Search Results (1,025)

Soil salinization severely constrains crop productivity and ecosystem services in arid regions. While the application of soil amendments represents a promising mitigation strategy, it remains uncertain whether this practice can effectively enhance soil quality index (SQI), crop productivity, and ecosystem service value (ESV) in saline–alkali farmlands. To address this, a three-year field experiment was conducted to analyze the effects of different amendments (rotary-tilled straw return (RT), plowed straw return (PL), biochar (BC), desulfurized gypsum (DG), DG combined with organic fertilizer (DGO), and an unamended control (CK)) on SQI, sunflower productivity, and ESV in a saline–alkali farmland of arid Northwest China. Results indicated that the BC treatment significantly reduced bulk density by 5.1–7.6% and increased porosity by 6.3–8.3% compared to CK. Both BC and DGO significantly increased soil organic matter and available nutrients while reducing saline ions (HCO₃⁻, Cl⁻, Na⁺), which reduced soil salinity by 21.2–33.6% and 19.9–26.5%, respectively. These synergistic improvements enhanced the SQI by 76.8% and 74.1% for BC and DGO, respectively, relative to CK. Correlation analysis revealed strong positive relationships between SQI and crop nitrogen uptake and yield. Accordingly, BC and DGO increased nitrogen uptake by 74.9–129.0% and yield by 12.2–45.2%, with BC offering more stable benefits over time. Furthermore, BC increased the values of agricultural product supply, nutrient accumulation and climate regulation, thereby increasing the total ESV by 13.7–53.9% relative to CK. In summary, BC and DGO are effective strategies to synergistically enhance soil quality, crop productivity, and ecosystem services in saline–alkali farmlands of arid regions. Full article

Sustainable development is crucial worldwide. Under the Paris Agreement, countries commit to Nationally Determined Contributions (NDCs) assessed every five years. China, a major contributor to global warming, has made significant efforts to reduce carbon emissions and achieve carbon neutrality, a key strategy for sustainable development. However, there is a lack of adequate attention to embodied emission reduction in rural residential construction, despite a surge in building to improve living standards. This paper evaluated the feasibility of applying a multi-ribbed composite wall structure (MRCWS) in rural China through a village service project. A full-scale shaking table test was conducted to study its seismic performance. Carbon emissions were analyzed using process-based life cycle assessment (P-LCA) and the emission-factor approach (EFA), while costs were estimated using life cycle costing (LCC) and the direct cost method (DCM). These analyses focused on sub-projects and specific structural members to validate the superiority of this prefabricated structure over common brick masonry. MRCWS blocks were prefabricated by mixing wheat straw with aerocrete, utilizing agricultural by-products from local farmlands, thus reducing both construction-related carbon emissions and agricultural waste treatment costs. Results show that this novel precast masonry structure exhibits strong seismic resistance, complying with fortification limitations. Its application can reduce embodied carbon emissions and costs by approximately 6% and 10%, respectively, during materialization phases compared to common brick masonry. This new prefabricated building product has significant potential for reducing carbon emissions and costs in rural housing construction while meeting seismic requirements. The recycling of agricultural waste highlights its adaptability, especially in rural areas. Full article

Soil total carbon (TC) and total nitrogen (TN) are key indicators of soil fertility and ecosystem stability, particularly in dryland agroecosystems. However, how rotational tillage combined with straw return affects aggregate formation and aggregate-associated TC and TN stabilization remains insufficiently understood. In this study, we aimed to clarify how rotational tillage affects aggregate structure, stability, and the spatial distribution of TC and TN, thereby revealing internal processes driving nutrient stabilization in dryland farming systems. A long-term field experiment was conducted at the Shenfeng site of Shanxi Agricultural University, China, including three rotational tillage systems with straw return: T1 (two years of no tillage (NT) + one year of deep tillage (DT)), T2 (two years of conventional tillage (CT) + one year of DT), and T3 (two years of DT + one year of CT). Soil aggregates were separated into total mechanical aggregate (TMA), 0.25–2 mm MA, and 2–10 mm MA, and they were further fractionated into water-stable aggregates (WM, Wm, and Wf) for TC and TN analysis. The results showed that aggregate stability, TC, and TN were positively correlated and decreased with soil depth, indicating strong surface enrichment. TC was mainly enriched in 0.25–2 mm MA, whereas TN was concentrated in 2–10 mm MA, and water-stable macroaggregates (WM) acted as the dominant reservoirs for R_C and R_N. Relative to the 2016 baseline (CK), TC in 2022 tended to be higher under rotational tillage with straw return, while NT-containing systems better maintained TN across the 0–60 cm profile. Among the treatments, T1 provided the most balanced performance, with a higher MWD and GMD, lower D, and improved aggregate-associated TC and TN retention. These findings suggest that rotational tillage with straw return, particularly the NT–NT–DT sequence, can support aggregate stability and is associated with improved aggregate-mediated TC and TN retention in the Loess Plateau dryland winter wheat system. Full article

Potassium (K) fertilization plays a key role in regulating stem morphology, particularly stem diameter, yet the influence of different K fertilizer formulations on stem structure and tensile strength remains insufficiently understood. Cereal straw is a key lignocellulosic by-product with growing importance in the circular bioeconomy. Thus, the aim of this study was to determine the links between potassium nutrition, stem structure, and mechanical behavior for four cereal species: wheat, barley, rye, and oats. There were three potassium fertilization levels (0, 60, and 120 kg K ha⁻¹) conducted in a field experiment in eastern Croatia (2021/2022). At maturity, stem morphology, macroelements (Ca, K, P, C, N), acid detergent fiber (ADF), neutral detergent fiber (NDF), and uniaxial tensile properties (maximum force, tensile strength, Young’s modulus) were determined. Cereal species was the dominant source of variation (p < 0.0001) for all traits, whereas the main effect of K was generally weak and significant only for stem diameter at the midpoint and N concentration, although K × species interactions were frequent. Oats and rye showed the most vigorous biomass production, whereas wheat exhibited by far the highest tensile strength (about 120 MPa) and stiffness (6.23 GPa), together with the highest ADF, while barley had the greatest NDF. Oat stems had the lowest ADF and NDF, indicating less lignified, more digestible tissues but mechanically weaker straw. Mechanical traits were tightly and positively correlated with ADF, NDF, and CN ratio, whereas P showed weak or negative associations with plant size and strength. Therefore, for targeted straw valorization, cereal species selection is paramount, with potassium fertilization playing a secondary, species-dependent role. Full article

Driven by the energy transition within the framework of the United Nations Framework Convention on Climate Change, second-generation (2G) ethanol stands out as a technical and sustainable alternative to fossil fuels. Although first-generation ethanol, produced from saccharine and starchy feedstocks, represents an advance in mitigating emissions, its expansion is limited by competition with areas destined for food production. In this context, 2G ethanol, obtained from residual lignocellulosic biomass, emerges as a strategic route for diversifying and expanding the renewable energy matrix. Thus, this work discusses the current state of 2G ethanol technology based on the gradual growth in production and the consolidation of this route over the last few years. Industrial second-generation ethanol plants operating around the world demonstrate the high potential of agricultural waste as a raw material, particularly corn straw in the United States, which offers a lower cost and significant yield in the production of this biofuel. Similarly, in Brazil, sugarcane by-products, especially bagasse and straw, are consolidating as the main sources for 2G ethanol, integrated into the biorefinery concept and the valorization of by-products obtained during the 2G ethanol production process. However, despite the wide availability of lignocellulosic biomass and its high productive potential, the consolidation of 2G ethanol is still conditioned by technical and economic challenges, especially the high costs associated with pretreatment stages and enzymatic cocktails, as well as the formation of inhibitory compounds that compromise the efficiency of the process. Genetic engineering plays a particularly important role in the development of microorganisms to produce more efficient enzymatic cocktails and to ferment hexoses and pentoses (C₆ and C₅ sugars) into ethanol. In this scenario, not only are technological limitations important but also public policies and tax incentives, combined with the integration of the biorefinery concept and the valorization of (by)products, which prove fundamental to reducing costs, increasing process efficiency, and ensuring the economic viability and sustainability of second-generation ethanol. Full article

In the maize systems of Liaonan, China, soil compaction and inefficient nitrogen use are key constraints to sustainable productivity. To enhance nitrogen (N) use efficiency and sustainable productivity in the maize systems of Liaonan, China, a field split-plot trial was conducted from 2018 to 2022 to investigate the synergistic effects of rotational tillage and N rates on root physiology and yield. Three straw return practices were tested as follows: NT (1 year no-tillage + 1 year subsoiling), PT (continuous subsoiling), and RT (continuous rotary tillage), each under three nitrogen levels: 150 (N150), 210 (N210), and 240 kg ha⁻¹ (N240). Root length density (RLD) and root surface area density (RSD) were monitored in situ, while root protein content, cellulose/lignin composition, root activity, and photosynthesis were analyzed at the tasseling (VT) and milk stage (R3). The results showed that NT-N210 treatment maximized deep root (30–50 cm) growth, increasing RLD by 54.5% compared to PT-N150 and RSD by 62.0% compared to RT-N150. NT was also associated with a stronger protein-associated FTIR signal and greater lignin accumulation, collectively correlating with delayed senescence. Photosynthesis and yield were strongly correlated with deep RLD (*r* = 0.82, p < 0.01). NT-N210 achieved the highest yield (12,896 kg ha⁻¹, 38.0% higher than PT-N150) with 12.5% less N than conventional practice. These findings indicate that combining the NT rotation with moderate N (210 kg ha⁻¹) optimizes deep root functionality and delays senescence. This improvement was correlated with shifts in protein-associated FTIR signals and cell wall composition (e.g., lignin accumulation), which collectively contributed to significantly improved resource use efficiency and yield. Therefore, adopting a biennial no-tillage/subsoiling rotation combined with moderate nitrogen application (210 kg ha⁻¹) is recommended as an effective strategy to alleviate soil compaction, enhance deep root growth, delay senescence, and achieve high maize yield with improved nitrogen use efficiency in similar agricultural systems. Full article

Climate change and unsustainable agricultural practices are triggering land degradation in semi-arid Mediterranean regions. Organic amendments, such as mulching materials, have shown promising potential to mitigate these impacts by improving soil chemical, physical, and biological properties, while enhancing grapevine growth and productivity. This study evaluated the effects of wheat straw mulch (M) and wheat straw combined with biochar (MB), together with vineyard topography (bottom vs. top), on grape chemical and phenolic composition in four Vitis vinifera L. cultivars (Syrah, Trincadeira, Alicante Bouschet, and Antão Vaz) grown in the Alentejo wine region. Grapes were sampled separately at top and bottom topographic positions, and classical and phenolic parameters were analyzed. The application of M and MB significantly modified must composition, mainly through changes in nitrogen and sugar levels across topographic positions. Only MB exhibited stronger effects, enhancing must quality, while MB and M reduced bottom–top variability. Similar patterns and positional effects were observed for phenolic and color parameters. Both organic treatments lowered total monomeric anthocyanin concentrations, although positional differences with wheat straw mulch were found. The results highlight that combining soil management with topography and variety response can optimize grape phenolic composition and promote sustainable viticulture through targeted, site-specific mulching strategies. Full article

The combined application of straw biochar and nitrogen fertilizer is an increasingly studied strategy to enhance soil fertility and crop yield. Optimizing the biochar-nitrogen interaction could be a choice for increasing nitrogen use efficiency (NUE) and reducing nitrogen loss in dryland agriculture. However, the mechanisms by which it regulates nitrogen allocation and absorption in foxtail millet (Setaria italica) are still limited in terms of mechanical understanding. Based on preliminary experiments, the optimal biochar-nitrogen interaction for soil nutrient absorption was identified. A field experiment was conducted with six treatments in an arid region of northwestern China: N1C1 (N1: 130 kg ha⁻¹ + C1: 100 kg ha⁻¹, control group), N2C4 (N2: 195 kg ha⁻¹ + C4: 250 kg ha⁻¹), N3C1 (N3: 260 kg ha⁻¹ + C1: 100 kg ha⁻¹), N3C2 (N3: 260 kg ha⁻¹ + C2: 150 kg ha⁻¹), N3C3 (N3: 260 kg ha⁻¹ + C3: 200 kg ha⁻¹), and N3C4 (N3: 260 kg ha⁻¹ + C4: 250 kg ha⁻¹). The results demonstrated that the biochar–nitrogen ratio significantly influenced topsoil total nitrogen, microbial biomass carbon (SMBC), and microbial biomass nitrogen (SMBN). All biochar-to-nitrogen combinations sharply increased soil total nitrogen by 133.11–151.52% compared to pre-sowing levels, providing a fundamental base for microbial-driven nitrogen transformation. Low nitrogen addition is more conducive to biomass accumulation, with N2C4 significantly increasing by 62.82%. Although a high biochar-to-nitrogen ratio reduced leaf relative chlorophyll content (SPAD) by 5.72–16.18% and net photosynthetic rate (Pn) by 16.09–52.65% at the heading stage, these did not compromise final yield. Importantly, N2C4, N3C1, and N3C4 significantly increased spike ¹⁵N abundance by 71.45%, 13.21%, and 19.43%, respectively. N2C4 grain production increases by 53.77–110.57% in two years and was positively correlated with spike ¹⁵N abundance, reflecting high nitrogen partial factor productivity. In conclusion, a reasonable biochar-nitrogen interaction enhances nitrogen allocation and grain yield by stimulating microbial activity and strengthening soil–plant synergy, the certified strategy effectively supports sustainable dryland agriculture by simultaneously increasing productivity and improving soil health. Full article

Straw returning, a core practice in conservation tillage, promotes sustainable intensification; however, it faces challenges such as inefficient decomposition, nutrient competition, and pathogen accumulation. To address these limitations, this study aimed to develop a multifunctional microbial consortium specifically designed for straw-incorporating cropping systems. The consortium comprises four Bacillus strains with complementary enzymatic systems, isolated from diverse ecological niches. It exhibited robust lignocellulolytic enzyme production, with manganese peroxidase (7709.33 U/L), laccase (450.65 U/L), endo-β-1,4-glucanase (154.67 U/mL), and filter paper activity (309.18 U/L). The consortium significantly enhanced rice straw degradation by 37.18% and increased nitrogen (N) release by 16.13% compared to the control. Moreover, the consortium exhibited a 67.56% inhibition rate against Magnaporthe oryzae and reduced both the incidence rate and disease index of leaf blast and panicle blast. Field trials revealed increases in the rice grain yield of 9.63% and 6.94% when applied alone and 6.75% and 5.18% when co-applied with straw residues. These findings highlight the multifunctional agricultural potential of the consortium and provide a sustainable strategy to overcome the limitations of straw-incorporating farming systems. Full article

Anaerobic digestion of straw is a crucial method for agricultural waste valorization, yet its efficiency is limited by complex factors. This study employed machine learning to predict methane yield and optimize process parameters in biochar-amended straw digestion. A comprehensive dataset integrating experimental and literature data (100 samples, 15 input variables) was constructed, incorporating operational conditions, straw characteristics, and biochar properties (e.g., dosage, particle size, specific surface area, and elemental composition). Prediction models were developed using Random Forest (RF), XGBoost, and Support Vector Machine (SVM). Results indicated that the RF model achieved the best predictive accuracy, with an R² of 0.81 and RMSE of 36.9, significantly surpassing other models. Feature importance analysis identified feeding load, biochar dosage, and biochar carbon content (C%) as the key governing factors, collectively accounting for 65.7% of the total contribution. The model-predicted optimal ranges for practical operation were 15–30 g for feeding load and 5–20 g/L for biochar dosage. This study provides data-driven validation of biochar’s enhancement mechanisms and demonstrates the utility of RF in predicting and optimizing anaerobic digestion performance, offering critical support for sustainable agricultural waste recycling and clean energy generation. Full article

This study investigated the effects of solid-state fermentation with a compound microbial inoculant on the nutritional composition, microbial community structure, and metabolic products of green jujube (Ziziphus mauritiana Lam.) straw. The results demonstrated that solid-state fermentation significantly enhanced the nutritional value of the straw, as evidenced by a marked increase in crude protein content and significant reductions in neutral detergent fiber (NDF), acid detergent fiber (ADF), and cellulose content. Metagenomic analysis revealed that fermentation substantially altered the microbial community structure of the straw, with a pronounced increase in the relative abundance of bacteria from the phylum Pseudomonadota (particularly genera such as Klebsiella and Enterobacter), and an upward trend in the abundance of fungi from the phylum Basidiomycota (Astraeus). Functional annotation indicated that fermentation enhanced the potential of the straw microbiota in genetic information processing, ABC transporters, and starch and sucrose metabolism, while attenuating the oxidative phosphorylation pathway. Metabolomic analysis identified 1176 differential metabolites, with significant increases in bioactive compounds such as peptides, amino acids, polyunsaturated fatty acids, and flavonoids following fermentation. Correlation analysis further revealed significant associations between specific microorganisms (Klebsiella, Enterobacter, and Aureobasidium) and key metabolites (amino acids, peptides, and flavonoids) in the fermented green jujube straw. This study confirms that solid-state fermentation can effectively improve the nutritional value and functional properties of the agricultural by-product green jujube straw by reshaping its microbial ecosystem and metabolic network. Full article

The rapid growth and seasonal availability of agricultural materials, such as straws, stalks, husks, shells, and processing wastes, present both a disposal challenge and an opportunity for renewable fuel production. Solar-assisted thermochemical conversion, such as solar-driven pyrolysis, gasification, and hydrothermal routes, provides a pathway to produce bio-oils, syngas, and upgraded chars with substantially reduced fossil energy inputs compared to conventional thermal systems. Recent experimental research and plant-level techno-economic studies suggest that integrating concentrated solar thermal (CSP) collectors, falling particle receivers, or solar microwave hybrid heating with thermochemical reactors can reduce fossil auxiliary energy demand and enhance life-cycle greenhouse gas (GHG) performance. The primary challenges are operational intermittency and the capital costs of solar collectors. Alongside, machine learning (ML) and AI tools (surrogate models, Bayesian optimization, physics-informed neural networks) are accelerating feedstock screening, process control, and multi-objective optimization, significantly reducing experimental burden and improving the predictability of yields and emissions. This review presents recent experimental, modeling, and techno-economic literature to propose a unified classification of feedstocks, solar-integration modes, and AI roles. It reveals urgent research needs for standardized AI-ready datasets, long-term field demonstrations with thermal storage (e.g., integrating PCM), hybrid physics-ML models for interpretability, and region-specific TEA/LCA frameworks, which are most strongly recommended. Data’s reporting metrics and a reproducible dataset template are provided to accelerate translation from laboratory research to farm-level deployment. Full article

Remediating cadmium (Cd) contamination in aquatic and terrestrial environments has become an urgent environmental priority. Biochar has been widely employed for heavy metal removal due to its wide availability, strong adsorption capacity, and potential for recycling agricultural waste. In this study, samples of alkali–Fe-modified biochar (Fe@NaOH-SBC, Fe@NaOH-HBC, and Fe@NaOH-MBC) were prepared from agricultural wastes (ginger straw, Sichuan pepper branches, and kiwi leaves) through NaOH and FeCl₃·6H₂O modification. A comprehensive characterization confirmed that the alkali–Fe-modified biochar exhibits a higher specific surface area, richer functional groups, and successful incorporation of the iron oxides Fe₃O₄ and α-FeOOH. The fitting parameter qmax from the Langmuir model indicates that the alkali–Fe modification of carbon significantly enhanced its maximum capacity for Cd²⁺ adsorption. Furthermore, a synergistic effect was observed between iron oxide loading and alkali modification, outperforming alkali modification alone. Furthermore, a 30-day soil incubation experiment revealed that the application of alkali–Fe-modified biochar significantly increased soil pH, SOM, and CEC while reducing the available cadmium content by 13.34–33.94%. The treatment also facilitated the transformation of highly bioavailable cadmium species into more stable, less bioavailable forms, thereby mitigating their potential entry into the food chain and the associated human health risks. Moreover, short-term spinach seed germination experiments confirmed that treatments with varying additions of alkali–Fe-modified biochar mitigated the inhibition of seed physiological processes by high concentrations of available cadmium to varying degrees. Overall, this study provides a sustainable and effective strategy for utilizing agricultural waste in the remediation of cadmium-contaminated water and soil systems. Full article

Atrazine (ATZ), a typical triazine herbicide with a long half-life and recalcitrant biodegradation, contaminates water and soil, necessitating efficient removal technologies. Conventional adsorbents have limited capacity and stability, while sesame straw-derived biochar realizes agricultural waste recycling and provides an efficient, economical, and eco-friendly adsorbent. Sepiolite, a natural mineral with a unique fibrous structure and a high specific surface area, has attracted widespread attention. Therefore, in this work, the agricultural waste of sesame hulls and sepiolite were used as precursors to prepare a composite material of sesame hull biochar/sepiolite (KNPB) through co-mixing heat treatment, followed by sodium hydroxide activation and pyrolysis. The results showed that, under the conditions of an adsorbent dosage of 3 g/L, pH of 6.8, and an adsorption time of 360 min, the removal rate of 3 mg/L ATZ by KNPB was 89.14%. Reusability experiments further demonstrated that KNPB has the potential for practical application in water treatment. Additionally, by integrating adsorption kinetics and isotherm analysis with a suite of characterization results from BET, FTIR, and XPS, the adsorption mechanism of KNPB for ATZ was further clarified to be primarily based on pore-filling, π–π interactions, and hydrogen bonding. This study not only provides a new idea for the resource utilization of waste sesame straw, but also provides scientific guidance for the solution of atrazine pollution, which has important environmental and economic significance. Full article

Acidic agricultural soils are frequently challenged by co-occurring heavy metal contamination and greenhouse gas (GHG) emissions. While biochar is widely used for integrated remediation, the specific role of silicon (Si) in modulating its effectiveness in cadmium (Cd) stabilization and nitrous oxide (N₂O) mitigation remains insufficiently understood. This study evaluated the co-remediation efficacy of two types of high-Si (bamboo leaves, ML; rice straw, RS) and two types of low-Si (Camellia oleifera leaves, CL; Camellia oleifera shells, CS) biochar, produced at 450 °C, within a Cd-contaminated and nitrogen-fertilized acidic soil. Results from a 90-day incubation showed that while all biochar effectively immobilized Cd, the low-Si CL biochar exhibited a superior stabilization efficiency of 66.2%. This enhanced performance was attributed to its higher soil organic carbon (SOC) and moderate dissolved organic carbon (DOC) release, which facilitated robust Cd²⁺ sorption and complexation. In contrast, high-Si biochar was more effective in mitigating cumulative N₂O emissions (up to 67.8%). This mitigation was strongly associated with an elevated abundance of the nosZ gene (up to 48.1%), which catalyzes the terminal step of denitrification. Soil pH and DOC were identified as pivotal drivers regulating both Cd bioavailability and N₂O dynamics. Collectively, low-Si biochar is preferable for Cd stabilization in acidic soils, whereas high-Si biochar is more effective at elevating pH and reducing N₂O emissions. These findings emphasize that optimizing co-remediation outcomes necessitates a targeted approach, selecting biochar based on the specific contamination profile and desired environmental benefits. Full article