Search Results (170)

In this study, to enhance the concentration of caproic acid generated from maize straw fermentation and clarify the structures of bacterial and fungal communities within the serially subcultured rumen microbial fermentation system, maize straw was used as the substrate. In a continuous subculture system, the impacts of ethanol addition on pH and gas production were explored, with a focus on the caproic acid yield in the final (eighth generation) generation and alterations in bacterial and fungal communities. The results showed that the relative abundances of unidentified_Clostridiales, Shuttleworthia, and Syntrophococcus in ethanol-driven caproic acid production were enriched by 5.36-fold, 2.61-fold, and 2.25-fold, respectively. This consequently increased the concentration of caproic acid in the fermentation broth to 1492 mg/L, representing a 3.7-fold increase. These findings are highly significant for the high-value utilization of maize straw waste to produce caproic acid via the carboxylic acid platform using rumen microorganisms in industrial processing. Full article

The environmental impact of petroleum-based plastics has driven a global shift toward sustainable alternatives like biodegradable polymers, including polylactic acid (PLA), polybutylene succinate (PBS), and polycaprolactone (PCL). Yet, these bioplastics often face limitations in mechanical and thermal properties, hindering broader use. Reinforcement with cellulose nanofibrils (CNFs) has shown promise, yet most research focuses on conventional sources like wood pulp and cotton, neglecting agricultural residues. This review addresses the potential of maize husk, a lignocellulosic waste abundant in South Africa, as a source of CNFs. It evaluates the literature on the structure, extraction, characterisation, and integration of maize husk-derived CNFs into biodegradable polymers. The review examines the chemical composition, extraction methods, and key physicochemical properties that affect performance when blended with PLA, PBS, or PCL. However, high lignin content and heterogeneity pose extraction and dispersion challenges. Optimised maize husk CNFs can enhance the mechanical strength, barrier properties, and thermal resistance of biopolymer systems. This review highlights potential applications in packaging, biomedical, and agricultural sectors, aligning with South African bioeconomic goals. It concludes by identifying research priorities for improving compatibility and processing at an industrial scale, paving the way for maize husk CNFs as effective, locally sourced reinforcements in green material innovation. Full article

Afforestation with Pinus sylvestris var. mongolica in northern China is hindered by soil degradation. This study evaluated a ternary amendment combining sewage sludge (SS), cattle manure (CM), and maize straw (MS) to rehabilitate degraded sandy soils in the Horqin Sandy Land. Five treatments were tested: control (CK), SS (T1), SS + CM (T2), SS+MS (T3), and SS + CM + MS (T4). The ternary amendment (T4) achieved optimal outcomes: soil pH decreased from 8.02 to 7.79, organic carbon increased 2.5–fold, and total nitrogen (127%) and phosphorus (87.5%) were enhanced compared to CK. Pinus sylvestris exhibited a 65.6% greater basal diameter and 29.5% height increase under T4, while heavy metal concentrations (Cd: −54.6%, Cu: −35.1%, Pb: −12.2% and Zn: −27.6%) were reduced. These findings highlight a synergistic waste valorization strategy for dryland afforestation, balancing soil fertility improvement with ecological safety. Future studies should prioritize long-term microbial community dynamics and field-scale validation. Full article

Integrating organic soil amendments such as vermicompost (VC) and vermicompost tea (VCT) in agriculture has received increasing attention as a sustainable strategy to improve soil fertility, enhance plant growth, and suppress pest infestations. This study aimed to evaluate the effects of varying concentrations of VCT (10%, 20%, and 40%), alone and in combination with VC (2.47 ton/ha), on the development and yield of corn (Zea mays), and suppression of fall armyworm (FAW, Spodoptera frugiperda) infestation. The experiment was conducted in seven raised beds with seven treatments: V0 (control), VCT10, VCT20, VCT40, VC1 + VCT10, VC1 + VCT20, and VC1 + VCT40. Six weekly applications of VCT were applied starting at the V2 stage, and soil and plant nutrient contents were determined post-harvest. Additionally, relative chlorophyll content, height, cob yield, dry biomass, and FAW infestations were assessed. Results show that both VC and VCT significantly enhanced soil nutrient content compared to the control treatment (V0). VCT20 and VC1 + VCT10 improved plant N, K, and micronutrient uptake. Corn treated with VCT10 and VC1 + VCT10 had the highest biomass (6.52 and 6.57 tons/ha, respectively), while VCT20 produced the highest cob yield (6.0 tons/ha), which was more than eight times that of V0. SPAD values and corn height were significantly high across all treatments, with VCT20 achieving the highest SPAD readings while the control achieved the lowest. For FAW infestation, the control treatment experienced moderate infestation. At the same time, there was complete suppression in VCT20 and VCT40 treatments and a reduction in VC + VCT treatments, likely due to the bioactive compounds and beneficial microbes in VC and VCT that strengthened plant immunity. The results suggest that VCT20 is a cost-effective, eco-friendly amendment for improving corn performance and FAW resistance. This study contributes to sustainable agriculture by demonstrating how organic amendments can enhance crop resilience while supporting environmentally friendly farming practices. Full article

This study evaluates the effects of solid-state fermentation inoculated with Aspergillus spp. on the nutritional profile of selected agro-industrial by-products (AIBPs: cowpea shell, groundnut shell, soybean hull, and maize shaft). These AIBPs were assessed as potential feedstuffs in weaner rabbit diets, which often exhibit digestive disorders when introduced to highly lignified feed ingredients. The AIBPs were milled to a particle size of 2 mm, sterilized, and subjected to fermentation with Aspergillus spp. under microaerophilic conditions at 28 ± 2 °C for 10 days. Samples (four replicates per treatment) were analyzed for chemical constituents (mineral and proximate composition, anti-nutritional factors, and fibre fractions) before and after fermentation. Digestible energy and digestibility coefficient of gross energy were calculated. Data were subjected to two-way analysis of variance (ANOVA). There was an increase (p < 0.05) in mineral profile, proximate composition, digestible energy, digestibility coefficient of gross energy, and dry matter, with a reduction (p < 0.05) in crude fibre, fibre fractions, and anti-nutritional factors. It was concluded that fermentation with Aspergillus spp. improved the nutritional value of the selected agro-industrial by-products. Therefore, fermented materials possess a better nutritional profile to be used in feeding programs for weaner rabbits. This will ensure sustainable animal production and add value to agricultural waste, which would otherwise constitute an environmental nuisance. Full article

Maize (Zea mays) is one of the most cultivated crops in South Africa, serving as a staple food, stock feed, and a key element in several industrial applications. It contributes significantly to the growth of the South African agricultural economy. The cultivation of maize generates a large amount of agricultural waste, mainly in the form of maize stover (MS), which encapsulates leaves, stalks, cobs, and husks. Approximately 5.15 metric tons (Mt) yr⁻¹ of MS are generated in South Africa. This corresponds to an energy potential of 94 PJ. There is immense potential to surpass the annual yield of MS by 126% up to about 11.66 Mt yr⁻¹ through practices such as zero tillage and improved agricultural production systems. MS may pose a serious threat to the environment if not managed in a sustainable and eco-friendly manner. Valorization of MS into biogas presents an excellent opportunity to effectively control biomass waste while contributing to renewable energy production and mitigating dependence on depleting fossil fuels. However, MS continues to be overlooked as a sustainable bioenergy resource due to its lignocellulosic structure. This study explores the potential of converting MS into biogas for heat and power generation, addressing both energy needs and waste management in South Africa. The purpose is to provide knowledge that will inform researchers, innovators, industrialists, policy makers, investors, and other key stakeholders interested in renewable energy systems. Collaborative efforts among multiple stakeholders are vital to leverage biogas as a technology to promote socio-economic development in South Africa. Full article

Water scarcity is a global crisis and of particular concern in arid regions like Morocco. One creative solution is mining unusual water sources, such as landfill leachate. The presence of nitrogen in the sediment was studied as part of the use of sugar lime sludge in treating landfill leachate for irrigation purposes. A volume of 40 L of landfill leachate was treated with three different concentrations of sugar lime sludge (25%, 35%, and 50%). After homogenization and agitation of the mixture for 24 to 36 h, it was permitted to settle through the concrete decantate and supernatant. Nitrogen was efficiently decanted into the sediment during the composting process with green waste, enhancing the quality of the finished compost. The supernatants underwent physicochemical and microbiological analyses to ascertain their suitability for irrigation. The findings showed that the number of fecal streptococci was decreased by 99.13% at a 25% concentration of sugar lime sludge. The percentage of organic matter in the sediment rose from 10% to 40%, suggesting that the leachate had partially depolluted. The pH and electrical conductivity of the supernatants were within irrigation guidelines. The safety of diluted supernatants for plant germination was verified by phytotoxicity experiments conducted on maize seeds. The compost made from the decantate and green waste showed acceptable physical and chemical properties. Statistical analysis was conducted using JAMOVI software version 2.6.26. One-way ANOVA was used to assess the significance of treatment effects on microbiological and physicochemical parameters. The results confirmed statistically significant differences (p < 0.05) between the sludge concentrations, supporting the effectiveness of the treatment process. This study demonstrates how sugar lime sludge can be used to turn landfill leachate into a sustainable and safe irrigation water source, resolving environmental issues and promoting creative water management techniques. Full article

Summer maize is an important grain crop in the North China Plain, but the problem of irrational application of water and fertilizer is becoming increasingly serious. Optimizing water and nitrogen management not only improves yield but also reduces water and fertilizer waste and environmental pollution. The Aquacrop model was calibrated and validated using a two-year summer maize field trial, and 16 different water and nitrogen scenarios were simulated and analyzed. In particular, the field trials were divided into 10 water–nitrogen treatments. The results showed that (1) the model has good applicability to the growth process of summer maize in the North China Plain. (2) Excessive water and nitrogen application would reduce yield by 5.6–33.7%, nitrogen bias productivity by 8.1–32.5%, and water use efficiency by 6.4–84.6%. (3) The optimal irrigation and nitrogen application program for furrow-irrigated summer maize is an irrigation quota of 360 mm in conjunction with nitrogen application of 240 kg/ha. This study provides a theoretical basis for a water-saving, fertilizer-saving, high-yield water and fertilizer management system for summer maize in the North China Plain. Full article

Biomass is an energy source with variable physico-chemical properties. Thermal treatments lower moisture and volatile matter contents. They also raise the high heating value (HHV). This is especially desirable for agro-wastes with low-energy potential, like maize cobs. To make pellets from biomass, it is important to keep the lignin intact. It is responsible for particle adhesion. This paper presents a study focused on high-temperature drying of maize cobs. The process temperatures were selected from a range between 60 and 220 °C. The upper temperature limit prevents significant lignin breakdown. We also do not exceed the self-ignition temperature of the raw material. The study analyzed changes in basic technical parameters. These include moisture content, ash content, volatile matter, and HHV. We tested the grinding and densification process. We measured the raw material’s particle size distribution (PSD), specific density, and the mechanical durability (DU) of the agglomerates. The study showed a positive effect of high-temperature drying on the technical parameters. We found that the drying of corn cobs at a temperature of 180 °C gives the best results. Both PSD and DU values indicate that it is possible to create quality compacted biofuels from this material. Full article

This study evaluated the phytoremediation of mine tailing-contaminated soils in Quiulacocha, Peru, using the combined application of biochar and compost, with Zea mays L. (maize) serving as the phytoremediator due to its high biomass production and stress tolerance. A factorial experimental design was implemented, varying two main factors: the mining tailings dose (30% and 60% w/w) and the biochar pyrolysis temperature (300 °C and 500 °C). The mine tailings were characterized by high concentrations of heavy metals and unfavourable physico-chemical properties (pH, low organic matter), whereas the biochar, produced from pine forest residues, and the compost, derived from urban organic waste, exhibited attributes that enhance soil quality. During the pot experiment, response variables including the Bioconcentration Factor (BCF) and Translocation Factor (TF) for various metals were evaluated to assess the capacity for contaminant immobilization and their distribution between plant roots and aerial tissues. The results demonstrated that the incorporation of biochar and compost significantly improved soil quality by increasing pH, cation exchange capacity, and nutrient retention, while simultaneously reducing the bioavailability of heavy metals and limiting their translocation to the aerial parts of maize. Factorial analysis further indicated that both the tailings dose and biochar pyrolysis temperature significantly influenced the efficacy of the phytoremediation process. In conclusion, the combined application of biochar and compost presents an effective and sustainable strategy for rehabilitating mine tailing-contaminated soils by stabilizing heavy metals and promoting the safe growth of Zea mays L. Full article

Improving the utilization of spent mushroom substrate and enhancing the digestibility of straw-based feed are critical for promoting environmental sustainability. However, the effects of replacing sawdust with straw in the cultivation of Pleurotus ostreatus—including changes in physicochemical properties, enzyme activities, and microbial community structure and function—remain unclear. In this study, corn straw was used as the substrate for P. ostreatus cultivation. Dynamic changes during the fermentation process were investigated through analyses of biological growth characteristics, physicochemical properties, enzyme activities, and amplicon sequencing. The results indicated a significant increase in mushroom yield, with the M80% treatment group achieving a yield of 156.09 ± 7.15 g. The nutritional value of the fermented feed was markedly improved; after 50 days of fermentation, crude protein (CP) and ether extract (EE) contents increased by 5.42% and 0.79%, respectively, while acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents decreased by 18.5% and 22.3%, compared to day 0. Activities of cellulase, xylanase, and laccase were also elevated, contributing to more effective lignocellulose degradation. Furthermore, Illumina sequencing revealed shifts in bacterial and fungal metabolic pathways. The fungal community was dominated by Ascomycota and Basidiomycota, with Pleurotus as the prevailing genus, while the bacterial community was mainly composed of antagonistic genera such as Bacillus and Bacteroides. These findings provide a theoretical basis for understanding the role of microbial interactions during straw substrate fermentation in improving feed quality and increasing P. ostreatus yield. Full article

Amid growing environmental concerns and the increasing demand for sustainable construction practices, the exploration of alternative materials in building applications has garnered significant attention. This paper provides a comprehensive review of the use of agricultural waste as an aggregate in cementitious composites, with a particular focus on palm kernel shells, coconut shells, hazelnut, peanut and pistachio shells, stone fruit shells and pits, date and grape seeds, rice husks, maize (corn) cobs, and sunflower seed shells. For each type of agro-waste, the paper discusses key physical and mechanical properties, global production volumes, and primary countries of origin. Furthermore, it offers an in-depth analysis of existing research on the incorporation of these materials into cement-based composites, highlighting both the advantages and limitations of their use. Although the integration of agro-waste into construction materials presents certain challenges, the vast quantities of agricultural residues generated globally underscore the urgency and potential of their reuse. In line with circular economy principles, this review advocates for the valorization of agro-waste through innovative and sustainable applications within the construction industry. Full article

Blue maize is rich in bioactive compounds which are at risk of extinction due to monoculture practices. Carrot bagasse, considered a byproduct of the food industry, contains compounds that have been shown to benefit human health while also enhancing sustainability. Ellagic acid can prevent and assist in the treatment of various pathologies. Extrusion is a process characterized by its use of low energy, which minimizes the degradation of nutrients and bioactive compounds compared to other technologies. The objective of this research was to develop a functional food with high value of sensorial acceptance, desirable physicochemical, and antioxidant properties, using an 85:13:2% mixture of nixtamalized blue maize flour, carrot bagasse flour, and ellagic acid, processed with optimal conditions of extrusion determined with a surface response model. Operational conditions using a central rotatable experimental design were die temperature (DT = 120–170 °C), and screw speed (SS = 50–240 rpm), while response variables were physicochemical properties (expansion index, bulk density, breaking force, water absorption index and water solubility index) and antioxidant activity (free phenols inhibition of ABTS and DPPH). Sensory analysis, bromatological characterization and ellagic acid content determination with HPLC-DAD in reversed phase were also made. The optimal operational conditions were found to be DT = 144 °C and SS = 207 rpm, resulting in a mixture with high sensorial acceptability on a five-point hedonic scale. The optimized functional food may be used to promote the utilization of endemic ingredients and reduce food waste in the treatment of pathologies and prevention of diseases due to its high antioxidant activity attributed to phenolic and terpene compounds. Full article

The pyrolysis of sewage sludge into biochar, enhanced by incorporating agriculture waste rich in inorganic minerals and lignocellulosic compounds, provides an effective approach for achieving sludge-harmless treatment and resourceful utilization. In this study, sewage sludge and maize straw-based biochar (SMB) was prepared using the co-pyrolysis method, and the effects of different application ratios (0%, 1%, 3%, and 5%, w/w) of SMB on soil properties, ryegrass growth, microbial community structure, and Pb content and speciation in the contaminated soil of constructed wetlands were investigated. The results showed that SMB had a high carbon content (28.58%) and was rich in functional groups (e.g., -C-O, -C-N). The results indicated that increasing SMB dosage (0–5% w/w) in Pb-contaminated soil elevated soil pH from 6.40 to 7.93, cation-exchange capacity (CEC) from 30.59 to 79.03 cmol/kg (+158%), and organic carbon content by 65% (from 176.79 mg/kg to 107.3 mg/kg), while reducing available phosphorus and potassium by 20% and 30%, respectively, resulting in a 6% decline in ryegrass leaf length. SMB application enriched Pb-resistant bacteria (e.g., Sphingomonas abundance increased from 10.3% to 11.2%) and enhanced Pb immobilization. After 55 days, the total soil Pb increased by 33%, and the residual fraction Pb significantly increased by 7.3% to 21.7%, driven by functional group complexation, ion exchange, pH, and CEC improvements. Full article

The aim of this study was to investigate in vegetation and laboratory experiments the impact of biochars derived from agro-food industry waste (wheat bran and cherry pits) on selected soil chemical properties, maize yield, and chemical composition, as well as their ability to adsorb zinc and copper, thereby reducing their uptake by plants. The obtained results indicate that biochars produced under the same pyrolysis conditions differ in chemical composition. Both biochars significantly increased the total organic carbon (TOC) and total nitrogen (TN) content in the soil, but they did not affect the availability of nutrients in the soil. The tested biochars did not enhance plant yields or increase the uptake of N, P, K, Mg, and Ca by plants. However, both biochars reduced the uptake of Zn and Cu by plants due to the adsorption of these elements by the biochars. The results obtained in the laboratory experiment indicate that biochar from wheat bran adsorbed approximately 438.5 mM(+) kg⁻¹ and 566.8 mM(+) kg⁻¹, while biochar from cherry pits adsorbed approximately 239.4 mM(+) kg⁻¹ and 303.5 mM(+) kg⁻¹ from the solution. The ion exchange contribution to the adsorption of Zn²⁺ and Cu²⁺ by biochar from wheat bran was approximately 65.8% and 65.0%, respectively. In contrast, for biochar from cherry pits, the contributions were approximately 59.4% and 44.7%, respectively. Full article