Straw Recycling Research Articles

Comparison and Experimental Study of Cotton Stalk Extraction via Nip Roller Based on Nip Motion Trajectory Equation

In the field of straw recycling, a cotton straw-harvesting mechanism is an important piece of agricultural equipment. The mechanistic analysis method of the harvesting mechanism is a major focus of research and development in this field. Currently, in the mechanistic analysis of the cotton straw recycling mechanism, the kinematic and mechanical analysis of the recycling mechanism is generally the main focus. There is not a lot of research based on the quantitative analysis between different recycling mechanisms. In this study, a clamped cotton straw pulling mechanism is optimized and designed, and two different pulling structures are designed. In addition, a two-dimensional modeling and analysis method is used to establish the two-dimensional equations of motion of the two pulling mechanisms, analyze the leakage and breakage rates of the two clamping structures, predict the final pulling effect, and verify the results of the field tests. According to the analysis, the belt-clamping side has more uniform clamping stress and a larger clamping contact area than the chain-clamping side, and the tangential stress on cotton straw is smaller. Based on the field-test verification, the band-clamping side had a higher pulling net rate by an average of 19.32% and a lower missed pulling rate by an average of 6.01% than the chain-clamping side. Therefore, it was determined that the main reason for the lower pulling net rate of the chain-gripped side than that of the belt-gripped side was the higher pulling breakage rate, and the secondary reason was the high leakage pulling rate. Thus, the feasibility and accuracy of the analytical method of this study are verified.

Those with constant property rights have perseverance: China’s land tenure reform promotes environment-friendly farming practices

Few studies have used large-scale household-level panel data to quantify the impact of land tenure reform on environment-friendly farming practices from a chemical fertiliser reduction perspective. This study attempts to fill this gap by exploring the relationship between land certification and farmers’ chemical fertiliser use. It employs nationally representative panel data from the Chinese Family Database and a propensity score matching and difference-in-difference approach. The results show that land certification significantly reduces the usage of chemical fertilisers, mainly by increasing long-term investment, promoting land renting, and inhibiting off-farm employment. This effect varies greatly between farmers with and without land certification experience before the new round of land certification, although no significant difference exists based on whether farmers have previous land adjustment experience. Furthermore, land certification also helps increase the probability of straw recycling and farm manure use. Accordingly, developing countries can combine land tenure reform with environment-friendly farming practices. Through large-scale land certification reforms, and the continuous enhancement of land tenure security, a solid foundation for a land tenure system for sustainable agricultural development can be established.

Promoting Straw Recycling to Accelerate the Sustainable Development of Agriculture

Guided by Xi Jinping’s thought of socialism of the new era with Chinese characteristics in the 14th Five-Year Plan, the comprehensive utilization of straw is closely integrated with the annual key tasks of improving rural areas, by adhering to the priority of agricultural use, industry-oriented, multi-measures, and focusing on counties and municipalities with larger amounts of straw resources. Agricultural modernization requires that provincial policies focus on promoting the utilization of straw as fertilizer, feed, energy production, substrate, raw material, and so on while emphasizing the establishment of a complete straw collection, storage, and transportation system. In response to the problem of the open burning of straw in recent years, China has adopted a variety of policies and measures to control pollution and rationally utilize straw resources. The state and provinces have issued many policy documents on straw resource management, which are divided into the management of straw burning, comprehensive utilization of straw, planning of the straw energy industry, and financial subsidies. Rational utilization of straw not only solves the key issues of employment of farmers but also promotes ecological efficiency and rural economic development. The research results of straw recycling have also made important progress in improving the utilization rate and value of straw, promoting the resource utilization of agricultural waste, and providing important technical support for the sustainable development of China’s agriculture and rural environmental protection.

Degradation of straw-based wick drain and its effect on consolidation

The recycling of straw, a type of agricultural waste in a large volume, has considerable attention, and attempts have been made to fabricate straw-based wick drains in soft clay ground improvement. Although it has low carbon emissions and is environmentally friendly, the biodegradation process of wick drains and its effect on consolidation need to be further investigated. In this study, the biodegradation process was examined by subjecting straw and plastic wick drains to degradation tests in soils from the prototypical project for comparison. The results show that the degradation of straw wick drains exhibits a decrease in the discharge capacity and tensile strength, and the degradation percentage of both exceeds by 30% after 240 days, whereas the mass loss is only 10%. After degradation, the abundance of cellulose-degrading bacteria increases by 3–10%, respectively. The biodegradable behavior of straw wick drains is achieved by the rapid community succession of multiple degrading bacteria and the population growth of cellulose-degrading bacteria. Afterwards, the theoretical calculation model considering the drain degradation was performed to understand the consolidation procedure, suggesting the effective substitution of straw wick drains.

Agricultural management practices in China enhance nitrogen sustainability and benefit human health.

The potential of enhanced agricultural management practices to drive sustainability is rarely quantified at grassroots level. Here we analyse nitrogen use and loss in Chinese cropland, drawing from data collected in 2,238,550 sites in two national agricultural pollution source censuses from 2007 to 2017. We find an upswing of 10% in crop yields and an 8% reduction in nitrogen pollution during this period, owing to the promotion and adoption of various management practices (including the combination of organic and chemical fertilizers, straw recycling and deep placement of fertilizer). These practices have collectively contributed to an 18% increase in nitrogen use efficiency in the country. By fully embracing them, we project that annual cropland pollution could be further reduced by up to 1.4 Mt of nitrogen without compromising crop yields. Environmental and human health benefits are projected to consistently outweigh implementation costs in the future, with total benefits reaching US$15 billion.

Fabrication of a straw-based degradable mulch film with magnetically controlled-release glyphosate

To solve three main problems in agriculture (plastic mulch pollution, difficult straw recycling, and low utilization efficiency of pesticides), a multifunctional mulch film (MF) was fabricated. In this study, corn straw was mixed with xanthan gum, glyphosate (Gly), Fe3O4, and MIL-100(Fe) to obtain a MF named as SMFG with magnetically controlled-release Gly. To improve the hydrophobicity and stability of SMFG, the surface was coated by amino silicone oil (ASO) to get SMFG@ASO. SMFG@ASO had well insulation and moisture retention properties close to polyethylene MF. Meanwhile, the weight loss ratio of SMFG@ASO increased with time and could reach 59% underground in 120 d, indicating the good biodegradation behavior of SMFG@ASO. Importantly, pot experiment showed that SMFG@ASO could significantly promote growth of crop and inhibit grass. Besides, earthworm experiment illustrated that SMFG@ASO possessed a high biosafety and could increase the relative abundance of beneficial bacteria (Flavobacterium) from 0.08 to 0.21 and soil quality. Thus, this study provides a new method to prepare a straw-based degradable MF for resolving the problems of plastic pollution and waste of straw resources simultaneously to realize the integration of herbicide and MF.

Rice straw returning enhances cadmium activation by accelerating iron cycling thus hydroxyl radical production in paddy soils during drainage

Straw returning is widely found elevating the bioavailability of cadmium (Cd) in paddy soils with unclear biogeochemical mechanisms. Here, a series of microcosm incubation experiments were conducted and spectroscopic and microscopic analyses were employed. The results showed that returning rice straw (RS) efficiently increased amorphous Fe and low crystalline Fe (II) to promote the production of hydroxyl radicals (OH) thus Cd availability in paddy soils during drainage. On the whole, RS increased OH and extractable Cd by 0.2–1.4 and 0.1–3.3 times, respectively. While the addition of RS effectively improved the oxidation rate of structural Fe (II) mineral (i.e., FeS) to enhance soil Cd activation (up to 38.5 %) induced by the increased OH (up to 69.2 %). Additionally, the existence of CO32− significantly increased the efficiency level on OH production and Cd activation, which was attributed to the improved reactivity of Fe (II) by CO32− in paddy soils. Conclusively, this study emphasizes risks of activating soil Cd induced by RS returning-derived OH, providing a new insight into evaluating the safety of straw recycling.

Comparative Study of Rice Straw Recycling Systems

Comparative Study of Rice Straw Recycling Systems

Predicting environmental impacts of smallholder wheat production by coupling life cycle assessment and machine learning

Wheat grain production is a vital component of the food supply produced by smallholder farms but faces significant threats from climate change. This study evaluated eight environmental impacts of wheat production using life cycle assessment based on survey data from 274 households, then built random forest models with 21 input features to contrast the environmental responses of different farming practices across three shared socioeconomic pathways (SSPs), spanning from 2024 to 2100. The results indicate significant environmental repercussions. Compared to the baseline period of 2018–2020, a similar upward trend in environmental impacts is observed, showing an average annual growth rate of 5.88 % (ranging from 0.45 to 18.56 %) under the sustainable pathway (SSP119) scenario; 5.90 % (ranging from 1.00 to 18.15 %) for the intermediate development pathway (SSP245); and 6.22 % (ranging from 1.16 to 17.74 %) under the rapid economic development pathway (SSP585). Variation in rainfall is identified as the primary driving factor of the increased environmental impacts, whereas its relationship with rising temperatures is not significant. The results suggest adopting farming practices as a vital strategy for smallholder farms to mitigate climate change impacts. Emphasizing appropriate fertilizer application and straw recycling can significantly reduce the environmental footprint of wheat production. Standardized fertilization could reduce the environmental impact index by 11.10 to 47.83 %, while straw recycling might decrease respiratory inorganics and photochemical oxidant formation potential by over 40 %. Combined, these approaches could lower the impact index by 12.31 to 63.38 %. The findings highlight the importance of adopting enhanced farming practices within smallholder farming systems in the context of climate change. Spotlights•China's smallholder wheat farming is increasingly exposed to climate threats, risking resource depletion and pollution•Increasing eco-impacts of smallholder wheat farming could be mitigated by regulated fertilizer use and straw recycling•Life cycle assessment combined with machine learning targets future environmental impacts in dynamic climate scenarios•The study offers actionable policy advice for sustainable smallholder wheat farming practices•Future work may probe machine learning's role in forecasting smallholder production behaviors and farming decision aid

Optimizing maize productivity: A sustainable approach integrating straw derivatives and film mulching in rainfed agriculture

Context or problemResource-use inefficiency, environmental degradation and food security are forcing a transformation from conventional to organic and sustainable agriculture. Objective or research questionRealizing synergistic use of light, water, and nitrogen resources for spring maize in a more circular straw utilization model, while comprehensively evaluating the sustainability of the scheme is the key to solving the above problems in rainfed areas, but there are few reports. MethodsAccording to a crop-livestock-biogas digester straw recycling model, straw can be returned to the field directly or in the form of cattle manure after fattening, or cattle manure can continue to be recycled by the digester as the only fermentation substrate, and ultimately returned to the field indirectly in the form of biogas residue. Therefore, according to different levels of straw recycling, four treatments were set up in this study: straw (S), cattle manure (M), biogas residue (BR) and control (CK) for a comparative study of water use efficiency, net solar radiation use efficiency, photosynthetic and leaf characteristics post-anthesis, annual nitrogen balance, spring maize yield, and sustainability index. ResultsThe results showed that straw and its derivatives effectively improve the utilization efficiency of light and water, potentially reducing the adverse effects of factors on yield variability. Maintaining high levels of photosynthetic activity after anthesis was mainly due to the positive effects of organic amendments on nitrogen content per unit leaf area. This led to significant increases in grain yield and harvested index by 5.95% to 13.22% and 3.41% to 6.37%, respectively. However, exogenous organic N addition promoted N2O emission and NH3 volatilization, resulting in a higher N surplus. The sustainable index of each treatment was in the following order: BR>M>CK>S. ConclusionsLong-term organic amendments, especially BR, can effectively improve the utilization and synergistic effects of critical production resources, constituting a high-yielding, efficient and sustainable spring maize population, which is consistent with our hypothesis that the sustainability index is higher in more circular straw utilization. Implications or significanceThis study provides a new plastic film cultivation strategy and evaluation perspective for sustainable spring maize production in the study area or similar areas.

Can straw recycling achieve sustainable agriculture at the smallholder level? A case in a semi-arid region

Diversified straw recycling practices are essential to achieve sustainable agriculture at the smallholder level. This study comprehensively evaluated the sustainability of two straw recycling models, agro-pastoral-biogas (CCBS) and carbonization (CBBS). The findings demonstrated that the economic indicators (such as spring maize yield and net economic benefits) accounted for a larger proportion of the total score in the CCBS model, indicating that the model is more sustainable for promoting smallholder economic income, while the CBBS model performed even better in carbon sequestration and emission reductions. These results were attributed to the more notable increase in spring maize productivity and the addition of two production units, fattening and biogas digester. However, the sustainability of the CCBS model declined as the straw recycling chain lengthened; the CBBS model had the highest sustainability index. Specifically, maize grain yield and SOC storage increased by 3.86%–11.7% and 11.66%–36.07%, respectively, and soil GHG emissions increased by 20.57% and decreased by 59.9%, respectively, for both models. Despite the substantial economic or environmental benefits, neither model can achieve the win-win goal of sustainability. We conservatively recommend the CCBS model and suggest more specialized smallholder production, but call for more interventions to optimize the CCBS model, as it encompasses multiple development objectives, such as combining planting and breeding, energy substitution, and carbon sequestration-emission reduction, which is more in line with the aspirations of smallholders and other groups.

Preparation of a honeycomb-like magnetically controlled release straw-based fertilizer

It is significant to improve fertilizers utilization efficiency (UE), realize the recycling of straw, and transform the traditional fertilization mode for fruit trees (ditch or hole). Therefore, a honeycomb-like magnetically controlled-release fertilizer (HMCRF) was prepared by combining corn straw (CS), urea, Fe3O4, modified starch adhesive (MSA), and amino silicone oil (ASO) in this work. CS served as a carrier for urea, MSA was an environmentally friendly adhesive, and Fe3O4 acted as a magnetic-sensitive material. The hydrogen bonds that exist among CS (-OH), urea (-NH2), and Fe3O4 (-FeO) played an essential role in urea adsorption. The magnetic field could effectively control the release of urea and improve urea UE. Thus, fertilizers could be provided to fruit trees according to their nutrient requirements at different growth stages to reduce waste. What's more, HMCRF could be applied directly on the soil surface, which not only saved labor but also differed from the traditional application method. The honeycomb-like structure was also favorable for rainwater storage and urea release in practice. Notably, HMCRF had a high biosafety on earthworms and could significantly boost the amount of beneficial microorganism in soil. The study offers a novel controlled-release fertilizer to promote urea UE, reduce labor, and achieve CS recycling.

Reimagining carbon emission mitigation in sustainable agriculture: uncovering farmers’ propensity for straw recycling

Reimagining carbon emission mitigation in sustainable agriculture: uncovering farmers’ propensity for straw recycling

Sustainable recycling of paddy straw through development of short-fiber-reinforced composites: exploring gainful utilization of agricultural waste

Sustainable recycling of paddy straw through development of short-fiber-reinforced composites: exploring gainful utilization of agricultural waste

Rice straw stems reveal higher sound absorption coefficient than crushed rice straw: a sustainable approach to the recycling of rice straw

Rice straw stems reveal higher sound absorption coefficient than crushed rice straw: a sustainable approach to the recycling of rice straw

Effect of greenhouse gas emissions on the life cycle of biomass energy production and conversion under different straw recycling modes

With the gradual growth of greenhouse gas (GHG) emissions during the agricultural cultivation cycle, GHG emissions specific to the production and conversion of biomass energy is becoming increasingly problematic. Current studies lack analysis of net GHG emissions generated during full life cycle of agricultural cultivation, straw use and bioenergy production. This study measures the global warming potential of biomass energy production and conversion processes under different agricultural cultivation cycle systems based on life cycle approach, accompanied by four straw treatment methods: fast pyrolysis, slow pyrolysis, flash pyrolysis and anaerobic fermentation. The demonstration of Heilongjiang Province showed that the net GHG emissions of rice and soybean over 52.39% and 101.57% higher than those of corn, respectively. The amount of standard coal saved by fast pyrolysis treatment, slow pyrolysis treatment and anaerobic fermentation treatment of straw was only 38.38%, 78.02% and 61.98% of that of flash pyrolysis treatment. The relationship between environmental pressure and economic growth was decoupled during 2011–2017 and coupled in 2017–2020. This study contributes to green production of biomass energy. The methodology in this paper can be used to account for and assess the carbon effect of the entire straw recycling chain in any region.

Benefits of organic amendments on soil C stock may be offset by increased methane flux in rice paddy field

Periodic application of organic manure (OM) has been suggested to increase soil carbon stock and mitigate global warming. However, in irrigated rice fields, OM amendment greatly increases methane (CH4) emissions, which in turn may offset the effect of increased soil carbon storage on mitigating global warming. Research on the effects of OM application on net global warming potential that integrates greenhouse gas (GHG) fluxes and soil carbon stocks change in rice cultivating systems has been elusive. To determine the impact of organic amendments on global warming in a rice paddy, chemical (NPK) and organic fertilization were installed, and straw removal and recycling plots were added in two fertilization treatments. Annual CH4 and nitrous oxide (N2O) fluxes were evaluated using the static closed chamber method. Soil C stock changes were estimated using the net ecosystem C budget (NECB) which indicates the difference between C input and output. In chemical fertilization, straw removal decreased soil C stock by an average of 751 kg C ha−1 year−1, but straw recycling significantly increased soil C stock by an average of 464 kg C ha−1 year−1. In organic fertilization, soil C stock was strongly affected by cover crop productivity. Under favorable climatic conditions for cover cropping, soil C stocks were greatly increased by green manuring and even more so by straw recycling. However, under an unfavorable climate, soil C stock was not statistically increased, regardless of straw addition. Straw recycling increased annual CH4 flux by approximately 220–310 and 130–190% over straw removal in chemical (7.9 Mg CO2-eq. ha−1 year−1) and organic fertilization (40 Mg CO2-eq. ha−1 year−1), respectively, but negligibly affected N2O flux. Irrespective of fertilization background, net GWP was mainly decided by CH4 flux with 54–98% coverage, and then followed by soil C stock change and N2O flux. As a result, straw addition increased net GWP by around 110–140 and 120–150% over straw removal in chemical and organic fertilization, respectively. Rice yield was stable between years in the chemical fertilization but showed a big difference in organic fertilization, due to the difference in cover crop biomass productivity. However, rice productivity was not significantly affected by straw recycling. Organic amendment and straw applications increased greenhouse gas intensity (GHGI) by an average of 131% and 269% in a rice paddy, respectively, due to a high increase of CH4 flux but a low increase of soil C stock. In conclusion, more effective OM management which can decrease CH4 emissions and increase SOC stock is required in rice paddies.

Design Optimization of Hammer Blade Crusher to Improve the Crushing Performance

China is a large agricultural country, each year will produce a large number of straw. The recycling of straw to China's agricultural development and environmental protection are very helpful, the recycling of straw is mainly energy, fertilizer, feed several uses, different uses need different crushing fineness, so adjust the crushing fineness can improve the recycling rate of straw. This paper mainly on the impact of straw crushing fineness factors for This paper focuses on the theoretical analysis and study of the factors affecting the fineness of straw crushing, and provides a general design plan for the crushing chamber.Firstly, the effect of different hammer and sieve gaps on the pulverisation fineness is studied and the straw pulverisation fineness is changed by changing the hammer and sieve gaps. The effect of hammer blade material, structure, arrangement, distribution density and hammer blade speed on the fineness of the straw is studied. Study the effect of the aperture size and arrangement of the sieve on the fineness of the crushing, and adjust the fineness of the crushing by changing the aperture size of the sieve. The study of the material in the crushing process generated by the "ring flow layer" mechanism, and by changing the shape of the crushing chamber structure to destroy the "ring flow layer" on the impact of the crushing performance of the crusher.Secondly, according to the production requirements of the hammer mill, the structure and material of the hammer blade and screen plate are designed and selected, and the hammer blade is analysed statically using Ansys, the rotor is analysed modally, a complete model of the crushing chamber is designed, and a three-dimensional model of the crushing chamber is built using SolidWorks.Finally, after simulation calculations, the design of the rotor headquarters structure is reasonable. An adjustable hammer and sieve clearance was achieved, reducing costs and improving the efficiency of the pulveriser crushing.

Crop – Livestock integration via maize straw recycling increased carbon sequestration and crop production in China

CONTEXTAgriculture production is crucial in mitigating climate change while securing food productivity. However, the impact of the practices such as organic waste (crop residue and animal manure) recycling or integrating crop-livestock system on productivity and carbon sequestration was unclear. OBJETIVEThis study presents a potential crop-livestock model to enhance carbon sequestration from a whole system perspective. This study aimed to (i) examine the effect of different organic waste recycling on contents of SOC, MBC, and EOC at a depth of 0–60 cm of soil; (ii) analyze the sequestration potential of SOC for different organic wastes recycling models using the substance flow balance method; and (iii) propose suitable organic wastes recycling models for crop and livestock production system in China from the whole-system perspective. METHODSThis study conducted a comparative assessment of carbon sequestration of diverse organic wastes in China using a four-year field experiment and substance flow balance method. The field experiment involved three types of organic waste (raw maize straw (MS), biogas slurry (BS), dairy manure (DM)) and two fertilizer application treatments (unfertilized control (CK), and only chemical fertilizer (CF)). Based on the field results, the carbon flow for different organic waste recycle models was compared using the substance flow approach. RESULTS AND CONCLUSIONSThe content and sequestration of SOC and its fractions increased with the application of organic wastes. The effect of organic wastes on SOC sequestration followed the order DM > MS > BS. Additionally, organic waste, especially DM, significantly increased the sequestration of MBC and EOC by 198% and 359%, respectively, compared to CF. The SOC, MBC, and EOC sequestration rates for DM treatment were 2.9–3.2, 0.3–0.6, and 2.7–3.0 Mg ha−1 yr−1, respectively. On a per-crop yield basis, the “crop straw-livestock-manure-field” model contributed about six times more for SOC sequestration than CF. Future estimation showed that the DM model could reduce chemical fertilizer use by 36% compared to CF, resulting in lower costs. Therefore, the “crop straw-livestock-manure-field” system benefits carbon sequestration and emphasizes the importance of expanding the organic waste management chain. SIGNIFICANCEThe findings have significant implications for the agricultural system, highlighting the importance of integrating the “crop straw-livestock-manure-field” model for carbon sequestration and sustained productivity. The results demonstrate that this model has successfully increased carbon sequestration in the agricultural system. These findings provide an essential option for achieving carbon neutrality in China and promoting sustainable development in agricultural system in other regions.

Use of a wheat straw covering to reduce nitrogen loss during pig slurry storage and reuse of the straw covering in biochar production for nitrogen retention in the slurry

Storing pig slurry (PS) and returning it to the field is one of the most important ways to recycle PS. However, during the storage of PS, the NH3 emissions cause a large loss of nitrogen (N), which reduces the fertilizer value of stored PS and cause environmental pollution. To reduce N loss during PS storage, we added different amounts of wheat straw powder (WSP) and wheat straw segments (WSSs) to the PS. The wheat straw cover was used for biochar production, and then, the biochar was used for N adsorption from the PS. The results showed that the N loss of PS was significantly decreased by use of the wheat straw covering. The N losses in treatments of WSP covering and WSSs covering were reduced by 4.8–53.1 and 0.8–14.2 percentage points compared with that in the control, respectively. Ammonia adsorption is an important reason for the reduction in N loss by straw covering during PS storage. After covering for 180 days in storage, the NH4+-N content in both the WSP covering and WSSs covering increased greatly, and the cover was reused for biochar production. The biochar yield was inversely proportional to the pyrolysis temperature, and the specific surface area and pore volume of the biochar were proportional to the pyrolysis temperature. We achieved the highest amount of NH4+-N adsorption (1.9 mg/g) with a biochar dosage of 0.2 g/L (treatment Y-400). This study provides a new straw-covered PS storage method to achieve straw recycling and low N loss during PS storage.