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This review provides an overview of use of natural fibers and potential use of rice straw fibers as reinforcement in composite. As it is known that after china, India is the second largest country in the world producing rice as food grains. As a result of producing more amount of rice a large amount of rice straw is left as a residue, some of which is used for fodder feeding and a large amount of which is just burned by the farmers .This burning off practice is very common in the country because it is the cheapest way in which farmers can rid of the waste material, It can be seen that every year our national capital gets into a cover of smog because of burning of parali (rice straw). Scientists have understood the potential of using rice straw natural fiber in place of wood fiber in various uses, hence many experimental labs and commercial research is being conducted in this field and a lot of startups are also being initiated on this. Various composites are being made and their properties are being tested in various parts of the world. These composites are mainly termed as green composites. These green composite have great potential in preventing our environment, giving sustainable replacement towards use of plastic, wood and all other materials in industrial use.

The primary objective of this research was to advance, through experimental research, knowledge on the use of agricultural straw fibre reinforcement in concrete. The focus is on the manufacture of straw composites, development of concrete matrix and investigation of concrete samples by various tests and standards to assess suitability for using in ground-floor slab application. Synthetic fibres such as steel and polypropylene used in construction industry are not only expensive, but carbon emissions produced during their manufacture and non-renewability of such fibres have been a big challenge in the construction industry. Due to recent trends and growth towards sustainable building materials, the focus of this research was into the use of straw fibres, which are a by-product of crops and are produced in large quantities. Straw also do not have significant economic usage and generally is disposed of by farmers often by open air burning. This practice has caused huge air pollution and deteriorates health of many people all over the world. Development of straw composites through this research not only helps to utilize the straw that are not utilized currently for any economic benefits, but also prevents unsafe disposal. This in fact leads to reduced greenhouse gas emissions by reducing open air burning, use of biodegradable locally available material and replace synthetic non-renewable fibres in construction practices. The composite fibres developed embodies a sustainable path for future researchers and fibre manufacturers towards a clean construction industry. Both rice and wheat straw fibres treated with boiled water displayed increase in tensile strength. There was increase in strength by 38% and 55% respectively as compared to its raw state. However, the tensile strength was not sufficient enough to form a stronger bond with concrete as a replacement of commercial fibres. Hence composite fibres were manufactured and tested that comprise of straw fibres mixed with different polymer compounds. Composite fibres with up to 35% straw fibre content was determined to be optimum fibre reinforcement in concrete. These composite fibres have similar tensile strength and ductility characteristics as industrially available synthetic fibres. For 1% volume fraction of concrete of straw composite fibre, the residual tensile strength was 1.88 MPa at 0.47 mm deflection of the beam and 1.33 MPa for 3.02 mm deflection. Through the successful completion of development of several series of straw polymer composite fibres, this study demonstrates that the use of straw fibres can be a viable alternative to synthetic fibres. These fibres are not only easy to manufacture and cost effective, they help to conserve energy, have higher design flexibility and reduce the emission of greenhouse gases.

The most abundant organic carbon source on Earth is cellulosic materials. Its main resources are crop straws which are not commonly used and produce environmental pollution. These resources can be a site of biological hydrolysis to primary sugars by cellulase enzymes, in which avicelase is the most efficient enzyme in the cellulase family. This work aimed to clone the avicelase gene, transfer it to E. coli, optimize its expression, saccharify rice straw to its primary sugars, and ferment it to bioethanol. The avicelase gene was cloned from the Bacillus subtilis strain and cloned into two E. coli (i.e., DH5α and Bl21) strains. The optimized avicelase activity was described by testing the effect of different media and growth conditions including different carbon and nitrogen sources, as well as pHs and shaking or static conditions. Avicelase enzyme was extracted and used to saccharify rice straw. The obtained glucose was subjected to fermentation by Saccharomyces cerevisiae F.307 under an aerobic condition growth for the production of bioethanol. The ethanol yield was 5.26% (v/v), and the fermentation efficiency was 86%. This study showed the ability to clone one of the cellulolytic genes (i.e., avicelase) for the valorization of rice straw for producing renewable energy and bioethanol from cellulolytic wastes such as rice straw.

Background: Rice plants generate a large amount of straw after harvesting, which is currently managed mainly by incineration or used as animal bedding, animal fodder or wrapping of materials during transport. Other technological uses, such as the production of energy and biofuels, pulp and paper production or construction materials have also been described. However, due to the current European Union (EU) restrictions, alternatives for waste management must be sought. Valorisation of rice straw is aligned with the Sustainable Development Goals agenda set by the EU, since interesting biocompounds have been described in their composition and, after a successful extraction and purification, they can be used in various sectors. Scope and approach: This review gathers the most relevant works related to the valorisation of rice straw. It focuses on polyphenolic extracts and cellulose derivatives obtained by different extraction techniques, either conventional or innovative. In addition, the different applications that these compounds have in the field of food and nutrition sciences are summarized. Key findings and conclusions: Polyphenols and cellulose fractions have shown their viability to be extracted from rice straw, showing great potential as antioxidants in the food sector or as nutritional components in the development of new food or packaging materials, respectively. In conclusion, the valorisation of rice straw as a rich source of valuable compounds has been demonstrated, which currently generates serious environmental and human problems due to difficulties in its management and incineration, adding value to these underutilized residues and contributing to the circular bioeconomy concept. This study was supported by the Spanish Ministry of Science Innovation and Universities, [PID2020-116496RB-C21 and PDC2021-121345-C21].

Returning straw to the field is the most significant straw utilization technique for China’s green development. It can provide nutrients for crop growth and improve soil organic matter content. However, there are no standard parameters for measuring the nutrient content of straw directly returned to the field. In addition, the nutrient content of straw in the field is disregarded and the least researched. Therefore, to address these issues, the current research examines the main nutrient composition of straw returned directly to fields and the potential substitution of straw for chemical fertilizers. This study used the latest data on the crop straw-to-grain ratio and straw’s direct return to the field from the Database of Agricultural Crops Straws Resources in China (DACSRC) as the basis for a detailed estimation of the amount of crop straw nutrient resources and straw’s direct return to the field. The straw nutrient resources were measured based on straw yield and the nitrogen (N), phosphorous (P2O5), and potassium (K2O) contents. The results reveal that the maximum amount of straw returned directly to the fields in China was 517 teragram (Tg), while 128 Tg (25%) of the total was not collected but left on the field. The North China region had an enormous amount of direct straw return at 176 Tg (34%), while South China had the least amount at 26 Tg (5%). The amounts of seasonally available N, P2O5, and K2O from straw directly returned to fields are 2 Tg, 1 Tg, and 7 Tg, respectively. In addition, the amount of available straw nutrient resources returned to the field per hectare (ha) was 78 kg. The quantity of straw-originating seasonally available nutrients corresponds to 23% of the chemical fertilizers applied, which can substitute 10% N, 9% P2O5, and 58% K2O. The study provides critical insights on effective ways to improve straw fertilization through an increased rate of straw returned directly to fields and releasing seasonal nutrients.

The rhizosphere and detritusphere are hotspots of soil enzyme-mediated microbial processes, but little is known about their spatio-temporal distribution and interactions in situ, especially after straw incorporation. To answer this question, we planted maize in rhizoboxes with three wheat straw localizations: a) straw incorporated in the upper 2 cm of soil (straw localized); b) straw mixed with all the soil (straw homogenized); and 3) without straw (control). Zymography was used to investigate the spatio-temporal distribution of soil C- and N- acquiring enzyme activities in the rhizosphere (living roots) and detritusphere (straw induced), which depends on straw localization (localized vs. homogenized) and time (7 vs. 15 days after planting). The hotspot area of enzyme activities was similar in the detritusphere compared to the rhizosphere at the early stage (day 7), suggesting the importance of detritusphere in driving C and N cycling. Compared with homogenized straw, higher C- and N-acquiring enzyme activities in detritusphere were observed in the treatment with localized straw, which indicates that straw localization had a marked impact on the enzyme activity in the detritusphere. Although enzyme activities in rhizosphere and detritusphere decreased with time from straw application, straw incorporation increased the enzyme activities in the rhizosphere (especially with localized straw) compared to control at the late stage (day 15). Furthermore, homogenized straw greatly reduced plant height (−36 %), leaf area (−49 %), SPAD (−49 %), and shoot weight (−53 %) than control at the late stage, but localized straw had little impact on plant performance. In conclusion, straw incorporation forms another soil enzyme activity hotspot (detritusphere) and promotes enzyme activities in the rhizosphere and soil profile. Collectively, homogenized straw incorporation intensified nutrient competition between microorganisms and roots and restricted plant performance.

Continuous monoculture, conventional flood fertigation and low soil fertility increase the risk of soil-borne diseases in greenhouse vegetable production systems. Drip fertigation with straw incorporation (DIF+S) significantly improves resource use efficiency and reduces environmental risks compared to conventional fertigation. However, it remains unclear whether DIF+S positively affects soil microbial diversity and community structure and reduces the occurrence of soil-borne diseases. Therefore, a two-factor field trial was conducted in a greenhouse tomato production system with drip vs. flood fertigation, with and without straw incorporation across the seven growing seasons. The experimental treatments were as follows: (i) conventional flood irrigation with overfertilization (CIF); (ii) CIF + straw incorporation; (iii) drip fertigation with reduced irrigation and fertilization (DIF); and (iv) DIF + straw incorporation. Across the seven growing seasons, the average water and nitrogen use efficiency (WUE and NUE) was two- and threefold higher for DIF than for CIF, respectively, whereas tomato yields remained high. DIF significantly increased soil bacterial diversity and network complexity compared to CIF but had no effect on the soil fungal community. DIF significantly reduced the relative abundance of Fusarium-induced tomato wilt. Moreover, straw application significantly decreased fungal diversity while increasing fungal network complexity, although no effect on the bacterial community was found. The relative abundance of plant pathogens, such as Cladosporium, Fusarium and Alternaria, which are related to soil-borne diseases of tomato plants, was significantly reduced when straw was incorporated. Our results highlight that drip fertigation combined with straw incorporation significantly positively affects soil microbial diversity and stability. Thus, DIF+S is a sustainable and effective technology for maintaining soil health and reducing pesticide use in greenhouse vegetable production systems.

Straw is an abundant natural bioresource, especially in developing and agricultural countries. Bio-hydrogen production from this renewable biomass through biological methods is an active research area. Because of its distinctive characteristic of being rich in cellulose, straw has been extensively considered as a promising raw material for clean energy production. In this paper, the recent progress of bio-hydrogen production from straw was reviewed with the emphasis on the advances in pretreatment and hydrolysis technologies. The future development of straw-based biohydrogen production was also analyzed. Based on the physicochemical properties of straw biomass and mechanisms of bio-hydrogen fermentation, various pretreatment procedures have been developed to make the straw substrate more available for hydrogen-producing bacteria to realize large-scale bio-hydrogen production from straw. This review summarized the recent technologies of straw pretreatment and hydrolysis as well as elaborated on the bottlenecks in the field of straw biotransformation in great detail. Furthermore, based on the current technology status and potential, the challenges, prospects and future directions of the production methods were further proposed.

Although flow in biological materials sometimes behaves like a continuous one, it cannot be simulated with continuity-based modeling when it comes to discontinuous flow behavior. The Discrete Element Method (DEM) in combination with Computational Fluid Dynamics (CFD) is a computational method for modeling particles in fluid flow by tracking their motion. DEM is widely used in the field of engineering, and its use in the agricultural field is increasing. This study analyzes the CFD-DEM relationship of biological material in aerodynamic systems and reviews current applications. In the article, the definition of aerodynamic systems as a basic principle, particle-fluid and particle-particle interaction forces in the system, modeling of particle motions, CFD-DEM coupling method, and analysis applications of agricultural aerodynamic systems are examined. In this study, simulation experiments were carried out at 100 g/s and 200 g/s straw feeding values at each value of 18-15-12-10-8-6-4 m/s air and straw inlet velocities. The flow near the cyclone walls caused the straw particles to be directed towards the lower exit end of the cyclone. At feed densities of 100 g/s and 200 g/s, the least particle output was obtained at a rate of 18 m/s. The highest cyclone output efficiency was obtained at feed densities of 100 g/s and 200 g/s at a velocity of 12 m/s. The compatibility of the trial simulation results with the literature showed that the CFD-DEM application is an important approach to study the behavior of particulate matter in fluids.

The availability of many forms of frozen dumpling and their filling in the market today has enabled the consumer to enjoy other forms of frozen products, however, most of the dumpling and their filling in the market seems to be the same or common as the products were mixing and filled with normal ingredients and edible filling before steaming of frying process taking place. This dumpling is unique as the filling was made from waste ingredients known as jackfruit straw and a mixture of traditional Chinese and Malay food. The purpose of this innovative product made is to diversify and enrich the usage of waste ingredients; treated jackfruit straw to be cooked in dendeng paste as a filling for dumplings. This Jackfruit Straw Dendeng Filling can be marketed, as cost-effective and easy to prepare as the raw materials used are cheaper compare to existing dumplings in the market. It makes this product able to be produced in mass production. Proper treatment of waste ingredients using food-grade preservatives and proper cooking methods able to enhance the taste and shelf life of the product are other reasons this product was developed. Before the dumpling is produced, treated jackfruit straw filling needs to be produced. Then, the treated filling is cool for a few hours. The ingredients of dumpling dough are being weighed accurately before the mixing, cooking, and filling process. Finding on a consumer preference test using Microsoft Excel 2016; untrained (n = 30) using sample code scale (7 scales) from extremely dislike to extremely like with 3 different samples (V1, V2 & V3). They are seven attributes being assessed i.e. aroma, texture, appearance, flavor, the thickness of filling, combination of skin and filling, and overall acceptability indicates the majority of the panels preferred V2 (frying jackfruit straw) with a 4.9 mean score followed by V3 with 4.8 mean scores (baking jackfruit straw) and lastly V1 with 4.7 mean score frying jackfruit straw with flour).

As the beverage industry, such as bubble tea, gains popularity among young people in the bustling streets, the use of non-biodegradable plastic straws presents a pressing global environmental crisis. In fact, our country, Malaysia, is currently grappling with the problem of mismanaged plastic waste, particularly in plastic straws. The government has launched extensive campaigns to reduce plastic usage, leading to the introduction of various biodegradable straw options in the market. This research focuses on using leaves as an alternative straw. Five common leaves in Malaysia, namely oil palm leaf, banana leaf, pandan leaf, coconut leaf, and corn leaf, were selected for potential leaf straw production. Preliminary studies showed that only banana leaf, pandan leaf, and corn leaf had minimal effects on water, particularly in terms of color. These three leaf straws then underwent water quality analysis, including pH value, water conductivity, and total dissolved solids (TDS). Throughout the one-hour analysis, the pH value of the water dropped slightly from 6.85 to around 6.50, water conductivity varied between 155 and 95 μS/cm, while TDS varied from 105 to 65 ppm. Overall, the results indicated that all three types of leaf straws had no significant effect on water quality. In conclusion, the research demonstrated the potential of using banana leaf, corn leaf, and pandan leaf as suitable alternatives to plastic straws in Malaysia. These biodegradable leaf straws have a minimal impact on water quality, making them environmentally-friendly choices for everyday use.

Conservation management practices with minimum soil mobilization, maintenance of amounts of straw in the soil, and chiseling of ratoons interrows can be beneficial to soil quality, nutrition and sugarcane yield; however, the combination of these practices and their influence over the culture cycle should be better understood. This study aimed to assess the effects of levels of remaining straw and chiseling in the cultivation of ratoons on soil fertility, nutritional status and yield of stalks and sugar in one sugarcane cycle (five ratoons), under no-tillage and conventional tillage systems. The study was performed in Dourados municipality, Mato Grosso do Sul, Brazil, in areas with a Oxisol (Latossolo) with very clayey texture. Design in randomized blocks was adopted, with four repetitions, in a subdivided portions scheme. Portions were composed of levels of remaining straw (0, 50 and 100 %), annually, and collected alternately in odd years (0I) and even years (0P) established after the plant harvest; sub-portions were composed of systems with and without chiseling. In the fourth ratoon, leaf diagnosis was made with quantification of macro-nutrient contents, and during the fifth ratoon soil samples were collected for chemical analyses. By the end of the cycle, accumulated yields of stalks and sugar were determined. In both management systems, keeping 100 % of straw improved soil fertility and kept higher yield levels in one sugarcane cultivation cycle, while chiseling did not influence soil fertility, nutrition and sugarcane yield. The use of no-tillage farming for sugarcane cultivation proved to be feasible in corrected environments, and did not reduce stalk and sugarcane yield. Straw removal influenced nutrient leaf contents, regardless of soil management.

Climate change is forcing physiological changes, especially in temperate trees, in which the reproduction phase has been affected harshly, eventually resulting in poor performance. Erratic fluctuations during the flowering periods, predominantly in cold-sensitive, yet industry-desired (sourced), hazelnut cultivars have been causing at least a 10-fold decline in the nut yield. Indoleamines have been noted to provide protection during such abiotic stress conditions. In this study, we investigated the potential involvement of the indoleamine pathway in countering reproductive depression in cold-sensitive hazelnuts by blanketing the ground with wheat straw mulch. The female flower ratio; titers of tryptophan, serotonin, and melatonin; and indoleamine pathway gene regulation were the endpoints for assessing the effects of straw mulch. In the preceding year, we noted that the occurrence of phenological events through the modulation of indoleamines was necessitated via percolation of snowmelt into the rootzone. Otherwise, reproductive depression was noted, especially in harsh conditions, such as ‘no snow’ or when the rootzone was covered with a plastic sheet to disallow water percolation. When cold-sensitive hazelnut cultivars that were subjected to such deleterious treatments in the preceding years’ experiments were treated with straw mulch, the female flower ratio was unaffected and remained on par with that of the cold-hardy locally adapted cultivars. Tryptophan accumulation improved in the (cold-sensitive) sourced cultivars treated with straw mulch and was available as serotonin to counter the cold stress. Lower titers of melatonin explained the slight improvement in female ratio in the sourced cultivars blanketed with straw mulch. ASMT gene regulation via straw mulch treatment emphasized its role in abiotic stress mitigation. A negative trend was noted when improved flowering was compared to the decreased expression of the ASMT gene. Horticultural changes, such as mulch, should provide mitigating solutions to relieve reproductive depression in cold-sensitive hazelnuts, alongside implications in other horticultural crops. The indoleamine toolkit (cellular markers) developed in this study provides insights into the mechanisms of cold sensitivity (abiotic stress) and plausible solutions, such as exogenous application of indoleamines, to propagate climate resilient plant materials with an enhanced capacity to mitigate abiotic stress conditions.

In order to improve and alleviate environmental pollution caused by the disposal of seedling pots, a rice straw fiber-based headed vegetable seedling pot material, which is suitable for mechanical transplantation and biodegradable, was studied. Used rice straw as the main raw material, a five-factor and five-level (1/2 full implementation) quadratic regression orthogonal rotation central of rotation combination test method. The experimental factors included the beating degree of rice straw fiber, quantity, the proportion of rice fiber, neutral sizing agents, and wet strength agent mass fraction. The performance evaluation index included dry and wet tensile strength, burst strength, tear strength, air permeance, and degradation period. The results showed that when the parameter combination of the beating degree of rice straw fiber was 50 ± 1°SR, the quantity was 87.5 ± 4 g/m2, the proportion of fiber in rice was 70%, the neutral sizing agents mass fraction was 1 ± 0.25%, and the wet strength agent mass fraction was 1.5 ± 0.1%. The dry tensile strength was ≥ 1.8 kN·m−1, the wet tensile strength was ≥ 0.7 kN·m−1, the burst strength was ≥ 140 kPa, the tear strength was ≥ 350 m·N, the air permeance was ≤ 1.33 μm/Pa·s, and the degradation period was ≤ 80 d. The dry tensile strength reduction rate was 0.0274 kN/(m·d) and the wet tensile strength reduction rate was 0.0113 kN/(m·d), during the nursery period [30, 40], while the dry tensile strength was ≥ 1 kN·m−1 and the wet tensile strength was ≥ 0.4 kN·m−1 during the transplanting period.

The rice-ratoon system has long been considered an important economic, time-saving, and labor-saving planting method. Optimal tillage and straw management are beneficial to increasing the growth and yield of recycled rice. However, there is little research on the physical and chemical properties of soil under tillage and straw management, and its effects on the yield and fertilizer utilization of recycled rice. A field experiment was conducted to study the effects of four types of tillage and straw management on rice yield and soil properties in central China during 2020–2021. The types of management were no-till with residues retained (NT+S); plow tillage with residue retention (PT+S); no-till with residues removed (NT-S); and plow tillage with residue removed (PT-S). Compared with PT, yield decreased by 38.8% in NT, while straw returning effectively increased the yield of regenerated rice. NT+S increased the yield of main season rice by 37.0% and ratoon rice by 45.3%. Compared with non-returning straw, straw returning increased soil total porosity, soil organic carbon, and activity of β-glucosidase and urease, among which TP and SOC were increased by 8.8% and 27.8%, respectively. The results showed that returning straw to the field could significantly reduce the yield loss caused by no-tillage and improve the soil structure. No-tillage combined with returning straw to the field of regenerative rice is a green, light, and simplified cultivation mode worthy of further exploration.

In order to test the short-term effects of straw amendment on soil organic C (SOC) stabilization, SOC protection mechanisms, and soil bacterial community, we examined which bacterial taxonomic groups were associated with protected C fractions via different soil depths. We conducted a 5-year field experiment including a total of four treatments: S0 (no straw amendment), S1 (0–20 cm straw-amended soil), S2 (0–40 cm straw-amended soil) and S3 (0–60 cm straw-amended soil). The core method was used for soil sampling, and 180 soil samples was collected. Our results showed that straw amendment significantly increased bulk soil C content, enhanced the constituents of physically separated fractions and their OC contents, and changed the soil bacterial community composition at different soil depths. SOC was more accelerated in macroaggregate-derived unprotected and microaggregate-derived physically protected fractions at soil depths of 0–20 cm. Physically protected and physico-biochemically protected fractions were the major C protection mechanisms at soil depths of 20–40 cm and 40–60 cm soil depths. Our study also provides evidence that straw amendment significantly increases the bacterial phyla abundance of Proteobacteria and Bacteroidetes at each soil depth. Moreover, straw amendment enhanced the relative abundances of Gemmatimonadetes and Nitrospirae at soil depths of 40–60 cm and have a positive correlation with physically and physico-biochemically protected C pools. These results indicate that straw amendment can regulate C sequestration processes by enhancing SOC physical protection and modulating bacterial community, especially in the deep soil. In addition, straw amendment in subsoil (0–40 cm or 0–60 cm) is more beneficial for C storage and stabilization.

Straw incorporation is known as an environmentally friendly agricultural practice that can effectively enhance soil nutrient contents and crop yields; its potential to suppress soil-borne disease has also been reported in recent years. Here, we perform a field experiment for two consecutive years (2017–2018) to evaluate the effectiveness of maize (Zea mays), rice (Oryzae sativa L.) and wheat (Triticum aestivum L.) straws incorporation in alleviating Chinese cabbage (Brassica rapa L. ssp. pekinensis) clubroot disease caused by Plasmodiophora brassicae Woronin. Microbial composition in Chinese cabbage rhizosphere and soil P. brassicae abundance were estimated by high-throughput amplicon sequencing and quantitative polymerase chain reaction (qPCR). Results showed that, during the two-year field experimental cycle, all three straw amendments promoted Chinese cabbage plant growth, inhibited clubroot disease and increased the alpha diversity of the bacterial community in Chinese cabbage rhizosphere. Rice and wheat straws also increased the alpha diversity of the fungal community. These straws diversified the composition of the Chinese cabbage rhizosphere microbial community. All three straws promoted Cryptococcus carnescens; both rice and wheat straws stimulated Lysobacter sp.; maize straw boosted Sphingomonas sp. and wheat straw increased Talaromyces sp. These microbial taxa are either considered to have positive influences on plant growth or potential biocontrol effects. In addition, straw amendments also increased soil pH, electrical conductivity, available nitrogen and available potassium contents in both years of the field experiment. Taken together, we concluded that these three gramineous straw amendments ameliorated Chinese cabbage rhizosphere microorganisms, inhibited clubroot disease and promoted the growth of Chinese cabbage, and that rice straw worked best amongst the three. This study could potentially provide a new tactic of massive grain crop straw utilization and a direction in dealing with clubroot disease.

Cereal straw is a biomaterial with great potential: about 144 million tons of biomass are grown annually in Europe. For any use of straw (fertilizer, biofuel, etc.), efficient chopping technology, i.e., the reliable and efficient operation of mobile or stationary choppers, is the key factor for further success. Since most of the straw is chopped at harvest time, the subject of the study is the wear of the combine’s chopping knives. Six blades of different materials and designs were tested under realistic conditions during wheat and rapeseed harvesting on 180 ha. The influence of hardness, composition, cutting edge angle, and position in the chopper on knife wear was analyzed. The study showed that the blades with the highest cutting edge hardness (568 ± 11 HV) and the lowest cutting edge angle (20.9°) had the lowest wear. The highest hardness of the induction hardened knives was due to the 0.42% carbon content of the steel. The study confirmed that wear was inversely proportional to the hardness of the cutting edge (the harder the cutting edge, the lower the wear) and directly proportional to the angle of the cutting edge (the higher the angle, the greater the wear). The SEM study showed that part of the tooth surface of the blades was covered by permanent deposits of the material to be shredded. This wear was not caused by the interaction between straw and blade but by microabrasive particles that contaminated the straw.

Contemporarily, the promotion and application of straw-to-field technology plays an important role in developing high-quality green agriculture, alleviating agricultural non-point source pollution and realizing the double carbon target. As the main subject of straw-to-field, a farmers’ willingness directly determines their straw-to-field behavior. To explore the influencing factors of farmers’ straw-to-field willingness and to improve the comprehensive utilization level of straw, this paper researches the relationship between government regulation, farmers’ subject cognition and straw-to-field willingness based on the survey data of 733 farmers in Heilongjiang province, and it examines the mediating role of farmers’ cognition in the process of government regulation affecting farmers’ willingness of straw-to-field. The results evidence that policy incentives and administrative constraints affect farmers’ willingness of straw-to-field by influencing ecological and technical cognition. However, farmers’ cognition of the cost and benefit of straw-to-field is biased; thus, this factor cannot effectively transform the willingness of straw-to-field into action.

The application of manure (M) and straw (S) will increase the Olsen P and phosphorus activation coefficient (PAC) in soil. Clarifying the increasing trend of Olsen P and PAC is crucial for rational fertilization. This study fitted the equation between the accumulated P surplus, Olsen P, and PAC in four treatments for 28 years and analyzed the changes and rates of P fractions. The results showed Olsen P and PAC increase linearly with NPK and NPKS treatments; for every 100 kg ha−1 of P surplus, Olsen P increased by 5.9 and 6.7 mg kg−1, and PAC increased by 0.52% and 0.50%. With M and MNPK treatments, the sigmoid curve equation was the best fitting method. The equilibrium values were 167 and 164 mg kg−1 for Olsen P, and 10.4 and 10.2 mg kg−1 for PAC. There was a correlation between Al-P, Ca2-P, Resin-P, NaOH-Pi, C/N, SOC, and pH, which had the highest interpretation rates for Olsen P and PAC. Manure is significantly better than straw in improving Olsen P in red soil. It is recommended to reduce the amount of manure applied for a long time to avoid a zero increase in Olsen P.

The combination of factors such as population growth, industrialization, urbanization, changes in production technologies and consumption patterns; cause climate change and environmental pollution problems. Therefore, the concept of sustainability and the transfer of resources to future generations are of great importance. The aim of this study is to design a wall for use in agricultural buildings where the climate effect, especially the wind and rain effect, is minimized and the paddy straw, which is an organic waste, is evaluated. This design is aimed to be sustainable, more sensitive to the environment, consuming less energy, having economical and at the same time ecological advantages, useful and ergonomic that can provide healthy living conditions. Gypsum-doped adobe (adobe with gypsum dod) was preferred as the material. Rice straw was used as the covering material. In order to make the design aesthetic, the De Stijl art movement was tried to be reflected in this wall design. The study consists of four stages. These stages are design process, projecting process, application process, static analysis. In this study, especially by trying to propose a protective, economical and sustainable solution, by building a wall in two directions with a height of 170 cm, in length of 140 cm was built. As a result, resistant, design alternative that minimizes the negative effects of wind and rain has been created for the implementers who will make construction for agricultural purposes. In this case study, It has been tried to offer a protective, economical and durable and environmentally friendly solution against variable climatic and environmental conditions for those who will construct agricultural buildings.

Construction solid waste and agricultural waste, as renewable resources, have gained increasing attention recently. This research aims to explore the mechanical and thermal properties of recycled-straw insulating concrete commonly made with construction waste and straw in northern Fujian, which can provide useful suggestions for the practical use of recycled-straw insulating concrete. The effects of recycled coarse aggregate, fly ash, and straw on the mechanical and thermal properties of recycled-straw insulating concrete were investigated by orthogonal tests. The results of the orthogonal tests were optimized by the total efficacy coefficient method to obtain the optimal mix ratio of recycled-straw insulating concrete. Combined with the finite element analysis software ANSYS Workbench, the heat transfer performance of the recycled-straw insulating concrete walls was analyzed to simulate the insulation performance of the walls. The compressive strength of the recycled-straw insulating concrete with the optimal ratio was found to be 30.93 MPa, and the thermal conductivity was 0.5051 W/(m·K). The steady-state thermal analysis of the recycled-straw insulating concrete wall and the plain concrete wall was carried out by finite element software, and the simulation results showed that the insulation performance of the recycled-straw insulating concrete walls was improved by 145% compared with the plain concrete wall. These results indicate that the recycled-straw insulating concrete wall has better thermal insulation performance and can be applied to building envelopes to save heating costs in winter and reduce carbon dioxide emissions, which has significant economic and environmental significance for areas with low outdoor temperatures in winter and long heating periods.

Conservation tillage is widely recognized as an important way to improve soil quality, ensure food security and mitigate climate change. However, relatively little attention has been paid to the subject in terms of sustainable evaluation of environmental and economic benefits of the combination of no tillage and straw returning for maize production in arid irrigated areas. In this study, grain yield (GY) and water use efficiency based on grain yield (WUEGY), soil carbon emission characteristics and economic benefits were investigated, and a sustainability evaluation index based on the above indicators was assessed in maize production under a wheat–maize rotation system from 2009 to 2012. Four wheat straw returning approaches were designed: no tillage with 25 to 30 cm tall wheat straw mulching (NTSMP), no tillage with 25 to 30 cm tall wheat straw standing (NTSSP), conventional tillage with 25 to 30 cm tall wheat straw incorporation (CTSP), and conventional tillage without wheat straw returning (CTP). The results showed that NTSMP treatment could effectively regulate water consumption characteristics of maize fields and meet the water conditions for high grain yield formation, thus gaining higher GY and WUEGY. NTSMP increased GY and WUEGY of maize by 13.7–17.5% and 15.4–16.7% over the CTP treatment, and by 5.6–9.0% and 2.3–11.2% over the CTSP treatment, respectively. Meanwhile, compared with CTP, the NTSMP treatment could effectively reduce carbon emissions from maize fields, where average soil carbon emission fluxes (ACf), carbon emission (CE) and water use efficiency based on carbon emission (WUECE) were reduced by 17.7–18.9%, 11.1–11.2% and 8.8–12.8% and carbon emission efficiency (CEE) was increased by 10.2–14.7%. In addition, the NTSMP and NTSSP treatments could effectively increase total output and reduce human labor and farm machinery input, resulting in higher economic benefit. Among them, the NTSMP treatment was the most effective, net income (NI) and benefit per cubic meter of water (BPW) were increased by 16.1–34.2% and 19.1–31.8% over the CTP treatment, and by 13.2–13.3% and 9.8–15.6% over the CTSP treatment, respectively. The sustainability analysis showed that the NTSMP treatment had a high sustainability evaluation index and was a promising field-management strategy. Therefore, no tillage with 25 to 30 cm tall wheat straw mulching is a sustainable maize-management practice for increasing economic benefits and improving environmental impacts in arid irrigated areas.

This article deals with the problem of harvesting combed straw by mixing it with the soil and the process of combed straw decomposition in particular. The idea and purpose of the research are also analysed in terms of circular economy, which represents a closed cycle. Combed straw is seen as a by-product which is reused as fertilizer to increase soil fertility, thus reducing the negative impact on the environment and increasing the efficiency of organic matter use. To analyse the qualitative aspect of the process, the introduction of an indicator is proposed—the straw decomposition coefficient. Experimental studies of straw decomposition in the soil were carried out using the mathematical theory of experimental design, where the response function is represented by the functional dependence of the straw decomposition coefficient on the length of its cutting and nitrogen and phosphorus application doses. For experimental studies, Box–Behnken design was used, which made it possible to calculate the regression coefficients by known formulas. Verification of the obtained coefficients according to Student’s t-test showed that all of them were significant. According to Fisher’s test, it was established that the model is adequate and can be used for further research. As determined by the experimental study, shredded straw incorporation improves soil properties and increases its biological activity. Ultimately, this improves plant nutrition and increases crop yields. The experiment results showed that reduced amounts of nitrogen and phosphorus fertilizers can be applied, thus leading to a reduction in the direct production costs of growing cereals in the following year. The integration of several technological processes, such as straw cutting, shredding, and incorporating it into the soil with simultaneous application of nitrogen and phosphorus fertilizers, increases the economic efficiency of grain production and a shortens the payback period for investment.

This study aimed to analyze rice straw alternative managements to maximize the rice-soybean succession yield and to quantify their impacts on soil properties. The experiment was set up in a completely randomized design with six replicates. Nine rice straw managements were evaluated: straw burning (M1), straw harvesting (M2), straw incorporation with disc harrow and two passes (M3) or three passes (M4) of leveling disc harrow, straw incorporation with knife-roller and soybean no-tillage (M5), straw incorporation with knife-roller and two passes (M6) or three passes (M7) of leveling disc harrow, straw incorporation with two passes of knife-roller and two passes (M8) or three passes (M9) of leveling disc harrow. Straw incorporation by knife-roller provided the lowest soil organic matter (SOM) contents due to slow mineralization of fresh straw incorporated shallow into the soil, although SOM increased in the surface layer related to the initial content. Rice-soybean succession yield was more affected by the physical than by the soil chemical properties. The straw incorporation with one pass of knife-roller and two passes of leveling disc harrow (M6) can replace the straw burning, without affecting the rice-soybean succession yield and soil physical quality, with a reduction in machinery operations, allowing early soil tillage. Made available in DSpace on 2022-08-23T11:20:02Z (GMT). No. of bitstreams: 1 rc-2022.pdf: 351346 bytes, checksum: 084e3820154a362375a0dc1d9c8e46f3 (MD5) Previous issue date: 2022

Surplus biomass is one of the most attractive feedstock as it is renewable and sustainable, which can be used for the production of biofuels/chemicals. However, biomass is contents higher oxygen, which is hindered in application as a fuel. For improving the bio-oil quality, a process parameter such as catalyst needs to be endured for production of fuel-grade bio-oil. Catalytic fast pyrolysis of rice straw (RS) and wheat straw (WS) were performed using basic (MgO and CaO) and acidic (ZSM-5 and Y-zeolite) catalyst at different reaction temperature. It was found the different compositions of feeds reacted differently with presence of different catalysts. Pyrolysis products were grouped as carbonyls, phenolics heterocyclic and aromatic hydrocarbons. Carbonyls were observed as major compounds under the non-catalytic condition. Higher amount of carbonyls (62.91%) was obtained at 400 °C in case RS, while in case of WS lower amount was found (57.72%) without use of catalysts. However, catalysts such as basic metal oxide are encouraged to formation of phenolics and ketones compound, while acidic catalysts were encouraged to formation of aromatic hydrocarbons. Moreover, higher amount of aromatic hydrocarbon (52.9%) was found with RS using Y-zeolite, whereas higher amount of phenolics (48.5%) was obtained with WS using CaO catalysts.

The packaging industry requires permeable materials capable of offering freshness of the packaging content. The use of fillers can enhance these permeable properties to the polymeric material. This work investigates the effect of incorporating different fillers (organophilic clay and corn straw) on the rheological, mechanical, permeability, water absorption and biodegradability characteristics of poly (butylene adipate co-terephthalate) (PBAT) processed in an internal laboratory mixer. Extruded films and specimens injection molded were produced. The results of torque rheometry suggest polymer matrix degradation during processing slightly increase, also evidenced by MFR results. Composite films showed a drop in tensile strength, higher stiffness and lower elongation. Incorporation of the fillers in the PBAT matrix enhanced the permeability to oxygen gas of the produced films. The presence of fillers significantly increased the capacity of water absorption. The incorporation of C20A and, mainly, CS tends to accelerate the biodegradation of PBAT. Adding small amounts of organoclay C20A and CS to PBAT leads to a material that combines maintenance or improvement of biodegradation combined with higher permeability to oxygen, which indicates the potential use of these systems in packaging industry for maintenance of freshness of content.

Copyrolysis biochar derived from rape straw (RSBC) was prepared through oxygen-limited pyrolysis at 500 °C and utilized to investigate its adsorption capability for single and complex trace elements (Fe2+, Mn2+, Cu2+, and Zn2+) in contaminated solutions. The microstructures, functional groups, and adsorption behaviors of RSBC were determined through scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and batch adsorption experiments, respectively. From these, the single/complex adsorption results showed that the adsorption capacity of RSBC for Fe2+, Mn2+, Cu2+, and Zn2+ was 32.21/23.78, 8.95/3.41, 28.12/7.19, and 13.77/4.92 mg/g, respectively. The Langmuir isotherm model fit better than that of Freundlich in the mixed adsorption system, while the pseudo-second-order kinetic model was the most suitable for single adsorption. Thermodynamic adsorption analysis revealed that the removal rate of the four ions by RSBC was 22.14%, 8.95%, 18.75%, and 13.77%, respectively. Moreover, the adsorption mechanism was primarily chemical adsorption, including ion exchange, precipitation, and complexation, because of the binding effects of aromatic structures and polar groups. Additionally, biochar, with its porous structure and high ash content also provided favorable conditions for adsorption of those ions. Through this simple procedure, this work provides a potential strategy to produce biochar with a high adsorption capacity to remediate trace elements in contaminated solutions.

This study focuses on the recycling of agricultural and industrial wastes, specifically wheat straw ash (WSA) and bamboo wood ash (BWA), in cement production to promote sustainable and environmentally-friendly concrete. The mechanical properties of WSA and BWA are investigated through tests measuring the compressive strength, flexural strength, and split tensile strength of concrete. Different percentages of WSA and BWA (5%, 10%, 15%, and 20% by weight of cement) are used as partially replacement materials in the concrete mix.The experimental results indicate a reduction in the strength performance of concrete when WSA and BWA are individually used as supplementary cementitious materials at various curing periods (7, 28, 56, and 90 days). The primary objective of this study is to examine the impact of WSA and BWA on the mechanical properties of concrete for the purpose of sustainable development. The heavy use of energy and raw materials in traditional cement manufacture leads to a significant release of carbon dioxide into the atmosphere, which contributes to environmental pollution and greenhouse gas emissions. The environmental impact of cement production can be minimised by using WSA and BWA as cementitious materials in concrete. This is a successful strategy for reducing the damaging consequences of cement production on the environment WSA and BWA can be used as cementitious materials in concrete to lessen the negative environmental effects of cement manufacture. This is a practical method for reducing the damaging environmental effects of cement manufacture.

Arid and semi-arid soils are low in organic matter and have poor fertility, making them a serious threat to crop production. Most organic amendments, such as crop residues and farmyard manure, are short lived because of rapid decomposition. Incubation and pot studies were conducted to assess the impact of wheat straw biochar (produced at 350 °C) on temporal changes in soil microbial biomass and fertility status and to evaluate the efficacy of biochar for maize production in the top layer of Typic calciargid. The incubation study compared four levels of biochar (control, 0.5, 1.0 and 2.0% on a w/w basis of soil) and two fertilizer rates, i.e., unfertilized (no NPK fertilizer) and fertilized (nitrogen, P2O5 and K2O with rates of 125, 80 and 52.5 mg kg−1 soil, respectively). After incubation, the 2.0% biochar significantly improved the soil cation exchange capacity, organic carbon and microbial biomass carbon by up to 35, 59 and 26%, respectively, while decreasing the soil pH by up to 1.5% compared to that of the control treatment. When fertilized, the 2.0% biochar improved the soil’s available phosphorous, extractable potassium and total nitrogen by up to 59, 39 and 28%, respectively, compared to those of the control. The results from the pot experiment showed that using the 1% biochar with fertilizer significantly increased the maize dry biomass and grain yield by up to 57 and 72%, respectively, compared to those of the control. Additionally, the nitrogen and phosphorus recoveries from the mineral fertilizers improved significantly (up to 26 and 38%, respectively) when using the 1.0% biochar compared to those of the control. Conclusively, the addition of 1.0% biochar significantly improved maize growth and yield by enhancing nutrient recovery from mineral fertilizer and improving soil properties.

Straw strip mulching (SM) is a new mulching technology. From 2012 to 2018, SM’s effects on soil moisture and temperature and production performances were compared with other mulching practices, using three treatments: full-cover plastic mulch (PM), no mulch with wheat sown in rows as the control (CK), and SM with 50% to 59% of the field area mulched. Compared with CK, on average over six growing seasons, SM and PM increased grain yield by 27.0% and 21.7%, straw yield by 21.6% and 22.6%, kernels ha−1 by 26.6% and 19.0%, net income by 29.8% and −25.0%, soil temperature at 5 cm by −1.5 °C and 0.2 °C from overwintering to maturity, and soil water storage at 0 to 200 cm by 25 and 22 mm, respectively. The increase in soil moisture in SM and PM was greater in the early period (overwintering to jointing) than in the later period (booting to maturity) and at 0 to 120 cm than at 120 to 200 cm in the early period. Although the mean evapotranspiration of whole growth period across six seasons was similar among treatments, SM and PM increased water consumption during the key formation period of yield components after overwintering by 16 and 32 mm, respectively, while reducing it before overwintering. Compared with CK, SM and PM had the effects of warming during overwintering and cooling after jointing. By increasing water consumption after overwintering and ratio of transpiration to evapotranspiration and providing favorable soil temperature for multiple growth stages and more sufficient soil moisture, SM and PM promoted vegetative growth and increased kernels ha−1, the main mechanisms by which SM and PM increased grain yield relative to CK. Relative to PM, SM is a more economically beneficial and environment-friendly technology for dryland wheat production.

The study, conducted to evaluate the effects of long-term straw management combined with the application of increasing nitrogen rates on the yield of twenty winter wheat varieties, as well as on soil properties, was carried out in a long-term field trial established in 1971. The trial was monitored for twenty growing seasons under rainfed conditions in a typical chernozem zone of the southern part of the Pannonian Plain. The cropping system was a winter wheat-maize-soybean rotation. The ten SN-treatments (combinations of straw management (S) and N-fertilization) were as follows: In the plot (treatment) with straw return (S1), seven variants of nitrogen fertilization (0–180 kg N ha−1) were included, while on the plot without straw return (S0) the variants of N-fertilization were 0, 90 and 150 kg N ha−l. Based on the high relative share in the total sum of squares, variance analysis showed that wheat grain yield (GY) was significantly affected by years, SN-treatments, and their interaction, and they can explain the largest part of the total variance of GY. The results showed that straw return integrated with N fertilization could increase wheat yield to varying degrees over 20 years. On average, for all years, the highest GYs were obtained in the treatment S1 and fertilization with 180 and 150 kg N ha−1. The overall results showed that long-term straw returning significantly increased GY by an average of 8.4 ± 4.5%, with a considerable simultaneous increase in yield stability compared to straw removal. In addition, straw incorporation (SI) significantly increased soil humus, total nitrogen (TN), and soil organic carbon (SOC) contents at a soil depth of 0–30 cm by an average of 4.2, 3.8, and 11.3%, respectively. The results of our study have demonstrated that the long-term practice of straw return, in combination with the application of mineral fertilizers, has the potential to serve as a sustainable soil management strategy that is economically viable and environmentally acceptable. However, additional research is required to investigate its interactive effects on both grain yield and soil productivity.

In the rice–rapeseed rotation system, straw incorporation plays an important role in achieving the rational utilization of resources and maintaining crop production. However, in the study of rice–rapeseed rotation, there was no study on the effect of straw and nitrogen (N) fertilizer in the rice season on the dry matter accumulation (DMA) and nutrient accumulation of subsequent rapeseed. So, this study relied on the localization experiment of rice–rapeseed rotation and annual straw incorporation (full straw returning to the field, SR; the control is full straw removal from the field, CK) with different N fertilizer application rates (N1: 0 kg ha−1, N2: 75 kg ha−1, N3: 150 kg ha−1, and N4: 225 kg ha−1) in the rice season. Based on the fourth year of experiment implementation, the effects of annual straw incorporation combined with the N fertilizer application rate in the rice season on the leaf area index (LAI), photosynthetic potential (PP), DMA and its distribution proportion and rate, and nutrient uptake and its allocation proportion in rapeseed were discussed. At the bolting stage (BS), initial flowering stage (IFS), terminal flowering stage (TFS), and mature stage (MS), the DMA of rapeseed in SR was significantly higher than that in CK by 69.90, 64.27, 62.90, and 41.27%, respectively. The accumulation of N, phosphorus (P), and potassium (K) in SR was significantly higher than that in CK at the BS, IFS, TFS, and MS. Straw treatment had a significant impact on the apparent surplus of N, P, and K in the rice, rapeseed, and annual seasons, while the application of N fertilizer in the rice season had a significant or extremely significant impact on the apparent surplus (AS) of N in the rice, rapeseed, and annual seasons, indicating that fertilization of previous crops had a certain aftereffect. Therefore, straw incorporation is a sustainable farmland management measure.

In the process of rice straw nutrient bowl tray drying, real-time detection of changes in moisture content to achieve automatic adjustment of drying factors is one of the important means to ensure its drying quality. At present, the main method for measuring the moisture content of rice straw nutrient bowl trays is the drying and weighing method. This method is not only time consuming, labor intensive, and complex to operate, but also has poor real-time performance, which cannot meet the demand for real-time detection of the moisture content in the production process of rice straw nutrient bowl trays. In this regard, a real-time moisture content detection method for rice straw nutrient bowl trays based on hyperspectral imaging technology was studied. In this study we took the rice straw nutrient bowl tray during the drying process as the research object, adopted a single factor experiment, took microwave power, hot air temperature, and hot air speed as the drying factors, and took the moisture content of the rice straw nutrient bowl tray as the drying index. The rice straw nutrient bowl tray was dried according to the designed drying conditions. When drying, we removed the rice straw nutrient bowl tray every 5 min for weighing and collected hyperspectral image data within the wavelength range of 400~1000 nm until its quality remained unchanged. A total of 204 samples were collected. Using the average spectrum of the region of interest as the sample for effective spectral information, spectral preprocessing was performed using multivariate scattering correction (MSC), standardization normal variables (SNV), and Savitzky–Golay convolution smoothing (SG) methods. Principal component analysis (PCA) and competitive adaptive reweighting (CARS) methods were adopted for the dimensionality reduction of the spectral data. Three prediction models of rice straw nutrient bowl tray moisture content, namely random forest regression (RF), particle swarm optimization support vector regression (PSO-SVR), and XGBoost model were constructed using the reduced dimension spectral data. Finally, the performance of the model was compared using the coefficient of determination (R2) and mean square error (RMSE) as evaluation indicators. The research results indicate that the PCA-PSO-SVR model established based on SG method preprocessing has the best predictive performance, with a training set decision coefficient R2C of 0.984, a training set mean square error RMSE-C of 2.775, a testing set decision coefficient R2P of 0.971, and a testing set mean square error RMSE-P of 3.448. The model therefore has a high accuracy. This study achieved rapid detection of water content in rice straw nutrition trays. This method provides a reliable theoretical basis and technical support for the rapid detection of rice straw nutrient bowl tray moisture content, and is of great significance for improving the quality of rice straw nutrient bowl trays; promoting the popularization and application of raising rice straw nutrient bowl tray seedlings and whole process mechanized planting technology system; improving soil structure; and protecting the ecological environment.

Crop straw retention in the rice-based rotation cropland has been widely accepted as an effective method to improve soil quality in China. Rice–wheat rotation cropland is one the most prevalent rice-based rotation patterns, where it only exploits a small proportion of the total agricultural land yet feeds the majority of the Chinese population. Previous studies indicated that the incorporation of fore-rotating crop straw can effectively facilitate soil carbon sequestration in rice paddy fields. However, the application of crop straw may increase methane (CH4) emissions from rice paddies due to the anaerobic soil condition. To mitigate CH4 emissions from rice paddies while still preserving their soil carbon sequestration ability, a field experiment was conducted in the 2012–2016 rice growing seasons to determine the optimal low-carbon crop straw retention strategy. Five treatments with different wheat straw retention strategies were employed in this study, including non-fertilization and non-straw (Control), conventional fertilization without straw incorporation (CF), conventional fertilization with wheat straw incorporation (FS), slow-release fertilizer combined with wheat straw (SFS), and conventional fertilization with wheat-straw-derived biochar (FB). The results indicated that FS, SFS, and FB treatments significantly increased soil carbon sequestration in comparison with CF treatment. However, the increment of soil carbon sequestration was offset by raw wheat straw induced excess CH4 emissions under FS and SFS treatments. In contrast, the application of wheat-straw-derived biochar significantly promoted soil carbon sequestration, but showed no significant effect on CH4 emissions. Collectively, to the farmers, who aim to achieve agricultural carbon neutrality, the application of straw-derived biochar is worthy of consideration in rice cultivation processes.

Current rice straw disposal practices have serious repercussions on the environment and, in addition, do not consider its energy potential. On the contrary, the anaerobic digestion of rice straw makes it possible to produce renewable energy and to reintroduce into the soil the nutrients present in the digestate, at the same time, reducing greenhouse gas emissions from paddies. For rice straw of different geographical origin, by applying a mass balance method to the digester, the minimum requirements in terms of conditioners (nitrogen, phosphorus and potassium) and water, which allow obtaining the maximum production of methane, were calculated. The results obtained show that after the first 30 days (hydraulic retention time) for each ton of rice straw digested, the daily water consumption varies considerably from one country to another, from a minimum value of 1.5 m3/d to a maximum of 4.3 m3/d. After the same time, the addition of nitrogen and phosphorus is only required for the optimal anaerobic digestion of Indian rice straw. The low presence of these elements in Indian straw requires an addition of 3 kg/d of urea and 1.5 kg/d of superphosphate to compensate for the lack of nitrogen and phosphorus, respectively. In all the examined cases, the concentration of potassium, even if higher than the optimal value, does not reach levels that can significantly affect the methane production.

Tema ovog završnog rada je prikaz sustava automatizacije idejne kuće koja bi se nalazila na seoskom turističkom imanju Stari zanati u Hlebinama. Cilj je da kuća teži potpunoj samoodrživosti u smislu proizvodnje vlastite električne energije, stjecanju „idealnih“ uvjeta u stakleniku za proizvodnju vlastite hrane tijekom cijele godine te sakupljanju i korištenju kišnice za zalijevanje vrta i uporabu u kućanstvu. Neposredno uz kuću nalazila bi se mala farma sa životinjama koje bi također dobivale hranu i vodu automatiziranim putem, a održavanje njihovog prostora bilo bi moguće daljinskim putem. Sustav na koji je usmjerena pozornost, a nema ga u konvencionalnom svijetu, jest protupožarni sustav za slamnate krovove (PSSK). U ovom će se radu opisati njegov razvoj, isplativost i praktična funkcionalnost. U zaključku će se prikazati okvirni proračun gradnje kuće prirodnim materijalima (zidovi od bala slama, žbuka od blata i gline, krov od slame te drvena konstrukcija) i ugradnjom automatiziranih dijelova, kako bi kuća i imanje bili samoodrživi i praktičniji za ljudsku upotrebu. The topic of this paper is the presentation of the automation system of the conceptual house that would be located on the Stari Zanati rural tourist estate in Hlebine. Aiming towards total self-sufficiency, the house will generate its own electricity, create "ideal" greenhouse conditions for year-round food production, and collect and use rainwater for household usage and garden irrigation. Directly next to the house, there would be a small farm with animals that would likewise receive food and water automatically, and their space could be maintained remotely. The system on which attention is directed, which is not available in the conventional world, is the fire protection system for straw roofs (FPSSR). This paper will describe its development, profitability, and usable functioning. In conclusion, an approximate budget for building a house with natural materials (straw bale walls, mud and clay plaster, straw roof, and wooden structure) and the installation of automated parts will be presented, in order to make the house and the property more self-sustaining and useful for human use.

In this work, we engineered a corn-straw-based bio-foam material under the inspiration of the intrinsic morphology of the corn stem. The explosion pretreatment was applied to obtain a fibrillated cellulose starting material rich in lignin. The in situ esterification of cellulose was adopted to improve the cross-linking network of the as-developed foam bio-material. The esterification of lignin was observed in the same procedure, which provides a better cross-linking interaction. The esterified corn-straw-derived bio-foam material showed excellent elastic resilience performance with an elastic recovery ratio of 83% and an elastic modulus of 20 kPa. Meanwhile, with surface modification by hexachlorocyclotriphosphazene-functionalized lignin as the flame retardant (Lig-HCCP), the as-obtained bio-foam material demonstrated quite a good flame retardancy (with 27.3% of the LOI), as well as a heat insulation property. The corn-straw-derived bio-foam material is prospected to be a potential substitution packaging material for widely used petroleum-derived products. This work provides a new value-added application of the abundant agricultural straw biomass resources.

To maximize the potential energy utilization of agricultural and forestry wastes and sludge, experimental studies were conducted on the co-gasification characteristics of two types of sludge (municipal sludge, MS; paper-mill sludge, PS) and a typical biomass straw (ST) under CO2 atmosphere. In this paper, the main two stages of the gasification process, the pyrolysis in the low-temperature region and the CO2-gasification in the high-temperature region, were separately studied and analyzed. The experimental results showed that biomass could effectively promote the pyrolysis of the sludge in the low-temperature region and improve the gasification in the high-temperature region. Due to the complex interactions between components, the characteristic parameters presented obvious nonlinear rules during the co-pyrolysis and co-gasification processes. For the MS-ST mixtures, when increasing the ST content, (i) in the pyrolysis process, the initial reaction temperature gradually decreased, but the final reaction temperature, the peak reaction rate and the corresponding temperature, and the pyrolysis index gradually increased; (ii) in the gasification process, the initial reaction temperature, the reaction final temperature, and the temperature corresponding to the peak gradually increased. Combined with the reaction kinetics analysis of the co-pyrolysis and the co-gasification processes, 25% may be a reasonable mixing ratio for ST for the MS-ST mixtures, which had a relatively lower reaction temperature, relatively high pyrolysis index and low activation energy (26.58 kJ·mol−1 and 178.29 kJ·mol−1 for the co-pyrolysis and co-gasification processes, respectively). For the PS-ST mixtures, when increasing the ST content, (i) in the pyrolysis process, the initial reaction temperature, the peak reaction rate, the temperature corresponding to the peak and the pyrolysis index gradually decreased, but the final reaction temperature gradually increased; (ii) in the gasification process, the initial and final reaction temperatures and the temperature corresponding to the peak gradually decreased, but the peak reaction rate gradually increased. Combined with the reaction kinetics analysis of the pyrolysis and the gasification processes, 25% may be a reasonable mixing ratio for ST for the PS-ST mixtures, which had a relatively lower reaction temperature, relatively high pyrolysis index and low activation energy (64.29 kJ·mol−1 and 301.16 kJ·mol−1 for the co-pyrolysis and co-gasification processes, respectively). These findings can provide useful information for the co-gasification of sludge and straw under CO2 atmosphere.

Straw burning is a long-term environmental problem in China’s agricultural production. At present, China relies mainly on satellite remote sensing positioning and manual patrol to detect straw burning, which are inefficient. Due to the development of machine learning, target detection technology can be used for the detection of straw burning, but the current research does not take into account the various scenarios of straw burning and the deployment of object detection models. Therefore, a lightweight network based on depthwise separable convolution and channel attention mechanisms is proposed to detect straw-burning smoke at a remote distance. Various regional and crop-burning smoke datasets were collected to make the algorithm more robust. The lightweight network was applied to automatically identify and detect straw-burning smoke in surveillance videos. The experiment showed that the amount of light network parameter was only 4.76 M, and the calculation performance was only 11.2 Gflops. For the intelligent detection of straw-burning smoke, performance verification accuracy was improved by 2.4% compared with Yolov5s. Meanwhile, the detection speed on the embedded Jetson Xavier NX device can reach 28.65 FPS, which is 24.67% better than the Yolov5s. This study proposes a lightweight target detection network, providing a possible method for developing low-cost, rapid straw-burning smoke detection equipment.

In China, increasing the quantity and quality of total carbon and nitrogen stocks in sandy soil used for crop production is an important research issue. Soil amendment with pelletized straw could improve both soil physical structure and fertility in sandy soils, but these aspects remain understudied. The present pot and field experiments examined the dynamic changes in sandy soil water holding capacity, soil bulk density, soil total carbon and nitrogen stocks, and the distribution of water-stable aggregates and soil total carbon stocks related to aggregates across the following treatments: no fertilization (i.e., study control (CK)), normal fertilizer rate (NM), soil amendment at 150 Mg ha−1 (S150), manure amendment at 150 Mg ha−1 (M150), pelletized straw amendment at 75 Mg ha−1 (PS75), and pelletized straw amendment at 150 Mg ha−1 (PS150). The results show that the pelletized straw incorporation significantly increased water holding capacity and decreased soil bulk density. PS150 notably increased the large macroaggregates (>2000 μm) proportion and decreased the ratio of

Biofertilizers have been suggested as alternatives to synthetic fertilizers, which could reduce soil degradation brought on by excessive chemical fertilization and have an impact on the bacterial diversity and community in the soil. The diversity and community of soil bacteria in tea plantations treated with wheat straw compost have, however, received relatively little attention. In this research, a two-year field trial was run to examine the effects of applying wheat straw compost on the characteristics of the soil and the quality of the tea. We also used high-throughput sequencing to investigate the response of the soil bacterial community, and Spearman’s rank correlation was used to estimate the relationship between the soil bacterial community, soil characteristics, and tea quality. It was noticed that applying chemical fertilizer along with compost increased the fertility of the soil and the quality of the tea. Based on a two-year thorough data analysis, the T4 treatment (compost fertilizers 15,000 kg ha−1 + chemical fertilizers 1050 kg ha−1, chemical fertilizer reduction 30%) was determined to be the best group. The diversity and community makeup of soil bacteria were impacted by fertilization management. After the initial compost replacement, soils with compost had a greater bacterial richness than soils with inorganic fertilizers. After the second compost substitution, PCoA analysis revealed that compost fertilizer could be easily differentiated from chemical fertilizer. In 2019, Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, and Patescibacteria were the most prevalent bacterial phyla. In 2020, Firmicutes and Chloroflexi overtook Bacteroidetes and Patescibacteria as the two major bacterial phyla. In addition to increasing the diversity of soil bacteria and having an impact on the bacterial population, the application of wheat straw compost mixed with chemical fertilizers can also control the soil’s characteristics and the quality of the tea produced in tea plantations. So, as a fertilization way with less environmental impact, wheat straw compost fertilization can be used in tea plantations.

Biomass fuels play an important role in the field of fluidized bed combustion, but due to the diversity and uncertainty of fuels, there are usually some problems of high CO emission that cannot be directly solved by combustion adjustment. In this paper, a 75 t/h biomass fluidized bed was taken as the research object. It was observed from the field test that the gas incomplete combustion loss reached 12.13% when mono-combustion of wheat straw was conducted, and the CO concentration in the exhaust gas exceeded 30k ppm. Combined with the CPFD numerical simulation, the combustion characteristics and influence of secondary air layout on CO reduction performance were discussed in detail. The results revealed that the gas temperature gradually increased along furnace height under the initial condition, and the maximum temperature was more than 1000 °C at furnace outlet. The air curtain of the secondary air jets was insufficient, and the wheat straw rose rapidly as it entered into the furnace. By arranging adjacent secondary air ports above each fuel-feeding inlet, the residence time of particles in the furnace could be significantly increased, thus, the furnace temperature distribution was more reasonable and the CO emission was reduced by 58.6%.

Frequent oil spills have caused serious consequences to the ecosystem and environment. Therefore, in order to reduce and eliminate the impact of oil spills on biology and the environment, oil spill remediation materials must be considered. As a kind of cheap and biodegradable natural organic cellulose oil-absorbing material, straw has an important practical significance in the treatment of oil spills. In order to improve the ability of rice straw to absorb crude oil, rice straw was first treated with acid and was then modified with sodium dodecyl sulfate (SDS) through a simple charge effect. Finally, the performance of oil absorption was tested and evaluated. The results illustrate that the oil absorption performance was greatly improved under the conditions of 10% H2SO4, for a 90 min reaction at 90 °C, under 2% SDS, and reacted for 120 min at 20 °C, and the rate of adsorption for rice straw to crude oil was raised by 3.33 g/g (0.83 to 4.16). Then, the rice stalks before and after the modification were characterized. Contact angle analysis shows that the modified rice stalks display better hydrophobic–lipophilic properties than unmodified rice stalks. The rice straw was characterized by XRD and TGA, and the surface structure of the rice straw was characterized by FTIR and SEM, which explain the mechanism of surface-modified rice straws with SDS to improve their oil absorption capacity.

This study aimed to investigate the impacts of straw and biochar on greenhouse gas (GHG) emissions and grain yield in a double rice cropping system under optimal N fertilizer reduction. Conventional fertilization (CF) was used as the control group, and treatments included optimal fertilization and 15% less nitrogen (OF), together with straw (S) or biochar (B) applied under different fertilization conditions, namely CF + S, CF + B, OF + S, and OF + B. The effects of treatments on soil CH4 and N2O emissions were studied, and changes in soil physicochemical properties were analyzed. The results showed that relative to CF, CF + S and OF + S increased the cumulative CH4 emissions by 11.80% and 2.35%, respectively, while CF + B and OF + B resulted in significant reductions in cumulative CH4 emissions by 27.80% and 28.46%, respectively. Biochar was effective in reducing N2O emissions, and OF further increased the potential, with CF + B and OF + B achieving the best N2O reductions of 30.56% and 32.21%, respectively. Although OF reduced yields by 0.16%, this difference was within reasonable limits; the remaining treatments increased grain yields by 2.55% to 3.47%. CF + B and OF + B reduced the global warming potential (GWP) by 27.93% and 28.63%, respectively, and ultimately reduced the greenhouse gas emission intensity (GHGI) by 30.42% and 30.97%. Both straw and biochar increased the soil organic matter, NH4+-N, and NO3−-N contents, and biochar increased the soil pH, which may be the potential mechanism regulating soil GHG emissions. Overall, OF + B is beneficial for reducing GHG emissions and may be a better agronomic cropping pattern in double season rice growing areas.

High-potential nanomaterials were derived from rice straw using the integrated biobased processes of enzymatic hydrolysis with green organic acid hydrolysis assisted with ultrasonication pretreatment. The optimization condition of nanocellulose preparation by enzymatic hydrolysis via central composite design (CCD) achieved a maximum nanocellulose content of 32.37 ± 0.47% using a cellulase concentration of 107.06 U/mL and 0.13% (w/w) of rice straw cellulose. The ultrasonication-assisted pretreatment prior to enzymatic hydrolysis improved nanocellulose preparation to 52.28 ± 1.55%. Integration with oxalic acid hydrolysis increased the nanocellulose content to 64.99 ± 0.16%. Granular nanocellulose was obtained and consisted of a 105–825 nm nanosize with a zeta potential value of −34.5 mV, and nanocellulose suspension showed high stability without aggregation. In addition, the remaining rice straw cellulose after oxalic acid was microcrystalline nanocellulose. All prepared nanocellulose represented a functional group as original cellulose but had a low crystallinity index (CrI) of 15.68% that could be classified as amorphous nanocellulose. Based on their characteristics, all nanocellose could be further applied in food, cosmetics, and pharmaceuticals. Moreover, the results indicated that the rice straw could be an alternative non-edible cellulose source for preparing potential nanocellulose via a controlled hydrolysis process.

Amorphous silica, a specialised silicate adsorbent is extensively extracted from agricultural residues for application in various environmental domains. Wheat straws are a rich source of silica that have earlier been overlooked however demand for value addition. The study presents an innovative approach to extracting silica from wheat straw and standardising the extraction process to produce clean product. The sodium silicate solution and the amorphous silica synthesis were obtained by modifying the template mediated sol–gel method. Optimum temperature, concentration and pH were identified for the cleaner production of silica with maximum yield and favourable adsorbent characteristics. The crystallographic properties analysed by the X-Ray Diffraction revealed the amorphous nature of silica extracted from ash at 650 °C for 4 h. The structure of phytolith present in the wheat straw was observed in the form of articulated elongate undulate epidermal phytolith under scanning electron microscopy. The Energy Dispersive X-ray spectrum exhibited higher amount of silica (Si %) of 70.10% with a minimal percentage of potassium (9.96%). The sharp bend at 1025 cm−1 is attributed to the siloxane (Si–O-Si) vibrations in Fourier transform infrared spectroscopic graph of amorphous silica. The specific surface area measurements of amorphous silica showed type II isotherm curve with a hysteresis of H3 type. The optimum conditions derived to produce amorphous silica were 3 M NaOH and 3 M H2SO4 at pH 9.

Current research efforts aim to develop insulating building materials to cope with hot tunnels by using crop straw fibers. The amount of straw fiber incorporated included different percentages of the gelling material mass: 0% (reference specimen), 2.5%, 5%, 7.5%, and 10%. The study focused on the concrete’s compressive strength, permeability, and thermal coefficient. The thermal coefficient of dry concrete decreased with increasing fiber content. However, the porosity of concrete mixed with more straw fibers increased, thus decreasing compressive strength. Concrete with a fiber content of 7.5% had the best overall performance, and it had a low thermal conductivity (0.158 W/(m·k)). According to COMSOL simulation results, the tunnel wind flow temperature of concrete with 7.5% fiber content was lower than the tunnel wind flow temperature of plain concrete. Thus, the obtained straw fiber heat-insulating concrete is a promising candidate material for tunnel insulation.