁, N₃P₂K₂, and N₄P₂K₂). A significant effect of fertilization on basic soil properties was demonstrated, including total soil carbon and nitrogen. PS and NPK fertilization also significantly affected the content of water-soluble and moderate labile fractions of P and K. These fractions were positively correlated with plant-available P and K (Mehlich 3). The best fertilization option, which resulted in the greatest increase in yield, was the use of PS and mineral fertilizers at the N₃P₂K₂ level. Increasing the nitrogen dose to the level of N₄ resulted in a decrease in the content of bioavailable forms of P and K in topsoil despite the application of PS. Full article

This study investigated the effects of liquid bio-fertilizer (LBF) on the growth, antioxidant activity, soil properties, and soil microbial composition of Chinese cabbage (Brassica rapa L. ssp. pekinensis). The LBF application significantly enhanced vegetative growth by increasing the leaf length, leaf width, fresh weight, and dry weight. Additionally, antioxidant activity increased with rises in total phenolic and flavonoid contents. However, the per-unit antioxidant concentrations decreased, likely due to rapid biomass accumulation. Soil analysis showed improvements in pH, organic matter, and available phosphorus. Microbial analysis revealed that Acidobacteria enrichment was associated with enhanced nutrient cycling despite reduced overall microbial diversity. Transcriptomic analysis identified 445 differentially expressed genes with upregulation in the metabolism and photosynthesis-related pathways, suggesting improved nutrient assimilation and energy production. These findings demonstrate that LBF enhances plant growth and soil fertility while influencing microbial dynamics and gene expression. Full article

Dewatering anaerobic digested sludge leaves a liquid fraction known as reject water, a liquid organic fertilizer containing high amounts of ammonium nitrogen (NH₄-N). However, its concentration should be enhanced to produce commercial fertilizer. Thus, reject water nitrification for stabilization as well as for nitrate capture in biochar to be used as a slow-release fertilizer is proposed. This study attempted to accomplish enhanced nitrification by tuning the operating parameters in two lab-scale sequential-batch reactors (SBRs), which were fed reject water (containing 520 ± 55 mg NH₄-N/L). Sufficient alkalinity as per stoichiometric value was needed to maintain the pH and free nitrous acid (FNA) within the optimum range. A nitrogen loading rate (NLR) of 0.14 ± 0.01 kg/m³·d and 3.34 days hydraulic retention time (HRT) helped to achieved complete 100% nitrification in reactor 1 (R₁) on day 61 and in reactor 2 (R₂) on day 82. After a well-developed bacterial biomass, increasing the NH₄-N concentration up to 750 ± 85 mg/L and NLR to 0.23 ± 0.03 kg/m³·d did not affect the nitrification process. Moreover, a feeding sequence once a day provided adequate contact time between nitrifying sludge and reject water, resulting in complete nitrification. It can be concluded that enhanced stable nitrification of reject water can be achieved with quick adjustment of loading, alkalinity, and HRT in SBRs. Full article

Applying organic amendments enhances agroecosystem multifunctionality (EMF), yet its mechanisms via soil food-web energetics remain unclear. A field experiment was conducted on China’s Loess Plateau in a winter wheat system, comparing mineral fertilizer with straw, biochar, and liquid organic fertilizer to assess their impacts on nematode communities and EMF (plant performance and carbon, nitrogen, phosphorus cycling). Using high-throughput sequencing and energy flux modeling, we found that straw and biochar enhanced nematode diversity and co-occurrence network complexity, while liquid organic fertilizer reduced network complexity. Straw balanced fungal- and bacterial-driven energy pathways, enhancing energy flow uniformity (1.05) and EMF. However, its high C:N ratio requires mineral fertilizers to alleviate nitrogen limitations, ensuring stable bacterial energy fluxes and preventing functional trade-offs. Biochar elevated total energy flux but prioritized bacterial- and herbivore-driven pathways, reducing energy flow uniformity (0.76) and functional balance. Liquid organic fertilizer favored omnivores-predators, destabilizing lower trophic functions with minimal functional gains. Amendment properties (C:N ratio, pH) shaped nematode-mediated energy distribution, linking biodiversity to multifunctionality. Overall, straw is optimal for supporting EMF when combined with mineral fertilizers, while biochar and liquid fertilizer require tailored management to mitigate functional trade-offs. These findings advance sustainable strategies for dryland agroecosystems in the Loess Plateau region and similar environments. Full article

Anaerobically digested liquid pig manure (LPM) is enriched with nutrients and thus can be used as an alternative nutrient source and substitute for chemical fertilizer (CF) in rice (Oryza sativa L.) farming. However, there are concerns regarding the contamination of the surrounding water due to the discharge of ponding water containing dissolved organic carbon (DOC), nitrogen (N), and phosphorus (P) from rice paddies fertilized using LPM. This study investigated the effects of the co-application of fly ash (FA) and zeolite (Z) amendments (FAZ amendments) on the concentration of DOC, N, and P in the ponding water of rice paddies fertilized with LPM at two different rates (standard (LPM_S) and double (LPM_D) at 11 and 22 g N m⁻², respectively). Rice was cultivated using four nutrient treatments, including no input, CF (11 g N m⁻²), LPM_S, and LPM_D, with or without FAZ amendments. When FAZ was not amended, LPM_S and LPM_D application increased the DOC concentration by 32% and 41%, respectively, compared to CF treatments (11 g N m⁻²), reflecting a high DOC concentration in LPM. The total N and P concentrations in the ponding water were lower in LPM_S treatment (by 5 and 8%, respectively) but higher (by 94% and 47%, respectively) in LPM_D treatment compared to CF treatments in the absence of FAZ, indicating a high potential for water pollution with a double LPM application rate. With a given nutrient treatment, FAZ amendments decreased DOC by 15–39%, supporting the immobilization of DOC by Z. FAZ consistently decreased the NH₄⁺ concentration by 6–51% across the nutrient treatments, likely via the sorption of NH₄⁺ onto the negatively charged sites of Z, but its effect on total N concentration was not consistent. Unexpectedly, total P concentration increased (by 77–167%) following the FAZ amendment. FAZ amendments tended to increase rice biomass and grain yield for LPM treatments, but these rice growth parameters were poor compared to CF regardless of FAZ amendment. Our results show that the application of LPM as a complete replacement for CF may hamper rice yield while increasing the likelihood of water pollution with DOC and P, although the co-application of FAZ may help to reduce rice yield loss and decrease DOC and NH₄⁺ concentrations. Full article

With growing importance in sustainable agriculture and environmental protection, the use of liquid organic fertilizers (LOFs) as a replacement for or supplement to chemical fertilizers has grown in popularity. The effectiveness of LOFs depends on the content of elemental nutrients as well as plant growth regulators. Three types of materials, i.e., brassica vegetables, mushrooms, and soybeans, were fermented for 60 days to produce LOFs. The soybean-based fertilizer (SOF) contained the highest concentrations of mineral nutrients (0.99% N, 0.11% P), organic carbon (6.75%), and IAA (24 µg/mL), followed by the mushroom-based fertilizer (MOF) and brassica-based fertilizer (BOF). During fermentation, polyamines (PAs) in LOFs dramatically increased with time, with MOF and SOF containing higher concentrations of PAs than BOF. Greenhouse-grown rice (Oryza sativa L.) plants at 21 d old were sprayed with diluted (1:75) solutions of LOFs or chemical fertilizers (CF) before being treated for 7 and 14 days with 100 mM NaCl. For both non-stress and salt-stress groups, the root and shoot dry weights, chlorophyll contents, net photosynthesis rates, and endogenous PAs of the LOF- and CF-treated plants were significantly higher than those of the plants receiving no fertilizers. The SOF was the most effective and enhanced growth and photosynthesis at a similar level as the chemical fertilizer and had good potential to be employed as an eco-friendly substitute for chemical fertilizer. Full article

During the process of producing potassium fertilizer from salt lake resources, a large amount of waste liquid brine, rich in raw materials such as magnesium chloride, is generated. In this work, a MoS₂/MgAl-LDH composite material was constructed using the secondary hydrothermal technique. Characterizations including X-ray diffractometer (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) confirmed the distribution of MoS₂ nanosheets on the surface of MgAl-LDH. Under full-spectrum irradiation, the degradation efficiency of Rhodamine B reached 85.5%, which was 69.2% higher than that of MgAl-LDH alone. The results from the electrochemical, UV-Vis, and XPS-VB tests indicate that the internal electric field accelerated the separation and transportation of charge carriers between MoS₂ and MgAl-LDH. These findings demonstrate the great potential of MoS₂/MgAl-LDH as a photocatalyst in the degradation of organic dyes, which will aid in the green recycling utilization of magnesium resources from salt lake by-products. Full article

This study evaluates the efficacy of innovative peat-free organic substrates and liquid fertilizers as alternatives to traditional peat substrates in the cultivation of Fagus sylvatica L. and Quercus robur L. seedlings in a newly established forest in Southern Poland. The experiment was conducted in a 2 × 2 × 4 experimental layout using a randomized complete block design, comprising eight treatments that combined four substrate types (three novel organic substrates and one peat-based control) with two types of fertilizers (solid and liquid). After one year of growth, biomass and nutrient allocation in the roots, shoots, and leaves of the seedlings were analyzed. The results showed that while solid fertilization enhances biomass accumulation, liquid fertilization supports more uniform growth across different substrates, particularly in oak seedlings. Also, peat substrates recorded the highest nutrient allocation. However, one novel substrate (R22) performed comparably, indicating its potential as a viable peat alternative. Significant interspecies differences were observed, with beech seedlings allocating more biomass to aboveground organs, while oak seedlings favored belowground nutrient allocation. These findings suggest that while peat substrates and solid fertilizers currently provide better outcomes, the innovative R22 substrate shows promise for sustainable forestry practices. Further refinement of the liquid fertilizer was recommended to enhance effectiveness. Full article

The cost of producing organic crops is increasing. Agricultural wastes can be used as biostimulants to increase plant growth and productivity and reduce the dependence on chemical fertilizers. A pouch assay and a potted greenhouse experiment were conducted to investigate the effect of pyroligneous acid (PA) and sea lettuce (SL) on kale (Brassica oleracea subsp. acephala (DC.) Metzg) seed germination and growth. Although previous studies have demonstrated that these two biostimulants could promote plant germination and growth, there is little research to compare their effects on seed germination and plant growth. The pouch assay showed that PA liquid affected the seed germination rate under different concentrations; the seed germination rate decreased as the concentration of PA liquid increased. However, the effect of seed germination was less pronounced in SL liquids. Kale seeds treated with 0.01% PA showed the best elongation and seedling growth performance. Moreover, the greenhouse experiment indicates that SL liquids significantly (p < 0.05) affected kale growth production, while PA liquid had less difference on kale growth under various concentrations. The 0.25% PA and 1% SL increased the aboveground fresh weight by ca. 26% and 29%, respectively. Also, the phytochemical contents of kale leaves, including phenolics, flavonoids, ascorbate, and protein, were significantly increased with 0.25% PA and 1% SL application. These results suggest that low concentrations of PA are more suitable for seedling root growth in kale and 1% SL had the most significant growth-promoting effect on kale. Hydrothermal carbonization sea lettuce liquid can be used as a good biostimulant for agricultural production to improve kale germination and growth. Full article