Controlled release fertilizer: A review on developments, applications and potential in agriculture

Lignin-polybutylene adipate-co-terephthalate(PBAT)-starch@urea bilayer nanohybrid biocomposite enable superior controlled slow-released fertilizer with good water-retention

Slow-release fertilizers (SRFs) have revolutionized agricultural practices by enhancing nutrient utilization efficiency and minimizing environmental contamination. However, conventional SRFs face significant limitations, including unpredictable release patterns, dependence on non-biodegradable synthetic coatings, and inadequate performance in arid soil conditions. To address these challenges, we have developed an innovative approach to transform agricultural waste biomass into a multifunctional lignin-based SRF with superior water retention properties. Our bilayer lignin-based slow-release urea fertilizer (PSLB-SRF) was engineered using cost-effective, biodegradable materials: starch, poly(butylene adipate-co-terephthalate) (PBAT), and lignin derived from corn stover, a major agricultural byproduct. The resulting nanohybrid biocomposite exhibits exceptional controlled-release properties, demonstrating only 55 % cumulative urea release over 28 days - well within the Chinese National Standard GB requirement of <60 %. Furthermore, the material shows remarkable water retention capabilities, as evidenced by its ability to maintain 100 % chickweed survival under simulated drought conditions in field experiments. This breakthrough highlights the composite's potential for arid region applications. This cost-effective, biodegradable, and multifunctional lignin-based nanohybrid biocomposite represents a significant advancement in sustainable agriculture, offering a dual solution for agricultural waste valorization and developing high-performance fertilizers for sustainable farming practices.

Microencapsulation of Bacillus megaterium in cationic starch/PVA-based matrices

The increasing demand for sustainable and effective agricultural bio-based products is driving innovation in encapsulation technologies for beneficial microorganisms, such as Bacillus strains, known for promoting plant growth and controlling pathogens. This study proposes an efficient methodology for encapsulating Bacillus megaterium within microparticles using a simple cross-linking/emulsion process based on Cationic Starch (CS) and Polyvinyl Alcohol (PVA). Citric acid (CA) and Sodium Trimetaphosphate (STMP) were employed as cross-linking agents, while bentonite (Bent) was added to modify the materials. The resulting microparticles exhibited a range of properties influenced by the cross-linking agents and bentonite. Encapsulation matrices with STMP and STMP-Bent demonstrated superior performance in providing controlled bacterial release and enhanced protection under adverse conditions. These matrices maintained up to 95 % of the initial cell viability after exposure to heat (55 °C for 24 h), and up to 98 % viability after exposure to UV light (180 min) or pesticides (30 °C for 24 h). In contrast, matrices containing CA or CA-Bent, as well as free bacteria, showed significantly lower bacterial survival rates in the same tests. In a high-salinity soil test (200 mM), STMP-based matrices provided the best protection for encapsulated bacteria, leading to a 10 % increase in B. megaterium growth. Furthermore, these matrices demonstrated an estimated shelf-life of over 40 months when stored at temperatures of 15 °C, 30 °C, and 45 °C. These findings suggest that CS/PVA matrices cross-linked with STMP offer a promising approach for developing more resilient and effective bio-based agricultural products.

Efficacy of stearic acid, potato starch, and polycaprolactone in the development of pH and temperature-responsive fertilizer for eco-resilient agriculture system

This study investigates the development of a biodegradable, pH- and temperature-responsive controlled-release fertilizer (CRF) using stearic acid, potato starch, and polycaprolactone to enhance nutrient use efficiency and mitigate environmental impacts in agriculture. Conventional fertilizers contribute to significant nutrient losses through leaching and volatilization, leading to pollution and reduced efficiency. In contrast, the proposed CRF gradually releases nutrients in response to environmental stimuli, minimizing nutrient loss and improving sustainability. The study demonstrates that the CRF formulation with 8 % stearic acid and 1 % potato starch exhibits superior nutrient release control under varying temperatures and pH levels, compared to other formulations. Scanning electron microscopy confirmed the structural integrity of the coated granules, while biofilm formation analysis revealed enhanced microbial activity, indicating potential benefits for soil health. The release profile of the CRF was temperature- and pH-dependent, with prolonged nutrient release observed at lower temperatures and acidic conditions. These findings highlight the potential of this eco-friendly CRF to improve crop productivity, reduce fertilizer waste, and support sustainable agricultural practices, presenting a significant advancement for eco-resilient farming systems.

Hybridizing Mg-Fe Layered Double Hydroxide with Pectin Natural Polymer for Organic Ligand-Responsive Phosphate Release: An Innovative Controlled-Release Phosphorus Fertilizer

Phosphorus (P) is vital for plant growth, but its agricultural use is limited by soil fixation and environmental loss. This study developed an organic ligand-responsive phosphate release system by hybridizing magnesium-iron-layered double hydroxides (Mg-Fe LDH) with pectin from apple and citrus (pectin-A/C). Structural properties and phosphate (PO4) release of LDH hybrids with different concentrations of metal precursors (0.5LDH-A/C, 2.5LDH-A/C) were evaluated. All hybrids exhibited higher PO4 sorption than pristine Mg-Fe LDH, with 2.5LDH-A reaching 118.2 mg g-1. Phosphate release kinetics showed that 0.5LDH-A/C provided slow release up to 1056 h, while 2.5LDH-A/C released 87.7% PO4 with 4 mM citrate, responding to organic ligands. Synchrotron spectroscopy revealed that Fe substitution in LDH layers and Fe(III)-P species was the key influencing PO4 release. The slow-release behavior of 0.5LDH-A/C and the ligand responsiveness of 2.5LDH-A/C highlight their potential to enhance sustainable agriculture by improving fertilizer efficiency, ensuring food security, and minimizing environmental impact.

Biomimetic Modification of Waterborne Polymer Coating Using Bio-Wax for Enhancing Controlled Release Performance of Nutrient

Waterborne polymer coated controlled release fertilizers (CRFs) are highly valued for their potential to enhance nitrogen use efficiency (NUE) and reduce fertilization labor costs. However, their application in crops with long growth periods, such as rice and maize, is limited by inadequate coating strength and suboptimal hydrophobicity. Inspired by the hydrophobic and anti-fouling structure of lotus leaf cuticles, this study biomimetically modified waterborne polyacrylate-coated urea (PACU) using natural bio-wax including rice bran wax (RBW), candelilla wax (CAW), bees wax (BW) and carnauba wax (CW), along with paraffin wax (PW) as a control. The modifications significantly extended nutrient release duration by 22 d compared to unmodified PACU, with CW providing the longest duration, followed by CAW, BW, RBW, and PW. Additionally, the modification of BW, CAW, and CW exhibited superior hydrophobicity and affinity to polyacrylate coatings, while the inferior hardness and toughness of PW compromised its controlled release performance. Field trials demonstrated that CW-modified CRFs effectively controlled nutrient release in rice and maize, resulting in a 7.2% increase in rice yield and a 37.9% increase in maize yield, as well as an 18.7% improvement in NUE compared to conventional fertilizers. These findings offered a novel approach for hydrophobic modification of waterborne polymer coatings, thereby enhancing the performance and applicability of waterborne polymer coated CRFs in long-season crops.

Mitigating life-cycle multiple environmental burdens while increasing ecosystem economic benefit and crop productivity with regional universal nitrogen strategy

INTRODUCTION

Nitrogen fertiliser is critical for increasing crop yields worldwide, but excessive use causes significant N losses in various forms and subsequent environmental issues, such as greenhouse gas (GHG) emissions. Establishing regional universal nitrogen strategy (RUNs) is indispensable for technology adoption, resource conservation, and pollution mitigation in crop production.

OBJECTIVES

This study aims to develop a regional universal nitrogen fertilizer strategy to address variations in N application effectiveness, balancing agricultural productivity with environmental and eco-economic benefits.

METHODS

We conducted a total of 48 site-year field experiments including no nitrogen application (Control), farmers' practice (FP), and the implementation of the RUNs with optimized nitrogen recommended formulas and one-off application method.

RESULTS

The RUNs significantly increased yields by 5.9%, 12%, and 11% for grain, sweet, and silage maize, respectively, compared with FP. Further, RUNs reduced life-cycle potentials of global warming, soil acidification, water eutrophication, and energy depletion by 22-45%, 63-76%, 51-73%, and 46-67%, respectively. The RUNs increased economic benefits by 11%-58.2%, and net ecosystem-economic benefits by 11.3-77.5%, particularly through the reduction of nitrogen fertiliser and labour-associated agricultural and ecological costs.

CONCLUSION

We propose that the RUNs reconciled crop yield, resource efficiency, environmental impacts, and ecosystem economic benefits, demonstrating a regional sustainable N strategy for global food security and resource conservation.

Enhancing nitrogen use efficiency in agriculture by integrating agronomic practices and genetic advances

Nitrogen is a critical nutrient for plant growth and productivity, but inefficiencies in its use in agriculture present both economic and environmental challenges. Enhancing nitrogen use efficiency (NUE) is essential for promoting sustainable crop production and mitigating the negative impacts of nitrogen loss, such as water pollution and greenhouse gas emissions. This review discusses various strategies aimed at improving NUE, with a focus on agronomic practices, genetic advancements, and integrated management approaches. Traditional agronomic methods, including split nitrogen application and the use of controlled-release fertilizers, are explored alongside precision agriculture techniques, which enable real-time adjustments to nitrogen application based on crop and soil conditions. Advances in genetics and biotechnology, such as conventional breeding, genetic modification, and genome editing, have contributed to the development of crop varieties with improved nitrogen uptake and assimilation. Additionally, the role of beneficial microbes, including nitrogen-fixing bacteria and mycorrhizal fungi, is highlighted as a natural means of enhancing nitrogen availability and reducing reliance on synthetic fertilizers. The review further emphasizes sustainable practices such as legume-based crop rotations, continuous cover cropping, and organic fertilization, which contribute to soil nitrogen enrichment and overall soil health. By combining these agronomic, genetic, and microbial strategies, a holistic nitrogen management approach can be achieved, maximizing crop yields while minimizing environmental impacts. This integrated strategy supports the development of resilient and sustainable agricultural systems, promoting long-term soil fertility and productivity.

Chitosan hydrogel membrane embedded by metal-modified biochars for slow-release fertilizers

Slow-release fertilizers show great promise for advancing agricultural sustainability by enhancing nutrient efficiency and mitigating environmental impacts. Herein, we propose an approach that embeds chitosan hydrogel membranes with metal-modified biochars to encapsulate N-P-K compound fertilizers, referred to as CS-MBC-SRFs. Our results demonstrate that CS-MBC-SRFs exhibit superior slow-release performance for N, P, and K compared to others (commercial NPK compound fertilizers, chitosan-coated, and biochar-embedded chitosan-coated fertilizers). Over a 33-day soil column test, CS-MBC-SRFs showed cumulative leaching ratios of <8.93 % for N, 18.4 % for P, and 14.4 % for K. Incorporating metal-modified biochar into the chitosan hydrogel membrane significantly enhances its swelling and mechanical properties while maintaining biodegradability and water-retention capacity. Mechanistic investigations reveal that nutrient release from CS-MBC-SRFs primarily occurs via diffusion through the hydrogel membrane, with the metal-modified biochar surface enhancing nutrient adsorption and delaying release. Additionally, the metal-modified biochars improved swelling and mechanical properties of the chitosan hydrogel membrane, significantly reducing nutrient diffusion. Pot tests demonstrated that CS-MBC-SRFs effectively promoted chili plant growth, ensuring high N-P-K utilization and improving chili fruit nutritional indices. Economic analysis further highlights the promising application prospects of CS-MBC-SRFs.

Diatom contained alginate-chitosan hydrogel beads with enhanced hydrogen bonds and ionic interactions for extended release of gibberellic acid

Hydrogels in agriculture offer controlled release, however, face issues with rapid disintegration, swift release, and inability to protect active ingredients. To overcome this, the study presents a hydrogel delivery system that uses dopamine-functionalized nanoporous diatom (DE-PDA) microparticles entrapped in alginate and chitosan matrices to deliver plant growth hormone, gibberellic acid (GA) that suffers from instability, limiting its field application. Developed GA@hydrogel beads exhibited an encapsulation efficiency of 85.2 % and demonstrated thermal and functional properties that suggested complex interactions between biopolymers. They showed enhanced stability, retention, and extended release for GA, improving tomato seed germination and plant growth. The GA release was governed by Fickian diffusion and the polymer relaxation with 86.3 % release by the 15th day, with a high swelling rate compared to a system without DE-PDA that only sustained GA release for 5 h. The GA@hydrogel system boosts tomato seed germination rates to 100 % on the third day for a 0.05 % GA@hydrogel formulation, demonstrating enhanced seedling growth. Also, they prove more effective than free GA in increasing the physiological parameters of tomato plants. Further, the pot experiments show enhanced plant growth, suggesting a new trend of GA delivery to plants through soil.

Preparation of slow-release fertilizer derived from rice husk silica, hydroxypropyl methylcellulose, polyvinyl alcohol and paper composite coated urea

There is a growing trend toward utilizing agricultural waste to create value-added products, addressing environmental concerns associated with their disposal. This study focuses on developing slow-release fertilizers (SRFs) using amorphous silica derived from rice husk, hydroxypropyl methylcellulose (HPMC), polyvinyl alcohol (PVA), waste paper, and urea. Experimental optimization was carried out using the response surface methodology central composite design (RSM-CCD). The optimal formulation included 8.63 g of silica, 1.04 g of HPMC, and 0.27 g of PVA. Two SRFs were prepared under these conditions: SRF1, consisting of silica, HPMC, and PVA, and SRF2, which additionally incorporated coated waste paper. Characterization techniques such as Fourier Transform Infrared (FTIR) spectroscopy, X-ray diffraction (XRD) Scanning Electron microscopy (SEM) and Brunauer-Emmett-Teller (BET) analysis were used to examine the materials. The rice-husk-derived silica exhibited a pore size of 2.140 nm and a BET surface area of 690 m2/g, providing an excellent surface for nutrient encapsulation. Although the addition of coated waste paper minimally influenced the slow-release behaviour of SRF2, however the other components effectively reduced nutrient leakage by trapping the nutrients. The swelling behaviour of the SRFs was analyzed in different media after 72 h, showing values of 2.66, 2.54 (g/g) in distilled water, 2.20, 2.58 (g/g) in pH 4, and 1.86, 3.09 (g/g) in pH 9 solutions. The swelling kinetics aligned with Scott's second-order kinetic model. Urea release tests in water revealed a release of 94 % and 97 % at 24 h for SRF1 and SRF2, respectively, compared to 98 % release of pure urea within 1 h. SRF2 demonstrated optimal nutrient release after 48 h. The release kinetics followed the first-order kinetic model for both SRF1 and SRF2, highlighting their potential as effective slow-release fertilizers.

Controlled-release nitrogen combined with ordinary nitrogen fertilizer improved nitrogen uptake and productivity of winter wheat

Background

Blending controlled-release nitrogen fertilizer (CRNF) with ordinary nitrogen fertilizer (ONF) is a strategic approach to improve winter wheat nutrient management. This blend provides nitrogen (N) to winter wheat in a balanced and consistent manner, ensuring long-term growth, reducing nutrient loss due to leaching or volatilization, and increasing N use efficiency (NUE).

Aims

CRNF aims to enhance N application suitability, optimizes soil nutrient dynamics, and its widespread use can boost crop NUE and yield. The study investigates how different CRNF and ONF blending ratios affect soil N content, winter wheat growth, and yield.

Methods

The experiment used two N application rates of 192(N1) and 240(N2) kg ha-1 of ONF, with five different blending ratios CRNF. The proportions of CRNF were 0%(F1), 30%(F2), 50%(F3), 70%(F4), and 100%(F5), respectively. The effects of changes in soil nitrate concentration, dry matter accumulation, N uptake, and transportation at various growth stages and yield were analyzed.

Results

CRNF at the jointing and anthesis stages helps maintain nitrate N levels throughout the growth cycle. Compared to full CRNF application at different N rates, this method also reduces nitrate N leaching in the soil. The 0-60 cm soil layer was primarily influenced by increasing the proportion of CRNF, especially from jointing to maturity. CRNF promotes a higher plant population during the turning green and jointing stages by increasing soil N content, thereby establishing a strong yield foundation for winter wheat. It increases winter wheat N accumulation and correlates positively with soil N content during key growth stages.

Conclusion

Winter wheat grain yield has increased, with significant yield increases observed at 70% blending with a higher amount of N at 240 kg ha-1 and achieved a 2.8% increase in NUE and a 3.0%-15.3% increase in grain yield. In order to improved winter wheat yields through effective N utilization, N2 application (240 kg ha-1) with the combination of (F4) 30% ONF + 70% CRNF would be recommended for northwest region of Shaanxi province in China. By increasing the amount of N accumulation at the anthesis stage, N transport is significantly increased after anthesis, and N accumulation and distribution ratio in grains are significantly increased at maturity.

Purple non-sulfur bacteria for biotechnological applications

In this review, we focus on how purple non-sulfur bacteria can be leveraged for sustainable bioproduction to support the circular economy. We discuss the state of the field with respect to the use of purple bacteria for energy production, their role in wastewater treatment, as a fertilizer, and as a chassis for bioplastic production. We explore their ability to serve as single-cell protein and production platforms for fine chemicals from waste materials. We also introduce more Avant-Garde technologies that leverage the unique metabolisms of purple bacteria, including microbial electrosynthesis and co-culture. These technologies will be pivotal in our efforts to mitigate climate change and circularize the economy in the next two decades.

ONE-SENTENCE SUMMARY

Purple non-sulfur bacteria are utilized for a range of biotechnological applications, including the production of bio-energy, single cell protein, fertilizer, bioplastics, fine chemicals, in wastewater treatment and in novel applications like co-cultures and microbial electrosynthesis.

Lignin-based controlled-release urea improves choy sum growth by regulating soil nitrogen nutrients and bacterial diversity

Lignin, as one of the few renewable resources among aromatic compounds, exhibits significant potential for applications in the agricultural sector. Nonetheless, there has been relatively limited research on the effects of lignin-based controlled-release urea (LCRU) on soil nitrogen nutrition and bacterial diversity. In this paper, the impact of LCRU on the growth of choy sum was investigated through a two-season field experiment. The findings suggest that the plant height, stem diameter, SPAD value, and above-ground dry weight under LCRU application surpassed those with conventional urea (CU), increasing by 40.27%, 26.97%, 52.02%, and 38.62%, respectively. Furthermore, the condition that the urea content was reduced by 15% (LCRU15) caused improvements of 24.76%, 26.97%, 43.23%, and 30.86% in the respective variables. Additionally, compared with the CU, the contents of vitamin C, soluble sugar, and soluble protein in choy sum were increased by the LCRU and LCRU15 treatments, and yet no significant differences were observed between the LCRU and LCRU15 treatments. Notably, the nitrogen used efficiency of choy sum increased to 68.90% with the LCRU15 treatment, compared to 64.29% with the LCRU treatment. The levels of soil available nitrogen, NO3 --N, and NH4 +-N were augmented by the LCRU and LCRU15 treatments. Meanwhile, soil urease and nitrate reductase activities were increased by 22.4%-28.6% and 12.3%-14.5%, respectively. Moreover, soil high-throughput sequencing results illustrated that the LCRU15 treatment enhanced the diversity and abundance of bacteria, particularly the abundance of Actinobacteria, Firmicutes, and Cyanobacteria, which can accelerate the decomposition of organic matter. In short, LCRU improves choy sum yield by influencing soil properties, enzyme activity, and microbial communities. These findings are anticipated to offer practical value for the sustainable application of LCRU in agriculture.

Effect of Polyethylene Glycol and Humic Acid Coating on NPK Release From Controlled-Release Fertilizer

Plants require essential macronutrients such as nitrogen (N), phosphorus (P), and potassium (K), but their availability in soil is often inefficient due to evaporation, leaching, and binding. Controlled-release fertilizers (CRFs) provide a solution by regulating nutrient release over time. This study evaluates the effects of two coating materials, polyethylene glycol (PEG) and humic acid, on the release patterns of N, P, and K during an 18-week incubation using Inceptisol from Bogor, Indonesia. Various CRF treatments were tested, including uncoated (A1, A2), PEG-coated (B1, B2), and humic acid-coated (C1, C2) formulations. Results showed that CRF with PEG (B2) demonstrated slower N release, with ammonium levels decreasing from 32.22% in week 1 to 9.36% by week 18. Nitrate release increased steadily from 26.37% to 37.36% between weeks 3 and 18. In contrast, CRF with humic acid (C2) showed slower nitrate release, reaching 36.26% by the end of incubation. P release patterns were similar across treatments, while K release was lowest in the humic acid-coated treatment (C2) at 24.48%. These findings underline the potential of coating materials like PEG and humic acid to optimize nutrient release, enhancing agricultural efficiency.

Evaluating nitrogen dynamic and utilization under controlled-release fertilizer application for sunflowers in an arid region: Experimental and modeling approach

Traditional nitrogen fertilizers (TNF), such as urea, percolate easily in arid fields, posing low nitrogen use efficiency (NUE) and a high non-point pollution risk. Controlled-release fertilizers (CRF) exhibit significantly lower deep seepage, rendering it a favorable choice in arid fields due to its ability to enhance NUE through slow-release mechanisms. However, current models do not fully account for the soil nitrogen dynamics and crop interactions under controlled-release conditions, and lack quantification. This study improved the APSIM model by adjustment the urea hydrolysis rate to assess the impact of CRF and TNF applications on soil health, crop growth, and water quality. Calibration and validation were conducted through experiments in the Hetao Irrigation District of China from 2019 to 2020, with different nitrogen application rates (135, 225, and 315 kg/ha). The model accurately simulated soil NO3-N concentration (SNC), cumulative NO3-N leaching (CNL), nitrogen uptake (NU), and sunflower yield. During the validation process, R2 and Nash-Sutcliffe efficiency (NSE) values were both above 0.75. Results indicated that the average SNC, NU, and yield under CRF application were significantly higher than those under TNF application, with increases of 38.62%, 44.92%, and 18.38%, respectively. Notably, the proportion of soil nitrogen available (PSNA), a novel metric proposed in this study, was 159.50% higher in the 0-40 cm soil layer with CRF compared to TNF. Additionally, CNL and NO3-N leaching loss rate (NLLR) decreased by 25.76% and 25.77%, respectively. Scenario simulations indicated that the optimal fertilization strategy for this region is to use 180-193.5 kg/ha of CRF with a release period of 80-85.5 d to balance agricultural productivity and ecological protection. This study confirms the significant advantages of CRF in enhancing yield, improving nitrogen management, and promoting environmental sustainability, providing a scientific basis for CRF management strategies and supporting the shift towards more efficient and environmentally friendly agricultural practices.

Nanomaterial-Based Biofortification: Potential Benefits and Impacts of Crops

Nanomaterials (NMs) have shown relevant impacts in crop protection, improvement of yields, and minimizing collateral side effects of fertilizer and pesticides in vegetable and fruit production. The application of NMs to improve biofortification has gained much attention in the last five years, offering a hopeful and optimistic outlook. Thus, we propose comprehensively revising the scientific literature about the use of NMs in the agronomic biofortification of crops and analyzing the beneficial impact of the use of NMs. The results indicated that different species of plants were biofortified with essential elements and macronutrients after the applications of Zn, Fe, Se, nanocomposites, and metalloid NPs. In addition, the physiological performances, antioxidant compounds, and yields were improved with NMs. Using nanofertilizers for the biofortification of crops can be considered a promising method to deliver micronutrients for plants with beneficial impacts on human health, the environment, and agriculture.

Optimization of Synthesis Conditions for Urea-Formaldehyde Slow-Release Fertilizer Using Response Surface Methodology

In this study, we optimized the preparation of urea-formaldehyde fertilizer using response surface methodology with a Box-Behnken experimental design. The aim was to maximize the difference between CWIR and HWIR to maximize the content of slow-release insoluble nitrogen. In this work, a model of the impact of reaction factors on CWIR and HWIR was established. Through analysis of variance, the final model was significant. According to this model, the optimal reaction conditions were: a reaction temperature of 42.5 °C, a reaction time of 66.2 min, a U/F of 1.68, and a pH 3.3. Under these optimal conditions, the CWIR and HWIR reached 55.65 and 33.92%, respectively. In addition, the samples were characterized by scanning electron microscopy and thermal stability analysis. This study accurately synthesized urea-formaldehyde products with specific release periods according to production needs in order to improve the efficiency of fertilizer utilization.

The response of non-point source pollution to climate change in an orchard-dominant coastal watershed

China is the largest global orchard distribution area, where high fertilization rates, complex terrain, and uncertainties associated with future climate change present challenges in managing non-point source pollution (NPSP) in orchard-dominant growing areas (ODGA). Given the complex processes of climate, hydrology, and soil nutrient loss, this study utilized an enhanced Soil and Water Assessment Tool model (SWAT-CO2) to investigate the impact of future climate on NPSP in ODGA in a coastal basin of North China. Our investigation focused on climate-induced variations in hydrology, nitrogen (N), and phosphorus (P) losses in soil, considering three Coupled Model Intercomparison Project phase 6 (CMIP6) climate scenarios: SSP1-2.6, SSP2-4.5, and SSP5-8.5. Research results indicated that continuous changes in CO2 levels significantly influenced evapotranspiration (ET) and water yield in ODGA. Influenced by sandy soils, nitrate leaching through percolation was the principal pathway for N loss in the ODGA. Surface runoff was identified as the primary pathway for P loss. Compared to the reference period (1971-2000), under three future climate scenarios, the increase in precipitation of ODGA ranged from 15% to 28%, while the growth rates of P loss and surface runoff were the most significant, both exceeding 120%. Orchards in the northwest basin proved susceptible to nitrate leaching, while others were more sensitive to N and P losses via surface runoff. Implementing targeted strategies, such as augmenting organic fertilizer usage and constructing terraced fields, based on ODGA's response characteristics to future climate, could effectively improve the basin's environment.

Development of Slow-Release Fertilizers with Function of Water Retention Using Eco-Friendly Starch Hydrogels

Over the past two decades, the development and commercialization of slow-release fertilizers (SRFs) have significantly advanced, with the primary aim of mitigating environmental issues associated with excessive fertilizer use. A range of methodologies, including chemical and physical reactions, incorporation into carriers with porous and layered structures, and coating techniques, have been explored and refined. On the other hand, global challenges such as drought and desertification further underscore the need for SRFs that not only control nutrient release but also improve soil moisture retention. This paper reviews the development and application of eco-friendly starch hydrogels as fertilizer carriers and water retention for SRFs, particularly starch-based superabsorbent polymers (SAPs) produced through grafting copolymerization with acrylamide. This review explores both scientific issues, such as the microstructures and releasing mechanisms of SAPs, and technical development, involving copolymerization technologies, multi-initialization processes, methods of loading fertilizer into hydrogel, etc. Starch, as both a biodegradable and renewable carbohydrate polymer, offers distinct advantages due to its excellent chemical stability and high reactivity. The fabrication techniques of SAPs have been developed from traditional batch polymerization in aqueous solutions to more efficient, solvent-free reactive extrusion. The benefits of SRFs based on SAPs encompass enhanced soil aeration, the prevention of soil deterioration, the minimization of water evaporation, environmental pollution control, reduction in plant mortality, and prolonged nutrient retention within soil. In this review, we summarize the current progress, identify limitations in existing technologies, and propose future research directions to further enhance the performance of starch-based SRFs.

Assessing Heavy Metal Contamination in Commonly Used Fertilizers for Polyculture Fish Ponds and Its Implications for Human Health: A Comprehensive Investigation

Over-fertilizing fish ponds can cause pollution, introducing heavy metals into the food chain and posing health risks. The present study investigated the incidence of heavy metals (Pb, Cu, Cd, and Cr) in commonly applied fertilizers, including nitrogen, phosphorus and potassium (NPK), triple superphosphate (TSP), and di-ammonium phosphate (DAP), and their association with heavy metals in water, sediment, and cultured fish species (Catla catla, Labeo rohita, and Cyprinus carpio) in polyculture fish ponds. The study was conducted over 4 months, with four groups in triplicates: control (no fertilizer), group 1 (NPK), group 2 (TSP), and group 3 (DAP). Heavy metal analysis was carried out using atomic absorption spectrophotometry before and after fertilizer application. Significantly (p < 0.05) higher levels of heavy metals were observed in water and sediment after applying fertilizers, with the most pronounced results in group 3 (DAP) followed by group 2 (TSP). The concentration of heavy metals was significantly (p < 0.05) higher in group 3 (DAP) fertilizers compared to other groups. Compared to the control, the concentration and bioaccumulation of heavy metals were significantly (p < 0.05) higher in the fertilizer-applied groups, with notably higher levels in group 3 (DAP). Cluster analysis and the correlation matrix did not show any significant association between the heavy metals and the fertilizers, indicating a complex interplay between the biotic and abiotic factors of the system. The health index (HI) value was < 1 in fish muscles of all studied groups, indicating the fish are safe for consumption. The study recommends monitoring and regulating fertilizer use, especially DAP, to prevent heavy metal contamination, and exploring sustainable alternatives to minimize environmental and health risks.

Review of current trends in chitosan based controlled and slow-release fertilizer: From green chemistry to circular economy

The demand for food is increasing rapidly with the growth of the global population. To ensure global food security, fertilizers are essential. Controlled-release fertilizers (CRFs) are a highly effective type of fertilizer that have been developed to meet this need. While CRFs offer significant advantages over traditional fertilizers, their use has been limited due to high production costs and negative impact on the environment. CRFs are manufactured and applied without considering the resource-use efficiency of the production process or the potential ecological consequences of fertilizer application. To tackle these issues, biopolymer-based CRFs have been developed. These innovative fertilizers are created by coating granules with biodegradable and eco-friendly biopolymers (chitosan, starch and cellulose). In addition, these groundbreaking fertilizers align with the tenets of the circular economy, which involve formulating products that enable a gradual and steady dispensation of nutrients over an extended period. Our objective in embracing these fertilizers is to transcend the traditional linear "take, make, dispose" approach and transition towards a more sustainable and circular model. This approach not only enhances nutrient delivery efficiency but also contributes significantly to reducing the environmental impact associated with conventional fertilizer use. Afterward, the research explored various aspects of controlled-release fertilizers (CRFs), including the mechanisms of nutrient release, the types of coating materials used, and the techniques employed for coating. The study also examined the benefits and challenges associated with CRFs and analyzed how specific parameters influence the nutrient release mechanisms.

Small molecule, big impacts: Nano-nutrients for sustainable agriculture and food security

Human existence and the long-term viability of society depend on agriculture. Overuse of synthetic fertilizers results in increased contamination of the land, water, and atmosphere as well as financial constraints. In today's modern agriculture, environmentally friendly technology is becoming more and more significant as a substitute for conventional fertilizers and chemical pesticides. Using nanotechnology, agricultural output can be improved in terms of quality, biological support, financial stability, and environmental safety. There is a lot of promise for the sustainable application of nano-fertilizers in crop productivity and soil fertility, with little or no negative environmental effects. In this context, the present review provided an overview of the benefits of using nanofertilizers, its application and types. Mechanistic approach for increasing soil fertility and yield via nanofertilizers also described in detail. We concluded this article to compare the advantages of nanofertilizers over chemicals and nano-chemicals. Nonetheless, additional investigation is required to comprehend the effects and possible hazards of nanomaterials in the food production chain.

Exploring the insights of bioslurry-Nanoparticle amalgam for soil amelioration

In response to global agricultural challenges, this review examines the synergistic impact of bioslurry and biogenic nanoparticles on soil amelioration. Bioslurry, rich in N, P, K and beneficial microorganisms, combined with zinc oxide nanoparticles synthesized through eco-friendly methods, demonstrates remarkable soil improvement capabilities. Their synergistic effects include enhanced nutrient availability through increased soil enzymatic activities, improved soil structure via stable aggregate formation, stimulated microbial activity particularly beneficial groups, enhanced water retention due to increased organic matter and modified soil surface properties and reduced soil pH fluctuations. These mechanisms significantly impact soil physico-chemical properties including cation exchange capacity, electrical conductivity and nutrient dynamics. This review analyses these effects and their implications for sustainable agricultural practices, focusing on crop yield improvements, reduced chemical fertilizer dependence and enhanced plant stress tolerance. Knowledge gaps such as long-term nanoparticle accumulation effects and impacts on non-target organisms are identified. Future research directions include optimizing bioslurry-nanoparticle ratios for various soil types and developing "smart" nanoparticle-enabled biofertilizers with controlled release properties. This innovative approach contributes to environmentally friendly farming practices, potentially enhancing global food security and supporting sustainable agriculture transitions. The integration of bioslurry and biogenic nanoparticles presents a promising solution to soil degradation and agricultural sustainability challenges.

Impact of microplastic residues from polyurethane films on crop growth: Unraveling insights through transcriptomics and metabolomics analysis

The utilisation of coated controlled-release fertilizers (CRFs) leads to the persistence of residual plastic films in agricultural soils, posing a potential threat to crop health. This study investigates the impacts of four residual films (0.39 %, w/w) derived from CRFs in soil, including petrochemical polyether, bio-based polyether, castor oil polyester, and wheat straw polyester polyurethane on wheat growth. This study found that PecPEUR significantly reduced wheat plant height, stem diameter, leaf area, and aboveground fresh weight by 24.8 %, 20.2 %, and 25.7 %. Through an in-depth exploration of transcriptomics and metabolomics, it has been discovered that all residual films disrupted glycolysis-related metabolic pathways in wheat roots, affecting seedling growth. Among them, PecPEUR significantly reduced the fresh weight of aboveground parts by 20.5 %. In contrast, polyester polyurethane residue had no discernible impact on aboveground wheat growth. This was attributed to the enrichment of wheat root genes in jasmonic acid and γ-aminobutyric acid metabolic pathways, thus mitigating oxidative stress, enhancing stress resistance, and ensuring normal plant growth. This study, for the first time, provides comprehensive insights into the effects of polyurethane film residue on wheat seedling growth, underscoring its potential as a promising alternative to conventional plastics in soil.

Response of hydrology and nutrient losses to different extreme rainfall conditions in a coastal watershed influenced by orchards

Global warming is altering the frequency of extreme rainfall events and introducing uncertainties for non-point source pollution (NPSP). This research centers on orchard-influenced planting areas (OIPA) in the Wulong River Watershed of Shandong Province, China, which are known for their heightened nitrogen (N) and phosphorus (P) pollution. Leveraging meteorological data from both historical (1989-2018) and projected future periods (2041-2100), this research identified five extreme rainfall indices (ERI): R10 (moderate rain), R20 (heavy rain), R50 (rainstorm), R95p (Daily rainfall between the 95th and 99th percentile of the rainfall), and R99p (>99th percentile). Utilizing an advanced watershed hydrological model, SWAT-CO2, this study carried out a comparison between ERI and average conditions and evaluated the effects of ERI on the hydrology and nutrient losses in this coastal watershed. The findings revealed that the growth multiples of precipitation in the OIPA for five ERI varied between 16 and 59 times for the historical period and 14 to 65 times for future climate scenarios compared to the average conditions. The most pronounced increases in surface runoff and total phosphorus (TP) loss were observed with R50, R95p, and R99p, showing growth multiples as high as 352 and 330 times, and total nitrogen (TN) growth multiples varied between 4.6 and 30.3 times. The contribution rates of R50 and R99p for surface runoff and TP loss in the OIPA during all periods exceeded 55%, however, TN exhibited the opposite trend, primarily due to the dominated NO3-N leaching in the sandy soil. This research revealed how the OIPA reacts to different ERI and pinpointed essential elements influencing water and nutrient losses.

Evaluation of the release kinetics of hydrophilic and lipophilic compounds from lipid-polymer hybrid nanoparticles

In disease treatment, maintaining therapeutic drug concentrations often requires multiple doses. Lipid/polymer hybrid nanoparticles (LPHNPs) offer a promising solution by facilitating sustained drug delivery within therapeutic ranges. Here, we synthesized poly(lactic-co-glycolic acid) (PLGA) nanoparticles coated with soy lecithin using nanoprecipitation and self-assembly techniques. These nanoparticles were incorporated into gelatin aerogels to ensure uniform distribution and increase the concentration. Our study focused on understanding the release kinetics of hydrophilic (gallic acid) and lipophilic (quercetin) compounds from this system. Nanoparticles exhibited hydrodynamic diameters of 100 ± 15 nm (empty), 153 ± 33 nm (gallic acid-loaded), and 149 ± 21 nm (quercetin-loaded), with encapsulation efficiencies of 90 ± 5% and 70 ± 10% respectively. Gallic acid release followed the Korsmeyer-Peppas kinetics model (n = 1.01), while quercetin showed first-order kinetics. Notably, encapsulated compounds demonstrated delayed release compared to free compounds in gelatin aerogels, illustrating LPHNPs' ability to modulate release profiles independent of the compound type. This study underscores the potential of LPHNPs in optimizing drug delivery strategies for enhanced therapeutic outcomes.

Synthesis and characterization of chitosan-modified membrane for urea slow-release fertilizers

Background

Urea is a fertilizer widely used by farmers, especially vegetable farmers, due to its high nitrogen content, around 46 %. However, plants only use a small amount of nitrogen, a maximum of 35 %, while the remaining nitrogen is wasted and released into the environment. Undeniably, it causes increases production costs and environmental problems. A slow-release urea fertilizer (SRF) has been formulated to resolve these issues.

Methods

In this study, the membrane was made of chitosan with several crosslinking agents such as Tripolyphosphate (TPP). In addition, calcium ion bonds are expected to increase the interaction with urea fertilizer through the encapsulation process.

The results

Our data showed that urea slow-release fertilizer (SRF) with the chitosan/TPP/Ca membrane, was successfully synthesized. This membrane has the characteristics of a thin white layer that is transparent. The physical and chemical characterization of SRF membranes with various coating membrane variations showed that the chitosan/TPP/Ca-urea membrane has Young's modulus of 7.75-22.05 N/mm2, swelling of 109.52-132.62 % and porosity of 0.756-1.06 %. Functional group analysis shows that several spectral changes indicate the presence of crosslinking process between the chitosan functional groups and TPP. The urea release results show that the membrane is released through a diffusion mechanism. Furthermore, SEM results show that these membranes have pores with various shapes and sizes.

Conclusion

Based on the result, it can be concluded that chitosan membrane modification with the addition of TPP and calcium oxide provides improved membrane characteristic cs including degree of development, hydrophobicity, membrane stress, and nitrogen release on the membrane. This membrane shows is indicating suitability as a slow-release fertilizer.

Exploring the Feasibility of Polysaccharide-Based Mulch Films with Controlled Ammonium and Phosphate Ions Release for Sustainable Agriculture

Bio-based polymers are a promising material with which to tackle the use of disposable and non-degradable plastics in agriculture, such as mulching films. However, their poor mechanical properties and the high cost of biomaterials have hindered their widespread application. Hence, in this study, we improved polysaccharide-based films and enriched them with plant nutrients to make them suitable for mulching and fertilizing. Films were produced combining sodium carboxymethyl cellulose (CMC), chitosan (CS), and sodium alginate (SA) at different weight ratios with glycerol and CaCl2 as a plasticizer and crosslinker, respectively, and enriched with ammonium phosphate monobasic (NH4H2PO4). A polysaccharide weight ratio of 1:1 generated a film with a more crosslinked structure and a lower expanded network than that featuring the 17:3 ratio, whereas CaCl2 increased the films' water resistance, thermal stability, and strength characteristics, slowing the release rates of NH4+ and PO43-. Thus, composition and crosslinking proved crucial to obtaining promising films for soil mulching.

Impact of fertilization depth on sunflower yield and nitrogen utilization: a perspective on soil nutrient and root system compatibility

Introduction

The depth of fertilizer application significantly influences soil nitrate concentration (SNC), sunflower root length density (RLD), sunflower nitrogen uptake (SNU), and yield. However, current studies cannot precisely capture subtle nutrient variations between soil layers and their complex relationships with root growth. They also struggle to assess the impact of different fertilizer application depths on sunflower root development and distribution as well as their response to the spatial and temporal distribution of nutrients.

Methods

The Agricultural Production Systems sIMulator (APSIM) model was employed to explore the spatial and temporal patterns of nitrogen distribution in the soil at three controlled-release fertilizer (CRF) placement depths: 5, 15, and 25 cm. This study investigated the characteristics of the root system regarding nitrogen absorption and utilization and analyzed their correlation with sunflower yield formation. Furthermore, this study introduced the modified Jaccard index (considering the compatibility between soil nitrate and root length density) to analyze soil-root interactions, providing a deeper insight into how changes in CRF placement depth affect crop growth and nitrogen uptake efficiency.

Results

The results indicated that a fertilization depth of 15 cm improved the modified Jaccard index by 6.60% and 7.34% compared to 5 cm and 25 cm depths, respectively, maximizing sunflower yield (an increase of 9.44%) and nitrogen absorption rate (an increase of 5.40%). This depth promoted a greater Root Length Density (RLD), with an increases of 11.95% and 16.42% compared those at 5 cm and 25 cm, respectively, enhancing deeper root growth and improving nitrogen uptake. In contrast, shallow fertilization led to higher nitrate concentrations in the topsoil, whereas deeper fertilization increased the nitrate concentrations in the deeper soil layers.

Discussion

These results provide valuable insights for precision agriculture and sustainable soil management, highlighting the importance of optimizing root nitrogen absorption through tailored fertilization strategies to enhance crop production efficiency and minimize environmental impact.

Examining the Correlation between the Inorganic Nano-Fertilizer Physical Properties and Their Impact on Crop Performance and Nutrient Uptake Efficiency

The physical properties of nano-fertilizers (NFs) are important in determining their performance, efficacy, and environmental interactions. Nano-fertilizers, due to their small size and high surface area-to-volume ratio, enhance plant metabolic reactions, resulting in higher crop yields. The properties of nano-fertilizers depend on the synthesis methods used. The nanoparticle's nutrient use efficiency (NUE) varies among plant species. This review aims to analyze the relationship between the physical properties of NF and their influence on crop performance and nutrient uptake efficiency. The review focuses on the physical properties of NFs, specifically their size, shape, crystallinity, and agglomeration. This review found that smaller particle-sized nanoparticles exhibit higher nutrient use efficiency than larger particles. Nano-fertilizer-coated additives gradually release nutrients, reducing the need for frequent application and addressing limitations associated with chemical fertilizer utilization. The shapes of nano-fertilizers have varying effects on the overall performance of plants. The crystalline structure of nanoparticles promotes a slow release of nutrients. Amorphous nano-fertilizers improve the NUE and, ultimately, crop yield. Agglomeration results in nanoparticles losing their nanoscale size, accumulating on the outer surface, and becoming unavailable to plants. Understanding the physical properties of nano-fertilizers is crucial for optimizing their performance in agricultural applications.

Antifungal Activity of Difenoconazole-Loaded Microcapsules against Curvularia lunata

Difenoconazole-loaded (CS-DIF) microcapsules were synthesized by encapsulating difenoconazole into biocompatible chitosan. The physical and chemical properties indicated that the encapsulation and chemical loading rates were 85.58% and 61.98%, respectively. The microcapsules exhibited prominent controlled-release and surface stability performance. The cumulative release rate was only 33.6% in 168 h, and the contact angle decreased by 11.73° at 120 s compared with difenoconazole. The antifungal activity of the CS-DIF microcapsules against Curvularia lunata was confirmed through observations of colony growth, in vitro and in vivo inoculation, mycelium morphology, as well as DNA and protein leakage. The antioxidant enzyme activity of superoxide dismutase, peroxidase, and catalase decreased by 65.1%, 84.9%, and 69.7%, respectively, when Curvularia lunata was treated with 200 μg/mL microcapsules, compared with the control in 24 h. The enzymatic activity of polyphenol oxidase decreased by 323.8%. The reactive oxygen species contents of hydrogen peroxide and superoxide anions increased by 204.6% and 164%, respectively. Additionally, the soluble sugar and soluble protein contents decreased by 65.5% and 69.6%, respectively. These findings provided a novel approach to control the growth of C. lunata efficiently, laying a foundation for reducing the quantity and enhancing the efficiency of chemical pesticides. The CS-DIF microcapsules exhibited a strong inhibitory effect on fungus, effectively preventing and controlling leaf spot disease and showing potential for field applications. This study might be of great significance in ensuring plant protection strategies.

Zinc-exchanged montmorillonite clay: A promising slow-release nanofertilizer for rice (Oryza sativa L.)

This study is to examine zinc exchanged montmorillonite (Zn-MMT) as a potential slow release nanofertilizer for rice crop. The effective intercalation of zinc within the montmorillonite inter layers was firmly established via analytical techniques including Zeta potential, FE-SEM (Field Emission Scanning Electron Microscopy) with Energy Dispersive X-ray Analysis (EDAX), Transmission Electron Microscope (TEM), X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). The efficacy of Zn-MMT was examined by evaluating its ability to facilitate controlled zinc release, as confirmed through an incubation study. Subsequently, the kinetics of zinc release was analyzed by different mathematical models such as Zero-order kinetics, First-order kinetics, the Higuchi model, and the Korsmeyer-Peppas model. From the pot culture study spanning 90 days the results indicated that Zn-MMT had significantly high plant height, Leaf Area Index (LAI), Dry Matter Production (DMP), number of tillers per hill, panicles length, increased grain and straw yield, in comparison with conventional zinc sulphate (ZnSO4). Total phenol, total protein and total chlorophyll content were significantly at higher levels with Zn-MMT treated rice crops as compared to conventional fertilizers and control. A similar trend was seen with phytochemicals such as Indole Acetic Acid (IAA), Superoxide Dismutase (SOD) and Carbonic Anhydrase (CA). Notably, rice grains harvested from Zn-MMTtreated crops exhibited significantly higher zinc content than those using other treatments. This Zn-MMT can be confirmed as a better alternative to conventional zinc sulphate fertilizers owing to its slow-release of nutrient into the soil and thus increased zinc use efficiency.

Climate adaptation through crop migration requires a nexus perspective for environmental sustainability in the North China Plain

Crop migration can moderate the impacts of global warming on crop production, but its feedback on the climate and environment remains unknown. Here we develop an integrated framework to capture the climate impacts and the feedback of adaptation behaviours with the land-water-energy-carbon nexus perspective and identify opportunities to achieve the synergies between climate adaptation and environmental sustainability. We apply the framework to assess wheat and maize migration in the North China Plain and show that adaptation through wheat migration could increase crop production by ~18.5% in the 2050s, but at the cost of disproportional increment in land use (~19.2%), water use (~20.2%), energy use (~19.5%) and carbon emissions (~19.9%). Irrigation and fertilization management are critical mitigation opportunities in the framework, through which wheat migration can be optimized to reduce the climatic and environmental impacts and avoid potential carbon leakage. Our work highlights the sustainable climate adaptation to mitigate negative environmental externalities.

Humic Acid-Functionalized Lignin-Based Coatings Regulate Nutrient Release and Promote Wheat Productivity and Grain Quality

The rational application of fertilizers is crucial for achieving high crop yields and ensuring global food security. The use of biopolymers for slow-release fertilizers (SRFs) development has emerged as a game-changer and environmentally sustainable pathway to enhance crop yields by optimizing plant growth phases. Herein, with a renewed focus on circular bioeconomy, a novel functionalized lignin-based coating material (FLGe) was developed for the sustained release of nutrients. This innovative approach involved the extraction and sustainable functionalization of lignin through a solvent-free esterification reaction with humic acid─an organic compound widely recognized for its biostimulant properties in agriculture. The primary objective was to fortify the hydration barrier of lignin by reducing the number of its free hydroxyl groups, thereby enhancing release control, while simultaneously harnessing the agronomic benefits offered by humic acid. After confirming the synthesis of functionalized lignin (FLGe) through 13C NMR analysis, it was integrated at varying proportions into either a cellulosic or starch matrix. This resulted in the creation of five distinct formulations, which were then utilized as coatings for diammonium phosphate (DAP) fertilizer. Experimental findings revealed an improved morphology and hardness (almost 3-fold) of DAP fertilizer granules after coating along with a positive impact on the soil's water retention capacity (7%). Nutrient leaching in soil was monitored for 100 days and a substantial reduction of nutrients leaching up to 80% was successfully achieved using coated DAP fertilizer. Furthermore, to get a fuller picture of their efficiency, a pot trial was performed using two different soil textures and demonstrated that the application of FLGe-based SRFs significantly enhanced the physiological and agronomic parameters of wheat, including leaf evolution and root architecture, resulting in an almost 50% increase in grain yield and improved quality. The results proved the potential of lignin functionalization to advance agricultural sustainability and foster a robust bioeconomy aligning with the premise "from the soil to the soil".

Agriculture and environmental management through nanotechnology: Eco-friendly nanomaterial synthesis for soil-plant systems, food safety, and sustainability

Through the advancement of nanotechnology, agricultural and food systems are undergoing strategic enhancements, offering innovative solutions to complex problems. This scholarly essay thoroughly examines nanotechnological innovations and their implications within these critical industries. Traditional practices are undergoing radical transformation as nanomaterials emerge as novel agents in roles traditionally filled by fertilizers, pesticides, and biosensors. Micronutrient management and preservation techniques are further enhanced, indicating a shift towards more nutrient-dense and longevity-oriented food production. Nanoparticles (NPs), with their unique physicochemical properties, such as an extraordinary surface-to-volume ratio, find applications in healthcare, diagnostics, agriculture, and other fields. However, concerns about their potential overuse and bioaccumulation raise unanswered questions about their health effects. Molecule-to-molecule interactions and physicochemical dynamics create pathways through which nanoparticles cause toxicity. The combination of nanotechnology and environmental sustainability principles leads to the examination of green nanoparticle synthesis. The discourse extends to how nanomaterials penetrate biological systems, their applications, toxicological effects, and dissemination routes. Additionally, this examination delves into the ecological consequences of nanomaterial contamination in natural ecosystems. Employing robust risk assessment methodologies, including the risk allocation framework, is recommended to address potential dangers associated with nanotechnology integration. Establishing standardized, universally accepted guidelines for evaluating nanomaterial toxicity and protocols for nano-waste disposal is urged to ensure responsible stewardship of this transformative technology. In conclusion, the article summarizes global trends, persistent challenges, and emerging regulatory strategies shaping nanotechnology in agriculture and food science. Sustained, in-depth research is crucial to fully benefit from nanotechnology prospects for sustainable agriculture and food systems.

Carrier-based delivery system of phytohormones in plants: stepping outside of the ordinary

Climate change is increasing the stresses on crops, resulting in reduced productivity and further augmenting global food security issues. The dynamic climatic conditions are a severe threat to the sustainability of the ecosystems. The role of technology in enhancing agricultural produce with the minimum environmental impact is hence crucial. Active molecule/Plant growth regulators (PGRs) are molecules helping plants' growth, development, and tolerance to abiotic and biotic stresses. However, their degradation, leaching in surrounding soil and ground water, as well as the assessment of the correct dose of application etc., are some of the technical disadvantages faced. They can be resolved by encapsulation/loading of PGRs on polymer matrices. Micro/nanoencapsulation is a revolutionary tool to deliver bioactive compounds in an economically affordable and environmentally friendly way. Carrier-based smart delivery systems could be a better alternative to PGRs application in the agriculture field than conventional methods (e.g., spraying). The physiochemical properties and release kinetics of PGRs from the encapsulating system are being explored. Therefore, the present review emphasizes the current status of PGRs encapsulation approach and their potential benefits to plants. This review also addressed the mechanistic action of carrier-based delivery systems for release, which may aid in developing smart delivery systems with specific tailored properties in future research.

Impact of Modifications from Potassium Hydroxide on Porous Semi-IPN Hydrogel Properties and Its Application in Cultivation

This study synthesized and modified a semi-interpenetrating polymer network hydrogel from polyacrylamide, N,N'-dimethylacrylamide, and maleic acid in a potassium hydroxide solution. The chemical composition, interior morphology, thermal properties, mechanical characteristics, and swelling behaviors of the initial hydrogel (SH) and modified hydrogel (SB) in water, salt solutions, and buffer solutions were investigated. Hydrogels were used as phosphate fertilizer (PF) carriers and applied in farming techniques by evaluating their impact on soil properties and the growth of mustard greens. Fourier-transform infrared spectra confirmed the chemical composition of SH, SB, and PF-adsorbed hydrogels. Scanning electron microscopy images revealed that modification increased the largest pore size from 817 to 1513 µm for SH and SB hydrogels, respectively. After modification, the hydrogels had positive changes in the swelling ratio, swelling kinetics, thermal properties, mechanical and rheological properties, PF absorption, and PF release. The modification also increased the maximum amount of PF loaded into the hydrogel from 710.8 mg/g to 770.9 mg/g, while the maximum % release of PF slightly increased from 84.42% to 85.80%. In addition, to evaluate the PF release mechanism and the factors that influence this process, four kinetic models were applied to confirm the best-fit model, which included zero-order, first-order, Higuchi, and Korsmeyer-Peppas. In addition, after six cycles of absorption and release in the soil, the hydrogels retained their original shapes, causing no alkalinization or acidification. At the same time, the moisture content was higher as SB was used. Finally, modifying the hydrogel increased the mustard greens' lifespan from 20 to 32 days. These results showed the potential applications of modified semi-IPN hydrogel materials in cultivation.

Effects of straw returning combined with blended controlled-release urea fertilizer on crop yields, greenhouse gas emissions, and net ecosystem economic benefits: A nine-year field trial

Although straw returning combined with blended controlled-release urea fertilizer (BUFS) has been shown to improve wheat-maize rotation system productivity, their effects on greenhouse gas (GHG) emissions, carbon footprints (CF), and net ecosystem economic benefits (NEEB) are still unknown. Life cycle assessment was used to investigate a long-term (2013-2022) wheat-maize rotation experiment that included straw combined with two N fertilizer types [BUFS and (conventional urea fertilizer) CUFS] and straw-free treatments (BUF and CUF). The results showed that BUFS and CUFS treatments increased the annual yield by 13.8% and 11.5%, respectively, compared to BUF and CUF treatments. The BUFS treatment increased the yearly yield by 13.8% compared to the CUFS treatment. Since BUFS and CUFS treatments increased soil organic carbon (SOC) sink sequestration by 25.0% and 27.0% compared to BUF and CUF treatments, they reduced annual GHG emissions by 7.1% and 4.7% and CF per unit of yield (CFY) by 13.7% and 9.6%, respectively. BUFS treatment also increased SOC sink sequestration by 20.3%, reduced GHG emissions by 10.7% and CFY by 23.0% compared to CUFS treatment. It is worth noting that the BUFS and CUFS treatments increased the annual ecological costs by 41.6%, 26.9%, and health costs by 70.1% and 46.7% compared to the BUF and CUF treatments, but also increased the net yield benefits by 9.8%, 6.8%, and the soil nutrient cycling values by 29.2%, 27.3%, and finally improved the NEEB by 10.1%, 7.3%, respectively. Similar results were obtained for the BUFS treatment compared to the CUFS treatment, ultimately improving the NEEB by 23.1%. Based on assessing yield, GHG emissions, CF, and NEEB indicators, the BUFS treatment is recommended as an ideal agricultural fertilization model to promote sustainable and clean production in the wheat-maize rotation system and to protect the agroecological environment.

Pb uptake, accumulation, and translocation in plants: Plant physiological, biochemical, and molecular response: A review

Lead (Pb) is a highly toxic contaminant that is ubiquitously present in the ecosystem and poses severe environmental issues, including hazards to soil-plant systems. This review focuses on the uptake, accumulation, and translocation of Pb metallic ions and their toxicological effects on plant morpho-physiological and biochemical attributes. We highlight that the uptake of Pb metal is controlled by cation exchange capacity, pH, size of soil particles, root nature, and other physio-chemical limitations. Pb toxicity obstructs seed germination, root/shoot length, plant growth, and final crop-yield. Pb disrupts the nutrient uptake through roots, alters plasma membrane permeability, and disturbs chloroplast ultrastructure that triggers changes in respiration as well as transpiration activities, creates the reactive oxygen species (ROS), and activates some enzymatic and non-enzymatic antioxidants. Pb also impairs photosynthesis, disrupts water balance and mineral nutrients, changes hormonal status, and alters membrane structure and permeability. This review provides consolidated information concentrating on the current studies associated with Pb-induced oxidative stress and toxic conditions in various plants, highlighting the roles of different antioxidants in plants mitigating Pb-stress. Additionally, we discussed detoxification and tolerance responses in plants by regulating different gene expressions, protein, and glutathione metabolisms to resist Pb-induced phytotoxicity. Overall, various approaches to tackle Pb toxicity have been addressed; the phytoremediation techniques and biochar amendments are economical and eco-friendly remedies for improving Pb-contaminated soils.

All-Natural Plant-Derived Polyurethane as a Substitute of a Petroleum-Based Polymer Coating Material

The development of efficient, biobased polyurethane controlled-release fertilizers from sustainable and eco-friendly biomaterials has received increased research attention, owing to concerns regarding global food security and environmental sustainability. Most previous studies focused on replacing petroleum-based polyols with biopolyols; however, the other main raw material, isocyanate, remained a petrochemical product. Herein, all-natural, plant-derived polyurethane-coated urea was successfully developed using castor oil and biobased isocyanate, and the performance of the coating shell before and after modification was compared. The results showed that the incorporation of a low dose of lauric acid copper into the coating material simultaneously enhanced the hydrophobicity and elasticity of the all-biobased polyurethane membrane, which prolonged the nitrogen release longevity from 3 to 112 days. In addition, the modified membrane showed excellent biodegradability in a soil environment. The novel all-biobased polyurethane coating material and modification technique provide insight for developing sustainable and eco-friendly controlled-release fertilizers.

Coriander response to nitrogen fertilizer sources in different competing levels of weeds

The competition of weeds with crops and nutrient management has a significant effect on the yield and economic efficiency of a country. This study aimed to evaluate the impacts of sulfur-coated urea and common urea on the yield and fatty acid composition of three coriander genotypes (Nahavandi, Pishgam, Ethiopia) under weeded and unweeded conditions. Traits including 1000 seeds weight, fruit yield, content of oil, and composition of fatty acids were examined. Nitrogen fertilizer and weeding treatments significantly improved the weight of 1000 seeds and weeds decreased the yield of fruit. The highest fruit yield was obtained by the Ethiopia genotype in weed-free conditions. Results showed that N fertilizer increased the oil percentage of coriander fruit. Urea fertilizer resulted in the highest oil content in the Nahavandi and Pishgam genotypes under weeded plots in the first and second years, respectively. Also, petroselinic, linoleic, and palmitic acids were the major coriander fatty acid composition. Nahavandi genotype showed the highest palmitic acid. Also, urea in the weed condition led to increase the linoleic acid content in the Nahavandi genotype. Overall, results showed that N fertilizer, especially urea, improved the quality characteristics of coriander fruits.

Development of alginate beads for precise environmental release applications: A design of experiment based approach and analysis

Controlled release of active ingredients are important for drug delivery and more recently environmental applications including modulated dosing of chemical and biological controls. This study demonstrates the importance of investigating various material science factors that can influence the diffusion rates of alginate beads to improve and tune their performance for marine environmental applications. This investigation aimed to design a rational workflow to aid in leveraging alginate bead use as a carrier matrix for releasing a specific active agent into water. Experiments were conducted to focus on the narrow a large list of relevant material formulation parameters, which included chitosan molecular weight, chitosan concentration, calcium concentration, drop height, and bead size. Once the most relevant material preparation methods were screened, a more robust statistic Design of Experiments approach was performed and results determined the important (and unimportant) factors for increasing dye release kinetics in marine water. The process was further streamlined by narrowing the critical experimental factors to a three-level based on the prior analysis: chitosan MW, chitosan concentration, and bead size. Analysis of the collected data indicated that while chitosan MW had a negligible impact (Fstatistic = 0.22), bead size (Fstatistic = 60.33) significantly influenced the diffusion rates based on surface area. However, chitosan MW had minor effects where lower chitosan MW enabled higher product release rates. This case investigation was a novel application of the design of experiment approach towards environmental applications to understand differences in release rates to marine waters for the first time and the workflow provided also serve as the basis for researchers to optimize other environmental applications requiring optimization when it is unknown how a large number of formulation variables will impact performance in different environmental scenarios.

Phosphorus extractors in soil under no-tillage system with 19 years of swine manure applications

The objective of this study was to evaluate the availability of phosphorus (P) in a soil under no-tillage system after successive applications of liquid swine manure (LSM) doses in soil samples collected at different depths and to select the most appropriate chemical extractors. It was used soil with LSM applications for 19 years, using doses of 0, 25, 50, 75 and 100 m3 ha-1 and mineral fertilization (350 kg ha-1 in formulation 02-20-18), evaluated at the following depths: 0-10, 10-20 and 20-40 cm. The extractors used were Mehlich-1, Mehlich-3, Prem, Olsen, Bray-1 and Resin. Successive fertilizations with LSM, especially with 100 m3 ha-1, increase the availability of P, especially in the 0-10 cm layer, as well adding P in the deeper layers evaluated (20-40 cm). The organic P content in relation to the total P ranged from 16 to 19 %. Bray-1, Olsen and Resin extractors are more efficient in extracting P in soil under no-tillage cultivation after successive fertilizations with liquid swine manure.

Revolutionizing agriculture: Harnessing nano-innovations for sustainable farming and environmental preservation

The agricultural sector is currently confronted with a significant crisis stemming from the rapid changes in climate patterns, declining soil fertility, insufficient availability of essential macro and micronutrients, excessive reliance on chemical fertilizers and pesticides, and the presence of heavy metals in soil. These numerous challenges pose a considerable threat to the agriculture industry. Furthermore, the exponential growth of the global population has led to a substantial increase in food consumption, further straining agricultural systems worldwide. Nanotechnology holds great promise in revolutionizing the food and agriculture industry, decreasing the harmful effects of agricultural practices on the environment, and improving productivity. Nanomaterials such as inorganic, lipid, and polymeric nanoparticles have been developed for increasing productivity due to their unique properties. Various strategies can enhance product quality, such as the use of nano-clays, nano zeolites, and hydrogel-based materials to regulate water absorption and release, effectively mitigating water scarcity. The production of nanoparticles can be achieved through various methods, each of which has its own unique benefits and limitations. Among these methods, chemical synthesis is widely favored due to the impact that various factors such as concentration, particle size, and shape have on product quality and efficiency. This review provides a detailed examination of the roles of nanotechnology and nanoparticles in sustainable agriculture, including their synthetic methods, and presents an analysis of their associated advantages and disadvantages. To date, there are serious concerns and awareness about healthy agriculture and the production of healthy products, therefore the development of nanotech-enabled devices that act as preventive and early warning systems to identify health issues, offering remedial measures is necessary.

Towards circular economy: Potential of microalgae - bacterial-based biofertilizer on plants

Biofertilizers encompass microorganisms that can be applied to plants, subsequently establishing themselves within the plant's rhizosphere or internal structures. This colonization stimulates plant development by enhancing nutrient absorption from the host. While there is growing literature documenting the applications of microalgae-based and bacterial-based biofertilizers, the research focusing on the effectiveness of consortia formed by these microorganisms as short-term plant biofertilizers is notably insufficient. This study seeks to assess the effectiveness of microalgae-bacterial biofertilizers in promoting plant growth and their potential contribution to the circular economy. The review sheds light on the impact of microalgae-bacterial biofertilizers on plant growth parameters, delving into factors influencing their efficiency, microalgae-bacteria interactions, and effects on soil health. The insights from this review are poised to offer valuable guidance to stakeholders in agriculture, including farmers, environmental technologists, and businesses. These insights will aid in the development and investment in more efficient and sustainable methods for enhancing crop yields, aligning with the Sustainable Development Goals and principles of the circular economy.

Water-resistant and pyknotic recyclable waste-cotton-derived bio-polyurethane-coated controlled-release fertilizer: Improved longevity, mechanism and application

Reasonably utilize the recyclable waste-cotton resource to develop the bio-polyurethane coatings had aroused more and more environmental interests recently. However, the terrible water resistance and porousness of the waste-cotton-derived bio-polyurethane coating caused the rapid nutrients release. In this work, the water-resistant and pyknotic cotton-fibre-derived coated-ureas (WPCUs) were fabricated with the recyclable low-cost waste-cotton-derived materials. The dramatically enhanced pyknotic and water-resistant characteristics of the WPCUs coatings can be obtained by the three-dimensional computerized tomography (2.33 to 1.19 %) and the water contact angle. The enhanced elasticity and the decreased water absorption were also vital to enhance the controlled-release performance. The accompanying controlled-release performance of the WPCUs was obviously improved (<2 h to 58.43 days). The modified WPCU75-10 with 4.0 % coating content exhibits the excellent controlled-release performance compared to the unmodified WPCU0-0. The controlled release mechanism can be clarified: The air column inside of the "small and few" micropores in the WPCUs coating only allow the gaseous water molecules to slowly penetrate and dissolve the inner urea cores (rather than liquid water). The obviously increased oilseed rape yield (128.75 %) showed the dependable agricultural application of the WPCUs. This work provides the resultful approach to develop the eco-friendly recyclable waste-plant-derived controlled-release fertilizers.

Chitosan microspheres-based controlled-release nitrogen fertilizers improve the biological characteristics of Brassica rapa ssp. pekinensis and the soil

Present study investigates the impact of chitosan microspheres-based controlled-release nitrogen fertilizer (Cm-CRNFs) on biological characteristics of Brassica rapa ssp. pekinensis (Chinese cabbage) and soil. The study was carried out under various four treatments, urea (0.8033 g), blank chitosan microspheres (without urea), Cm-CRNFs (0.8033 g), and a control group (CK). The results indicated that Cm-CRNFs significantly prolonged the nitrogen release and enhanced the plant shoot length, shoot diameter, number of branches, pods, total amino acids, and vitamin C of Brassica rapa ssp. pekinensis as well as increased the soil nutrient availability. Chao index of bacterial diversity analysis showed a significant reduction of 15.89 % in Cm-CRNFs, but the Shannon index value in Cm-CRNFs was increased by 23.55 % compared to CK. Furthermore, Cm-CRNFs treatment significantly influenced genus richness level of Arthrobacter, Archangium, Bacillus, and Flavihumibacter. Moreover, relative abundance of bacteria significantly enhanced Cm-CRNFs, including Acidobacteriota, Acitinobacteriota, Cloroflexi, Cyanobacteria, and Patescibacteria. Soil enzyme activity such as: urease, acid phosphatase, and catalase enzymes in Cm-CRNFs and urea treatment significantly increased. Besides, other enzymes such as: cellulase and β-glucosidase activity decreased in the Cm-CRNFs treatment. It was concluded that Cm-CRNFs potentially prolonged discharge of micro/macronutrients and improved soil bacterial diversity, which ultimately enhanced the soil fertility and improved the soil enzyme activity.

A comprehensive review on starch: Structure, modification, and applications in slow/controlled-release fertilizers in agriculture

This comprehensive review thoroughly examines starch's structure, modifications, and applications in slow/controlled-release fertilizers (SRFs) for agricultural purposes. The review begins by exploring starch's unique structure and properties, providing insights into its molecular arrangement and physicochemical characteristics. Various methods of modifying starch, including physical, chemical, and enzymatic techniques, are discussed, highlighting their ability to impart desirable properties such as controlled release and improved stability. The review then focuses on the applications of starch in the development of SRFs. It emphasizes the role of starch-based hydrogels as effective nutrient carriers, enabling their sustained release to plants over extended periods. Additionally, incorporating starch-based hydrogel nano-composites are explored, highlighting their potential in optimizing nutrient release profiles and promoting plant growth. Furthermore, the review highlights the benefits of starch-based fertilizers in enhancing plant growth and crop yield while minimizing nutrient losses. It presents case studies and field trials demonstrating starch-based formulations' efficacy in promoting sustainable agricultural practices. Overall, this review consolidates current knowledge on starch, its modifications, and its applications in SRFs, providing valuable insights into the potential of starch-based formulations to improve nutrient management, boost crop productivity, and support sustainable agriculture.