Search Results (473)

This study is an economic evaluation of a composting facility in southeastern Spain (applying Life Cycle Costing), a key region in European horticulture with a significant availability of agricultural biomass. Composting helps reduce dependence on inorganic fertilizers, aligning with European policies that promote the transition toward organic fertilization practices. In addition, compost enhances soil health, increases soil organic carbon, and supports climate change mitigation. Despite its agronomic and environmental benefits, and the large availability of biomass in this region, there is a notable lack of literature addressing the economic costs of composting, which is the first step in assessing the sustainability of a production process. The proposed facility (production: 9000 tonnes of compost per year) utilizes pruning residues and manure to produce high-quality organic amendments. The analysis includes infrastructure, equipment, and every operational input. Likewise, the analysis also provides socio-economic indicators such as employment generation and contribution to the regional economy. Three scenarios were evaluated based on the pruning–shredding location: at the plant, at the farm with mobile equipment, and at the farm with conventional machinery. The most cost-effective option was shredding at the farm using mobile equipment, reducing the unit cost to EUR 65.19 per tonne due to the transport of a smaller volume of prunings and, therefore, lower fuel consumption. The plant also demonstrates high productivity per square metre and generates stable employment in rural areas. Overall, the findings highlight composting as a viable and competitive strategy within circular and low-carbon agricultural systems. Full article

This study evaluated the long-term effects of organo-mineral fertilization on floristic diversity, species diversity, and vegetation structure in an HNV grasslands of the Apuseni Mountains. The experiment included five fertilization variants (control, organic, organo-mineral, mineral, and intensive organo-mineral), applied over a period of more than 15 years. Floristic diversity was assessed using a modified Braun–Blanquet method and multivariate methods—cluster analysis, principal coordinate analysis (PCoA), MRPP procedure, and indicator species analysis (ISA). Our analysis showed a trophic gradient, from oligotrophic Festuca rubra grasslands to mesotrophic (Agrostis capillaris–Trisetum flavescens) and eutrophic (Agrostis capillaris–Centaurea pseudophrygia) communities, depending on the intensity of organo-mineral fertilization applied. Moderate organo-mineral fertilization maintained a balanced floristic diversity and higher Shannon and Simpson indices compared to variants fertilized only with mineral inputs. Organo-mineral inputs improved soil fertility and ecosystem resilience, supporting soil microbiota activity and reducing nutrient losses. Intensive mineral fertilization led to a reduction in floristic richness and the dominance of nitrophilic species. This study demonstrates that moderate organo-mineral fertilization (≤10 t ha⁻¹ manure combined with N₅₀P₂₅K₂₅) provides an optimal balance between grassland productivity and biodiversity conservation, offering practical guidance for the sustainable management of High Nature Value mountain grasslands. Full article

Dissolved organic carbon (DOC) represents the most readily available and crucial carbon source for soil microorganisms, influencing their community structure, nutrient cycling, and metabolic functions. However, the interplay between functional genes and the organic components of DOC remains poorly understood. In this study, a 33-year fertilization experiment on black soil was carried out, setting up five fertilization treatments: unfertilized control (CK), nitrogen and potassium (NK), nitrogen, P and potassium (NPK), NPK plus straw (NPKS), and NPK plus manure (NPKM). The variation characteristics of soil DOC composition and carbon-degrading functional gene abundance under different fertilization treatments were systematically analyzed. The study found that applying chemical fertilizers combined with organic materials significantly increased soil organic carbon (SOC) and DOC contents in the thin-layer black soil of Gongzhuling. The soil DOC in this region is primarily derived from external inputs (Fresh plant-derived materials). Parallel factor analysis identified four fluorescent components: C1 as visible fulvic acid-like substances, C2 as humic acid-like substances, C3 as ultraviolet fulvic acid-like substances, and C4 as long-wavelength humic-like substances. Among these, NPK plus straw significantly enhanced the fluorescence intensity of the humic acid-like component (C2) and the total fluorescence intensity. The fluorescence intensity of the humic acid-like component increased by 36.0–208.9%, and the total fluorescence intensity increased by 23.8–270.9% compared to the CK. Moreover, the study found that the phylum composition of carbon-degrading microorganisms remained stable under different fertilization treatments. However, NPK plus straw significantly reduced the total abundance of carbon-degrading genes and influenced the composition and transformation of DOC by regulating the expression of key carbon-degrading genes ICL and abfA. These results offer new insights into the mechanisms by which fertilizer management affects the composition and stability of DOC in black soils via microbial functional gene pathways. Full article

Three organic soil amendments of different origins (chicken manure, fungal biomass obtained through biological fermentation, and a leonardite-based humic acid product) were applied to young chestnut trees, alongside mineral fertilizer, which when applied alone served as the control. During the second year, bud break pattern, photosynthetic activity, leaf carbohydrate concentrations, soil properties, and leaf nutrient content were evaluated across multiple sampling events. Sampling time significantly influenced most measured parameters. The addition of organic amendments accelerated bud break, influenced plant nutrient uptake, and modified soil properties. Notably, soil organic matter increased following chicken manure and fungal biomass applications, available phosphorus decreased under fungal biomass and leonardite-based humic acids (to 14.5 and 12.4 ppm, respectively, compared to 17.5 ppm in the mineral fertilizer control), and soil iron concentrations tripled under leonardite-based humic acids relative to the control. However, no significant effects were observed on photosynthetic performance or leaf carbohydrate concentrations. Discriminant and hierarchical cluster analyses revealed clear differences among amendments, with the humic acid-based product exerting distinct effects. As there are not many data available in the literature on the efficacy of organic amendments in chestnut cultivation, the present results underscore the importance of the site-specific selection of organic amendments, tailored to soil characteristics (in the present trial, an acidic soil) and specific nutritional objectives to optimize tree physiological performance. Full article

The vegetative mycelium of Pleurotus ostreatus (oyster mushroom) exhibits the ability to reduce nematode populations. This property may be utilized in integrated management programs targeting harmful nematodes such as Heterodera schachtii, a major pest of sugar beet crops. In addition to sugar beet, many other plant species serve as hosts for this nematode; susceptible plants promote H. schachtii development and population growth. Current control strategies rely on integrated plant protection methods, including the use of tolerant cultivars, fallowing, and trap crops such as oilseed radish and white mustard. This study aimed to determine whether sugar beet cv. Janetka or nematocidal plants—oilseed radish cv. Romesa and white mustard cv. Bardena—affect the nematocidal activity of P. ostreatus mycelium when applied together. Specifically, the influence of root or seed secretions from these plants on the activity of ten P. ostreatus mycelial strains was assessed using the model nematode Caenorhabditis elegans and the target pest H. schachtii. Experiments were conducted under laboratory conditions on water agar media colonized by P. ostreatus mycelium. Seeds or root exudates of the tested plants were applied to the mycelial surface. Following incubation, nematode mobility (C. elegans) and cyst entwining by the mycelium (H. schachtii) were evaluated, along with the ability of the mycelium to produce toxocysts. The results indicate that trap plants did not significantly alter the nematocidal activity of the mycelium. However, certain mycelial strains were slightly stimulated by seed diffusates or root exudates. Oilseed radish moderately influenced the nematocidal activity of four mycelial strains against C. elegans, whereas in the case of H. schachtii, similar effects were observed with white mustard. The mycelial elimination of H. schachtii occurred through cyst entwining, which was generally more effective in the presence of plant exudates. Overall, the findings demonstrate that incorporating trap crops such as oilseed radish cv. Romesa or white mustard cv. Bardena, as green manure in crop rotation systems, does not interfere with the nematocidal activity of P. ostreatus mycelium and simultaneously may enrich the soil with nutrients. The study further confirms that P. ostreatus maintains its ability to effectively entwine and eliminate H. schachtii cysts even in the presence of sugar beet, supporting its potential role as a biological control agent. To our knowledge, this is the first experiment that integrates the activities of trap plants and sugar beet with the nematocidal effects of P. ostreatus mycelium. Full article

Veterinary drugs are widely present in animal manure and manure-based fertilizers, making their safety for use as soil amendments still ambiguous. This study investigated the concentrations of 17 typical veterinary drugs in animal manure and manure-based fertilizers from Shandong Province using solid-phase extraction coupled with high-performance liquid chromatography–tandem mass spectrometry and assessed their environmental risks to soil organisms based on risk quotient values. The established method demonstrated robust performance, with drug recovery rates ranging from 72.9% to 109%. Tetracyclines were identified as the most prevalent contaminants, with mean concentrations of 1522 μg/kg in animal manure and 144 μg/kg in manure-based fertilizers. Drug concentrations in manure-based fertilizers were generally lower than those in animal manure. Livestock manure contained higher drug concentrations compared to poultry manure. Influenced by farming practices, drug concentrations were higher in beef cattle manure than in dairy cattle manure, and higher in broiler manure than in layer manure. Manure-based fertilizers primarily derived their drug content from chicken, cattle, and sheep manure. Tetracyclines in swine and sheep manure posed high risks to soil organisms, while those in beef cattle manure and dairy cattle manure posed medium risks. In contrast, most drugs in manure-based fertilizers exhibited low risks. Comprehensive analysis of both concentration levels and ecological risks indicates that manure-based fertilizers represent a more feasible option for soil amendment. This study provides a theoretical foundation for better understanding the feasibility of applying animal manure and manure-based fertilizers to agricultural land. Full article

Restoring soil microbial functioning in reclaimed coal gangue soils is critical for ecosystem recovery, yet how different organic amendments, particularly industrial by-products, regulate bacterial communities remains unclear. Here, we tested three organic inputs—the residue after evaporation (RAE) from vitamin C production, Trichoderma inoculation, and cattle manure—applied alone and in combination in a photovoltaic agroforestry system on coal gangue spoil. Our results indicate that the treatment based on manure increased bacterial α-diversity and favored taxa associated with organic matter transformation, including Actinobacteria and Acidobacteriota, suggesting expanded niche partitioning in response to heterogeneous substrates and nutrients. RAE alone supported communities closer to non-manure controls but, when co-applied with manure, further enhanced network connectivity and the prevalence of positive associations, indicating strengthened cooperative interactions and functional redundancy. In contrast, RAE combined with Trichoderma in the absence of manure reduced diversity, and simplified the co-occurrence network, suggesting resource monopolization and antagonism. Overall, RAE acted as a key driver of microbial cooperation and potential ecosystem resilience, and RAE-based amendments, particularly when integrated with manure, appear to be effective strategies for improving soil microbial functionality in degraded coal gangue soils. Full article

The application of organic fertilizer is an effective way to improve soil fertility and promote seedling growth. Toona fargesii (T. fargesii) is a fast-growing tree with high commercial value due to its excellent timber quality. However, the mechanism underlying its rapid growth at the seedling stage in red soil remains unclear. Here, we investigated the effects of cow manure application (OF group) on soil nutrients and rhizosphere microbial communities in red soil, as well as how it promotes the seedling growth of T. fargesii. Seedlings in the OF group showed a significantly higher specific growth rate than those in the unfertilized control (CK) group (73.51 ± 11.82% vs. 34.90 ± 5.49%, p = 0.022). This growth promotion was accompanied by an increase in soil pH (6.36 ± 0.01 vs. 6.22 ± 0.02, p = 0.001) and a concurrent decrease in NO₃⁻-N (10.60 ± 3.20 vs. 22.58 ± 3.49, p = 0.044). High-throughput sequencing demonstrated that cow manure tended to enhance bacterial diversity while decreasing fungal diversity. The OF treatment significantly enriched the relative abundances of bacterial phyla Myxococcota, Bacteroidota, Firmicutes, and Proteobacteria, while reducing Chloroflexi. For fungi, the relative abundances of Calcarisporiellomycota and Chytridiomycota were reduced under OF treatment. Redundancy analysis indicated that soil pH and organic matter (OM) content were the main environmental drivers shaping rhizosphere microbial communities. Our results demonstrated that short-term cow manure application raised soil pH and shifted the microbiome, coinciding with promoted seedling growth. This study provides insights into the microbiome-mediated rapid growth of tree seedlings in red soil. It implies that applying cow manure is an effective way to promote seedling performance in the early stages. Full article

Biochar has gained attention as a promising soil amendment capable of improving soil structure, nutrient retention and plant resilience to stress. However, its performance in perennial horticultural systems, particularly during the early stages of orchard establishment, remains insufficiently documented. This study, conducted in 2021 in a newly established apple orchard (‘Gala Brookfield Baigent’/P 60) in Wieluń, Central Poland, aimed to evaluate the effectiveness of three methods of using cattle-manure-derived biochar at a dose of 10 t ha⁻¹ (application before ploughing prior to orchard establishment, application to planting holes and surface spreading). Neither tree growth nor fruiting potential were affected by biochar, which made the comparison of its application methods inconclusive. According to the principal component analysis performed, mineral nitrogen showed a tendency to promote the formation of mixed-type buds on short shoots, a propitious growing pattern for intensive orchard management. In contrast, compost fertilisation favoured vegetative growth over generative development, as reflected by the significantly negative coefficient in regression analysis (b = −0.12; 95% CI: −0.25 to –0.00 for the Box-Cox-scaled fruiting-to-growth potential ratio). Nonetheless, the overall growth response of apple trees in the first year after planting to the applied soil-enriching practices was rather modest, with this observation validating the strategy of reducing fertiliser doses during orchard establishment on productive soils maintained in good agricultural condition. Long-term studies under abiotic or nutrient-limiting constraints, as well as the combined use of biochar with microbial inoculants, are recommended to fully elucidate its potential in apple production. Full article

The ponkan (Citrus reticulata Blanco cv. Ponkan), an important citrus crop, is increasingly threatened by soil acidification. This study evaluated the efficacy of various soil amendments, including lime alone (L), lime with gypsum and organic fertilizer (LGOF), lime plus K₂CO₃ (LK), and lime with chicken manure ash (LCMA), in mitigating soil acidification and improving ponkan seedling growth. Surface-applied lime raised topsoil pH and acid buffering capacity while reducing exchangeable Al. However, combined amendments (LGOF, LK, LCMA) more effectively alleviated acidity throughout the soil profile. They significantly increased pH and buffering capacity, decreased exchangeable H and Al in the 20–40 cm layer, and elevated exchangeable base cations (K⁺, Ca²⁺, Mg²⁺). These changes reduced Al content in roots, stems, and leaves, promoted deeper root growth, and increased biomass and nutrient uptake (N, P, K). Physiologically, combined amendments enhanced photosynthetic performance (chlorophyll, Pn, ΦPSII) and increased activity of key metabolic enzymes (Rubisco, SS, SPS, NR, GS), promoting sucrose, starch, and protein accumulation. LK rapidly raised subsoil pH and potassium levels, ideal for K-deficient orchards. LGOF and LCMA improved overall fertility by supplying Ca and Mg, with LGOF additionally enhancing soil structure in poorly structured acidic soils. Full article

Animal manure application is widely recognized for its agronomic benefits in enhancing soil fertility and crop productivity through organic matter enrichment and nutrient supply, but the critical application time governing its greenhouse gas emission trade-offs remains unresolved. The objective of this study was to investigate the effects of pig manure compost application timing on nitrous oxide (N₂O) emissions and maize yields in Northeast China through a four-year field experiment. The treatments included: (1) inorganic fertilizers (NPK); (2) NPK plus pig manure compost applied in spring (NPK-MS); and (3) NPK plus pig manure compost applied in autumn (NPK-MA). The N₂O fluxes, NH₄⁺-N contents, NO₃⁻-N contents, and maize yields were analyzed. The results showed that compared with NPK, NPK-MA increased N₂O emissions by 44.4%. Applying pig manure compost in autumn promotes N₂O emissions during the freeze–thaw period. However, there was no significant effect of NPK-MS on N₂O emissions compared with NPK (p > 0.05). Spring-applied manure compost (NPK-MS) resulted in an 11.9% increase in maize yield compared to NPK. In contrast, autumn-applied manure compost (NPK-MA) did not significantly affect maize yield (p > 0.05). Furthermore, yield-scaled N₂O emissions were significantly increased in NPK-MA (p < 0.05). Overall, spring application of pig manure compost is recommended for increasing maize yield without significantly increasing N₂O emissions while in Northeast China. Full article

Grassland degradation stems from disordered energy flow and material cycling caused by heavy grazing pressure. Fertilization is an effective measure to restore degraded grasslands. However, the mechanisms through which organic fertilizers influence soil nematode communities remain poorly understood. The objective of this study was to explore the correlation between soil nematode community structure and key environmental variables, and to identify the optimal local fertilization rates. This study was conducted in subalpine meadows located in the southeastern Qinghai-Tibetan Plateau, where organic fertilizer was applied for two consecutive years. The type of organic fertilizer is fully decomposed sheep manure. A total of seven treatments were established, including a no-fertilizer control group (CK) and six organic-fertilizer-application gradient groups (O1 to O6). The application rates of organic fertilizer for the gradient groups were as follows: 2250 kg·ha⁻¹, 3750 kg·ha⁻¹, 5250 kg·ha⁻¹, 6650 kg·ha⁻¹, 8250 kg·ha⁻¹, and 9750 kg·ha⁻¹, respectively. The results demonstrated that organic fertilizer significantly improved soil fertility and increased the relative abundance of phytophagous nematodes. In the soil nematode community, Aporcelaimellus, Criconemoides and Acrobeles were the dominant genera. Key environmental factors, including alkaline nitrogen (AN), soil bulk density (BD), soil pH (pH), and aboveground biomass (AGB), were identified as the primary drivers of changes in nematode community structure across different trophic types. The results of the principal component analysis (PCA) showed that O4 (6750 kg·ha⁻¹, corresponding to 135 kg·ha⁻¹ nitrogen and 67.5 kg·ha⁻¹ phosphorus) was the ideal fertilizer rate for the region. This approach aimed to provide a scientific foundation for the enhanced restoration of degraded subalpine meadows. Full article

Soil salinization is a major threat to agriculture and food security globally. The effectiveness of amendments on soil quality and crop production is management-dependent, and low-cost management practices are essential for developing countries. In this 3-year field study, the effects of cattle manure and gypsum amendments on the physicochemical properties of saline–alkali soil were evaluated. We found that both single gypsum and mixed amendments significantly reduced soil hardness, bulk density, pH, and soil salt content in 20–40 cm in 2015 and 2017. A more significant decrease in soil EC and density was observed with the mixed amendments compared to single gypsum after three years of reclamation. Specifically, applying mixed amendments (M-G15) led to a significant increase in Hordeum yield by 60.94%, whereas the application of single gypsum increased Hordeum yield by 25.20–53.14%. This indicated that co-application of cattle manure can reduce the amount of gypsum needed to achieve similar improvements in soil properties and Hordeum yield, with a long-term cumulative effect. Na⁺/(Ca²⁺ + Mg²⁺) showed the largest negative contribution to Hordeum yield under amendments, while soil bulk density showed the second largest number of negative effects on Hordeum yield under mixed amendments. Single gypsum improved the soil’s physical quality during the early stage of saline–alkali soil remediation, and mixed amendments improved the soil’s physicochemical properties and Hordeum yield during the late stage of remediation. Na⁺/(Ca²⁺ + Mg²⁺) in topsoil was confirmed to be the dominant factor under the mixed amendments affecting Hordeum yield, followed by the soil bulk density. These results confirm that the co-application with cattle manure achieves a similar reclamation effect with a reduced gypsum dosage, thereby lowering the reclamation costs of saline–alkali land in semi-arid areas. Full article

Soil salinity disrupts rhizosphere interactions, impairing root–microbe symbioses, nutrient uptake, and water relations in onion (Allium cepa L.) and garlic (Allium sativum L.). This study evaluated the efficacy of biofertilizers (Azotobacter chroococcum SARS 10 and Azospirillum lipoferum SP2) and organic amendments (sewage sludge and poultry manure) in salt-affected soils in Kafr El-Sheikh, Egypt. Five treatments were applied: (T1) control (no amendments); (T2) biofertilizer (3 L/ha for onion, 12 L/ha for garlic) + inorganic P (150 kg/ha P₂O₅ for onion, 180 kg/ha for garlic) and K (115 kg/ha K₂SO₄ for onion, 150 kg/ha for garlic); (T3) 50% inorganic N (160 kg/ha for onion, 127.5 kg/ha for garlic) + 50% organic manure (6000 kg/ha for onion, 8438 kg/ha for garlic) + P and K; (T4) biofertilizer + T3; and (T5) conventional inorganic NPK (320 kg/ha N for onion, 255 kg/ha N for garlic + P and K). Soil nutrients (N, P, K), microbial biomass carbon (MBC), dehydrogenase activity, and microbial populations were analyzed using standard protocols. Plant growth (chlorophyll, photosynthetic rate), stress indicators (malondialdehyde, proline), and yield (bulb diameter, fresh yield) were measured. Treatment T4 increased MBC by 30–40%, dehydrogenase activity by 25–35%, available N (39.7 mg/kg for onion, 35.7 mg/kg for garlic), P (17.9 mg/kg for onion), and K (108 mg/kg for garlic). Soil organic matter rose by 8–12%, and cation exchange capacity by 26–36%. Chlorophyll content improved by 25%, malondialdehyde decreased by 20–30%, and fresh yields increased by 20–30% (12.17 tons/ha for garlic). A soybean bioassay confirmed sustained fertility with 20–25% higher dry weight and 30% greater N uptake in T4 plots. These findings highlight biofertilizers and organic amendments as sustainable solutions for Allium productivity in saline rhizospheres. Full article

This study aimed to investigate the influence of different organic fertilizers and their concentrations on the growth of ‘Orah’ (Citrus reticulata Blanco) seedlings, as well as on the mineral nutrient contents, chemical and biological properties, and microbial community of the soil. Five types of organic fertilizers and three concentrations were studied. The seedling growth indexes, leaf mineral elements, soil mineral elements, soil enzyme activity, and soil microorganisms were measured. The results showed that organic fertilization significantly increased the contents of eight mineral elements in leaves, depending on the types and concentrations used. Specifically, rapeseed cake fertilizer was found to significantly increase the content of iron (Fe), manganese (Mn), and zinc (Zn) in the leaves. Furthermore, compared with applying only chemical fertilizers or no fertilizers at all, the application of organic fertilizer significantly increased the content of soil organic matter (SOM) and several mineral elements in the soil. The bacterial species composition of soil treated with common organic fertilizer and bio-organic fertilizer, and sheep manure were similar; however, the bacterial composition was significantly different in the soil which been treated with rapeseed cake compared to these other three fertilizers. Additionally, PICRUSt function predicting indicates that the core microbial community in the rapeseed cake group could promote synthesis and the transport of sugar, iron and other substances. Organic fertilizer can change soil chemical and biological properties by affecting the core microbial community structure, and further promote accumulation of mineral elements in the leaves of citrus seedlings. Full article