Film Mulching Research Articles

Preparation and characterization of a novel high barrier mulching film with tunicate cellulose nanocrystals/sodium alginate/alkali lignin

In this study, the base film (CSL) was prepared by blending tunicate cellulose nanocrystals (TCNCs) extracted from tunicate shells, with sodium alginate (SA) and alkali lignin (AL). Then, the mulching film (CSL-WK) was prepared using water-borne polyurethane (WPU) as binder to install low-energy Kaolin on the surface of CSL film. The influences of composition with different concentrations on mechanical properties were studied. The tensile strength and elongation at break of CSL-WK film could reach 86.58 MPa and 50.49 %, respectively. The mulching films were characterized by degradability test, SEM, FTIR, and TGA. TCNCs had good compatibility with SA and AL, and a rough structure was formed on the surface of the film to improve the hydrophobicity. The barrier properties, including ultraviolet resistance, water contact angle, water vapor permeability, water retention, and flame retardancy, were tested. The results showed that CSL-WK films could block 97 % of ultraviolet light, reduce about 25 % of soil water loss, and self-extinguish within 7 s of open flame ignition. Note that the secondary spraying method significantly improved the barrier property of films. This study lays a foundation for the preparation of ecologically friendly, biodegradable, and high barrier mulching film, and expands the application of marine resources.

Coupling input and output intensity to explore the sustainable agriculture intensification path in mainland China

Sustainable intensification (SI) of agriculture is widely regarded as an important way to alleviate the contradiction between the food gap and ecosystem health. Correlate input intensity and output intensity have been regarded as an important dimension in most estimation frameworks of SI. But in practice, this correlation is generally expressed in terms of efficiency metrics and calculated as the ratio of output intensity to input intensity, which cannot quantitatively explain the impact of input intensity on output intensity and provide a threshold value for estimating the suitability of SI. This study's goals are to propose an input—output coupled method to explain the impact of input intensity on output intensity and thereby estimate the suitability of provincial SI. Provincial annual input intensity and output intensity were estimated from an emergy-based perspective by taking China as a case study. The K-means algorithm was used to identify the structural pattern of arable land input intensity. A sliding window-based partial correlation index method was proposed and applied to reveal the interaction process between input intensity and output intensity. The results show that there are two main change paths in the pattern of input intensity: one path in the western irrigation regions and the other path in the eastern northeast China Plain and middle-lower Yangtze Plain. The former path can be expressed as a small increase in fertilizer and agro-machinery input intensity with a decrease in labour force input intensity. The latter path shows a larger increase in fertilizer and pesticide input intensity. For each type of input intensity except mulching film, its correlation to output intensity has experienced a similar coupling—decoupling—recoupling process in both plain provinces and mountainous or plateau provinces. According to Landau's theory of phase transition, the complex coupling of input and output undergoes a phase transition process from order to disorder and then to order, depicted by the sliding window-based partial correlation coefficient as the order parameter from a holistic perspective. The inflection points of coupling relation changes show that the phenomenon of fertilizer and pesticide overuse has steadily occupied most provinces in eastern China and is spreading westwards. Although the “zero growth action for fertilizers and pesticides” has made considerable achievements in reducing the input intensity of fertilizer and pesticides since 2015, the situation of superfluous fertilizer and pesticide input has not changed substantially. The input intensity of fertilizer and pesticides still needs to be further reduced. This study can contribute to the estimation method system of SI. The input—output coupled method is applicable for other spatial scales and regions (or countries) to estimate the suitability of SI.

Combined effects of mulch film-derived microplastics and pesticides on soil microbial communities and element cycling

Pesticides and microplastics (MPs) derived from mulch film in agricultural soil can independently impact soil ecology, yet the consequences of their combined exposure remain unclear. Therefore, the effects of simultaneous exposure to commonly used pesticides (imidacloprid and flumioxazin) and aged mulch film-derived MPs on soil microorganisms and element cycles in cotton fields were investigated. The combined exposure influenced soil microorganisms, alongside processes related to carbon, nitrogen, and phosphorus cycles, exhibiting effects that were either neutralized or enhanced compared to individual exposures. The impact of pesticides in combined exposure was notably more significant and played a dominant role than that of MPs. Specifically, combined exposure intensified changes in soil bacterial community and symbiotic networks. The combined exposure neutralized NH4+, NO3-, DOC, and A-P contents, shifting from 0.33 % and 40.23 % increase in MPs and pesticides individually to a 40.24 % increase. Moreover, combined exposure resulted in the neutralization or amplification of the nitrogen-fixing gene nifH, nitrifying genes (amoA and amoB), and denitrifying genes (nirS and nirK), the carbon cycle gene cbbLG and the phosphorus cycle gene phoD from 0.48 and 2.57-fold increase to a 2.99-fold increase. The combined exposure also led to the neutralization or enhancement of carbon and nitrogen cycle functional microorganisms, shifting from a 1.53-fold inhibition and 10.52-fold increase to a 6.39-fold increase. These findings provide additional insights into the potential risks associated with combined pesticide exposure and MPs, particularly concerning soil microbial communities and elemental cycling processes.

The color of biodegradable mulch films is associated with differences in peanut yield and bacterial communities

Biodegradable mulch films (BDMs) are increasingly used in agricultural production as desirable alternatives to the current widespread use of polyethylene (PE) mulch films in China. However, potential effects of different colors of BDMs on field crop production and microbiomes remain unexplored. Here, the differences in bacterial communities of peanut rhizosphere soil (RS) and bulk soil (BS) under non-mulching (CK), PE, and three different colors of BDMs were studied. The results indicated that all treatments could increase the soil temperature, which positively affected the growth of the peanut plants. Moreover, mulching affected the bacterial community structure in RS and BS compared to CK. Furthermore, certain BDM treatments significantly enriched N-fixing bacteria (Bradyrhizobium and Mesorhizobium) and functional groups, increased the closeness of bacterial networks, and harbored more beneficial bacteria as keystone taxa in the RS. This in turn facilitated the growth and development of the peanut plants under field conditions. Our study provides new insights into the micro-ecological effects of mulch films, which can be affected by both the mulch type and color. The observed effects are likely caused by temperature and prevalence of specific microbial functions under the employed films and could guide the development of optimized mulching materials.

Evaluating the impacts of long-term saline water irrigation on soil salinity and cotton yield under plastic film mulching: A 15-year field study

In the context of dwindling freshwater resources, it is imperative to comprehensively evaluate crop productivity and soil resource sustainability when considering the use of saline water for irrigation (SWI). This study aimed to investigate the effects of SWI on soil salinity variation and sustainability of flat sowing cotton (Gossypium hirsutum L.) through a comprehensive 15-year field experiment conducted in the North China Plain, encompassing six levels of irrigation water salinity (ECiw of 1.3, 3.4, 7.1, 10.6, 14.1, and 17.7 dS m−1, respectively). The results of the 15-year SWI revealed an increase in soil salinity within the cotton root zone, with increases of 5%, 20%, 39%, 67%, 116%, and 156%, respectively, observed across the six treatments. In treatments with higher ECiw values (14.1 and 17.7 dS m−1), salt accumulation extended to a depth of 3.0 m. Long-term SWI has a risk of causing soil sodicity and alkalinity. Sodium adsorption ratio (SAR) and pH in the treatments with ECiw ≥ 7.1 dS m−1 increased significantly (P < 0.05) after cotton harvest in the 15th year of continuous SWI. Cotton yield performance exhibited a distinct response to varying levels of ECiw. The treatment with an ECiw of 3.4 dS m−1 yielded the highest average cotton yield of 3419 kg ha−1, while cotton yields in treatments with an ECiw of 14.1 and 17.7 dS m−1 were more than 13% and 20%, respectively, lower than the maximum yield (P < 0.05). The sustainability index of cotton yield was at its lowest (0.68) in the treatments with an ECiw of 7.1 dS m−1, with values between 0.72 and 0.75 in the other treatments. Additionally, long-term SWI resulted in changes in cotton quality, including a decrease in micronaire value and an increase in elongation index. A quadratic correlation analysis identified a threshold ECiw of 6.8 dS m−1 for optimum cotton yield. In summary, it is recommended that the ECiw should not exceed 6.8 dS m−1 to ensure the sustainability and safety of long-term SWI for cotton production in this research region.

Environmental Impact of Various Rice Cultivation Methods in Northeast China through Life Cycle Assessment

Rice, a crucial staple in China, is cultivated through various techniques, including seedling transplanting, dry direct seeding, and film mulching. Despite its significance, rice production is a considerable environmental burden. Using a life cycle assessment (LCA) methodology, this study aimed to evaluate the environmental impacts of four rice cultivation methods (transplanting rice, dry direct-seeding rice, dry direct-seeding rice with polyethylene film (PE), and dry direct-seeding rice with biodegradable film) in Northeast China. The results indicate that the magnitude of environmental impacts among treatments was consistent across years. The potential values of all environmental impacts of the four different cultivation methods of rice in the 2021 field trial were smaller than the results of the same cultivation method of rice system in the 2022 field trial. Among the four rice cultivation methods, the consumption of energy showed inconsistency over the two years, with the highest energy consumption in the first year being for dry seeding with PE film and in the second year for dry seeding without film. Additionally, transplanting exhibited the highest impact on water resource consumption and climate change. Dry direct-seeding rice displayed the highest eutrophication and ecotoxicity. Dry direct-seeding rice with a biodegradable film had the least impact in terms of acidification. Moreover, dry direct-seeding rice with a biodegradable film minimized water consumption and greenhouse gas emissions without compromising yield.

Biodegradable Mulch Films and Bioformulations Based on Trichoderma sp. and Seaweed Extract Differentially Affect the Metabolome of Industrial Tomato Plants.

The use of biostimulants and biofilms in agriculture is constantly increasing, as they may support plant growth and productivity by improving nutrient absorption, increasing stress resilience and providing sustainable alternatives to chemical management practices. In this work, two commercial products based on Trichoderma afroharzianum strain T22 (Trianum P®) and a seaweed extract from Ascophyllum nodosum (Phylgreen®) were tested on industrial tomato plants (Solanum lycopersicum var. Heinz 5108F1) in a field experiment. The effects of single and combined applications of microbial and plant biostimulants on plants grown on two different biodegradable mulch films were evaluated in terms of changes in the metabolic profiles of leaves and berries. Untargeted metabolomics analysis by LC-MS Q-TOF revealed the presence of several significantly accumulated compounds, depending on the biostimulant treatment, the mulch biofilm and the tissue examined. Among the differential compounds identified, some metabolites, belonging to alkaloids, flavonoids and their derivatives, were more abundant in tomato berries and leaves upon application of Trichoderma-based product. Interestingly, the biostimulants, when applied alone, similarly affected the plant metabolome compared to control or combined treatments, while significant differences were observed according to the mulch biofilm applied.

Synthesis of lignin-based polyurethane (LPU) and fabrication of degradable mulch film through LPU coating on cellulose paper

The use of non-degradable plastic mulch film causes significant environmental pollution and poses a threat to human and ecological safety. To address this issue, a viable solution is to develop bio-based and biodegradable paper mulch films to replace non-biodegradable ones in agricultural soils. In this study, a green and straightforward process was used to synthesize lignin-based polyurethane (LPU), which was then coated on cellulose paper (CP) of low basis weight of 30 g/m2 to fabricate a composite LPU/CP mulch film. An ultra-thin and lightweight LPU/CP mulch film was successfully fabricated with basis weight, thickness, and specific density of 40 g/m2, 80 µm, and 0.5 g/cm3, respectively. It was observed that surface coating was very effective in improving the physical strength of composite film as indicated by the improvement of tensile index from 19.3 N·m/g of CP to 65.0 N·m/g of LPU/CP mulch film. Moreover, LPU/CP mulch film presented excellent water resistance properties as suggested by the water contact angle of 107° and the water vapor transmission rate of 639.3 g/m2·day. LPU/CP mulch film also shows a balance between degradability and durability that it starts to break down into fractions after being buried for 28 days as a result of microbiological degradation. This work provides a feasible technology for fabricating eco-friendly, cost-effective, and biodegradable paper mulch film.

Natural aging and adsorption/desorption behaviors of polyethylene mulch films: Roles of film types and exposure patterns

Polyethylene (PE) mulch films are an important source of microplastics (MPs) in agricultural soils, which may further affect the bioavailability of coexisting pollutants. In this study, white (WM), black (BM), and silver-black (SM) PE mulch films were aged on the soil surface and under soil burial to simulate the two exposure patterns of abandoned mulch films in the field. Results indicated that the soil-surface exposure induced more pronounced aging characteristics, and WM seemed the most susceptible. Serious surface deterioration by aging led to a drastic decrease in the tensile properties of the films, suggesting the tendency to fragment. Oxygen-containing functional groups were generated on the film surfaces, with oxygen/carbon ratios increasing by up to 29 times, which contributed to the prominent increase in Pb adsorption on the film-derived MPs. Additionally, the film surface became more hydrophobic when exposed to the soil surface but more hydrophilic in the soil-burial exposure, which was in agreement with the change in triclosan adsorption, i.e., promotion and suppression, respectively. Aging generally decreased the desorption potential of the adsorbed pollutants in simulated gastrointestinal solutions due to increased interactions. By comparison, exposure patterns were revealed to be the critical factor for these changes, regardless of film types.

Dry Direct-Seeded Rice Yield and Water Use Efficiency as Affected by Biodegradable Film Mulching in the Northeastern Region of China

In the realm of agriculture, biodegradable films are emerging as a promising substitute for traditional polyethylene (PE) films. Despite their potential, there has been a notable lack of extensive research on their effectiveness in the context of dry direct-seeded rice cultivation. Addressing this gap, a comprehensive biennial study was conducted in the northeastern regions of China, focusing on the ‘Baonong 5’ rice variety. This study meticulously compared three distinct cultivation methods: (1) employing biodegradable film mulching, (2) using conventional plastic film mulching, and (3) cultivating without any mulch. The findings revealed that biodegradable film mulching significantly enhanced soil moisture control, increased leaf area, and improved rice yield and water utilization efficiency (p &lt; 0.05) compared to the plots without mulch. Notably, there was no marked difference in outcomes between the plastic film mulching and the unmulched plots. This research underscores the profound benefits of biodegradable film in rice cultivation, particularly from an environmental sustainability perspective. This innovative method not only boosts agricultural productivity but also addresses critical environmental challenges like climate change and water conservation. The application of biodegradable mulch has proven to be remarkably effective in improving irrigation efficiency and crop water conservation, leading to enhanced rice development and higher yields. The study recorded a substantial increase in water productivity—30% in 2021 and between 52.85% and 60% in 2022—compared to traditional cultivation practices. Furthermore, the use of biodegradable mulch resulted in significantly higher rice yields than the non-mulched plots, thus contributing to increased profitability. Such methods not only yield higher crop outputs but also mitigate environmental issues like water pollution and help alleviate prevalent water shortages in rice farming.

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.

Fabrication and Evaluation of an Alginate-Based Dual Network Mulch Film Reinforced with Multiscale Cellulose Fibers

Fabrication and Evaluation of an Alginate-Based Dual Network Mulch Film Reinforced with Multiscale Cellulose Fibers

Ecological and Economic Benefits of Greenhouse Gas Emission Reduction Strategies in Rice Production: A Case Study of the Southern Rice Propagation Base in Hainan Province

Developing tailored emission reduction strategies and estimating their potential is crucial for achieving low-carbon rice production in a specific region, as well as for advancing China’s dual carbon goals in the agricultural sector. By utilizing water-saving and drought-resistant rice (WDR) with enhanced water and nitrogen utilization efficiency, the mitigation strategies were constructed for rice production systems, and their potential for emission reduction was estimated in the southern rice propagation base of Hainan Province. This study revealed that the implementation of a reduction strategy, which involves dry direct seeding and dry cultivation, combined with a 53% reduction in nitrogen fertilizer, can effectively synergize the mitigation of methane (CH4) and nitrous oxide (N2O) emissions from rice paddies. Compared with traditional flooded rice cultivation, this integrated approach exhibits an impressive potential for reducing net greenhouse gas (GHG) emissions by 97% while simultaneously doubling economic benefits. Moreover, when combined with plastic film mulching, the strategy not only sustains rice yields but also achieves a remarkable emission reduction of 92%, leading to a fourfold increase in economic benefits. Our study provides a comprehensive low-carbon sustainable development strategy for rice production in the southern rice propagation base of Hainan Province and offers valuable insights for researching GHG emissions in other regions or crops. These emission reduction pathways and the assessment method could contribute to the realization of low-carbon agriculture.

Drip irrigation under film mulch used on flat-bed increased vegetable yield by altering soil microbe community structure and soil nitrogen

Drip irrigation under film mulch used on flat-bed increased vegetable yield by altering soil microbe community structure and soil nitrogen

Application of hyperspectral technology for leaf function monitoring and nitrogen nutrient diagnosis in soybean (Glycine max L.) production systems on the Loess Plateau of China

Farmland mulching and nitrogen application are the main agricultural management measures to improve soybean (Glycine max L.) production in dryland agriculture on the Loess Plateau. However, the interaction effects of various farmland mulching materials and nitrogen application rates on soybean leaf functionality and nitrogen nutrition status remains contradictory and inconclusive, and effective and rapid diagnostic of the leaf functionality and nitrogen status are still not well-understood. Therefore, the aim of this study is twofold: 1) to investigate the interactive effects of different mulching methods and nitrogen application levels on soybean leaf growth, physiological traits, and final grain yield throughout the entire growth period; 2) to establish a chlorophyll content monitoring model based on spectral parameters and a diagnostic model for soybean nitrogen status, and to assess the effectiveness of the latter in accurately diagnosing soybean nitrogen requirements. A two-year (2021 and 2022) field experiment, which consisted of four nitrogen levels (0, 60, 120 and 180 kg N ha−1) and four mulching strategies (NM: no mulching, SM: straw mulching, FM: film mulching, SFM: straw and film mulching), was conducted in the soybean growing seasons. Subsequently, nitrogen dilution curves were established based on chlorophyll content and the optimal spectral index to compute corresponding nitrogen nutrition index (NNI) values. The results indicated that: 1) FM, in comparison to SM and SFM, had the ability to delay leaf senescence, increase chlorophyll content, and improve physiological growth parameters, thereby increasing seed yield; 2) the application of 120 kg N ha−1 stood out, boosting soybean photosynthetic productivity and providing a solid foundation for high soybean yields; 3) the Random forest (RF) model had the highest accuracy in chlorophyll content estimation (R2 =0.854, RMSE=2.765 and MRE=5.758 % in validation set); and 4) both the nitrogen dilution curves constructed based on chlorophyll content and the optimal spectral index proved to be reasonably accurate in quantitatively diagnosing the nitrogen status of soybeans. Specifically, N0 and N180 indicated sustained nitrogen deficiency and excess, respectively, while N60 and N120 effectively met soybean's nitrogen requirements. In summary, the FMN120 effectively stabilized seed yield by regulating key functional traits in soybean leaves. This study provides a theoretical basis for the application of precision agriculture and remote sensing technology in monitoring and diagnosing plant nitrogen nutrition in soybean production.

Response of plastic film mulched maize to soil and atmospheric water stresses in an arid irrigation area

Water stress can severely decrease crop productivity by restricting photosynthesis, while the use of plastic film mulching can mitigate these water stress effects. However, the intricacies of photosynthetic and stomatal responses to soil water stress under plastic film mulching, particularly when combined with atmospheric water stress, have not been well studied, especially in arid irrigation areas. Limited research has investigated photosynthetic chlorophyll fluorescence parameters, stomatal responses, grain filling process and crop productivity to soil and atmospheric water stress under plastic film mulching. Our study addresses this knowledge gap through a comprehensive field experiment in an arid irrigation area involving maize (Zea mays L.). Well-watered and water deficit conditions with and without plastic film mulching treatments, alone or combined with atmospheric water stress (different vapor pressure deficits) were conducted. Our findings revealed that soil water stress significantly increased stomatal limitations (by 6.4–12.4 %) and may cause non-stomatal limitations. Plastic film mulching significantly improved plant photosynthetic performance (increased net photosynthesis rate by 12.2–39.8 %), chlorophyll fluorescence parameters, and stomatal regulation. Under mulched conditions, soil water stress primarily affected photosynthetic performance through stomatal limitations. Moreover, plastic film mulching significantly improved grain filling process (increased grain-filling rate by 6.3–78.5 %) and productivity (increased grain yield by 12.1–45.8 %) in spring maize subjected to soil water stress. Atmospheric water stress, alone or combined with soil water stress, influenced plant photosynthetic performance, decreasing the net photosynthesis rate and stomatal conductance. Mulching enhanced photosynthetic performance under atmospheric water stress. Overall, the positive effect of mulching on spring maize photosynthetic performance and productivity under soil and atmospheric water stresses holds promise for alleviating water resource shortages and addressing global climate warming issues in arid irrigation areas.

Estimation of Soil Moisture Content Based on Fractional Differential and Optimal Spectral Index

Applying hyperspectral remote sensing technology to the prediction of soil moisture content (SMC) during the growth stage of soybean emerges as an effective approach, imperative for advancing the development of modern precision agriculture. This investigation focuses on SMC during the flowering stage under varying nitrogen application levels and film mulching treatments. The soybean canopy’s original hyperspectral data, acquired at the flowering stage, underwent 0–2-order differential transformation (with a step size of 0.5). Five spectral indices exhibiting the highest correlation with SMC were identified as optimal inputs. Three machine learning methods, namely support vector machine (SVM), random forest (RF), and back propagation neural network (BPNN), were employed to formulate the SMC prediction model. The results indicate the following: (1) The correlation between the optimal spectral index of each order, obtained after fractional differential transformation, and SMC significantly improved compared to the original hyperspectral reflectance data. The average correlation coefficient between each spectral index and SMC under the 1.5-order treatment was 0.380% higher than that of the original spectral index, with mNDI showing the highest correlation coefficient at 0.766. (2) In instances of utilizing the same modeling method with different input variables, the SMC prediction model’s accuracy follows the order: 1.5 order &gt; 2.0 order &gt; 1.0 order &gt; 0.5 order &gt; original order. Conversely, with consistent input variables and a change in the modeling method, the accuracy order becomes RF &gt; SVM &gt; BPNN. When comprehensively assessing model evaluation indicators, the 1.5-order differential method and RF method emerge as the preferred order differential method and model construction method, respectively. The R2 for the optimal SMC estimation model in the modeling set and validation set were 0.912 and 0.792, RMSEs were 0.005 and 0.004, and MREs were 2.390% and 2.380%, respectively. This study lays the groundwork for future applications of hyperspectral remote sensing technology in developing soil moisture content estimation models for various crop growth stages and sparks discussions on enhancing the accuracy of these different soil moisture content estimation models.

Effects of farmland residual mulch film-derived microplastics on the structure and function of soil and earthworm Metaphire guillelmi gut microbiota

Microplastics derived from polyethylene (PE) mulch films are widely found in farmland soils and present considerable potential threats to agricultural soil ecosystems. However, the influence of microplastics derived from PE mulch films, especially those derived from farmland residual PE mulch films, on soil ecosystems remains unclear. In this study, we analyzed the bacterial communities attached to farmland residual transparent PE mulch film (FRMF) collected from peanut fields and the different ecological effects of unused PE mulch film-derived microplastics (MPs) and FRMF-derived microplastics (MPs-aged) on the soil and earthworm Metaphire guillelmi gut microbiota, functional traits, and co-occurrence patterns. The results showed that the assembly and functional patterns of the bacterial communities attached to the FRMF were clearly distinct from those in the surrounding farmland soil, and the FRMF enriched some potential plastic-degrading and pathogenic bacteria, such as Nocardioidaceae, Clostridiaceae, Micrococcaceae, and Mycobacteriaceae. MPs substantially influenced the assembly and functional traits of soil bacterial communities; however, they only significantly changed the functional traits of earthworm gut bacterial communities. MPs-aged considerably affected the assembly and functional traits of both soil and earthworm gut bacterial communities. Notably, MPs had a more remarkable effect on nitrogen-related functions than the MPs-aged in numbers for both soil and earthworm gut samples. Co-occurrence network analysis revealed that both MPs and MPs-aged enhanced the synergistic interactions among operational taxonomic units (OTUs) of the composition networks for all samples. For community functional networks, MPs and MPs-aged enhanced the antagonistic interactions for soil samples; however, they exhibited contrasting effects for earthworm gut samples, as MPs enhanced the synergistic interactions among the functional contents. These findings broaden and deepen our understanding of the effects of FRMF-derived microplastics on soil ecosystems, suggesting that the harmful effects of aged plastics on the ecological environment should be considered.

Responses of soil nutrients, enzyme activities, and maize yield to straw and plastic film mulching in coastal saline-alkaline

Responses of soil nutrients, enzyme activities, and maize yield to straw and plastic film mulching in coastal saline-alkaline

Cultivation of forage maize in boreal conditions – Assessment of trade-offs between increased productivity and environmental impact

The cultivation of whole crop forage maize (Zea mays L.) for cattle feed has a potential for increased forage yield while reducing nitrogen (N) fertilisation compared to perennial grass-based systems. However, the possible environmental trade-offs of forage maize cultivation remain unknown in the boreal region due to the short growing season which limits cultivation practices. The aim of this study was to compare the environmental impact of forage maize with more widely cultivated forage crops in Finland that include perennial silage grass mixtures and whole crop spring cereal harvested as silage. The use of plastic mulch film in forage maize cultivation was included in the assessment as well. A life cycle assessment (LCA) was conducted including impact categories for global warming potential; marine and freshwater eutrophication; terrestrial acidification; freshwater, marine and terrestrial ecotoxicity; land use; and fossil resource depletion. Additionally, soil organic carbon (SOC) stock changes under long-term cultivation of the studied forage crops were simulated with the C-TOOL and Yasso20 models with methodological comparisons. The only clear differences between the studied crops were that the land use was lower (−26–48%) for forage maize, and the freshwater eutrophication (+59–67%) and terrestrial acidification (+10–57%) were higher for perennial grasses compared with other forages. A risk for decreased SOC stock under continuous forage maize cultivation was observed. Forage maize could be used to supplement perennial grass cultivation without major associated environmental risks. Future research shall be conducted on the effect of forage choices on the environmental impact of boreal dairy milk production and on decreasing the current high uncertainty associated with nitrous oxide (N2O) emission factors and SOC stock modelling choices.