This work aims to isolate and screen the fungicidal endophytic bacterial strains for biocontrol efficacy against Phytophthora palmivora, a soil-borne pathogenic fungus that kills durian trees worldwide. Among more than 100 isolates, 6 strains were screened as potential fungicidal strains with inhibitory efficiency of 67.4-79.8%. Based on 16S rRNA gene sequencing and phylogenetic analysis, these strains were identified as Bacillus amyloliquefaciens EB.CK9, Bacillus methylotrophicus EB.EH34, Bacillus amyloliquefaciens EB.EH18, Bacillus siamensis EB.KN10, Bacillus velezensis EB.KN15 and Paenibacillus polymyxa EB.KN35. In greenhouse tests, the two strains P. polymyxa EB.KN35 and B. velezensis EB.KN15 significantly reduced the damage to diseased roots by P. palmivora (33.3 and 35.6%, respectively), increased the rate of survival of durian trees (only 20.8 and 22.9% plant death, respectively), and showed a positive effect on promoting durian plant growth. Notably, the potential fungicidal effect of last two strains against P. palmivora was recorded for the first time in this work. HPLC analysis showed that these strains can secret several plant growth-promoting compounds, including gibberellic acid (GA3), indole-3-acetic acid (IAA), kinetin, and zeatin. Of these, GA3 and zeatin were produced with a significant amount by both strains. The volatiles bio-synthesized by these isolates were also identified using GC-MS analysis, and some major volatiles were found as fungicidal agents. This study suggested that P. polymyxa EB.KN35 and B. velezensis EB.KN15 may be potential biocontrol candidates for durian P. palmivora and bio-fertilizers for the sustainable production of durian crops.
With an increase in global demand for food without unwanted environmental issues stresses a need for sustainable agriculture. Up till now, conventional agricultural methods focused on obtaining great crop yields from the use of chemical fertilizers but overlooked the hazardous concerns that are leading to soil depletion. These chemical fertilizers adversely affect soil structure, decrease fertility, damage soil flora, and lead to soil erosion. In this scenario, understanding the natural mechanisms of plant-microbe interactions in the rhizospheric environment can potentially lead a way towards eco-friendly agriculture, as the plant associating bacteria prompting phytostimulation can be the key players in unlocking sustainable alternative for conventional fertilizers. Plant growth-promoting bacteria (PGPB) are a distinct class of soil microorganisms that promote plant growth and yields by enhancing nutrient delivery and shielding the plants against diseases. N fixing bacteria such as Rhizobium and Azotobacter, for instance, fix atmospheric nitrogen into a usable form for plants, Pseudomonas and Bacillus induce root and shoot elongation by synthesizing phytohormones. These bacteria also provide protection to plants by synthesizing antimicrobial substances and increasing the competitive nature of the rhizosphere. Bacteria like Azospirillum, Enterobacter, and Flavobacterium also stimulate plant growth by producing phytohormones under specific envirnmental conditions. Utilization of PGPB as bio-stimulants in agriculture is a promising method for sustainable agriculture dependence on chemical fertilizers and maintaining soil health. This approach would play an important role in sustaining a balanced ecosystem along with increasing agricultural productivity.
Addressing saline soil issues while ensuring agricultural productivity requires innovative technologies. This study investigated the impact of adding an innovative remediation preparation, specifically leguminous compost containing 50 g (LCT+CS-1), 100 g (LCT+CS-2), or 150 g of corn silk kg-1 (LCT+CS-3), to saline soil (ECe = 11.05 dS m-1) on soil characteristics and fenugreek plant performance during the 2022/2023 and 2023/2024 seasons. All organic supplementations significantly improved soil organic matter content, nutrient levels, and enzyme activities (urease, acid and alkaline phosphatase, and catalase) while reducing soil pH and Na+ content compared to the control. These results reflected decreased Na+ content, oxidative stress indicators (hydrogen peroxide and superoxide radicals), and oxidative damage (leaf electrolyte leakage and malondialdehyde levels) in fenugreek plants. On the other hand, leaf integrity (chlorophyll and carotenoid contents, membrane stability index, and relative water content) and nutrient contents improved. Furthermore, K+/Na+ ratio, osmoregulatory compounds (soluble sugars and proline), antioxidant levels (glutathione, ascorbate, phenols, and flavonoids), and antioxidant activity increased notably. Thus, notable increases in plant growth and yield traits and seed quality (trigonelline, nicotinic acid, total phenols, and flavonoids) were achieved. LCT+CS-2 was the most effective treatment for saline soil (ECe = 11.05 dS m-1), alleviating salinity effects and improving fenugreek growth, yield, and seed quality traits.
AimsPecan (Carya cathayensis Sarg.) is an important forest trees in China, the application of chemical pesticides for disease control has caused severe damage to the soil, including reduced fertility and disruption of microbial communities. Although Trichoderma treatment has been shown to promote plant growth and improve soil quality, its effects on the growth promotion of pecan and the impact on soil microbial communities and physicochemical properties remained unclear.MethodsIn this study, we investigated the impact of T. asperellum TCS007 spore suspension and its fermented crude extract on the growth and development of pecan seedlings. We also explored the effects of TCS007 treatment on the nutrients, enzyme activities, and microbial diversity in the rhizosphere soil of pecan seedlings during their three main growth stages.ResultsTreatment with TCS007 spore suspension or crude extract promoted the growth of pecan seedlings, with significantly higher levels of leaf hormones and defense enzyme activity compared to the control (CK). Moreover, the content of soil organic matter and ammonium nitrogen, as well as the activity of soil enzymes such as catalase and urease, were all significantly higher than CK after treatment, and the soil pH shifted from slightly acidic to slightly alkaline. The results indicated that TCS007 treatment significantly increased the richness of beneficial fungi and bacteria in the soil.ConclusionThe results demonstrated that TCS007 treatment significantly promoted the growth of pecan plants, increased enzyme activity and nutrient content in the soil, and improved the soil micro-ecological environment.
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-MBCSRFs. 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 chitosancoated 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.
The growing demand for sustainable and environment-friendly materials has driven extensive research on biopolymers for applications in agriculture, food science, and environmental remediation. Among these, nanocellulose-hydrogel hybrids (NC-HHs) have gained significant attention as an innovative class of bio-based materials that uniquely combine the remarkable physicochemical properties of nanocellulose with the functional versatility of hydrogels. These hybrids are characterised by exceptional water retention, mechanical strength and biodegradability, enabling advances in precision agriculture, smart food preservation and contaminant remediation. This review provides a comprehensive understanding of the synthesis, properties, and multifunctional applications of NC-HHs, emphasising their innovative role in sustainability. In agriculture, NCHHs enhance soil moisture retention, support plant growth, and serve as carriers for controlled-release fertilizers, optimizing water and nutrient use efficiency. In the food industry, they enable intelligent packaging solutions that extend shelf life, monitor food freshness, and inhibit microbial growth. Additionally, NC-HHs present groundbreaking strategies for environmental remediation by effectively immobilizing pollutants in water and soil. Beyond summarizing recent advances, this review presents an in-depth mechanistic perspective on the interactions between NC and HH, critically evaluating their structure-property relationships, functional adaptability and application-specific performance. By integrating recent advances in nanocellulose functionalisation, polymer chemistry and the development of responsive hydrogels, this review critically examines the key technological innovations and future prospects of NC-HHs, underscoring their transformative potential in addressing global challenges related to food security, environmental sustainability, and sustainable agricultural practices.
Nanotechnology, which involves manipulating matter at the atomic and molecular scales to produce structures and devices ranging from 1 to 100 nm, is increasingly being applied in agriculture. Nanoscale materials possess distinct optical, electrochemical, and mechanical properties that enable the smart, targeted delivery of pesticides, fertilizers, and genetic materials to plants, as well as rapid sensing and on-site monitoring of plant health, soil fertility, and water quality in a digital format. This review explores the application of nanotechnology in agriculture, examining the challenges and benefits related to all aspects of crop production, with a particular focus on regulatory issues. Key findings indicate that nanotechnology can improve crop production and reduce the environmental footprint of agriculture through precise input management. However, several critical issues need to be addressed, including the limited knowledge of the long-term environmental impacts associated with agricultural nanotechnology and the ambiguity of current regulations. This underscores the need for further research to elucidate its impact on soil, water, and environmental and human health, to inform evidence-based regulations. (c) 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Polymer-coated controlled-release fertilizers (PC-CRFs) are valued for nutrient efficiency, but concerns remain about the long-term impacts of their plastic coatings on soil health. This study investigates the physicochemical characteristics of two commercially available PC-CRFs, type A and B, and their changes during nutrient release. Accelerated nutrient release experiments were conducted for 25 d in ultrapure water (free water) and saturated soil with five wet-dry cycles. Total phosphorus and total nitrogen release were measured, with lower concentrations found in soil column effluent compared to water. Additionally, studying microplastic (MP) release from type A PC-CRFs during nutrient release showed that a significantly greater number of MPs were released in the soil column than in water. The results also indicated a preferential migration of smaller MPs to the deeper layers of the soil column. Microscopic pores and cracks were observed through surface morphology analysis, likely caused by osmotic pressure during nutrient release, potentially contributing to MP generation. Mechanical degradation of the type A PC-CRF microcapsules was assessed through surface wear and shear tests to simulate the forces exerted by soil particles and agricultural machinery. Our results showed that longer surface wear duration increased the number of generated MPs, while higher loading in surface wear experiments resulted in a larger median diameter of the MPs.
Background and aims Nursery and field growth of micro-propagated banana plantlets is influenced by pests, nutrients and substrate quality. This study aims to evaluate the potential of locally produced microbial inoculant to reduce nematode and borer weevil (Cosmopolites sordidus) pest effects on micro-propagated banana plantlets and stimulate growth. Methods The potential of locally produced microbial inoculant to reduce nematode and borer weevil pest effects on micro-propagated banana plantlets and stimulate growth was tested in nursery and field conditions. Plantlets were grown in polybags with three substrates (Soil + Coffee husk, Soil + Cocoa pod, and Soil + Empty palm fruit bunch) and two nutrient sources (chemical NPK fertilizer and microbial inoculant) relative to untreated control. Results Significant (P < 0.05) root necrosis occurred following nematode inoculation with/without borer weevil at planting or ten weeks after, with lower necrosis in pesticide and microbial inoculant than untreated control. Similarly, significant (P < 0.01) corm damage occurred following borer weevil inoculation with/without nematode at planting or ten weeks after, with lower corm damage in pesticide and microbial inoculant than untreated control. Although similar nursery growth of micro-propagated banana plantlets was observed across substrates, significant (P < 0.05) variation occurred between nutrient sources, with higher growth for NPK and microbial inoculant than untreated control. Similarly, field growth of banana plantlets was higher for NPK and microbial inoculant than untreated control (P < 0.05). Conclusion These findings open up avenues for further investigation on role of locally produced microbial inoculant as promising option to reduce effects of nematode and borer weevil pests on micro-propagated banana plantlets and stimulate growth.
An Integrated Process Intensification (IPI) technology-based roadmap is proposed for the utilization of renewables (water, air and biomass/unavoidable waste) in the small-scale distributed production of the following primary products: electricity, H-2, NH3, HNO3 and symbiotic advanced (SX) fertilizers with CO2 mineralization capacity to achieve negative CO2 emission. Such a production platform is an integrated intensified biorefinery (IIBR), used as an alternative to large-scale centralized production which relies on green electricity and CCUS. Hence, the capacity and availability of the renewable biomass and unavoidable waste were examined. The critical elements of the IIBR include gasification/syngas production; syngas cleaning; electricity generation; and the conversion of clean syngas (which contains H-2, CO, CH4, CO2 and N-2) to the primary products using nonthermal plasma catalytic reactors with in situ NH3 sequestration for SA fertilizers. The status of these critical elements is critically reviewed with regard to their techno-economics and suitability for industrial applications. Using novel gasifiers powered by a combination of CO2, H2O and O-2-enhanced air as the oxidant, it is possible to obtain syngas with high H-2 concentration suitable for NH3 synthesis. Gasifier performances for syngas generation and cleaning, electricity production and emissions are evaluated and compared with gasifiers at 50 kWe and 1-2 MWe scales. The catalyst and plasma catalytic reactor systems for NH3 production with or without in situ reactive sequestration are considered in detail. The performance of the catalysts in different plasma reactions is widely different. The high intensity power (HIP) processing of perovskite (barium titanate) and unary/binary spinel oxide catalysts (or their combination) performs best in several syntheses, including NH3 production, NOx from air and fertigation fertilizers from plasma-activated water. These catalysts can be represented as BaTi1-vO3-x{#}(y)N-z (black, piezoelectric barium titanate, bp-{BTO}) and (M3-jMkO4-m)-M-(1)-O-(2){#}(n)N-r/SiO2 (unary (k = 0) or a binary (k > 0) silane-coated SiO2-supported spinel oxide catalyst, denoted as M/Si = X) where {#} infers oxygen vacancy. HIP processing in air causes oxygen vacancies, nitrogen substitution, the acquisition of piezoelectric state and porosity and chemical/morphological heterogeneity, all of which make the catalysts highly active. Their morphological evaluation indicates the generation of dust particles (leading to porogenesis), 2D-nano/micro plates and structured ribbons, leading to quantum effects under plasma catalytic synthesis, including the acquisition of high-energy particles from the plasma space to prevent product dissociation as a result of electron impact. M/Si = X (X > 1/2) and bp-{BTO} catalysts generate plasma under microwave irradiation (including pulsed microwave) and hence can be used in a packed bed mode in microwave plasma reactors with plasma on and within the pores of the catalyst. Such reactors are suitable for electric-powered small-scale industrial operations. When combined with the in situ reactive separation of NH3 in the so-called Multi-Reaction Zone Reactor using NH3 sequestration agents to create SA fertilizers, the techno-economics of the plasma catalytic synthesis of fertilizers become favorable due to the elimination of product separation costs and the quality of the SA fertilizers which act as an artificial root system. The SA fertilizers provide soil fertility, biodiversity, high yield, efficient water and nutrient use and carbon sequestration through mineralization. They can prevent environmental damage and help plants and crops to adapt to the emerging harsh environmental and climate conditions through the formation of artificial rhizosphere and rhizosheath. The functions of the SA fertilizers should be taken into account when comparing the techno-economics of SA fertilizers with current fertilizers.