Film Mulching Research Articles

Response of terrestrial crustacean Porcellio scaber and mealworm Tenebrio molitor to non-degradable and biodegradable fossil-based mulching film microplastics

Agricultural mulching films are potential sources of microplastics (MPs) in soil. As an alternative to conventional non-degradable mulching films, a variety of different biodegradable mulching films are used. However, it is not yet known whether MPs from biodegradable mulching films pose a lower risk to terrestrial invertebrates compared to MPs from conventional mulching films. In this study, the effects of MPs produced from two conventional polyethylene (PE-1 and PE-2) and two biodegradable (starch-based poly(butylene adipate co-terephthalate); PBAT-BD-1, and PBAT-BD-2) fossil-based mulching films on terrestrial crustacean woodlice Porcellio scaber and mealworm Tenebrio molitor were compared. A key finding was that no clear differences in induced responses between biodegradable and conventional MPs were detected. No adverse effects on P. scaber after two weeks and on T. molitor after four weeks of exposure were observed up to 5 % (w/w dry soil) of either MP type. However, some sublethal physiological changes in metabolic rate and immune parameters were found in P. scaber after two weeks of exposure indicating a response of organisms to the presence of MP exposure in soil. In addition, it was demonstrated that both types of MPs might affect the soil water holding capacity and pH. In conclusion, we confirmed that biodegradable MPs can induce responses in organisms hence further studies testing the environmental hazard of biodegradable MPs are justified.

Carbon and Water Balances in a Watermelon Crop Mulched with Biodegradable Films in Mediterranean Conditions at Extended Growth Season Scale

The carbon source/sink nature and the water balance of a drip-irrigated and mulched watermelon cultivated under a semi-arid climate were investigated. Biodegradable films, plants and some fruits were left on the soil as green manure. The study spanned from watermelon planting to the subsequent crop (June–November 2023). The eddy covariance technique was employed to monitor water vapor (H2O) and carbon dioxide (CO2) fluxes, which were partitioned into transpiration, evaporation, photosynthesis and respiration, respectively, using the flux variance similarity method.This method utilizesthe Monin–Obukhov similarity theory to separate stomatal (photosynthesis and transpiration) from non-stomatal (respiration and evaporation) processes. The results indicate that mulching films contribute to carbon sequestration in the soil (+19.3 g C m−2). However, the mulched watermelon crop presented in this study functions as a net carbon source, with a net biome exchange, representing the net rate of C accumulation in or loss from ecosystems, equal to +230 g C m−2. This is primarily due to the substantial amount of carbon exported through marketable fruits. Fixed water scheduling led to water waste through deep percolation (approximately 1/6 of the water supplied), which also contributed to the loss of organic carbon via leaching (−4.3 g C m−2). These findings recommend further research to enhance the sustainability of this crop in terms of both water and carbon balances.

Mechanized No-Tillage Planting with Maize Straw Mulching Improves Potato Yield and Water Use Efficiency in Arid Regions of Northwest China

To explore the yield-increasing mechanism of mechanized potato planting with corn straw mulching, a two-year (2021 and 2022) field experiment was conducted to study the effects of mechanized no-tillage with straw mulching on potato yield and water use efficiency. This experiment included mechanized no-tillage potato planting with corn straw mulch covering (JG), plastic film mulching (HM), and open flat planting (CK). The results showed that mechanical no-tillage with straw mulching significantly affected soil water content in the 0–100 cm soil layer, yield, and water use efficiency (p < 0.05). There was no significant difference in yield between JG and HM, but it was significantly higher than that of CK. The yield of JG was 3.09~12.27% higher than that of CK. The yield increase was mainly achieved by increasing the potato weight per plant (0.697~0.862 **) and the average single potato weight (0.048~0.631). The tuber weight per plant was positively correlated with the plant height at the seedling stage (0.03~0.92 **) and positively correlated with the dry weight of stems and leaves at the tuber expansion stage and starch accumulation stage (0.74 **~0.95 **). It was negatively correlated with the number of branches at the tuber formation stage (−0.33~−0.88 **). Compared with CK, JG could significantly improve the water use efficiency of potatoes and reduce water consumption during the whole growth period of crops. In 2021, JG was 6.5% higher than CK, and HM was 6.88% lower than CK. In 2022, JG and HM increased water use efficiency by 26.17% and 14.50% compared with CK. When HM is applied in heavy soil areas, soil compaction can easily occur, which affects seedling emergence and reduces yield. At the same time, JG has strong adaptability to soil types and good yield stability. It can be seen that JG is a green and efficient mechanized potato cultivation technology suitable for dry farming areas.

Multigenerational toxicity of microplastics derived from two types of agricultural mulching films to Folsomia candida

Degradation and fragmentation of mulching films represents an increasing source of microplastics (MPs, plastic particles 1 μm to 5 mm in size) to agricultural soils. MPs have been shown to affect many soil invertebrates, including springtails. However, these studies typically use test materials representing less environmentally relevant particle types, such as pristine uniform MPs, which do not represent the large range of particle sizes and morphologies found in the field. This study aimed at providing insight into the adverse effects of MPs originating from agricultural mulching films, by using artificially aged MPs derived from both biodegradable (starch-polybutadiene adipate terephthalate (PBAT)) blend, as well as conventional (linear low-density polyethylene (LLDPE)) plastic polymers. The soil dwelling springtail Folsomia candida was exposed to these MPs for five generations in order to elucidate population effects due to possible reproduction toxicity, endocrine disruption, mutagenesis or developmental toxicity. F. candida were exposed to 0, 0.0016, 0.008, 0.04, 0.2, 1, 2, 3, 4 and 5 % (w/w dry soil) MPs in Lufa 2.2 soil, which includes concentrations within the range of environmental relevance. Juveniles produced at each concentration were transferred to the next generation, with the parental, F2 and F4 generations being exposed for four weeks and F1 and F3 generations for five weeks. No concentration-dependent effects on F. candida survival or reproduction were observed in exposures to either of the MPs, in any of the generations. These results suggest that the particular MPs used in this study, derived from mulching films used on agricultural soils, may not be potent toxicants to F. candida, even after long-term exposure and at elevated concentrations.

Classification of Degradable Mulch Films and Their Promotional Effects and Limitations on Agricultural Production

Classification of Degradable Mulch Films and Their Promotional Effects and Limitations on Agricultural Production

Development of bio-composite mulch film from cotton gin wastes: Study of pesticide residue and outdoor stability and degradation

Non-degradable plastic mulch films used in agriculture are polluting the environment by leaving residues and microplastics in the soil. They are also difficult to recycle due to contamination during their use. Biodegradable mulch films are needed as alternatives so that they can be used effectively during the growing season and later be ploughed to be degraded in soil. However, market-available so-called biodegradable mulch films are very slow to degrade in the natural environment and thus do not fit with crop rotation demands or annual cultivation. In this study, we have developed mulch films from cotton gin trash (CGT) and/or gin motes (GM) in combination with biodegradable polycaprolactone and demonstrated their effectiveness over 3 months in outdoor conditions. Both the stability and degradation behaviours of mulch film samples were observed when they were placed on top of the soil and buried in the soil, respectively. Pesticide residue analysis also was carried out on CGT powder to identify and quantify individual pesticides against a matrix of known pesticides. The mulch films prepared in this study showed comparable and stable mechanical properties compared to commercial biodegradable mulch film, though were much quicker to degrade when buried in the soil. No pesticides were detected in the CGT samples. The films produced were vapour-permeable and may be useful in practical agricultural settings by being able to maintain consistent soil moisture and allowing precipitation to penetrate gradually. The lab-scale production cost for the film was 98.8 AUD/kg, which could be lowered by integrating a continuous film line in large-scale production.

Incorporating straw‐derived biochars enhances soil nitrogen accumulation and mitigates nitrogen leaching to facilitates crop productivity of mulching farmland in semiarid regions

AbstractThe long‐term use of film mulching and conventional chemical fertilizers in semiarid regions has resulted in soil degradation and suboptimal fertilizer utilization, necessitating a reevaluation of agricultural practices to enhance resource utilization efficiency and ensure the sustainability of dryland crop production. We conducted a 5‐year study (2017–2021) field experiment in northwest of China, to assess the impact of straw or biochar incorporation on soil water accumulation, crop nitrogen transport, and maize yield under film mulching field. The experiment had six treatments (flat planting without mulching [NN], flat planting with straw incorporation [NS], flat planting with biochar incorporation [NB], film mulching [MN], film mulching with straw incorporation [MS], and film mulching with biochar incorporation [MB]). We undertook a comprehensive assessment over the two growing seasons in 2020–2021. The film mulching and straw/biochar treatments improved soil water storage. The MB treatment significantly decreased 60–200 cm soil NO3−‐N content by 28.37% compared with MN. Biochar incorporation significantly increased soil total and alkali‐hydrolyzable N contents, whereas MS decreased soil alkali‐hydrolyzable N content compared with MN. The maize plant N transportation and grain contribution rates were significantly higher under MS (17.46% and 29.84%) and MB (28.00% and 31.69%) than under MN, respectively. Straw and biochar incorporation significantly increased water use efficiency, nitrogen fertilizer recovery efficiency, and maize yield, on average, by 9.62%, 9.14%, and 14.6%, respectively. In conclusion, incorporating biochar, in particular, positively mitigated N losses, enhanced N utilization efficiency, and increased maize yield in long‐term film mulching farmland in semiarid region.

Effects of microplastics derived from biodegradable mulch film on different plant species growth and soil properties

Biodegradable mulch residues contribute significantly to the presence of microplastics in soil ecosystems. The environmental impact of microplastics, especially biodegradable microplastics (bio-MPs), on soil and plants is of increasing concern. In this study, the responses of five crop species potted in soil treated with different mass concentrations of bio-MPs were assessed for one month. The shoot and root biomasses of cabbages and strawberries were inhibited by bio-MPs treatment. There was little variation in the growth indicators of identical plants with the addition of different mass concentrations of bio-MPs; however, a significant difference was observed among different plants with the addition of the same concentration of bio-MPs. The detrimental effects of bio-MPs were more pronounced in strawberries and cabbages than in the other plant species. Moreover, bio-MPs can affect the availability of soil nutrients and enzyme activities. Structural equation modeling showed that changes in soil properties may indirectly affect plant growth and nutrient uptake when exposed to bio-MPs. This study provides a theoretical basis for understanding the ecological effects of biodegradable mulch films.

Mechanical, thermal and biodegradation studies of highly degradable composite films of pectin/guar gum/ polyvinylpyrrolidone with rice crop residues: a future vision of packaging and mulch films

ABSTRACT In the present work, eco-friendly composites were fabricated using pectin/guar gum/ polyvinylpyrrolidone blend as matrix and agriculture waste like rice husk and rice straw as reinforcements. Rice husk and rice straw are treated with an alkali solution and then incorporated into the matrix by solvent casting method. The amount of rice husk/rice straw varied from 5% to 15% of the total polymer content. The interaction between polymers and reinforcements is studied by FTIR which shows the presence of hydrogen bonding among the components. SEM images were used to confirm the homogeneous distribution of rice husk/rice straw in the composite films. Thermogravimetry analysis of the composites and the control (blend) film shows that there is an improvement in thermal degradation stability upon the incorporation of reinforcements. The tensile strength of composites is also augmented when compared with the control film (24.61 MPa) and the composite with 10% rice husk has a maximum (29.41 MPa) tensile strength. The biodegradation study of the composite films is performed by the soil burial method.

Effect of straw and plastic mulches on growth and yield of zero tillage potato (Solanum tuberosum L.) in the Coastal Khulna Region of Bangladesh

A randomized complete block design experiment was undertaken at the field laboratory of the Agrotechnology Discipline, Khulna University, Khulna, from November 2021 to March 2022 to ascertain the impact of various mulch treatments on zero tillage potato cultivation. The experiment employed BARI Alu 78 as the planting material and utilized three replications with five distinct mulch treatments. These mulch treatments were identified as follows: Straw mulch (T1), Mulch film (T2), Black polythene (T3), White polythene (T4), and Blue polythene (T5). The metrics that were recorded included the number of sprouts, plant height, number of leaves per plant, leaf width, leaf length, number of tubers, tuber length, tuber breadth, number of defective tubers, weight of defective tubers, and tuber weight. Different mulching techniques significantly influenced the overall crop yield and the underlying factors that influenced the results. The mulch film treatment resulted in the highest yield, with a production of 34.76 tons per hectare, followed by black polythene (28.11 tons per hectare), straw mulch (23.74 tons per hectare), white polythene (20.44 tons per hectare), and blue polythene (18.66 tons per hectare). The economic analysis revealed that mulch film had a high benefit cost ratio along with high input and output. Black polythene came in second place when the benefit cost ratio was compared to that of mulch film and the rest of the three treatments. Combining zero tillage with mulch film or black polythene demonstrates significant potential for becoming a cost-effective practice in the coastal region of Bangladesh.

The fate of post-use biodegradable PBAT-based mulch films buried in agricultural soil

The fate of black biodegradable mulch film (MF) based on starch and poly(butylene-adipate-co-terephthalate) (PBAT) in agricultural soil is investigated herein. Pristine (BIO-0) and UV-aged film samples (BIO-A192) were buried for 16 months at an experimental field in southern Italy. Visual, physical, chemical, morphological, and mechanical analyses were carried out before and after samples burial. Film residues in the form of macro- and microplastics in soil were analyzed at the end of the trial.Progressive deterioration of both pristine and UV-aged samples, with surface loss and alterations in mechanical properties, occurred from 42 days of burial. After 478 days, the apparent surface of BIO-0 and BIO-A192 films decreased by 57 % and 66 %, respectively. Burial determined a rapid depletion of starch from the polymeric blend, especially for the BIO-A192, while the degradation of the polyester phase was slower. Upon burial, an enrichment of aromatic moieties of PBAT in the film residues was observed, as well as microplastics release to soil. The analysis of the MF degradation products extracted from soil (0.006–0.008 % by mass in the soil samples) revealed the predominant presence of adipate moieties. After 478 days of burial, about 23 % and 17 % of the initial amount of BIO-0 and BIO-A192, respectively, were extracted from the soil. This comprehensive study underscores the complexity of biodegradation phenomena that involve the new generation of mulch films in the field. The different biodegradability of the polymeric components, the climate, and the soil conditions that did not strictly meet the parameters required for the standard test method devised for MFs, have significantly influenced their degradation rate. This finding further emphasizes the importance of implementing field experiments to accurately assess the real effects of biodegradable MFs on soil health and overall agroecosystem sustainability.

Agricultural film-derived microplastics elevate the potential risk of pesticides in soil ecosystem: The inhibited leaching by altering soil pore

The residue of mulch film is a crucial source of microplastics (MPs) in agricultural fields. The effects of mulch film-derived MPs on the environmental behavior of pesticides in agriculture remain unclear. In the present study, the effects of MPs of different sizes (5 mm, 1 mm, 30 µm, and 0.3 µm) at environmentally relevant concentrations on pesticide transport were evaluated, and the mechanism was explored with respect to adsorption and pore structure using fluorescence visualization, the extended Derjaguin–Landau–Verwey–Overbeek model, and microcomputed tomography. MPs were found to be retained in the soil due to size limitation, pore capture, and surface adhesion. The presence of mm-sized MPs (5 and 1 mm) at a concentration of 0.25 % inhibited the leaching behavior of atrazine, metolachlor, and tebuconazole. MPs did not significantly alter the pesticide adsorption ability of the soil. The reduced leaching originated from the impact of MPs on soil pore structure. Specifically, the porosity increased by 16.2–25.0 %, and the connectivity decreased by 34.5 %. These results demonstrate that mm-sized MPs inhibit pesticide leaching by obstructing the pores and altering the transport pathways, thereby potentially elevating environmental risks, particularly to the soil ecosystem.

Straw returning and nitrogen reduction: Strategies for sustainable maize production in the dryland

Implementing continue straw returning practices and optimizing nitrogen application can mitigate nitrogen losses and enhance nitrogen use efficiency (NUE) in dryland. 15N-labeled technique offers a robust approach for tracking fertilizer nitrogen fate and assessing nitrogen use efficiency. Based on the continue (>6 yr) experiment, we conducted a two-year experiment (2020 and 2021) to evaluate the effects of straw returning and nitrogen management under plastic film mulching on 15N recovery rates, N2O emissions and maize yield with three treatments: no straw returning with 225 kg N·ha−1 under plastic film mulching (RP-N225), straw returning with 225 kg N·ha−1 under plastic film mulching (RPS-N225), and straw returning with 20% nitrogen reduction (180 kg N·ha−1) under plastic film mulching (RPS-N180). After six years, both continue straw returning with plastic film mulching increased uptake of fertilizer nitrogen, had higher 15N recovery rates than RP-N225, leading to increased 15N accumulation in grain and aboveground biomass, ultimately enhancing yield. The RPS-N225 treatment exhibited the highest spring maize yield and nitrogen harvest index. The RPS-N180 treatment significantly increased maize yield more than RP-N225 and had the highest NUE, partial factor productivity of nitrogen fertilizer, and nitrogen uptake efficiency, with improvements ranging from 1.7 to 2.4%, 19.3–29.6%, and 17.3–27.5%, respectively, compared to the other treatments. Moreover, RPS-N225 resulted in significantly higher cumulative N2O emissions and yield-scaled N2O emissions than the other treatments, whereas the RPS-N180 treatment significantly decreased yield-scaled N2O emissions compared to RP-N225. Hence, combining continue straw returning with appropriate nitrogen reduction can effectively increase maize yield and yield-scaled N2O emissions. By offering insights into optimizing nitrogen fertilizer management after continue maize straw return, this study is contributed to widespread adoption of straw return practices and sustainable agricultural development in semi-arid areas.

The impacts of film mulching and ridging on N2O emissions, relevant functional genes, and microbial communities in rain-fed potato fields

Rain-fed potato (Solanum tuberosum) fields in drylands significantly contribute to nitrous oxide (N2O) emissions, making them an important focus of agricultural greenhouse gas research. Film mulching and ridging are key agricultural methods in potato cultivation. Investigating the impact of these methods on N2O emissions, nitrifying/denitrifying functional genes, and microbial communities can provide a theoretical basis for soil emission reduction and more sustainable dryland agriculture. We examine the effects of flat tillage with mulching, ridge tillage with mulching, flat tillage without mulching, and ridge tillage without mulching, on potato fields under natural rainfall conditions in Wuchuan County, China. N2O emission fluxes were monitored using a static (dark) chamber and gas chromatography. Real-time quantitative PCR (q-PCR) was used to quantify abundances of nitrifying and denitrifying bacteria related to N2O emissions at various potato-growth stages. Illumina high-throughput sequencing was used to investigate microbial community structure by targeting 16S rRNA genes; related soil elements (soil temperatures and moisture) are analyzed. Mulching and ridging indirectly influence N2O emissions, nitrifying/denitrifying functional gene copy numbers, and microbial community structure by altering soil temperature and moisture. Cumulative N2O emissions and emission intensity were both consistently higher in ridge tillage with mulching during the potato-growing period. Ammonia-oxidizing archaea are the main microorganisms that control N2O emissions, with nitrification-coupled denitrification also being an important mechanism contributing to high N2O emissions during soil dry–wet cycles. Increased soil temperature and moisture elevated N2O emissions and functional gene copy numbers. The combination of mulching and ridging effectively uses the characteristics of both practices, making Nitrospira the dominant genus, and significantly increases N2O emissions.

Willingness to adopt biodegradable mulch among farmers in Saudi Arabia: implications for agricultural extension

Biodegradable mulch (BDMs) films are ecologically safe substitutes for polyethylene mulches (PEMs) in agricultural systems. However, since it is an innovative technology on the market, it is not easy for farmers to adopt it. Understanding farmers' familiarity with BDM and their willingness to adopt it in the future could play a crucial role in the design and implementation of effective agricultural interventions for promoting the adoption of BDM to reduce environmental pollution. Therefore, a study was undertaken to assess farmers' familiarity with BDM and their willingness to adopt it in the future. Data were collected from fruit and vegetable growers located in Al-Kharj, Saudi Arabia, using a simple random sampling approach with the help of a pre-tested paper-based questionnaire. The findings revealed that most of the farmers were not familiar with BDM. Despite the lack of awareness, a considerable portion indicated their willingness to adopt BDM in the future. The farmers' education level, farm size, and membership in agricultural cooperatives significantly influenced their familiarity with BDM. Education level, farming experience, and membership in agricultural cooperatives also showed significant relationships with their willingness to adopt BDM in the future. Moreover, the farmers were not aware of the potential benefits of this new innovation. The study recommends that extension education programs through the active involvement of agricultural cooperatives should be implemented to make farmers aware of the advantages of BDM over PEM. In addition, the government should facilitate the adoption of this promising innovation by enhancing its availability on the market and affordability to farmers.

Reproduction, growth and oxidative stress in earthworm Eisenia andrei exposed to conventional and biodegradable mulching film microplastics

Plastic contamination in agricultural soils has become increasingly evident. Plastic mulching films are widely used in agricultural practices. However, the increased use of biodegradable plastics has, to some extent, replaced their non-degradable counterparts. The fragmentation of plastics generates microplastics (MPs), posing risk to soil functions and organisms. In this study the effects of low-density polyethylene microplastics (PE-MP) and polybutylene adipate terephthalate biodegradable microplastics (PBAT-BD-MP) originating from mulching films on the earthworm Eisenia andrei were studied. The earthworms were exposed to seven concentrations (0, 0.005, 0.05, 0.1, 0.5, 1, and 5 % w/w) based on environmentally relevant levels and worst-case scenarios on soil contamination. Survival, growth, reproduction, and biomarkers for oxidative stress [superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione S-transferase (GST), glutathione (GSH), and lipid peroxidation (LPO)] were analysed. Additionally, the Integrated Biomarker Response Index (IBR) was calculated to assess the overall oxidative stress status of the earthworms. Results showed that PE-MP exposure slightly decreased the biomass of the earthworms towards higher concentrations, whereas PBAT-BD-MPs induced growth at lower concentrations. MPs did not have a significant effect on Eisenia andrei reproduction; however, a slight negative trend was observed in juvenile production with increasing PE-MP concentrations. Both PE-MP and PBAT-BD-MP affected antioxidant system, PE-MPs with changes in CAT and GR levels and PBAT-BD-MPs inducing effects on SOD and LPO levels. Additionally, both MPs exhibited effects on soil parameters, resulting in increased soil pH and water-holding capacity at 5 % concentration. Changes in soil parameters can further affect soil organisms such as earthworms. This study provides understanding of the ecotoxicological effects of conventional and biodegradable microplastics on the earthworm Eisenia andrei. It also shows that MP particles of both conventional and biodegradable mulching films induce oxidative stress, considered as an early-warning indicator for adverse ecological effects, in environmentally relevant concentrations.

Environmentally relevant concentrations of microplastics from agricultural mulch and cadmium negatively impact earthworms by triggering neurotoxicity and disrupting homeostasis

Recent research has highlighted the ecological risk posed by microplastics (MPs) from mulching film and heavy metals to soil organisms. However, most studies overlooked real environmental levels of MPs and heavy metals. To address this gap, pristine and aged polyethylene (PE) mulching film-derived MPs (PMPs, 500 mg/kg; AMPs, 500 mg/kg) were combined with cadmium (Cd, 0.5 mg/kg) to assess the acute toxicity to earthworms and investigate associated molecular mechanisms (oxidative stress, osmoregulation pressure, gut microbiota, and metabolic responses) at environmentally relevant concentrations. Compared to Cd alone and Cd + PMPs treatments (11.15 ± 4.19 items/g), Cd + AMPs treatment resulted in higher MPs bioaccumulation (23.73 ± 13.14 items/g), more severe tissue lesions, and increased cell membrane osmotic pressure in earthworms’ intestines. Cd + AMPs induced neurotoxicity through elevated levels of glutamate and acetylcholinesterase. Earthworm intestines (0.98 ± 0.49 to 3.33 ± 0.37 mg/kg) exhibited significantly higher Cd content than soils (0.19 ± 0.01 to 0.51 ± 0.06 mg/kg) and casts (0.15 ± 0.01 to 0.25 ± 0.05 mg/kg), indicating PE-MPs facilitated Cd transport in earthworms’ bodies. Metabolomic analysis showed Cd + AMPs exposure depleted energy and nucleotide metabolites, disrupted cell homeostasis more profoundly than Cd and Cd + PMPs treatments. Overall, co-exposure to AMPs + Cd induced more severe neurotoxicity and disruption of homeostasis in earthworm than Cd and PMPs + Cd treatments. Our study, using Cd and MPs with environmental relevance, underscores MPs’ role in amplifying Cd accumulation and toxicity in earthworms.

Residual Mulching Film Detection in Seed Cotton Using Line Laser Imaging

Due to the widespread use of mulching film in cotton planting in China, residual mulching film mixed with machine-picked cotton poses a significant hazard to cotton processing. Detecting residual mulching film in seed cotton has become particularly challenging due to the film’s semi-transparent nature. This study constructed an imaging system combining an area array camera and a line scan camera. A detection scheme was proposed that utilized features from both image types. To simulate online detection, samples were placed on a conveyor belt moving at 0.2 m/s, with line lasers at a wavelength of 650 nm as light sources. For area array images, feature extraction was performed to establish a partial least squares discriminant analysis (PLS-DA) model. For line scan images, texture feature analysis was used to build a support vector machine (SVM) classification model. Subsequently, image features from both cameras were merged to construct an SVM model. Experimental results indicated that detection methods based on area array and line scan images had accuracies of 75% and 79%, respectively, while the feature fusion method achieved an accuracy of 83%. This study demonstrated that the proposed method could effectively improve the accuracy of residual mulching film detection in seed cotton, providing a basis for reducing residual mulching film content during processing.

Joint effect of black carbon deriving from wheat straw burning and plastic mulch film debris on the soil biochemical properties, bacterial and fungal communities

Black carbon (BC) formed after straw burning remains in farmland soil and coexists with plastic mulch film (PMF) debris. It is unclear how BC influences soil multifunctionality in the presence of PMF debris. In this study, we determined the joint effects of BC and PMF debris on soil biochemical properties and microbial communities. We conducted a soil microcosm experiment by adding BC formed by direct burning of wheat straw and PMF debris (polyethylene (PE) and biodegradable PMF (BP)) into soil at the dosages of 1 %, and soils were sampled on the 15th, 30th, and 100th day of soil incubation for high-throughput sequencing. The results showed that the degradation of PMF debris was accompanied by the release of microplastics (MPs). BC decreased NH4+-N (PE: 68.63 %; BP: 58.97 %) and NO3−-N (PE: 12.83 %; BP: 51.37 %) and increased available phosphorus (AP) (PE: 79.12 %; BP: 26.09 %) in soil containing PMF debris. There were significant differences in enzyme activity among all the treatments. High-throughput sequencing indicated that BC reduced bacterial and fungal richness and fungal diversity in PMF debris-exposed soil, whereas PMF debris and BC resulted in significant changes in the proportion of dominant phyla and genera of bacteria and fungi, which were affected by incubation time. Furthermore, BC affected microorganisms by influencing soil properties, and pH and N content were the main influencing factors. In addition, FAPRPTAX analysis indicated that BC and PMF debris affected soil C and N cycling. These findings provide new insights into the response of soil multifunctionality to BC and PMF debris.

Facing the solid waste of cotton straw and plastic mulch film mixture in China: Centralized or decentralized pyrolysis facility?

The widespread use of plastic mulch film (PMF) has led to significant environmental pollution, with PMF residues dispersed and mixed with straw and soil, posing challenges for recycling. Here, we proposed the mobile pyrolysis facility for the cotton straw and mulch film mixture (CMM) to mitigate the collection, storage, and transportation costs, while the application of co-pyrolysis technology for CMM conversion could improve the added value of products. Additionally, centralized combustion power generation and centralized pyrolysis systems were also established to evaluate and compare their sustainability from economic and environmental perspectives. Results showed that mobile pyrolysis has better economic performance than the centralized scenarios, due to its high internal rate of return (31 %) and significant net present value (29.21 M USD). Meanwhile, the mobile pyrolysis facility achieved a GWP of −1.298 kgCO2-eq/kg, reducing emissions by 70.79 % and 38.82 % compared to the two centralized scenarios. In conclusion, mobile pyrolysis technology provides a promising solution for PMF residue recycling because of its economically competitive approach with a lower carbon footprint.