Search Results (7,298)

The rising demand for sustainable agriculture and circular resource management has intensified interest in converting wastewater sludge into value-added products. This review explores the transformation of sewage sludge into slow- and controlled-release fertilizers (CRFs), with a focus on biochar production and encapsulation technologies. Sewage sludge is rich in essential macronutrients (N, P, K), micronutrients, and organic matter, making it a promising feedstock for agricultural applications. However, its use is constrained by challenges including compositional variability, presence of heavy metals, pathogens, and emerging contaminants such as microplastics and PFAS (Per- and Polyfluoroalkyl Substances). The manuscript discusses a range of stabilization and conversion techniques, such as composting, anaerobic digestion, pyrolysis, hydrothermal carbonization, and nutrient recovery from incinerated sludge ash. Special emphasis is placed on coating and encapsulation technologies that regulate nutrient release, improve fertilizer efficiency, and reduce environmental losses. The role of natural, synthetic, and biodegradable polymers in enhancing release mechanisms is analyzed in the context of agricultural performance and soil health. While these technologies offer environmental and agronomic benefits, large-scale adoption is hindered by technical, economic, and regulatory barriers. The review highlights key challenges and outlines future perspectives, including the need for advanced coating materials, improved contaminant mitigation strategies, harmonized regulations, and field-scale validation of CRFs. Overall, the valorisation of sewage sludge into CRFs presents a viable strategy for nutrient recovery, waste minimization, and sustainable food production. With continued innovation and policy support, sludge-based fertilizers can become a critical component of the green transition in agriculture. Full article

Soil degradation and poor fertility severely constrain vegetation growth in urban ecosystems, particularly in compacted and nutrient-depleted tree pits. Mulching has emerged as an effective strategy to improve soil quality and regulate soil–microbe–plant interactions, yet the combined use of organic and inorganic mulching in urban landscapes remains underexplored. In this study, a one-year field experiment was conducted to evaluate the effects of four mulching treatments on soil bacterial community diversity and functional potential. Four treatments were applied green waste compost + wood chips (GW), green waste compost + wood chips + volcanic rocks (GWV), green waste compost + wood chips + pebbles (GWP), and a non-mulched control (CK). Organic mulching (GW) effectively reduced bulk density, enhanced cellulase and protease activities, increased bacterial community richness and balance, and enriched microbial genes associated with carbon and nitrogen metabolism, while organic–inorganic mulching further promoted soil nutrition and reshaped bacterial community structure. Soil pH, nitrogen content, and protease activity served as key drivers of bacterial community structure and function. These findings demonstrate that different mulching practices provide distinct ecological advantages, and together highlight the role of mulching in regulating soil–microbe–plant interactions and improving urban tree pit management. Full article

As a staple cereal worldwide, winter wheat plays a pivotal role in food security. Leaf chlorophyll serves as a direct indicator of photosynthetic performance and nitrogen nutrition, making it critical for precision management and yield gains. Consequently, rapid, nondestructive, and high-accuracy remote-sensing retrievals are urgently needed to underpin field operations and precision fertilization. In this study, canopy hyperspectral reflectance together with destructive chlorophyll assays were systematically acquired from Yangling field trials conducted during 2018–2020. Three families of spectral indices were devised: classical empirical indices; two-dimensional optimal spectral indices (2D OSI) selected by correlation-matrix screening; and novel three-dimensional optimal spectral indices (3D OSI). The main contribution lies in devising novel 3D OSIs that combine three spectral bands and demonstrating how their fusion with classic two-band indices can improve chlorophyll quantification. Correlation analysis showed that most empirical vegetation indices were significantly associated with chlorophyll (p < 0.05), with the new double difference index (NDDI) giving the strongest relationship (R = 0.637). Within the optimal-index sets, the difference three-dimensional spectral index (DTSI; 680, 807, and 1822 nm) achieved a correlation coefficient of 0.703 (p < 0.05). Among all multi-input fusion schemes, fusing empirical indices with 3D OSI and training with RF delivered the best validation performance (R² = 0.816, RMSE = 0.307 mg g⁻¹, MRE = 11.472%), and external data further corroborated its feasibility. Altogether, integrating 3D spectral indices with classical vegetation indices and deploying RF enabled accurate, nondestructive estimation of winter wheat chlorophyll, offering a new hyperspectral pathway for monitoring crop physiological status and advancing precision agricultural management and fertilization, can guide in-season fertilization to optimize nitrogen use, thereby advancing precision agriculture. Full article

Coal mining in the aeolian sandy regions of western China has caused extensive land degradation. Traditional single-component soil amendments have proven inadequate for ecological restoration, underscoring the need for integrated and sustainable strategies to restore soil fertility and vegetation. A pot experiment using alfalfa (Medicago sativa L.) evaluated the effects of weathered coal, cow manure, and potassium polyacrylate combined in a three-factor three-level orthogonal design on plant growth, nutrient uptake, and soil properties. Results showed that compared with the control (C0O0P0), amendment treatments significantly increased alfalfa fresh weight (+47.57~107.38%), dry weight (+43.46~104.93%), plant height (+43.46~104.93%), and stem diameter (+12.62~31.52%), along with improved plant phosphorus and potassium concentrations (+15.41~46.65%). Soil fertility was also notably enhanced, with increases in soil organic matter, total nitrogen (TN), total phosphorus (TP), available nitrogen (AN), available phosphorus (AP), and available potassium (AK) ranging from 4.25% to 777.78%. In contrast, soil pH and bulk density were significantly reduced. The optimal amendment combination was identified as 10 g·kg⁻¹ weathered coal, 5 g·kg⁻¹ cow manure, and 0.6 g·kg⁻¹ potassium polyacrylate. Structural equation modeling revealed that the amendments promoted plant growth both directly by improving soil conditions and indirectly by enhancing nutrient uptake. However, high doses (30 g·kg⁻¹) of weathered coal may inhibit plant growth, and the co-application of high-dose weathered coal or manure with potassium polyacrylate may lead to antagonistic effects. This study provides fundamental insights into soil–plant interactions and proposes a sustainable amendment strategy for improving aeolian sandy soils, which could support future ecological reclamation efforts in coal mining area. Full article

Understanding the long-term impact of agricultural practices on soil parameters is essential for improving soil quality and sustainability. Soil Organic Carbon (SOC) and total Nitrogen (N) are key indicators due to their influence on crop productivity, nutrient cycling, and microbial activity. This study assesses the effects of tillage intensity (inversion vs. non-inversion) and organic amendments (manure vs. no manure) on SOC and total N dynamics in Mediterranean rain-fed arable systems. Data were collected over a ten-year field trial (2011–2020) in Catalonia, under cereal–legume rotation and organic management, focusing on two soil depths (0–10 and 10–20 cm). Fertilization was the main driver of SOC and N changes. Non-inversion tillage promoted topsoil accumulation and microbial colonization, especially during the first period (2011–2015). The combination of manure and reduced tillage led to faster and greater SOC increases. Moreover, initial SOC levels were negatively related to SOC changes in the topsoil. These results revealed the combination of manure and non-inversion tillage as the more suitable management practice to preserve soil quality in organic arable rain-fed systems, emphasizing the importance of understanding the impact of agricultural management in the long-term under Mediterranean conditions. Full article

Fertility is key for calf production. Direct selection for female fertility under field conditions is hindered by low accuracy and selection response. An alternative widely implemented is selection for scrotal circumference (SC), genetically correlated with daughter fertility. This study performed a genome-wide association study (GWAS) to identify genomic regions and candidate loci linked to SC and female fertility in Retinta cattle. A multivariate ssGBLUP was applied using SC records from 1061 bulls, fertility-related traits from 59,254 females and genotypes from 1230 animals using the Axiom™ Bovine Genotyping v3 Array (65k). The ssGWAS revealed 23 1-Mb windows explaining >1% of additive genetic variance for SC, one on chromosome 2 and 22 on chromosome 3. Within these windows, 198 regions spanning 118 protein-coding genes and 80 RNA genes were identified. Several genes, including GSTM3, SPATA1, HFM1, and MSH4, were previously associated with male fertility. Six regions overlapped across male and female traits, containing two protein-coding genes (THSD7B and ENSBTAG00000021755). Identification of genomic markers linked to both female fertility and male SC enables selection of superior animals, improving reproductive efficiency and advancing knowledge of the genomic basis of male–female fertility relationships. Full article

Sustainable fertilizers are needed to improve nutrient efficiency and reduce environmental impacts. Greenhouse experiments were conducted to evaluate matrix-based organo-mineral fertilizers (OMFs) for Zea mays over 60 days. The study took place during the dry season in Jaboticabal, São Paulo, using 5.5 dm³ plastic pots. Biosolids, deinked paper sludge (cellulose), and sawdust were used as organic matrices. Four treatments (n = 6) were tested: BC (biosolids/cellulose), BS (biosolids/sawdust), FF (uncoated NPK), and NF (no fertilizer). FF received 4.0 g NPK (4-14-8) per pot in two split doses; BC and BS each received 2.0 g NPK entrapped in 2.0 g matrix, applied once at sowing. BC provided the most controlled nutrient release and outperformed FF, increasing plant height by 20.4%, stem diameter by 13.7%, and leaf area by 5.3%. Considering nutrient uptake, BC exceeded FF by 22.5% for N, 38.6% for P, and 22.7% for K while using half the mineral fertilizer. Overall, matrix-based OMFs improved Zea mays growth and nutrient assimilation and may reduce nutrient losses relative to conventional split applications. Because the results derive from a single dry-season greenhouse trial with pots, field-scale validation to the production stage is required to confirm agronomic performance and quantify economic and environmental benefits. Full article

Extensive practice has demonstrated that the continuous pursuit of high yields in the black soil region of Northeast China resulted in imbalances in soil nutrients and declines in both soil quality and water use efficiency. Alternate wetting and drying (AWD) irrigation offers a promising solution for increasing rice yield and maintaining soil fertility. However, the success of this irrigation method largely depends on its scheduling. This study examined the threshold effects of AWD on rice growth, yield, and soil nutrient availability in the Sanjiang Plain, a representative black soil region in Northeast China. A two-year trial was conducted from 2023 to 2024 at the Qixing National Agricultural Science and Technology Park. “Longjing 31”, a local cultivar, was selected as the experimental material. The lower limit of soil water content under AWD was set as the experimental factor, with three levels: −10 kPa (LA), −20 kPa (MA), and −30 kPa (SA). The local traditional irrigation practice, continuous flooding, served as the control treatment (CK). Indicators of rice growth and soil nutrient content were measured and analyzed at five growth stages: tillering, jointing, heading, milk ripening, and yellow ripening. The results showed that, compared to CK, AWD had minimal impact on rice plant height and tiller number, with no significant differences (p > 0.05). However, AWD affected leaf area index (LAI), shoot dry matter (SDM), yield, and soil nutrient availability. In 2023, control had little effect on rice plant height and tiller number among the different irrigation treatments. The LAI of LA was 11.1% and 22.5% higher than that of MA and SA, respectively, while SDM in LA was 10.5% and 17.2% higher than in MA and SA. Significant differences were found between LA and MA, as well as between LA and SA, whereas no significant differences were observed between MA and SA. The light treatment is beneficial to the growth and development of rice, while the harsh growth environment caused by the moderate and severe treatments is unfavorable to rice growth. The average contents of nitrate nitrogen (NO₃⁻-N), available phosphorus (AP), and available potassium (AK) in LA were 11.4%, 8.4%, and 9.3% higher than in MA, and 16.7%, 11.5%, and 15.0% higher than in SA, respectively. Significant differences were observed between LA and SA. This is because the light treatment facilitates the release of available nutrients in the soil, while the moderate and severe treatments hinder this process. Although panicle number per unit area and grain number per panicle in LA were 7.5% and 2.3% higher than in MA, and 10.8% and 2.2% higher than in SA, these differences were not statistically significant. Seed setting rate and thousand-grain weight showed little variation across irrigation treatments. The yield of LA was 10,233.3 kg hm⁻², 9.1% and 14.1% higher than that of MA and SA, respectively, with significant differences observed. Compared with the moderate and severe treatments, the light treatment increases indicators such as the number of panicles per unit area, grains per panicle, thousand-grain weight, and seed setting rate, resulting in significant differences among the treatments. Water use efficiency (WUE) decreased as the control level increased. The WUE of all AWD irrigation treatments was significantly higher than that of the control treatment (CK). Compared with CK, AWD reduces evaporation, percolation, and other water losses, leading to a significant decrease in water consumption. Meanwhile, the yield remains basically unchanged or even slightly increases, thus resulting in a higher WUE than CK. The trends in rice growth, soil nutrient indicators, and WUE in 2024 were generally consistent with those observed in 2023. In 2024, the yield of LA was 9832.7 kg hm⁻², 14.9% and 17.3% higher than that of MA and SA, respectively, with significant differences observed. Based on the results, the following conclusions are drawn: (1) AWD irrigation can affect the growth of rice, alter the status of available nutrients in the soil, and thereby cause changes in yield and WUE; (2) LA is the optimal treatment for increasing rice yield, improving the availability of soil available nutrients, and improving WUE; (3) Both MA and SA enhanced WUE; however, these practices negatively impacted rice growth and the concentration of soil available nutrients, leading to a concurrent decline in yield. To increase rice yield and maintain soil fertility, LA, with an irrigation upper limit of 30 mm and a soil water potential threshold of −10 kPa, is recommended for the Sanjiang Plain region. Full article

Excessive application of nitrogen (N) fertilizer increases the risk of soil NO₃⁻-N leaching in fluvial soil, threatening soil and groundwater quality and safety. Enhancing soil carbon (C) by returning straw to the field can efficiently improve soil quality. The process of increasing C/N by straw returning to regulate soil nitrogen transformation and mitigate NO₃⁻-N leaching, and the ecological threshold of straw application rate in fluvial soil need to be further explored. This study aims to research a series of soil C/N ratio treatments (including no straw, CK; C/N of 15, 20, 25, 30, 35 and 40), which were set up by adding straw at different application rates, and to investigate the underlying process of increasing C/N ratio by incorporating straw to mitigate NO₃⁻-N leaching. As the soil C/N ratio increased, the total soil nitrogen showed a fluctuating increase with the highest value in S40 treatment (increased by 358 mg kg⁻¹), while the NO₃⁻-N leaching amount reached the lowest value at the C/N ratio of 20, with an average reduction of 45% (decreased by 29.3 mg kg⁻¹). Increasing soil C/N ratio significantly increased soil microbial biomass, cellulase, urease and N-acetyl-β-D-glucosaminidase activities while it decreased the net N mineralization rate, ammonification rate and nitrification rate. Principal component analysis showed that the NO₃⁻-N leaching was positively correlated with the ammonification rate, nitrification rate and net N mineralization rate, and negatively correlated with the abundances of bacteria, fungi and nitrogen-fixing genes (nifH) (p < 0.01). Structural equation model analysis showed that straw-regulated C/N, dissolved organic N and soil fungi were the most important factors affecting NO₃⁻-N leaching, followed by the ammonification rate. Overall, increasing soil C/N by adding straw could enhance soil microbial biomass (especially fungi) and enzyme activities to promote soil N storage and reduce net N mineralization, ammonification and nitrification to decrease NO₃⁻-N leaching. Full article

The composting of organic waste is a sustainable strategy for waste management and soil fertility improvement. However, the composting process is often associated with greenhouse gas (GHG) emissions, having a negative impact on the environment. This study investigated the effects of BC pyrolysis temperature (300 °C, 600 °C) and application rate (5% and 10%) on GHG emissions during the thermophilic phase and compost quality. The experimental treatments were a control and four BC treatments varying in pyrolysis temperature (300 °C, 600 °C) and application rate (5%, 10%). As a result, BC pyrolyzed at 600 °C and added at 10% (T2R2) resulted in the highest thermophilic temperature (63.5 ± 0.5 °C). This treatment significantly achieved substantial reductions in NH₃, N₂O, CH₄, and CO₂ emissions by 55 ± 2.7%, 50 ± 2.7%, 88 ± 4.2%, and 23 ± 2.3%, respectively, relative to the control. Compost quality was enhanced notably, with dry matter increasing to 46.4 ± 0.11% (T2R1), organic matter reaching 30.9 ± 0.05% in T2R1, and total nitrogen peaking at 0.8 ± 0.001% (T1R2). The C:N ratio decreased from 27:1 in the control to 21:1 in the treatment of T1R2, indicating an accelerated composting process. The NH₄-N levels were the highest in T1R2 and T2R2 (659 ± 0.1 and 416 ± 0.2 mg kg⁻¹), while EC increased to 9.5 ± 0.006 ms/cm (T2R1), and bulk density decreased to 410 ± 0.08 kg/m³ (T1R1). These results demonstrate that high-temperature biochar, especially at a rate of 10%, is effective in reducing emissions and improving compost quality. Future research should explore long-term effects and microbial mechanisms to optimize biochar use in composting systems. Full article

Nitrogen (N) fertilization critically regulates the storage and availability of soil carbon (C) and N pools. However, the internal mechanism through which stratified N application affects soil organic carbon (SOC) sequestration and soil quality index (SQI) remains unclear. To investigate the effects of stratified N application on C sequestration and SQI in both topsoil and subsoil, this study established six treatments (N_0:0, N_1:0, N_4:1, N_3:2, N_2:3, N_1:4) and analyzed soil biochemical indicators. The results showed that compared to N_1:0, stratified N fertilization did not significantly improve soil C and N content in the 0–20 cm layer. In contrast, the N_2:3 and N_1:4 treatments even led to a significant reduction in soil C and N pools in the topsoil. In the 20–40 cm, compared to N_1:0, stratified N fertilization increased SOC, TN, labile C fractions, N fractions (particulate organic N and microbial biomass N), enzyme activity and C pool management index (CPMI), increasing by 0.52–7.94%, 2.05–8.42%, 4.77–42.59%, 14.46–56.01%, 6.34–45.82%, and 31.26–51.93%, respectively. In 0–20 cm, compared to N_0:0, N application increased SQI by 24.84–45.77%, and N_2:3 and N_1:4 treatments were lower SQI than N_1:0. Furthermore, N_2:3, N_3:2, and N_1:4 treatments in 20–40 cm were higher than other treatments. N fertilizer application drives the synergistic changes in C and N fractions by regulating enzyme activity and stoichiometric ratio, thus affecting CPMI and SQI. Thus, the 3:2 stratified N fertilization (0–20 cm:20–40 cm) method achieves synergistic dual-layer enhancement-maintaining surface C and N pools while boosting subsoil C sequestration and quality-through enzyme-mediated precision regulation of C/N stoichiometry. The study provides a scientific foundation for integrated C emission reduction and cropland quality enhancement in the North China. Full article

Postovulatory aging (POA) significantly contributes to fertility decline, primarily through oxidative stress, which impairs oocyte quality, reduces embryonic developmental competence, and may adversely affect offspring health. Edaravone (EDA), a potent free radical scavenger, is known for its cytoprotective effects in various disease models. This study aimed to evaluate whether EDA can mitigate the detrimental effects of POA on mouse oocyte and embryo quality and confirm its reproductive safety. Supplementation with 10 nM EDA significantly reduced meiotic abnormalities, restored mitochondrial distribution, enhanced mitochondrial membrane potential and ATP production, and decreased intracellular reactive oxygen species (ROS) in aged oocytes. Although EDA did not markedly improve fertilization or blastocyst formation rates, it enhanced embryo quality, with morphokinetic parameters comparable to those of young oocytes. Moreover, F₁ offspring derived from embryos produced by EDA-treated POA oocytes were healthy, and female progeny exhibited normal reproductive competence. These findings demonstrate that EDA safely improves oocyte quality by alleviating POA-induced oxidative damage, offering a potential antioxidant strategy to enhance assisted reproductive technology (ART) outcomes when applied to IVF clinics. Full article

Balancing soil nitrogen leaching with production benefits remains a critical challenge in sustainable greenhouse tomato cultivation. This study evaluated the effects of reduced water-soluble nitrogen fertilizer (N) application rates on soil environmental parameters and production outcomes to optimize nitrogen management strategies. Four treatments were implemented across two growing seasons: control (CK), high-N (H), medium-N (M), and low-N (L) nitrogen fertilizer applications in soil solution (SS) and autumn–winter (AW) systems. Results demonstrated that reduced nitrogen inputs significantly decreased soil electrical conductivity and soil nitrogen retention by 88% and 83% in SS and AW, respectively, while reducing soil residual nitrate nitrogen. The tomato yield decreased by 14–26% under low fertilizer treatment, while fruit quality was substantially enhanced, with soluble solid content increasing by 56% in SS and 217% in AW for the L treatment compared to the CK. Nitrogen-use efficiency improved by 54.7% and 34.78% in SS and AW, respectively, demonstrating superior resource utilization under reduced fertilizer applications. Principal component analysis revealed that fruit quality was primarily influenced by soluble solid content, organic acid, total soluble solids, and sugar–acid ratio. Gray relational analysis identified the L treatment (361.62 kg ha⁻¹ in SS and 182.6 kg ha⁻¹ in AW) as optimal for comprehensive performance evaluation. The findings demonstrate that strategic nitrogen reduction effectively balances production benefits with environmental sustainability, providing a practical framework for sustainable nitrogen management in controlled environment agriculture. Full article

Soybean inoculation with nitrogen (N) fixing bacteria can be highly promising for enhancing biological nitrogen fixation (BNF) and improving crop productivity. It helps to reduce dependency on chemical fertilizers, promotes sustainable agricultural practices, and minimizes environmental impacts. Therefore, understanding the specific aspects and conditions is essential for establishing the BNF process in particular environments. In this study, we investigated whether soybean inoculation is an effective strategy in cool-climate regions beyond their typical northern distribution, and which soybean varieties and microbial strains are the most effective for optimizing soybean productivity and performance in relatively cool environments. To address these questions, a natural abundance nitrogen stable isotope ratio analysis was conducted on two soybean varieties of different maturity groups, which were inoculated with three Bradyrhizobium japonicum strains, along with organic fertilizer and new promising endophyte treatments. This approach aimed to determine the differences in biological and chemical parameters of soybean, as well as the origin of N sources, its uptake, and the isotopic distribution within the plants. It was demonstrated that inoculation with Bradyrhizobium japonicum was more effective than fertilization, as the strains had a significant effect on nitrogen derived from the atmosphere (Ndfa), produced stable nitrogen isotope ratios close to 0‰, and substantially increased nitrogen content, particularly in beans. Soybean varieties Laulema and Merlin, representing different maturity groups, exhibited distinct nitrogen uptake patterns. Bradyrhizobium japonicum strain AGF78 consistently produced the greatest effect on biological parameters in both varieties, particularly in seed yield and grain weight, with the later-maturing Merlin achieving the highest average yield of 3066.89 kg ha⁻¹. Notably, the Merlin inoculated with AGF78 resulted in the highest nitrogen fixation in beans, with 66.8%NDFA and 134.0 kg/ha of fixed nitrogen. Similarly, Laulema inoculated with AGF78 resulted in 88.2%NDFA and 123.2 kg/ha of fixed nitrogen. Inoculation with selected bacterial strains significantly increased protein content from 30% to 41%, with the effects being both strain- and variety-specific. Our study showed that establishing effective soybean–microbe interactions by choosing soybean variety and microbial strain is crucial for optimizing agricultural practices and improving crop performance, especially in sustainable and environmentally conscious farming systems under cool climatic conditions of Europe. Full article

This study evaluated the effects of applying a biofertilizer, alone and in combination with nanoparticles (NPs), under controlled greenhouse conditions to improve soil quality and wheat performance (soil from the region of General Cepeda, Coahuila, Mexico, was used). The integration of the biofertilizer with Fe_xO_x NPs proved particularly effective in enhancing soil physical and biological parameters as well as promoting superior crop growth compared with individual treatments. The incorporation of NPs markedly improved the biofertilizer’s biocompatibility and stability, reinforcing its potential for optimizing plant nutrition, nutrient use efficiency, and overall agricultural sustainability. In addition, the combined treatments enhanced the utilization of native microbial diversity, thereby contributing to increased soil fertility and the quality and yield of crops in the study region. The best yield obtained in previous harvests (8.3 Mg ha⁻¹) was improved to 8.48 Mg ha⁻¹ with application of the biofertilizer with Fe_xO_x NPs. Moreover, shoot length increased significantly with the combination of the biofertilizer and ZnO NPs as well as with Fe_xO_x NPs separately, whereas root length was maximized with the addition of the biofertilizer alone. These findings underscore the synergistic effects of combining biofertilizers with metal-based nanoparticles to sustainably enhance wheat growth and productivity. Full article