Search Results (2,963)

Lignin-containing cellulose nanofibrils (LCNFs) are mainly produced commercially from treated wood pulp, which can decrease some of the carbon-negative benefits of utilizing biomass feedstock. In this work, LCNFs are prepared from non-wood feedstocks, including agricultural residues such as hemp, wheat straw, and flax. These feedstocks allowed for the preparation of LCNFs with a variety of properties, including tailored hydrophobicity. The feedstocks and their subsequent LCNFs are extensively characterized to determine the roles that feedstocks play on the morphology and properties of their resultant LCNFs. The LCNFs were then incorporated into paper handsheets to study their usefulness in papermaking applications, which indicated good potential for the use of wheat straw LCNFs as a surface additive to improve the oil resistance coating. Full article

Rice husk (RH) and straw are common agricultural wastes in Asian countries, and they are potential bioresources for building materials. RH contains a large amount of SiO₂, and many studies have burnt RH to ash and then used it as a silica supplement in cement and concrete. However, the combustion of RH has an additional cost and exacerbates CO₂ emissions and air pollution. RH inherently has a low bulk density and porous structure; therefore, it should be possible to directly use RH as a lightweight additive in concrete. The purposes of this study were to use RH in the production of autoclaved lightweight concrete (ALC) and to examine the effects of RH on ALC properties. Four RHs with different particle sizes, i.e., >1.2 mm, 0.6–1.2 mm, 0.3–0.6 mm, and <0.3 mm, were used as lightweight additives, and the ALC specimens were prepared with 0–20 wt.% RHs by autoclaving at 189 °C for 12 h. The >0.3 mm RH was applicable to prepare the ALC specimens, and the decomposition effect of <0.3 mm RH was significant. Both the bulk density and the compressive strength of the ALC specimens decreased with increasing RH size. RH with a particle size larger than 1.2 mm seems more appropriate for ALC production than RH with a smaller particle size because of the lower bulk density and higher compressive strength. The Ca/Si ratio decreased with increasing RH size, which affected the formation of tobermorite and thus reduced the compressive strength of the ALC specimens. With a suitable water-to-solid (W/S) ratio, the use of RHs as lightweight additives can yield ALC specimens that meet the requirements of commercial products. Full article

Despite quinoa (Chenopodium quinoa Willd.) gaining international popularity in the early 21st century for its nutritional benefits, there remains a critical need to optimize its cultivation practices in arid regions. Current research often overlooks the combined effects of supplemental irrigation and foliar treatments on quinoa’s yield and water efficiency, particularly under challenging environmental conditions like those in Borg El-Arab, Egypt. Field studies were conducted in Borg El-Arab, Alexandria, Egypt, during the winter seasons of 2021/2022 and 2022/2023 to determine the influence of supplemental irrigation (rainfed, 2000, and 4000 m³/hectare, respectively) and foliar spraying of sodium silicate (control, 200, and 400 ppm) on yield, yield components, seed quality, and water usage efficiency in quinoa cv. Chibaya grown in arid lands. Three replications were used in a split-plot design. The main plots were designated for irrigation, while the subplots were designated for foliar spraying. The results indicate that applying irrigation at a rate of 4000 m³/hectare significantly increased leaf dry weight per plant by 23.5%, stem dry weight per plant by 18.7%, total dry weight per 25 plants by 21.4%, leaf area per plant by 19.2%, and straw yield by 26.8% compared to the control treatment. There were no significant differences between irrigation with the rate of 4000 m³ or 2000 m³/hectare on biological yield kg/hectare, N (%), P (mg/100 g), and protein (%). The utilization of sodium silicate had no significance on all studied features except for straw yield kg ha⁻¹ at the rate of 200 or 400 ppm. The results regarding the RAPD1 primer revealed that the 2000+0 silicon treatment was the only treatment that resemble the control with no up- or downregulated fragment. Moreover, 20 upregulated fragments were observed in all treatments, while 19 DNA fragments were downregulated. Furthermore, the results obtained regarding the RAPD2 primer revealed that 53 fragments were upregulated and 19 downregulated. Additionally, the RAPD3 primer demonstrated that 40 DNA fragments were upregulated, whereas 18 downregulated DNA fragments were detected. It may be inferred that the application of irrigation at a rate of 4000 m3 ha⁻¹ might serve as a supplemental irrigation method. Spraying sodium silicate at a 400 mg L⁻¹ concentration could alleviate the dry climate on the Egyptian shore. Full article

Sustainable agriculture faces challenges balancing the need for increasing crop production with environmental protection. Straw mulching is widely used to improve crop productivity, while reducing nitrogen application is an effective strategy to reduce greenhouse gas (GHG) emissions. However, the comprehensive evaluation of soil properties, GHG emissions, and soil quality under straw mulching conditions with different N application rates has not been extensively studied, especially in the Loess Plateau region of Central Gansu. Therefore, a two-year field experiment was conducted, involving two tillage practices (CT: conventional tillage, CTS: conventional tillage + straw mulching) and three fertilization levels (LN: low nitrogen fertilizer, 55 kg N ha⁻¹; MN: medium nitrogen fertilizer, 110 kg N ha⁻¹ HN: high nitrogen fertilizer, 220 kg N ha⁻¹). Based on the greenhouse gas emission intensity (GHGI), the minimum data set (MDS) was constructed by principal component analysis, correlation analysis, and Norm value, and the weighted index method was applied to comprehensively evaluate the soil quality. Our results showed that compared with CT, CTS significantly increased crop yields and improved the content of soil nutrients, and it was more effective when applying moderate amounts of nitrogen fertilizer. Wheat field soil behaves as a nitrous oxide (N₂O) emission source and a methane (CH₄) absorption sink. CTS–MN and CTS–LN reduced N₂O emission by 52.95–87.76%, increased total CH₄ uptake by 16.69–43.60%, and slowed down global warming potential (GWP) by 35.70–48.17% compared with CTS–HN in 2021–2022. They also reduced GHGI. Furthermore, CTS enhanced soil quality at different nitrogen application levels compared with CT, with CTS–MN exhibiting the highest Soil Quality Index (SQI) over the two years. Consequently, considering both economic and environmental benefits, CTS–MN can be regarded as a key practice for the sustainable development of agroecosystems in the Loess Plateau region of Central Gansu. Full article

Earthen materials have been used as economic building materials since ancient times and continue to be used today, particularly in our modern society that pursues sustainability. As a form of agricultural waste, straw stalks are reused in civil engineering to avoid being burnt, which not only saves costs but also avoids environmental impacts. In the following paper, we present an experimental study on the mechanical properties of rammed red clay reinforced by straw fibers. Straw stalks were cut into different lengths and mixed evenly with red clay in different proportions before being compacted. The compressive strength, flexural strength, and shear strength of the stabilized rammed straw were analyzed. The results show that straw stalks, as a single reinforcing material, can significantly improve the mechanical properties of rammed red clay. Straw stalks had varying effects on improving the mechanical indexes of rammed red clay. When the length of the straw stalks was 15 mm and the straw stalk content was 0 Sust.3%, the straw stalks had the best effect on improving the mechanical properties of rammed red clay. Full article

As a by-product of wastewater treatment, sewage sludge can be used for natural, agricultural, or energy purposes. One method of preparing sludge for management and use is solar drying. To intensify the drying process, natural additives can be used to alter the structure of the sludge and accelerate the evaporation of water. This research aimed to evaluate the influences of different organic additives in sewage sludge mixtures on the physicochemical and energy parameters of briquettes. This research was carried out without thermal boosting in a 4 × 2.5 × 2 m plastic tunnel. The tunnel was equipped with three drying stations and control and measuring equipment. In two test series, sludge additives in the form of straw and lignocellulosic materials, sawdust, bark, woodchips, and walnut shells, were used. Briquettes were made from the resulting mixtures and then subjected to physical and chemical analyses. This research showed high variability in the contents of trace elements, nitrogen, and sulphur in relation to an increase in the amount of sludge in the briquettes, which, for the briquettes made from sewage sludge, was nearly twice as high as for the briquettes made from the mixtures. The results of the flue gas analysis for the briquettes with sawdust and wood chip additives were very similar. The briquettes made from sewage sludge with lignocellulosic materials (bark and wood chips) had fuel properties similar to woody biomass, with a calorific value and heat of combustion of 15–16 MJ/kg. Fibrous additives (straw) significantly increased the strength parameters of the briquettes, by more than 50% of the value. The compositions and properties of the mixtures affected the following briquetting parameters: temperature and compressive force. The briquettes made from sewage sludge and additives can be classified according to ISO 21640 as SRFs (solid recovered fuels). In most of the results, the net calorific value (NCV) was 3 to 4; the chlorine content (CL) was 2 to 1; and the mercury content (Hg) was 1. The sewage sludge mixtures facilitated the agricultural and energy use of the briquettes. Full article

In recent years, biomass utilization has significantly increased, presenting challenges in its incorporation into various systems. Effective handling requires reliable data on biomass flow properties for designing warehouses and processing equipment. This study investigates the physical properties of ground barley grains, ground oak leaves, ground straw, and cut jute. Barley grains, oak leaves, and straw bales were milled, and jute was cut into 2–3 mm lengths and oven-dried. Particle size distribution, bulk density, Hausner ratio, Carr’s index, moisture content, static angle of repose, and flowability tests and SEM analysis were conducted. The study found that ground barley, having the smallest particle size and highest bulk density, showed superior flow properties due to its rounded particles and clusters, as reflected by a low Hausner ratio. In contrast, jute fibers had a low bulk density and poor flowability, while ground straw exhibited hindered flow due to its larger, more irregular particles. Additionally, the biomass sliding behavior varied with particle size and surface irregularities, with ground barley adhering well to plywood and ground oak leaves adhering well to aluminum. These findings underscore the pivotal roles of particle shape and interparticle forces in determining the biomass flow properties, pointing towards a future where precise environmental control and advanced analytical methods drive innovations in biomass utilization. Full article

As a plasticizer, vegetable oil can improve the compatibility between straw fibers and an asphalt matrix and promote the uniform dispersion of fibers, thereby improving the viscoelastic properties of the composite material. This paper selected three vegetable oils: tall oil, rapeseed oil, and palm wax. Through dynamic shear rheology tests, low-temperature bending beam rheology tests, contact angle tests, and infrared spectroscopy tests, the vegetable-oil-reinforced straw fiber modification was analyzed from different points of view. The research results show that palm wax significantly improves the high-temperature rheological properties of straw-fiber-modified asphalt but has a negative impact on low-temperature properties. Tall oil can most significantly improve the low-temperature rheological properties of straw-fiber-modified asphalt. Rapeseed oil has the most obvious effect in improving the adhesion and water damage resistance of straw-fiber-modified asphalt. In addition, the research shows that all three vegetable oils exist in the modified asphalt in adsorbed form, and no new compounds are generated. These research results provide theoretical guidance value for the application of straw-fiber-modified asphalt pavement in different environments. Full article

Soil in karst areas is rare and precious, and karst carbon sinks play an important role in the global carbon cycle. Therefore, the purpose of karst soil improvement is to improve soil productivity and a carbon sink effect. Biomass amendment experiments in this study included three schemes: filter mud (FM), filter mud + straw + biogas slurry (FSB), and filter mud + straw + cow manure (FSC). The characteristics of soil CO₂ production, transport, and the effect on soil respiration carbon emissions in two years were compared and analyzed. The results were as follows: 1. The rate, amount, and depth of CO₂ concentration were affected by the combinations with biogas slurry (easy to leach) or cow manure (difficult to decompose). 2. The diurnal variation curves of soil respiration in the FSB- and FSC-improved soils lagged behind those in the control soil for three hours. While the curves of FM-improved soil and the control soil were nearly the same. 3. Soil–air carbon emissions increased by 35.2 tCO₂/(km²·a⁻¹) under the FM scheme, decreased by 212.9 tCO₂/(km²·a⁻¹) under the FSB scheme, and increased by 279.5 tCO₂/(km²·a⁻¹) under the FSC scheme. The results were related to weather CO₂ accumulation in the deep or surface layers under different schemes. Full article

This experiment was conducted to determine the nutrient composition of three agricultural by-products, namely garlic peel, sweet potato vine, and cotton straw, calculate their relative feeding value, effective energy value, and other indexes, and comprehensively evaluate their nutrient value by combining with rumen in vitro fermentation technology, with the aim of providing data references for the development and utilization of non-conventional feed resources for ruminants. The results showed that: 1) the dry matter (DM), ash, ether extract (EE), and crude protein (CP) contents of cotton straw were significantly higher than the other two feeds (p < 0.05), while the acid detergent fiber (ADF) and neutral detergent fiber (NDF) contents of garlic peel were highly significantly higher than the others (p < 0.05); 2) the relative feed value (DMI, DDM, TDN, RFV, and RFQ) and effective energy value (GE, DE, ME, NE_m, NE_g, and NE_L) indexes of cotton straw were significantly higher than garlic peel and sweet potato vine (p < 0.01); 3) after 48 h of in vitro fermentation, the dry matter degradation rate (IVDMD) of sweet potato vine was significantly higher than the other two feeds (p < 0.01), and the cumulative gas productions (mL) and estimated gas parameters (a, b, a + b, and c) of sweet potato vine were significantly (p < 0.01) higher than those of garlic peel and cotton straw; 4) the sweet potato vine had lower pH but higher NH₃-N compared to garlic peel and cotton straw (p < 0.05). The sweet potato vine had higher propionate, iso-butyrate, butyrate, iso-valerate, and total VFA than the other two roughages, which also had the lowest acetate-to-propionate ratio. Garlic peel produced the lowest acetate, while it produced the highest valerate (p < 0.05). These findings demonstrate that all three by-products have high potential as livestock feed based on their nutritive value parameters. Comparatively, sweet potato vines exhibit higher feeding value due to their relatively moderate NDF content and superior rumen fermentation performance. Full article

Mulching plays a pivotal role in modern sustainable agriculture, offering a versatile solution to enhance soil quality, improve soil health, conserve resources, and optimize crop performance. This study examined the effects of various mulching materials on soil properties, seasonal variations in soil and environmental variables, and yam production in a tropical environment, with a focus on sustainable agricultural practice. We applied a range of mulch treatments, including black polythene, weedmat, sugarcane straw, organic compost, cowpea-live, juncao grass, sawdust, and a control with no mulch. The results indicated that the organic compost mulch significantly increased soil pH and soil electrical conductivity (EC). The control treatment resulted in the highest soil moisture content, while the highest soil temperature were recorded for the black polythene and organic compost mulch treatments. The organic compost mulch enhanced the soil organic carbon (SOC) content, soil available phosphorus (SAP) content, and soil exchangeable calcium (SECa) content. The weedmat mulch showed the highest soil exchangeable potassium (SEK) content, and the control treatment exhibited the highest soil exchangeable magnesium (SEMg) and sodium (SENa) content. In terms of micronutrients, the sawdust mulch and black polythene mulch significantly increased soil exchangeable iron (SEFe) and copper (SECu) levels, respectively. Notable seasonal variations in soil pH, temperature, and environmental humidity were observed during the crop period. The soil pH fluctuated from slightly acidic levels in August 2023 to neutral levels in October, and then decreased to slightly acidic levels in early 2024 before stabilizing by March 2024. The soil temperature peaked in November and dropped in January, while the environmental humidity ranged from 48.25% in December to 76.33% in February. The study demonstrated that the organic compost mulch stood out as an advantageous choice because of its capacity to enhance the soil’s properties and offer a balanced nutrient mix, making it particularly beneficial for yam cultivation. It also proved to be a reliable and balanced option to enhance soil quality with stable soil quality indices (SQIs). The weedmat mulch proved to be highly effective in enhancing yam growth and productivity. The weedmat mulch is the most profitable and cost-effective option for yam cultivation, providing the highest net returns and strong financial viability. This study emphasizes the value of choosing the right mulching materials to support soil quality, crop productivity, and economic returns in tropical settings, making strides toward more sustainable farming practices. Full article

Chrysanthemum, an agricultural economic crop with ornamental, medicinal, and edible values, faces the problem of continuous cropping obstacles in its cultivation. As a potential soil conditioner used to address continuous cropping obstacles (CCOs), the applicability of biochar in chrysanthemum cultivation has become a research hotspot. This study explored the effects of three different types of biochar (rice straw biochar = RB, pig manure biochar = PB, and sludge biochar = SB) on soil for chrysanthemum that had been continuously cultivated for eight years through pot experiments. The results indicate that the addition of biochar significantly reduced soil water loss. Compared with CK, the water retention rates of the SB and PB treatments increased by 25.4% and 18.4%, respectively. In the PB treatment, the contents of available phosphorus (AP) and available potassium (AK) increased by 85% and 164%, respectively. The available nitrogen (AN) content showed the highest increase under the SB treatment. All three types of biochar could improve the pH value of chrysanthemum soil with CCOs (increased by 0.4–5.4%). The results of microbial community diversity showed that, compared with CK, PB and RB slightly reduced the diversity of bacterial communities in chrysanthemum soil with CCOs (by 1.50% and 0.41%, respectively). However, the SB treatment increased the diversity of bacterial communities in chrysanthemum soil with CCOs (by 0.41%). At the same time, SB and PB significantly inhibited the diversity of fungal communities (reduced by 15.15% and 6.67%, respectively), while RB promoted the diversity of fungal communities (increased by 5.45%). Furthermore, the analysis results of bacterial phyla and genera indicated that PB and SB had enhancing effects on the beneficial bacterial phylum Actinobacteriota (8.66% and 4.64%) and the beneficial bacterial genus Nocardioides (23.29% and 9.69%). Additionally, the PB treatment enhanced the beneficial bacterial phylum Firmicutes (7.03%). The analysis results of fungal genera and phyla indicated that PB contributed to an increase in the beneficial fungal phylum Ascomycota (1.51%). RB significantly enhanced the beneficial fungal genus Chaetomium (56.34%). Additionally, all three types of biochar effectively reduced the abundance of the harmful fungal phylum Basidiomycota (30.37–73.03%). In the PB and SB treatments, the harmful fungal phylum Mucoromycota was significantly decreased (by 36.22% and 62.60%, respectively). Finally, all three types of biochar reduced the abundance of harmful fungal genera Acremonium (1.15–35.19%) and Phoma (97.1–98.7%). In this study, we investigated the effect of three kinds of biochar (RB, PB, and SB) on the soil of chrysanthemum continuous cropping through potting experiments and found that they could significantly reduce water loss, enhance water retention, increase the soil nutrient content, improve the pH value, regulate microbial communities, increase beneficial microorganisms, and reduce harmful microorganisms. These results provide a scientific basis for addressing barriers to continuous cropping (CC) while supporting the sustainability of agriculture and the development of agroecology. Full article

Returning straw to the field is a crucial practice for enhancing soil quality and increasing efficient use of secondary crop products. However, maize straw has a higher carbon-to-nitrogen ratio compared to other crops. This can result in crop nitrogen loss when the straw is returned to the field. Therefore, it is crucial to explore how different methods of straw return affect maize (Zea mays L.) farmland. In this study, a field experiment was performed with three treatments (I, no straw returned, CK; II, direct straw return, SR; and III, straw returned in deep furrows, ISR) to explore the effects of the different straw return modes on soil carbon and nitrogen content and greenhouse gas emissions. The results indicated that the SR and ISR treatments increased the dissolved organic carbon (DOC) content in the topsoil (0–15 cm). Additionally, the ISR treatment boosted the contents of total nitrogen (TN), nitrate nitrogen (NO₃⁻-N), ammonium nitrogen (NH₄⁺-N), dissolved organic nitrogen (DON), and DOC in the subsurface soil (15–30 cm) compared with CK. When it comes to greenhouse gas emissions, the ISR treatment led to an increase in CO₂ emissions. However, SR and ISR reduced N₂O emissions, with ISR showing a more pronounced reduction. The ISR treatment significantly increased leaf and grain biomass compared to CK and SR. The correlation analyses showed that the yield was positively correlated with soil DOC, and soil greenhouse gas emission was correlated with soil NO₃⁻-N. The ISR technology has great potential in sequestering soil organic matter, improving soil fertility, and realizing sustainable agricultural development. Full article

The salinity and alkalinity of soils are two fundamental factors that limit plant growth and productivity. For that reason, a field study conducted at Sakha Agric. Res. Station in Egypt during the 2022–2023 winter season aimed to assess the impact of gypsum (G), compost (C), and zinc foliar application in two images, traditional (Z₁ as ZnSO₄) and nanoform (Z₂ as N-ZnO), on alleviating the saline–sodic conditions of the soil and its impact on wheat productivity. The results showed that the combination of gypsum, compost, and N-ZnO foliar spray (G + C + Z₂) decreased the soil electrical conductivity (EC), sodium adsorption ratio (SAR), and exchangeable sodium percentage (ESP) by 14.81%, 40.60%, and 35.10%, respectively. Additionally, compared to the control, the G + C + Z₂ treatment showed improved nutrient content and uptake as well as superior wheat biomass parameters, such as the highest grain yield (7.07 Mg ha⁻¹), plant height (98.0 cm), 1000-grain weight (57.03 g), and straw yield (9.93 Mg ha⁻¹). Interestingly, foliar application of N-ZnO was more effective than ZnSO₄ in promoting wheat productivity. Principal component analysis highlighted a negative correlation between increased grain yield and the soil EC and SAR, whereas the soil organic matter (OM), infiltration rate (IR), and plant nutrient content were found to be positively correlated. Furthermore, employing the k-nearest neighbors technique, it was predicted that the wheat grain yield would rise to 7.25 t ha⁻¹ under certain soil parameters, such as EC (5.54 dS m⁻¹), ESP (10.02%), OM (1.41%), bulk density (1.30 g cm⁻³), infiltration rate (1.15 cm h⁻¹), and SAR (7.80%). These results demonstrate how adding compost and gypsum to foliar N-ZnO can improve the soil quality, increase the wheat yield, and improve the nutrient uptake, all of which can support sustainable agriculture. Full article

Using rapeseed straw as a raw material and potassium bicarbonate (KHCO₃) and urea (CO(NH₂)₂) as modification reagents, the pyrolysis raw materials were mixed in a certain proportion, and the unmodified biochar GBC800, KHCO₃-modified biochar KGBC800, and (KHCO₃)/(CO(NH₂)₂) co-modified biochar N-KGBC800 were, respectively, prepared using the one-pot method at 800 °C. The physicochemical properties, such as surface morphology, pore characteristics, functional group distribution, and elemental composition of the three biochars, were characterized, and the adsorption performance and mechanism of the typical antibiotic tetracycline (TC) in water were studied. The results showed that the surface of GBC800 was smooth and dense, with no obvious pore structure, and both the specific surface area and total pore volume were small; the surface of KGBC800 showed an obvious coral-like three-dimensional carbon skeleton, the number of micropores and the specific surface area were significantly improved, and the degree of carbonization and aromatization was enhanced; N-KGBC800 had a coral-like three-dimensional carbon skeleton similar to KGBC800, and there were also many clustered carbon groups. The carbon layer changed significantly with interlayer gaps, presenting a multi-level porous structure. After N doping, the content of N increased, and new nitrogen-containing functional groups were formed. When the initial TC concentration was 100 mg/L, pH ≈ 3.4, the temperature was 25 °C, and the dosage of the three biochars was 0.15 g/L, the adsorption equilibrium was reached before 720 min. The adsorption capacities of GBC800, KGBC800, and N-KGBC800 for TC were 16.97 mg/g, 294.86 mg/g, and 604.71 mg/g, respectively. Fitting the kinetic model to the experimental data, the adsorption of TC by the three biochars was more in line with the pseudo-second-order adsorption kinetic model, and the adsorption isotherm was more in line with the Langmuir model. This adsorption process was a spontaneous endothermic reaction, mainly chemical adsorption, specifically involving multiple adsorption mechanisms such as pore filling, electrostatic attraction, hydrogen bonds, n−π interaction, Lewis acid–base interaction, π−π stacking, or cation −π interaction between the aromatic ring structure of the carbon itself and TC. A biochar-adsorption column was built to investigate the dynamic adsorption process of tetracycline using the three biochars against the background of laboratory pure water and salt water. The adsorption results show that the Thomas model and the Yoon–Nelson model both provide better predictions for dynamic adsorption processes. The modified biochars KGBC800 and N-KGBC800 can be used as preferred materials for the efficient adsorption of TC in water. Full article