Search Results (326)

Common wheat (Triticum aestivum ssp. vulgare) is one of the three basic cereal crops worldwide that plays a key role in global food security. A key factor affecting the yield and traits of common wheat is an adequate nitrogen supply. Improving the efficiency of soil nitrogen use can be achieved through the application of appropriate mineral fertilizers and the proper selection of cultivars. The aim of this study was to determine the impact of residual nitrogen (N_res) after maize cultivation (the preceding crop) on the yield and chemical composition of winter and spring wheat grain. It was shown that both the variety selection and the type of nitrogen carrier had a significant impact on the characteristics related to wheat yield and grain quality. The most stable effect of the type of nitrogen, regardless of the type of corn variety, was recorded for ammonium nitrate with N-Lock. The average yield was approximately 6.1 t ha⁻¹. With the exception of the variant with N-Lock, the most progressive reaction to the type of fertilizer occurred in the stand with a three-line corn hybrid (TC, stay green). The advantage of this corn variety as a winter wheat forecrop results from the value of the site in a site without nitrogen. In the nitrogen control, the increase in yield compared to the single corn hybrid (SC) was 14%. However, in the U + N-Lock variant, it was 17%, and SG Stabilo as much as 32%. The increase in the weight of 1000 wheat grains in the stands after the SC and TC hybrid compared to stay green + roots power indicates a compensatory mechanism that became visible in the grain filling phase. Current challenges in agriculture caused by population growth and the need to ensure sufficient food production require greater awareness and knowledge regarding improved nitrogen management, including recognizing the role of residual nitrogen remaining in the soil after the preceding crop. A major advantage of slow-release fertilizers is that the nutrient (N) is released in response to the dynamic demand of the crop. This, on the one hand, increases grain yield and, on the other, does not negatively impact the agrosystem (eutrophication). Full article

Slow- or controlled-release fertilizers have been used widely to enhance fertilizer nutrient release efficiency and decrease nutrient pollution. To further evaluate the effectiveness of controlled-release fertilizers in water or soil, conventional NPK (16N-4P-8K) fertilizers were encapsulated with beeswax, and their effects on water, soil, and morphological features (root-to-shoot ratio, shoot and root weight) of maize plants were analyzed and compared with uncoated fertilizer. The results indicated that beeswax-coated fertilizer reduced the NPK dissolution rate from 30% to 50% in water within 24 h. In soil conditions, the beeswax coating resulted in a slightly but insignificantly slower release of NPK over 4–6 days. No significant differences were observed between uncoated and beeswax-coated fertilizers in maize morphological features, likely due to the limited persistence of the beeswax-coating film in water and soil. Findings from this study suggest that beeswax coating exhibits strong hydrophobic properties in reducing NPK leaching in water, with the potential for further optimization. Full article

The use of biodegradable polymers in slow-release NPK fertilizers is gaining prominence for reducing overdosing, minimizing nutrient loss, and enhancing efficiency. This study prepared modified and unmodified thermoplastic starch (TPS) systems via extrusion, incorporating collagen and potassium phosphate. Controlled-release nutrient systems utilizing nitrogen from an organic source were developed and characterized. The materials were characterized using Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), contact angle measurements, and biodegradability in the soil. The biodegradability of the polymeric matrix was evaluated through mass loss, with up to 78.9% degradation observed after 60 days for TPS-based systems containing collagen. Structural modifications in the TPS matrix led to changes in crystallinity and hydrophilicity, which directly influenced degradation rates. The nutrient release effect was assessed by monitoring the growth of chili pepper seedlings over 15 days. Seedlings grown in soil containing polymeric systems with 20% collagen or 6.2% urea reached average heights between 5.2 and 7.8 cm, compared to 5.0 cm for the unmodified TPS and 0 cm in treatments with pure urea, which caused seedling mortality. The polymeric systems containing collagen exhibited superior performance as a sustainable nitrogen source, ensuring a slower and more controlled release while yielding positive outcomes for early plant development. Full article

Stalk lodging is one of the major constraints limiting global maize yield. Chemical regulation and fertilization are essential agronomic practices that play critical roles in improving maize yield and lodging resistance. This study aimed to investigate the effects of different fertilization methods on maize plant morphology, stem mechanical properties and chemical composition, and yield under spraying chemical regulator (EDAH, consist of 27% ethephon and 3% DA-6). The experiment was conducted from 2023 to 2025, using Jiangyu668 (JY668) and Jiangyu877 (JY877) with different plant heights. Three fertilization methods (no fertilization, N0; conventional fertilization, N15; and slow-release fertilization, SN15) were set up. Chemical regulation and fertilization methods had significant effects on plant morphology, stem mechanical properties and chemical composition, lodging rate, and grain yield. The combination of spraying EDAH and slow-release fertilization optimized ear position coefficient and gravity center, decreased stem–leaf angle, and increased leaf orientation value, which was beneficial for improving leaf photosynthetic capacity. EDAH and slow-release fertilization also increased the stem internode diameter and aerial root layers; enhanced bending resistance and puncture strength; and increased cellulose, hemicellulose, and lignin contents and the lodging resistance index. These changes synergistically increased grain number and weight, ultimately increased maize yield, and decreased the lodging rate. CSN15 had highest yield and lowest lodging rate in different years and varieties. SN15 increased yield by 10.58% compared with N15, and CSN15 increased yield by 10.53% compared with CN15. JY877, as a medium- to high-stem maize variety, had better performance in plant morphology and yield than JY668 (dwarf maize variety) under EDAH and slow-release fertilization. These findings demonstrate that the strategy of combining chemical regulation and slow-release fertilization represents an optimal management approach for enhancing grain yield by optimizing plant morphology and improving stem mechanical properties and stem chemical composition in maize production. This strategy can increase agricultural productivity by enhancing yield and lodging resistance and provide significant environmental benefits and a scientific basis for agronomic practice recommendations. Full article

Increasing grain production is crucial for national food security, and fertilizer management is one of the most effective ways to achieve this. In traditional agricultural production, excessive nitrogen (N) application often leads to reduced N use efficiency and increased environmental pollution. Compound slow-release fertilizers can effectively improve N use efficiency while still meeting the nutritional demands of rice. However, research on these compound slow-release fertilizers remains limited. The effects of fertilizer management measures (controlled-release fertilizer ratios and N fertilizer levels) on rice yield, material accumulation, photosynthetic characteristics, and N use efficiency are not yet fully understood. In particular, the relationships between yield and material accumulation, photosynthetic characteristics, and N use efficiency require further study. Therefore, this study was conducted in 2021 and 2022 using Jinongda 667 as the material, with three N fertilizer rates of 90 (N1), 120 (N2), and 150 kg ha⁻¹ N (N3). Six controlled-release fertilizer ratios of sulfur-coated urea (SCU) and resin-coated urea (RCU) were tested: 1:0 (C1), 0:1 (C2), 3:1 (C3), 4:1 (C4), 5:1 (C5), and 6:1 (C6) (optimized in 2022 to three ratios: 3:1, 4:1, and 5:1, with traditional split-application fertilization (CF) added as a control). The results showed that the N3C5 treatment achieved the highest yield of 9246.7 kg ha⁻¹ among all combinations of slow-controlled release compound fertilizer ratios and N levels. In 2021, under the same N gradient, yields followed the order C5 > C4 > C3 > C2 > C1, whereas the C6 treatment exhibited a declining yield trend across different N levels. The yield pattern observed in 2022 was consistent with that of 2021. Further comparisons of C3, C4, and C5 under different N levels with the traditional fertilization treatment (N3CF) indicated that, under the same N level, the C5 treatment produced significantly higher yields than the C3 and C4 treatments. Photosynthetic rates at various stages under the C5 treatment increased by 1.9% to 12.7% compared to the C3 and C4 treatments. The N2C5 and N3C5 treatments increased yield by 1.3% and 9.4%, respectively, compared with N3CF, with effective panicle numbers increasing by 6.7% and 11.1%, respectively. The N2C5 treatment reduced N application by 20% compared with N3CF, while significantly increasing N Apparent Use Efficiency (NAUE) by 56.6% and Agronomic N Agricultural Utilization Efficiency (NAE) by 41.8%. Therefore, applying a 5:1 controlled-release fertilizer at a N application rate of 120 kg ha⁻¹ can reduce N use while enhancing efficiency. This approach provides a theoretical basis for green, high-yield rice cultivation. Full article

The rapid expansion of the salmon industry has generated increasing amounts of waste sludge with negative environmental impacts. Sustainable alternatives, such as using stabilized sludge in agriculture, are needed to mitigate these effects. At the same time, fruit production has grown globally, with hazelnut (Corylus avellana L.) emerging as a crop of high economic importance. However, the effect of salmon sludge application on hazelnut orchards is poorly understood. This study evaluated the application of thermally stabilized fish farming sludge (DS) compared with a slow-release mineral fertilizer (MF) intwo hazelnut varieties, ‘Barcelona’ (B) and ‘Tonda di Giffoni’ (TDG). Growth parameters including trunk cross-sectional area (TCSA), cumulative growth, shoot growth rate, leaf mass area (LMA) and chlorophyll index (SPAD), as well as soil physicochemical properties and enzymatic activities (fluorescein diacetate, β-glucosidase, acid phosphatase) were assessed. No significant differences (p > 0.05) in physiological parameters were found between DS and MF. However, the DS application increased soil pH by up 18%, electrical conductivity by ~48% at peak values, and enzymatic activities by 44% (acid phosphatase in B variety), 38% (β-glucosidase in TDG) and 169% (FDA in TGD), suggesting a great organic matter contribution and enhanced soil metabolic activity. Additionally, the B variety showed superior physiological performance, while TDG exhibited higher enzymatic activity. Overall, these findings provide a preliminary assessment of DS as a sustainable supplement to mineral nitrogen fertilization in hazelnut orchards, supporting both soil quality improvement and circular economy strategies in agriculture and aquaculture. Full article

Hygienization by hydrothermal carbonization (HTC) of chicken manure (CM) at 250 °C allows its valorization as soil amendment or even organic fertilizer. To test if this hypothesis is also valid for feedstocks from free-range breeding, respective material of a small farm in southern Spain was comprehensively chemically characterized. The hydrochar of the manure collected from the ground of the farm was rich in mineral matter. After HTC, 68% of the organic carbon (C) was recovered, whereas 82% of the nitrogen (N) was lost most likely by volatilization and with the discarded process water. Despite this, 2.8% of the total N in the hydrochar was identified as inorganic N (N_i). Solid-state ¹³C and ¹⁵N NMR spectroscopy revealed aromatization of organic C and N, although alkyl C and amide N still contributed with 23% and 35% to the total organic C and N, respectively. The obtained distribution of N-forms indicated that enough N_i is plant-available for early plant growth, while the remaining N occurs in structures that can be slowly mobilized during advanced plant development. Low heavy metal concentrations suggest low phytotoxicity. Pot experiments with lettuce, sunflower, and tomato plants confirmed species- and dosage-dependent effects. A dosage of 3.25 t ha⁻¹ improved lettuce and sunflower yields, whereas a dosage of 6.5 t ha⁻¹ provided no additional growth benefits but caused phytotoxic reactions of the tomato plants. Our results support HTC as a strategy to valorize CM from free-range farms, although, due to the high variability of such materials, we recommend a thorough chemical characterization and phytotoxic tests before its application. Full article

Understory vegetation plays a pivotal role in enhancing forest biodiversity, and its restoration is crucial for sustainable forest development, energy flow, and nutrient cycling. However, the dynamics of the biomass, diversity, and species composition of understory vegetation in plantations in south China, along with their key drivers, remain poorly understood. This study investigated four mature plantation types (Pinus massoniana, Pinus caribaea, Cunninghamia lanceolata, and mixed Chinese fir–broadleaf forests) in south China through plot surveys, environmental factor measurements, and structural equation modeling (SEM) to explore the diversity, biomass allocation patterns, and driving mechanisms of understory vegetation. The results demonstrated the following. (1) The introduced Caribbean pine forests exhibited higher shrub biomass than native Masson pine forests, which was driven by their high canopy openness favoring light-demanding species (e.g., Melicope pteleifolia, IV = 33.93%), but their low mingling degree limited herb diversity. (2) Masson pine forests showed superior shrub diversity due to their random spatial distribution and higher soil total potassium (TK) content. (3) Mixed Chinese fir–broadleaf forests achieved 24.50–66.06% higher herb biomass compared to coniferous monocultures, supported by high mingling degree, random spatial configuration, and phosphorus-potassium-enriched soil, with concurrently improved herb diversity. SEM revealed that stand structure (DBH, density, mingling degree) directly drove shrub diversity by regulating light availability, while herb biomass was primarily governed by soil total phosphorus (TP) and pH. Canopy-induced light suppression negatively affected herb diversity. We recommend optimizing stand density and canopy structure through thinning and pruning to enhance light heterogeneity alongside supplementing slow-release P fertilizers in P-deficient stands. This study provides theoretical support for the multi-objective management of south China plantations, emphasizing the synergistic necessity of stand structure optimization and soil amendment. Full article

The young stem of rapeseed is a highly nutritional vegetable, but there is a lack of information on quality regulation by slow-release fertilizers (SRFs). This study aims to evaluate the effects of SRFs on nutritional contents, including vitamin and sugar profiles and regulatory mechanisms, using enzymatic activity and gene expression analysis. A field experiment was conducted with a split-plot design, in which treatments with two fertilizers (traditional compound fertilizer (TF) and SRF) served as the main plot and two harvesting stages (main stem harvesting (S1) and the first branch harvesting (S2)) served as the sub-plot. The results showed that vitamin E (VE) content under the SRF treatment was 48.31% and 18.44% higher than that under the TF treatment at both stages. The contents of vitamin C (Vc) at the S2 stage and vitamin B6 (VB6) at the S1 stage under the TF treatment were 7.56% and 2.95% higher than under SRF treatments. Water-soluble sugar (WSS) and glucose contents under the SRF treatment were significantly higher than under the TF treatment at both stages, while fructose, trehalose, and sorbitol contents exhibited the opposite trend. The offset effect of the activity of ascorbate oxidase (AAO) and dehydroascorbate reductase (DHAR) between the two fertilizers resulted in a non-significant difference in Vc content at the S1 stage. Under the TF treatment, sucrose phosphate synthase had greater activity as compared to the SRF treatment. The selected key genes involved in vitamin and carbohydrate metabolism were generally in agreement with the changes in enzymatic activity. This study highlights the importance of SRF for the quality formation of young stems of rapeseed as a vegetable. Full article

Optimizing fertilizer management is essential for reducing salinity-related risks and improving nutrient efficiency in ornamental plant production. Fertilization enhances plant performance; however, excessive nutrient inputs can disrupt substrate chemistry, elevate salinity, and promote nitrogen leaching—particularly in containerized systems with limited rooting volume. This study evaluated the growth, physiological performance, and soil–plant nutrient dynamics of Sabal palmetto (cabbage palm) cultivated under six fertilization regimes over 180 days in a subtropical shade-house environment. Treatments ranged from a single baseline application of 15 g per plant (T0) to a cumulative 75 g (T5) using granular slow-release fertilizer. Morphological traits (plant height: 26–70 cm; leaf number: 4–18) and physiological indices (atLEAF⁺: 34.3–66.4; NDVI: 0.26–0.77) were monitored every 30 days. Substrate nitrogen and carbon concentrations increased from 0.57% and 41.78% at baseline to 1.24% and 42.94% at 180 days, while foliar nitrogen ranged from 1.46% to 2.57%. Fertilization significantly influenced all parameters (p < 0.05). Higher fertilization levels elevated electrical conductivity, salinity, and nitrogen leaching, with principal component analysis revealing strong positive associations among total nitrogen, electrical conductivity, and salinity. Moderate fertilization (T2 = 45 g) maintained favorable substrate chemistry, high foliar nitrogen, and balanced canopy growth with minimal nutrient losses. Sensor-based chlorophyll indices (atLEAF⁺ and NDVI) correlated strongly (r = 0.71, p < 0.001), confirming their reliability as non-destructive diagnostics for nitrogen management. These findings demonstrate that integrating optical monitoring with adaptive fertilization mitigates substrate salinization, sustains ornamental quality, and promotes the sustainable cultivation of Sabal palmetto in urban horticultural systems. Full article

Graphene oxide (GO) was prepared by a waterless synthesis route to generate GO sheets, which were then applied to coat calcined oyster shell with fertilizer (OSF) pellets, resulting in the creation of an OSF-GO particle. The GO sheets (ID/IG = 0.86) were characterized by Raman spectroscopy, which showed that the GO-coated OSF pellet features a compact coating approximately 13.68 μm thick. SEM and AFM analyses revealed that the GO sheets displayed a monolayer configuration with a crinkled topography (about 0.91 nm). The EDS analysis confirmed that the core was primarily composed of Ca, K, P, O, N, and C elements. The hydroponic experiment results showed that a GO concentration of 80 mg/L significantly enhanced plant height, stem thickness, and root length in loose-leaf lettuce, while higher concentrations induced oxidative stress. In pot experiments, the OSF-GO composite effectively raised the soil pH from 5.38 to 6.41 and improved nutrient availability. OSF-GO composite functions effectively as both a soil conditioner and slow-release fertilizer (SRF), simultaneously remediating degraded soils and optimizing nutrient delivery. Full article

Although pastures cover nearly half of Brazil’s agricultural land and form the backbone of national livestock production, they have historically received limited attention regarding management and fertilization, resulting in widespread degradation. Sustainable intensification of these pasture-based systems is therefore essential to meet growing global demand for animal products while minimizing environmental impacts. This review highlights recent technological innovations in pasture fertilization in Brazil, with a particular focus on alternative phosphorus sources such as natural reactive phosphates, which offer slow-release nutrients at lower costs compared to conventional fertilizers. Efforts to enhance nitrogen use efficiency through nitrification and urease inhibitors show promise in reducing nutrient losses and greenhouse gas emissions, despite current cost constraints limiting adoption. The integration of grass-legume intercropping, especially with Arachis pintoi, has been shown to enhance forage quality and system persistence when appropriately managed. Moreover, plant growth-promoting microorganisms emerge as sustainable biotechnological tools for restoring degraded pastures and boosting forage productivity without adverse environmental consequences. Properly treated agro-industrial residues also present a viable nutrient source for pastures, provided environmental regulations are strictly followed to prevent pollution. Together, these innovations offer a comprehensive framework for enhancing the productivity and sustainability of Brazilian livestock systems, highlighting the pressing need for continued research and the adoption of advanced fertilization strategies. Full article

The Aloe vera industry discards large amounts of outer leaf tissue (“shavings”), creating an opportunity to repurpose this byproduct as a sustainable fertilizer. This study evaluated whether aloe shavings can serve as a plant-based alternative to compost in organic Aloe vera production. A field trial in the Lower Rio Grande Valley of Texas tested three treatments: aloe shavings (applied to supply 39 kg N ha⁻¹), organic compost (39 kg N ha⁻¹), and a non-fertilized control. Laboratory incubations further assessed nitrogen mineralization and microbial respiration. Aloe shavings significantly enhanced vegetative growth: leaf number increased from 5.7 to 12.3 leaves per plant (+115% over the season), and leaf length rose from 20 to 32 cm, with the greatest gains in September and March (p < 0.05). At harvest, plants receiving aloe shavings produced 456 g total leaf weight and 151 g gel weight per plant, compared to 375 g and 108 g in the control. Incubations showed initial nitrogen immobilization (negative mineralization) but subsequent slow release, while microbial respiration was higher in compost (2.3 mg CO₂-C kg⁻¹ day⁻¹) than aloe shavings (1.4 mg CO₂-C kg⁻¹ day⁻¹). These results highlight aloe shavings as a low-cost, slow-release organic amendment that reduces waste, supports circular economy practices, and enhances Aloe vera growth without mineral nitrogen addition. Full article

In this study, a slow-release fertilizer (SRF) was obtained by occluding NPK 10–10–10 into two matrices and compared with the uncoated mineral fertilizer (F). The first matrix, FOMI, used biosolids/paper sludge at 3:1 (w/w); the second, FOMII, used biosolids/clay at 1:1 (w/w). Materials and pellets were physiochemically and microbiologically characterized. Release kinetics were evaluated in water and in soil columns packed with acid-washed sand; matrix-only controls and sand blanks confirmed negligible background N, P, and K. The uncoated mineral fertilizer (F) showed a rapid burst, whereas occlusion slowed release. FOMII reduced release relative to F, and FOMI produced the slowest, controlled profiles: kinetic fits yielded lower k values for FOMI than for FOMII and F. FOMI also exhibited higher water-retention capacity (WRC) and cation-exchange capacity (CEC), consistent with its greater organic-matter content. In soil, FOMI released less than 15% at 48 h and no more than 75% at 30 d, meeting European Committee for Standardization (CEN) SRF criteria; FOMII released faster than FOMI but slower than F, which exceeded 90% within the test period. Therefore, FOMI is a biodegradable, low-cost SRF that improves fertilizer-use efficiency while returning organic matter to agricultural soils; FOMII shows intermediate yet beneficial performance. Full article

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