Search Results (39)

Agricultural systems in Mediterranean-type climates are increasingly threatened by drought, salinity, extreme temperatures, heavy metal contamination, and pathogen pressure, all of which undermine crop productivity and agroecosystem stability. In this context, arbuscular mycorrhizal fungi (AMF), natural symbionts of most terrestrial plants, emerge as key biological agents capable of enhancing crop resilience. Following PRISMA guidelines, this systematic review synthesizes current knowledge on the role of AMF in mitigating abiotic and biotic stresses, highlighting their potential as a central component of sustainable Mediterranean agriculture. The available evidence demonstrates that AMF symbiosis significantly increases plant tolerance to multiple stressors across major crop families, including Poaceae, Fabaceae, Solanaceae, and Asteraceae. Under abiotic constraints, AMF improve water and nutrient uptake via extensive hyphal networks, modulate ion homeostasis under salinity, enhance tolerance to thermal extremes, and reduce heavy metal toxicity by immobilizing contaminants. Regarding biotic stresses, AMF induce systemic resistance to pathogens, stimulate secondary metabolite production that deters herbivores, and suppress parasitic nematode populations. Moreover, co-inoculation with other biostimulants, such as plant growth-promoting rhizobacteria, shows synergistic benefits, further improving crop productivity and resource-use efficiency. Overall, AMF represent an effective and multifunctional nature-based tool for improving the sustainability of Mediterranean agroecosystems. However, further research is required to evaluate AMF performance under simultaneous multiple stress factors, thereby reflecting real-world conditions and enabling a more integrated understanding of their agronomic potential. Full article

Biochar has gained significant attention as a multifunctional material linking biomass energy technologies with sustainable agriculture, providing combined benefits in soil improvement, waste valorization, and climate mitigation. This review examines biochar within the context of thermochemical conversion processes—pyrolysis, gasification, and torrefaction—and summarizes the operational parameters that influence both energy yields and biochar quality. It synthesizes agronomic, environmental, and engineering research to explain the mechanisms through which biochar enhances soil structure, nutrient retention, water availability, microbial activity, and carbon stability. The review also assesses its role as a long-term carbon sink and its potential integration into negative-emission systems such as bioenergy with carbon capture and storage (BECCS). However, the way that biomass conversion factors concurrently influence energy performance, biochar physicochemical quality, and its agronomic and climate-mitigation consequences across many environmental contexts is rarely integrated into a unified analytical framework in current evaluations. To close that gap, this review identifies cross-cutting patterns, trade-offs, and uncertainties while methodically integrating the information on the co-behavior of various aspects. Circular economy initiatives, carbon markets, and rural development are mentioned as key potential. On the other hand, economic variability, variable performance across soil types, lack of regulatory harmonization, rivalry for biomass, and logistical limits are big hurdles. Standardized production techniques, long-term field research, life cycle and techno-economic evaluations, and integrated system design are among the top research priorities. Overall, the evidence suggests that biochar is a promising tool for creating resilient and low-carbon agriculture and energy systems, provided that scientific, technological, and governance advancements are coordinated. Full article

The rise in greenhouse gases underscores the urgency of carbon dioxide removal (CDR) as a complement to emission reductions. Enhanced rock weathering (ERW) holds promise by coupling geochemical carbon sequestration with agronomic benefits, although integrative experimental evidence remains limited. This study evaluated two amendments (recycled concrete in wheat, C₃, and basalt in maize, C₄) under ambient and elevated CO₂ conditions (~1000 ppm). Conducted in a greenhouse over 21 weeks using loam soils, the experiment evaluated four treatments comprising three different particle-size ranges (<2 mm, 2–6 mm, and 6–15 mm) and a control. Plant growth (height, total and partitioned biomass), grain quality (N and protein), and soil properties (pH, electrical conductivity, and carbonates) were measured. Elevated CO₂ enhanced biomass, particularly vegetative biomass in wheat (+42.6%) and root biomass in maize (+55%), without significantly increasing yield. In wheat, particle size was decisive: intermediate fractions (2–6 mm) yielded the best results. In maize, basalt effects were less consistent. Concrete amendments increased soil pH and carbonate content, especially with coarse particles and elevated CO₂, whereas basalt-induced responses were slower and more variable. These findings confirm the potential of ERW as a dual climate–agronomic strategy while highlighting the need for long-term, field-scale validation. Full article

China has promoted renewable energy development to adjust its energy structure and improve energy security. The decision-makers consider manure-to-energy a feasible possibility because manure contains a substantial amount of organic materials that are potentially useful for generating power, and its use would also alleviate environmental pressures. Southern China, including Anhui, Fujian, Guangdong, and Zhejiang provinces, has launched policies to support manure facilities and energy sales. This study employs a lifecycle analysis and techno-economic assessment to evaluate whether manure application could be an economically feasible alternative. The results indicate that the thermophilic system has greater energy potential, and the mesophilic mode can yield greater agronomic benefits with digestate application. Hog manure can generate biopower ranging from 5599 to 5683 GWh, and it is 653 to 1887 GWh for cattle, 2481 to 2963 GWh for poultry manure, and 1109 to 1536 GWh for sheep manure. The aggregate emission offset could also be substantial. If all manures are properly utilized, the net emission offset could be up to 12.07 million metric tons of CO₂ equivalent, with an aggregate energy revenue of approximately USD 1086 million annually. In addition to the aggregate result, this study also indicates that manure application would yield a profit ranging from USD 8.36 to USD 34.3, and the benefit from biofertilizer would be roughly between USD 27.72 and USD 43.49. Nevertheless, regional characteristics, such as temperature, precipitation, and soil quality, generally influence agricultural systems, and the benefits associated with agrarian feedback would involve a higher uncertainty. On the contrary, energy sales could be considered a more reliable and stable source of income, even without government subsidies. Full article

Solar photovoltaic systems now produce the lowest-cost electricity in history and coupling with agriculture in agrivoltaics increases crop yields. This indicates solar will continue to experience explosive growth. Concerns exist, however, about the long-term end-of-life decommissioning of solar farms. For example, due to fossil fuel decommissioning mismanagement, Alberta is inundated with orphaned oil and gas wells that have remediation cost estimates of CAD$100 billion. Such comparisons have prompted preemptive legislation targeting solar farms, but is the fear justified? This study addresses this question by (1) analyzing warranted and actual lifespans of key agrivoltaic system components, (2) experimentally measuring microclimate impacts of two agrivoltaic arrays (fully powered with electricity extraction and unpowered to simulate post-inverter-failure conditions) and (3) quantifying agrivoltaic yield gains based on crops previously shown to respond positively to such conditions. Experimental results indicate that unpowered photovoltaic shading not only moderates soil temperatures but also enhances soil moisture conservation relative to unshaded conditions. This study demonstrates that agrivoltaic systems, even after the cessation of power generation, can continue to deliver meaningful agronomic and economic value through passive shading and policy frameworks should adapt to this dual-use reality. Integrating agronomic co-benefits into decommissioning policy supports long-term farm productivity and climate resilience. Full article

Circular agriculture reclaims nutrients from waste streams to reduce fertilizer imports, mitigate environmental impacts, and close material loops. This review evaluates the agronomic performance of nitrogen, phosphorus, and potassium products recovered from wastewater, crop residues, and manure compared with conventional fertilizers. A structured literature survey identified 85 pot and field trials published between 2010 and 2024, covering ammonium salts, struvite, ashes, compost, digestate, biochar, hydrochar, and biostimulants. Ammonium sulfate and nitrate consistently matched synthetic yields (95–105%) due to their solubility and immediate N availability, while aqueous ammonia showed variable results depending on application timing and soil pH. Struvite and phosphorus-rich ashes performed best (90–100%) in neutral to slightly acidic soils, whereas organo-mineral phosphate fertilizers (85–95%) were less effective in alkaline soils. Potassium-rich ashes and waste mica were effective (80–95%) in soils with moderate cation exchange, though mica underperformed (60–75%) in coarse soils. Biochars and hydrochars improved soil water retention and nutrient exchange, yielding 90–110% of synthetic performance, while biostimulants increased yields by 8–20%. Recovered products demonstrate agronomic equivalence while offering co-benefits for soil health, waste management, and circular economy goals. Future work should prioritize long-term field validation, techno-economic analysis, and regulatory integration to enable large-scale adoption. Full article

The prolonged and intensive use of chemical inputs in agriculture, particularly synthetic fertilizers, has generated a variety of environmental and agronomic challenges. This has intensified the need for alternative, viable, and sustainable solutions. Plant-associated microbes have emerged as promising candidates in this regard. While research has largely focused on bacteria and fungi, comparatively less attention has been paid to other microbial groups such as microalgae and cyanobacteria. These photosynthetic microorganisms offer multiple agronomic benefits, including the ability to capture CO₂, assimilate essential micro- and macroelements, and synthesize a wide range of high-value metabolites. Their metabolic versatility enables the production of bioactive molecules with biostimulant and biocontrol properties, as well as biofertilizer potential through their intrinsic nutrient content. Additionally, several cyanobacterial species can fix atmospheric nitrogen, further enhancing their agricultural relevance. This review aims to summarize the potential of these microorganisms and their application in the agriculture sector, focusing primarily on their biofertilization, biostimulation, and biocontrol capabilities and presents a compilation of the products currently available on the market that are derived from these microorganisms. The present work also identifies the gaps in the use of these microorganisms and provides prospects for developing a suitable solution for today′s agriculture. Full article

Controlled-release urea (CRU) can improve nitrogen (N) use efficiency and yield, but comprehensive evaluations of its agronomic, physiological, and environmental impacts remain limited. Through a two-year field experiment comparing three CRU types with conventional urea at five N rates (0-280 kg N ha⁻¹), we demonstrate that CRU at 180 kg N ha⁻¹ maintained high maize yields (13.9 Mg ha⁻¹) while improving N use efficiency, with thermosetting polymer-coated samples (TCU) showing superior performance. There was a significant increase in the net photosynthetic rate by 7.9–32.7% and intercellular CO₂ concentration by 20.6–40.0% under CRU treatments during the silking and milking stages. The CRU treatments also sustained optimal levels of hormones, N metabolism enzymes, and sucrase and urease activities. Compared to common urea, life cycle assessment indicates that CRU has achieved a 47.5% reduction in reactive N losses and an 18.7% decrease in greenhouse gas emissions. Economically, CRU outperformed common urea, with TCU providing the highest net benefit through yield stability and labor savings. These findings establish TCU at 180 kg N ha⁻¹ as an optimal strategy of maize production in the North China Plain, balancing productivity, profitability, and environmental protection. Full article

Salinity is a major abiotic stress limiting black gram (Vigna mungo) productivity, particularly in arid and semi-arid regions. Saline soils negatively impact plant growth, nodulation, nitrogen fixation, and yield. This study evaluated the efficacy of co-inoculating salt-tolerant plant growth-promoting bacteria Paenibacillus sp. SPR11 and Bradyrhizobium yuanmingense PR3 on black gram performance under saline field conditions (EC: 8.87 dS m⁻¹; pH: 8.37) with low organic carbon (0.6%) and nutrient deficiencies. In vitro assays demonstrated the biocontrol potential of SPR11, inhibiting Fusarium oxysporum and Macrophomina phaseolina by 76% and 62%, respectively. Germination assays and net house experiments under 300 mM NaCl stress showed that co-inoculation significantly improved physiological traits, including germination rate, root length (61.39%), shoot biomass (59.95%), and nitrogen fixation (52.4%) in nitrogen-free media. Field trials further revealed enhanced stress tolerance markers: chlorophyll content increased by 54.74%, proline by 50.89%, and antioxidant enzyme activities (SOD, CAT, PAL) were significantly upregulated. Electrolyte leakage was reduced by 55.77%, indicating improved membrane stability. Agronomic performance also improved, with co-inoculated plants showing increased root length (7.19%), grain yield (15.55 q ha⁻¹; 77.04% over control), total biomass (26.73 q ha⁻¹; 57.06%), and straw yield (8.18 q ha⁻¹). Pod number, seed count, and seed weight were also enhanced. Nutrient analysis showed elevated uptake of nitrogen, phosphorus, potassium, and key micronutrients (Zn, Fe) in both grain and straw. To the best of our knowledge, this is the very first field-based report demonstrating the synergistic benefits of co-inoculating Paenibacillus sp. SPR11 and Bradyrhizobium yuanmingense PR3 in black gram under saline, nutrient-poor conditions without external nitrogen inputs. The results highlight a sustainable strategy to enhance legume productivity and resilience in salt-affected soils. Full article

The objective of this study was to evaluate the physiological, biochemical, and productive effects of the foliar application of bioregulators, based on auxin, cytokinin, and gibberellic acid, on yellow melon, cultivar DALI^®, plants subjected to different salinity levels in a protected environment to simulate Brazil’s semi-arid conditions. The experiment was conducted using a completely randomized block design, in a 4 × 3 factorial scheme, with four salinity levels (0, 2, 4, and 6 dS m⁻¹) and three doses of the bioregulator, Stimulate^® (0%, 100%, and 150% of the recommended dose), with six weekly applications. The physiological variables (chlorophyll a fluorescence and gas exchange) and biochemical parameters (antioxidant enzyme activity and lipid peroxidation) were evaluated at 28 and 42 days after transplanting, and the agronomic traits (fresh fruit mass, physical attributes, and post-harvest quality) were evaluated at the end of the experiment. The results indicated that salinity impaired the physiological and productive performance of the plants, especially at higher levels (4 and 6 dS m⁻¹), causing oxidative stress, reduced photosynthesis, and decreased yield. However, the application of the bioregulator at the 100% dose mitigated the effects of salt stress under moderate salinity (2 dS m⁻¹), promoting higher CO₂ assimilation rates of up to 31.5%, better water-use efficiency, and reduced lipid peroxidation. In addition, the fruits showed a greater mass of up to 66%, thicker pulp, and higher soluble solids (> 10 °Brix) content, making them suitable for sale in the market. The 150% dose did not provide additional benefits and, in some cases, resulted in inhibitory effects. It is concluded that the application of Stimulate^® at the recommended dose is effective in mitigating the effects of moderate salinity, up to ~3 dS m⁻¹, in yellow melon crops; however, its effectiveness is limited under high salinity conditions, requiring the use of complementary strategies. Full article

The application of digestate as a fertilizer offers a promising alternative to synthetic inputs on permanent grasslands, with benefits for productivity and environmental performance. This four-year study evaluated the impact of two digestate application methods—disc injection (I) and band spreading (S)—combined with four dose variants (0, 20, 40, and 80 m³·ha⁻¹), including split-dose strategies. Emissions of ammonia (NH₃), carbon dioxide (CO₂), and methane (CH₄) were measured using wind tunnel systems immediately after application. Vegetation status was assessed via Sentinel-2-derived Normalized Difference Vegetation Index, Normalized Difference Water Index, and Modified Soil Adjusted Vegetation Index, and agronomic performance through dry matter yield (DMY), net energy for lactation (NEL), and relative feed value (RFV). NH₃ and CO₂ emissions increased proportionally with digestate dose, while CH₄ responses suggested a threshold effect, but considering solely the disc injection, CH₄ flux did not increase markedly with higher application rates. Disc injection resulted in significantly lower emissions of the monitored fluxes than band spreading. The split-dose I_40+40 variant achieved the highest DMY (3.57 t·ha⁻¹) and improved forage quality, as indicated by higher NEL values. The control variant (C, no fertilization) had the lowest yield and NEL. These results confirm that subsurface digestate incorporation in split doses can reduce emissions while supporting yield and forage quality. Based on the findings, disc injection at 40+40 m³·ha⁻¹ is recommended as an effective option for reducing emissions and maintaining productivity in managed grasslands. Full article

CO₂ enrichment in protected agriculture is a key strategy for enhancing crop productivity and quality, optimizing photosynthetic efficiency, and mitigating the impacts of climate change. In this study, a comprehensive bibliometric analysis of research on CO₂ enrichment is conducted by compiling and evaluating 171 relevant documents published between 1982 and 2024 in Scopus, utilizing R-Studio and VOSviewer for data processing. The analysis explores scientific output trends, predominant research methodologies, influencing factors, and emerging applications in controlled-environment agriculture. The findings reveal an exponential growth in scientific publications since 2015, with Asia and Europe leading the research landscape. The physiological and agronomic benefits of CO₂ enrichment in C3 crops, particularly tomatoes and lettuce, include enhanced photosynthesis, improved nitrogen assimilation, and reduced abiotic stress. Additionally, advancements in sustainable CO₂ capture and delivery technologies, such as industrial capture and fermentation-based systems, have been documented. However, significant challenges remain regarding the economic feasibility, accessibility for small-scale farmers, and environmental sustainability of CO₂ enrichment strategies. A network analysis of scientific collaboration highlights an increasing trend of international cooperation, with China, the United States, and Japan emerging as key contributors. The integration of plant physiology, agricultural engineering, and environmental sustainability reflects a transition toward multidisciplinary approaches aimed at optimizing CO₂ utilization in controlled environments. This study underscores the potential of CO₂ enrichment as a transformative tool in protected agriculture. However, its large-scale adoption necessitates international collaboration, rigorous research on socio-economic and environmental impacts, and the development of context-specific technologies. Strengthening global research networks and fostering applied innovation will be essential to ensuring the widespread and sustainable implementation of CO₂ enrichment strategies in protected agriculture. Full article

Nitrogen (N) sources critically influence both agronomic performance and secondary metabolism in medicinal plants. Understanding how different forms of nitrogen affect plant growth and the biosynthesis of valuable secondary metabolites is essential for optimizing cultivation practices and enhancing crop medicinal quality. In this study, Erigeron breviscapus (Vant.) Hand.–Mazz., a medicinal herb renowned in traditional Chinese medicine for its bioactive flavonoids such as scutellarin with neuroprotective and cardiovascular therapeutic effects, was cultivated under various N treatments—nitrate (NO₃⁻–N), ammonium (NH₄⁺–N), and urea [CO(NH₂)₂]—and compared to an N-free control. All N treatments significantly enhanced plant height, leaf area, biomass, and overall yield, with nitrate-N providing the most pronounced growth benefits. Metabolomic profiling identified 387 known metabolites, primarily flavonoids, exhibiting distinct accumulation patterns under each N form. Transcriptomic analyses revealed substantial differences in gene expression, with nitrate-N inducing the greatest number of differentially expressed genes (DEGs). Integration of metabolomic and transcriptomic data uncovered co-expression modules linking candidate regulatory genes, such as cytochrome P450s, MYB transcription factors, and glycosyltransferases, to specific flavonoids, including quercetin-3-O-glucoside and apigenin. These findings elucidate how different N sources modulate flavonoid biosynthesis in E. breviscapus, revealing molecular mechanisms underlying N-mediated flavonoid biosynthesis, which can contribute to optimized fertilizer strategies. This research enhances both the medicinal quality and yield of this important medicinal plant by revealing key gene–metabolite networks, thereby offering valuable insights for metabolic engineering and sustainable cultivation practices. Full article

Biochar undergoes significant transformations in soil as a result of chemical, physical, and biological processes. These alterations can impact its initial properties, influencing both its agronomic effectiveness and its capacity for carbon sequestration. Long-term observations of biochar-aging effects in soil are limited but highly relevant, as they provide a more realistic picture of the agronomic and societal benefits of biochar than short-term studies with relatively “fresh” biochar. This study aimed to describe the aging effects of biochar and their impact on a range of soil properties at a long-term biochar experiment in Bayreuth, Germany. For this purpose, soil and biochar samples were taken 13 years after application (two variants: 1. co-composted and 2. pristine biochar) and compared with a fresh variant in which the same unaged biochar was freshly mixed with the control soil. The soil quality parameters, pH and electrical conductivity, decreased significantly (p < 0.05) during biochar aging. Specifically, the pH dropped from 7.4 in freshly biochar-amended soil to 6.8 in the pristine aged biochar variant and 6.9 in the co-composted aged biochar variant. Electrical conductivity decreased from 217.0 µS cm⁻¹ in the freshly amended soil to 81.1 µS cm⁻¹ in the pristine aged variant and 87.6 µS cm⁻¹ in the co-composted aged variant. Nitrogen retention was enhanced in the soil amended with co-composted aged biochar compared to the pristine aged biochar soil. Total nitrogen (TN) was higher at 1.94 g kg⁻¹ versus 1.57 g kg⁻¹ (p < 0.05), and ammonium-N (NH₄⁺-N) was slightly elevated at 35.7 mg kg⁻¹ versus 33.0 mg kg⁻¹, although the difference was not statistically significant. The nitrate-N (NO₃⁻-N) content was significantly lower in all biochar-amended soil variants compared to the control soil. Total carbon (TC) levels decreased during biochar aging in all soil variants. However, the reduction was significantly lower in the co-composted aged biochar soil (25.0 g kg⁻¹) compared to the pristine aged biochar soil (20.5 g kg⁻¹, p < 0.05). This study identified multiple aging effects on biochar following 13 years of exposure in loamy soil. Importantly, the results showed that compared to the amendment of pristine biochar, co-composting did not diminish the TC of the treated soil, and more N could be retained, 13 years after amendment. In fact, co-composting prior to soil application is recommended to fully realize the potential agronomic benefits. Full article

The rice–crab co-culture (RC) system is a multidimensional integrated farming model with significant potential for balancing ecological and economic benefits in paddy fields. However, improper nitrogen (N) fertilizer application exacerbates greenhouse gas (GHG) emissions, degrades water quality, and disrupts the balance of the RC ecosystem. Therefore, optimizing and improving N management strategies for the RC system is crucial to maximize its ecological and economic benefits. This study conducted a two-year field experiment to assess the impact of optimizing N application on the productivity, sustainability, and economic benefits in RC systems. Comparisons were made to compare rice and crab productions, GHG emissions, and net ecosystem economic benefit (NEEB) between the RC and rice monoculture (RM) systems under different N application rates (0, 150, 210, and 270 kg ha⁻¹) with the aim of identifying the optimal N application rate for the RC system. The results showed that the N application rate of 210 kg ha⁻¹ in the RC system improved the agronomic traits and N use efficiency, leading to a 0.4% increase in rice yield (7603.1 kg ha⁻¹) compared to the maximum rice yield in the RM system at 270 kg ha⁻¹. At this application rate, surface water quality was optimal for crabs, resulting in the highest crab yields (370.1 kg ha⁻¹) and average weights (81.1 g). The lower N application reduced the greenhouse gas intensity (GHGI) of the RC system by 13.7% compared to the RM system. The NEEB at the optimal N application rate of 210 kg ha⁻¹ in the RC system reached 8597.5 CNY ha⁻¹, which was 1265.7% higher than that of the RM system at 270 kg ha⁻¹. In summary, optimizing N application in the RC system conserves N fertilizer resources, increases rice and crab yields, and reduces GHG emissions, thereby synergistically enhancing both economic and ecological benefits. Optimizing the N application rate has greater potential in other innovative RC models, and the productivity, sustainability, and economic efficiency should be further investigated. Full article