ArticleLiterature Review

Plastic mulching in agriculture. Trading short-term agronomic benefits for long-term soil degradation?

Authors:
  • RPTU Kaiserslautern-Landau
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Plastic mulching has become a globally applied agricultural practice for its instant economic benefits such as higher yields, earlier harvests, improved fruit quality and increased water-use efficiency. However, knowledge of the sustainability of plastic mulching remains vague in terms of both an environmental and agronomic perspective. This review critically discusses the current understanding of the environmental impact of plastic mulch use by linking knowledge of agricultural benefits and research on the life cycle of plastic mulches with direct and indirect implications for long-term soil quality and ecosystem services. Adverse effects may arise from plastic additives, enhanced pesticide runoff and plastic residues likely to fragment into microplastics but remaining chemically intact and accumulating in soil where they can successively sorb agrochemicals. The quantification of microplastics in soil remains challenging due to the lack of appropriate analytical techniques. The cost and effort of recovering and recycling used mulching films may offset the aforementioned benefits in the long term. However, comparative and long-term agronomic assessments have not yet been conducted. Furthermore, plastic mulches have the potential to alter soil quality by shifting the edaphic biocoenosis (e.g. towards mycotoxigenic fungi), accelerate C/N metabolism eventually depleting soil organic matter stocks, increase soil water repellency and favour the release of greenhouse gases. A substantial process understanding of the interactions between the soil microclimate, water supply and biological activity under plastic mulches is still lacking but required to estimate potential risks for long-term soil quality. Currently, farmers mostly base their decision to apply plastic mulches rather on expected short-term benefits than on the consideration of long-term consequences. Future interdisciplinary research should therefore gain a deeper understanding of the incentives for farmers and public perception from both a psychological and economic perspective in order to develop new support strategies for the transition into a more environment-friendly food production.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... Among several techniques to track the decomposition of plastics [1,37], stable isotope analysis is very promising to distinguish the origin of the intermediate products of plastic decomposition in the case of difference in isotopic signature between plastics and SOM [38][39][40]. The use of naturally occurring 13 C tracers in soil studies is based on the different photosynthetic pathways between C3 and C4 plants [41]. The δ 13 C values of C4 plants, such as maize or sugarcane, range from −12‰ to −10‰ [42]. ...
... The δ 13 C values of C4 plants, such as maize or sugarcane, range from −12‰ to −10‰ [42]. C4 plant-derived products demonstrate higher 13 C content than C3 plants. Thus, an application of C4-bio-based plastics to a C3 soil enables the identification of the origin of the end products. ...
... Thus, an application of C4-bio-based plastics to a C3 soil enables the identification of the origin of the end products. As plastic decomposition is monitored indirectly by the CO 2 emission, the possible shift in the 13 C signature of the SOM and its mineralization products due to: (i) 13 C isotopic fractionation, i.e., the difference between heavy and light coexisting isotopes of an element; or (ii) 13 C isotopic discrimination (see below) needs to be considered in the calculations [40]. Such a shift is caused either by: (i) the preferential use of substances with light 12 C versus heavy 13 C [43]; or (ii) by the preferential utilization of heavy 13 C-substrate of high availability (sugars, cellulose) versus the light 12 C of low availability (lignin, lipids) [44]. ...
Article
Full-text available
Expanding the use of environmentally friendly materials to protect the environment is one of the key factors in maintaining a sustainable ecological balance. Poly(butylene succinate-co-adipate) (PBSA) is considered among the most promising bio-based and biodegradable plastics for the future with a high number of applications in soil and agriculture. Therefore, the decomposition process of PBSA and its consequences for the carbon stored in soil require careful monitoring. For the first time, the stable isotope technique was applied in the current study to partitioning plastic- and soil-originated C in the CO2 released during 80 days of PBSA decomposition in a Haplic Chernozem soil as dependent on nitrogen availability. The decomposition of the plastic was accompanied by the C loss from soil organic matter (SOM) through priming, which in turn was dependent on added N. Nitrogen facilitated PBSA decomposition and reduced the priming effect during the first 6 weeks of the experiment. During the 80 days of plastic decomposition, 30% and 49% of the released CO2 were PBSA-derived, while the amount of SOM-derived CO2 exceeded the corresponding controls by 100.2 and 132.3% in PBSA-amended soil without and with N fertilization, respectively. Finally, only 4.1% and 5.4% of the PBSA added into the soil was mineralized to CO2, in the treatments without and with N amendment, respectively.
... The deficiency of proper handling of the waste plastic has created numerous environmental problems and the amassing of plastic fragments in the world's oceans (Klingelhöfer et al., 2020;Ateia et al., 2020), and soil environment . The waste plastic residues from plastic mulching practices in agriculture that are left over after use are broken into small particles by different processes in the soil environment (Thompson, 2006;Ryan et al., 2009), eventually gain size of <5 mm known as microplastics (MPs) (Steinmetz et al., 2016;Horton et al., 2017a;Huang et al., 2020;Yu et al., 2021). The leftover waste plastic materials from mulching operations are gradually changing into smaller and smaller residues, and ultimately change into microplastics by the action of physical chemical and biological process such as ultraviolet radiations, by water or air erosion and by earthworms (Wright and Kelly, 2017). ...
... MPs are composed of synthetic polymers generally found in the form of solid particles, having the size which ranges 1-5, 000 µm, insoluble in water, with thermoplastic characteristics (Järlskog et al., 2021). These residues may integrate within soils and further break down into pieces to generate particles down to a nanoscale or smaller (Steinmetz et al., 2016). The existing progress in many scientific fields have proven the presence and harmful effects of MPs in different environments and trophic levels which are needed to be further studied (Sun et al., 2018;Alimba and Faggio, 2019;Koelmans et al., 2019). ...
... Many researchers, such as Hidalgo-Ruz (2012), have detailed types of MPs in accordance with residual MP shapes such as nurdles, microbeads, fragments, foam, and fibres, as shown in Fig. 4. Microplastics have also been categorised into large MPs (1-5 mm) (Horton, 2017b;Ng et al., 2018;Zuo et al., 2019), small MPs (0.3-1 mm) (Claessens, 2011), and nanoplastics (<100 nm) (Ng et al., 2018; EFSA Panel on Contaminants in the Food Chain, 2016). The possibility of recycling these residual plastics is difficult because of practical challenges in addition to high economic costs (Steinmetz et al., 2016;Kasirajan and Ngouajio, 2012). Therefore, the soil has become the ultimate sink for residual plastics (Machado et al., 2018;Mahon et al., 2017;Liu et al., 2019). ...
Article
Full-text available
Environmental pollution of microplastics (MPs) is known to be anthropogenically mediated menace to biosphere and becoming a debatable concern globally. Large quantities of plastic fragments are left behind after crop cultivation. The leftover plastic debris, gradually degrade into minute fragments with a diameter of less than 5 mm, known as MPs. MPs are responsible for many changes in the soil physicochemical characteristics, including porosity, enzymatic activities, microbial activities, plant growth, and yield. Because of their ubiquitous nature, high specific surface area and strong hydrophobicity, MPs play an important role in the transportation of toxic chemicals such as plasticisers, polycyclic aromatic hydrocarbons (PAHs), antibiotics, and potentially toxic elements (PTEs). MPs may be transported deep into the soil and can pollute underground water. This review paper investigates the deleterious effects of MPs on the soil environment, enzymatic activities, soil microbes, flora, fauna and crop production, and highlights the general concept of MPs contamination as well as its possible environmental consequences. The review also converses some of the key areas for future research and for key stakeholders concerned with policymaking
... Mulches can be defined as materials that are applied or grow on the soil surface ( latter are the living mulches), in contrast to soil-incorporated materials [21]. They m provide many services to the soil: improvement of moisture content, reduction in s compaction and erosion, mitigation of temperature excesses and defects, and impro ment to plant establishment and growth [22,23]. Not to mention, organic and livi mulches can improve soil nutrition, degrade pesticides, and reduce weed pressure [21,2 27]. ...
... Mulches can be defined as materials that are applied or grow on the soil surface (the latter are the living mulches), in contrast to soil-incorporated materials [21]. They may provide many services to the soil: improvement of moisture content, reduction in soil compaction and erosion, mitigation of temperature excesses and defects, and improvement to plant establishment and growth [22,23]. Not to mention, organic and living mulches can improve soil nutrition, degrade pesticides, and reduce weed pressure [21,[24][25][26][27]. Mulching materials can be classified into three types: organic materials (products of vegetable or animal origin), synthetic materials, and special materials (e.g., gravel); they can be used in combination, based on the specific aims [28]. ...
... The climatic conditions of the cultivation area must also be considered when choosing the mulching method [28]. The large-scale production of plastic films and the high persistence of the latter in the environment have raised alarms about a potential massive accumulation of pollutants in the environment [23]. Furthermore, the residues of plastic films left in the soil over time fragment and become smaller and smaller, to the point of becoming microscopic, i.e., "microplastics" [32]. ...
Article
Full-text available
The use of plastic mulch films is widespread in agriculture for specialty cropping systems because of several benefits. In this article, we critically review, for the first time under a holistic approach, the use of biodegradable plastic mulches (BdPMs) in soil as a sustainable alternative to conventional petroleum-based plastics, highlighting the current state of understanding of their degradation in soil and their effect on soil microorganisms, weed control, and soil properties. In addition, we provide a detailed focus on the history and economic importance of mulching. BdPMs are effective for use in vegetable production in that they improve physical, chemical, and biological soil properties, as well as enhancing microbial biodiversity, controlling weeds, and maintaining soil moisture. BdPMs could be useful to limit the use of agrochemicals and reduce tillage and irrigation supplies for sustainable management.
... Plastic-film mulching (PFM) has become a widely used farming practice to increase crop yield under temperatemonsoon climates, as it improves soil temperature, soil moisture contents, and nutrient availability and controls weed and pest, particularly under unfavorable cold and dry climate conditions (Steinmetz et al. 2016). According to a meta-analysis, PFM increased crop yields up to 48.6%, with the greatest increases in spring maize . ...
... As soil temperature and moisture increased under PFM, soil microorganisms proliferated, resulting in increased mineralization of soil organic matter (SOM) and thus depleting soil organic C (SOC) (Liu et al. 2021). Several studies have observed increased yield with decreased SOM under PFM (Steinmetz et al. 2016;Lee et al. 2019), raising concerns regarding sustainable agriculture by PFM practice. It has been reported that the SOM loss under PFM can be offset by increasing C inputs to soil through organic matter addition (Steinmetz et al. 2016). ...
... Several studies have observed increased yield with decreased SOM under PFM (Steinmetz et al. 2016;Lee et al. 2019), raising concerns regarding sustainable agriculture by PFM practice. It has been reported that the SOM loss under PFM can be offset by increasing C inputs to soil through organic matter addition (Steinmetz et al. 2016). ...
Article
Full-text available
While cover crop residue (CR) incorporation offsets soil organic C (SOC) losses caused by plastic-film mulching (PFM), the microbial modulators and mechanisms of SOC accumulation remain poorly understood. Using functional gene microarray, soil enzyme activities, and soil density fractionation approaches, we investigated the mechanism, by incorporating CR (13.0 and 9 Mg ha−1 on a dry weight basis) under PFM in organic maize cropping systems, spanning 2 consecutive years. Compared to no-mulching, PFM without CR amendment significantly decreased SOC stock by 23%, corresponding to an increase in CO2 efflux by 74%, a decrease in light fraction C (LFOC) and heavy fraction C (HFOC) by 13 and 11%, respectively, and an increase in relative abundances of labile as well as recalcitrant C-degrading genes and related soil enzyme activities. However, PFM with CR amendment reduced the SOC stock loss to 11%, corresponding to 36% increase in CO2 efflux, 22% decrease in LFOC but 12% increase in HFOC, and an increase in relative abundances of labile C-degrading genes and related soil enzyme activities but a decrease in relative abundances of recalcitrant C-degrading genes and related soil enzyme activities. Our results, based on microbial functional genes, suggest that reduced degradation of recalcitrant C was responsible for increased mineral-associated C and thus SOC accumulation under PFM in organically cultivated maize.
... The global market in 2016 for agriculture plastic film was four million tons and is projected to increase by 5.6% per year through 2030 (Xu et al., 2020). Worldwide, plastic mulching is being practiced on 20 million hectares of farmland, with China having the highest proportion (~90%) (Ren et al., 2021;Steinmetz et al., 2016). Despite the enormous agriculture and economic benefits of plastic mulch, one main environmental problem of mulch is the residual plastic that is left in the soil after harvest (Changrong et al., 2014). ...
... Every year new plastic mulch is used and added to the soil as residues after harvest. This results in the accumulation of large amounts of mega, macro, and micro plastics in agricultural soil (Rillig et al., 2017;Steinmetz et al., 2016). ...
... Plastic film mulching (PM) has been widely used to increase crop yield by reducing evaporation and increasing soil temperature in arid, semi-arid, and sub-humid areas (Kader et al., 2017). However, the improved soil temperature and moisture with PM have the potential to accelerate the mineralization of soil organic carbon (SOC) and increase GHG emissions (Cuello et al., 2015;Steinmetz et al., 2016). Straw mulching (SM) has been identified as a simple and feasible way to increase SOC (Lenka and Lal, 2013), but it has not always had a positive effect on yield. ...
... RFPS has been reported to be more effective in increasing crop production than PM and SM (Hu et al., 2019;Jia et al., 2021). In the RFPS system, straw-mulched furrows could increase SOC content (Lenka and Lal, 2013), while the modified soil hydrothermal environment of the plastic film-mulched ridges may enhance the decomposition of SOC and increase GHG emissions (Cuello et al., 2015;Steinmetz et al., 2016). Therefore, it is necessary to examine and compare the effects of RFPS, PM, and SM on SOC. ...
... Both, black and transparent films are generally used for mulching. Advancement in plastic chemistry has resulted in development of films with optical properties that are ideal for a specific crop in a given location (Steinmetz et al., 2016). ...
... Mulch can be expensive in terms of labour, transport, setting removal, and disposal. The plastic film has intimate contact with soil which creates fragment and contaminants to soil (Steinmetz et al. 2016). Many types of organic mulching such as grass and straw contain seeds that may allow to grow weeds and release acid to soil (Chalker- ...
Article
Full-text available
A balanced diet helps to improve the immune system and to protect it from pathogenic organisms such as viruses, fungi, bacteria, and parasites. In order to fight against foreign bodies increased rate of metabolism is required which can be from the energy sources, biosynthesis substrates, and regulatory molecules & above all are derived essentially from the diet. Several vitamins (A, B6, B9, B12, C, D, and E) and trace elements such as zinc, copper, selenium, and iron were found to play a crucial role in strengthening the human immune system and reducing inflammatory risk. Dietary approaches to balanced microbiota play a major role in the immune system. According to the COVID – 19 description Gut dysbiosis is a characteristic of infectious diseases. A serious infection with respiratory epithelium might lead to a condition known as cytokine's acute respiratory distress syndrome (ARDS) which is evident from COVID-19. Although there is no medication for COVID-19 as yet, preventive steps to improve our immune system under current conditions are accompanied by conventional medicinal sources (Kupferschmidt 2020; Gorbalenya et al., 2019). Having a healthy diet with adequate fruits and vegetables promotes a well-functioning and efficient system to protect against infection and various diseases. Intake of immune-boosting foods such as spices and other foods protected the immune system and increased the survival rate of coronary patients in India. “Whenever the immune system cells are affected by the disease-causing agent's human body produces antibodies to support their survival”. Overcoming the consumption of nutrient-rich foods is essential to avoid defects that could weaken the immune system. Keywords: Immunity boosting foods, Anti-viral effect, vitamins, micronutrients, COVID-19.
... The global market in 2016 for agriculture plastic film was four million tons and is projected to increase by 5.6% per year through 2030 (Xu et al., 2020). Worldwide, plastic mulching is being practiced on 20 million hectares of farmland, with China having the highest proportion (~90%) (Ren et al., 2021;Steinmetz et al., 2016). Despite the enormous agriculture and economic benefits of plastic mulch, one main environmental problem of mulch is the residual plastic that is left in the soil after harvest (Changrong et al., 2014). ...
... Every year new plastic mulch is used and added to the soil as residues after harvest. This results in the accumulation of large amounts of mega, macro, and micro plastics in agricultural soil (Rillig et al., 2017;Steinmetz et al., 2016). ...
Article
Agro-ecosystem contamination with microplastics (MPs) is of great concern. However, limited research has been conducted on the agricultural soil of tropical regions. This paper investigated MPs in the agro-ecosystem of Hainan Island, China, as well as their relationships with plastic mulching, farming practices, and social and environmental factors. The concentration of MPs in the study area ranged from 2800 to 82500 particles/kg with a mean concentration of 15461.52 particles/kg. MPs with sizes between 20 and 200 μm had the highest abundance of 57.57%, fragment (58.16%) was the most predominant shape, while black (77.76%) was the most abundant MP colour. Polyethylene (PE) (71.04%) and polypropylene (PP) (19.83%) were the main types of polymers. The mean abundance of MPs was significantly positively correlated (p < 0.01) with all sizes, temperature, and shapes except fibre, while weakly positively correlated with the population (p = 0.21), GDP (p =0.33), and annual precipitation (p = 0.66). In conclusion, plastic mulching contributed to significant contamination of soil MPs in the study area, while environmental and social factors promoted soil MPs fragmentation. The current study results indicate serious contamination with MPs, which poses a concern regarding ecological and environmental safety.
... The PFM effectively improves microclimatic conditions, such as topsoil temperature which can be 2-7 • C higher than in control fields Zhang et al., 2022). The PFM also indirectly affects the soil organic carbon (SOC) pool (Ding et al., 2021;Steinmetz et al., 2016;Zhang et al., 2022). Meta-analysis and most experimental studies have shown that PFM reduces labile C pools by promoting microbial mineralization Ma et al., 2018;Ma et al., 2020). ...
Article
Plastic film mulch (PFM) is effective to save soil water and increase temperature and consequently, to increase crop yield. Therefore, PFM has become one of the most widely used on-farm management practices for maize cultivation in semi-arid regions. The effects of PFM-induced warming on the labile carbon (C) pools and microorganisms remain unclear. We used high-throughput genomic sequencing to assess bacterial community structure and metabolic functions in soils after short- (2 years) and long-term (10 years) cover with PFM in a dryland agriculture system. Strong decrease of dissolved organic C (DOC) pool (14–18 % less than in Control soil) by warming (2.4 °C) raised bacterial ⍺-diversity. The short-term mulch reduced the absolute abundance of bacteria by 36–43 % due to the temperature rise and labile C reduction. Bacteria developed with lower abundance (e.g., smaller colonies) but with higher diversity in soils with less available resources. During the long-term mulching and microbial acclimation to increased temperature and the reduced labile C, the bacterial community strongly changed towards an oligotrophic life history. The PFM increased the abundance of bacterial species with high nutrient uptake (e.g. Patescibacteria increased by 83 %), while chemotrophs that prefer eutrophic conditions were reduced in the PFM soil (e.g. Actinobacteriota by 11 %). The PFM increased the complexity of co-occurring networks of bacterial communities and decreased their stability. Almost all bacterial marker taxa screened by random forest algorithm differed between Control and Mulch soils. Long-term mulching reduced the rate of bacterial metabolism associated with organic matter degradation, such as metabolism of carbohydrates, esters (propanoate and butanoate decreased strongly), lipids (the greatest reduction was for fatty acids), and amino acids (lysine, valine, leucine, and isoleucine degradation pathways dropped the most). Structural equation modeling indicated that bacterial metabolism was mainly influenced by bacterial community structure. Consequently, the metabolic functions of bacteria were reduced after the decrease of C availability induced by warming under PFM, and this reduction was dependent on the duration of PFM application.
... The effect of plastic covers on soil microbes can propagate in different ways to higher tropic levels of the food web. E.g. by positively affecting overall arthropod diversity and doubling omnivorous insect but decreasing springtail, predatory nematode, ground beetle or earthworm abundances (Steinmetz et al 2016). ...
Article
Full-text available
The impact of micro plastics (MPs) on the bivalve larvae at different developmental stages throughout their life history, especially for the metamorphic stage is not at all available. In organisms, consequences of plastic ingestion include exposure to environmental pollutants and toxin accumulation, causing endocrine disruption, inflammatory and physiological stress. The transfer of micro plastics has been shown to transfer across food webs, however, the micro plastic accumulations across terrestrial food webs have examined but it has limited studies only. The different type of micro plastic exposure, exposure time, as well as physiological and behavioral differences among organisms exposed to micro plastics can show some of these differences in effects. If the organism ingested by the micro plastics, its interact within the gastrointestinal tracts differently in terms of the anatomy and structure of the tract, its mechanical action, transit time and chemical enzymatic action. Further, the characteristics of micro plastics such as size, shape, solubility, and surface properties also play an important role in the toxicity of micro plastics. Micro plastic pollution in the soils harms the fitness of multiple soil organisms, animals and birds underscoring the ecological risk posed by micro plastics within terrestrial ecosystems.
... The use of plastic in agriculture and the accumulation of microplastics in agricultural soil has been highlighted (United Nations Environment Programme, 2021b). Vegetable crop production, including in organic farming, is a major user of plastic, particularly as mulch and tunnels for several purposes (e.g. earlier production, higher yield, weed control, cleaner vegetables) (Lamont, 2017(Lamont, , 2005, which is a threat to long-term soil quality (Steinmetz et al., 2016). Massive use of plastic, especially in organic farming, has caused controversy (Held, 2019). ...
Thesis
En France, le maraichage en agriculture biologique est un secteur dynamique, composé de fermesprésentant différents niveaux d’agroécologie laissant supposer une potentielle bifurcation entre desfermes biologiques « conventionnalisées » reposant sur l’utilisation d’intrants, et des fermes« agroécologiques » valorisant les ressources de l’écosystème. Cette hétérogénéité interroge sur ladiversité potentielle des impacts environnementaux associés. S’appuyant sur des donnéesessentiellement qualitatives collectées auprès de 165 fermes et sur un cadre d’analyse conceptuel, lathèse propose une caractérisation de la diversité des fermes et identifie quatre types : 1) lesmicrofermes diversifiées et utilisant peu d’intrants ; 2) les maraîchers diversifiés de taille moyenne ; 3)les producteurs spécialisés dans la culture sous abri ; et 4) les maraîchers spécialisés dans la culture deplein champ. Les caractéristiques des fermes et leur variabilité confirment l’existante de deux pôles« conventionnalisées » et « agroécologiques », tout en montrant qu’il s’agit d’une visionsimplificatrice, la majorité des fermes se trouvant entre ces deux pôles.Afin d’évaluer les performances environnementales de ces systèmes maraichers, l’analyse du cycle devie (ACV) a été mobilisée. Les fermes complexes, cultivant une grande diversité de légumes en lesassociant sur de petites surfaces dans une approche agroécologique systémique, posent des défis àcette méthode dans la prise en compte de leurs impacts sur la biodiversité et les interactions spatialeset temporelles sur lesquelles elles reposent. En adaptant le système expert SALCA-BD, j’ai comparédes fermes par rapport à leur impact sur la biodiversité, et mis en évidence l’importance des habitatssemi-naturels pour la biodiversité. SALCA-BD permet une évaluation détaillée de l’impact sur labiodiversité qui peut servir de base pour développer des méthodes d’évaluation combinant impactsglobaux et locaux dans un cadre d’ACV.Une approche système de l’ACV a été employée. Cette approche aborde la ferme comme un toutproduisant différents produits et où tous les intrants, opérations, et émissions sont rapportés à laproduction annuelle totale. Cette optique correspond à la logique de l'agroécologie, où beaucoupd’intrants sont raisonnés à l’échelle de la ferme et non à la culture, et où les cultures sontcomplémentaires les unes des autres. Préférée à une ACV par culture, l’approche système prend encompte les interactions au sein du système, et permet de comparer les systèmes entre eux. D’un pointde vue pratique, elle est adaptée au format des données souvent disponibles dans les fermesdiversifiées et évite des allocations.ivL’application de cette approche de l’ACV à trois fermes contrastées a permis l’analyse des forces etfaiblesses de ces fermes vis-à-vis de l’environnement, faisant apparaître de grandes différences entreles systèmes dans leurs principaux postes d’impact. Avec l’utilisation de plusieurs catégories d’impactet unités fonctionnelles, aucune ferme ne ressort clairement meilleure qu’une autre pourl’environnement. Exprimé par unité de surface, la ferme de plein champ, plus extensive, a le moinsd’impact et la ferme spécialisée sous tunnel a le plus d’impact, quelle que soit la catégorie d’impact.En revanche, quand les impacts sont exprimés par kg de produit ou par la valeur des produits (en Euro)les différences entre les trois fermes sont plus faibles. La comparaison des systèmes doit se faire engardant à l’esprit que les fermes ont des productions différentes et complémentaires. Les interactionset complémentarités entre ces modèles méritent d’être étudiées.Enfin, l’application de l’ACV système a permis d’identifier des perspectives de développementméthodologiques pour mieux estimer les émissions de nitrate, pour harmoniser l’évaluation desimpacts environnementaux des fertilisants organiques et pour intégrer la question de la pollution parles (micro)plastiques.
... The environmental issues raised by MPs were first recognized in marine environments (Bläsing and Amelung, 2018), however the amount of plastic waste retained in continental land masses is estimated to be 4-23 times higher than the amount released into the oceans (Horton et al., 2017). Despite this disparity, considerably less is known about MPs in the terrestrial environment (Steinmetz et al., 2016). Soil may be an essential gathering place for MPs in the environment. ...
Article
Full-text available
This study analyzed the role of micro polyethylene (mPE) and micro polypropylene (mPP) on cadmium (Cd) adsorption and desorption in soil. Cd adsorption in soils reached equilibrium within 240 min with or without mPP/mPE. The largest Cd adsorption amount was 923.88 mg kg−1 in the control treatment (no MPs). The Cd adsorption amount in the mPP treatment was 872.21 mg kg−1, greater than that in the mPE treatment (780.21 mg kg−1). MPs reduced the soil adsorption of Cd to some extent. Soils supplemented with mPE were more inhibitory to Cd adsorption than mPP. The pseudo-second-order model equation proved to be the most optimal equation for describing Cd adsorption dynamics in the presence of different MPs, while the Freundlich equation was best for describing isothermal adsorption of Cd in the presence of MPs. MPs facilitate the desorption of metals from the soil.
... However, potentially promote soil degradation and soil water repellency. [52,53]. Many countries have been facing the problem of microplastics in agronomies such as., Europe, China, Bangladesh, Australia, Mexico, India, and Switzerland (54,55,56,57). ...
Article
Full-text available
Technological advancement has tremendously accelerated the promotion of microplastics in our environment. In early 2020, the COVID-19 pandemic accelerated the production and use of plastics in the form of facemasks, face shields and PPE kits across the globe has intensified and becomes a new environmental challenge. As scientific knowledge is limited concerning the source, exposure, toxicity, and bioavailability of microplastics in the surroundings, this review has been aimed to provide comprehensive information about microplastics present in the environment with special emphasis on their deposition and related increasing menace in India, during and after the COVID 19 period. We have focussed on the 5 key research needs, involving (1) the occurrence and abundance of microplastics (2) sources, fate, and occurence of microplastics in different media (water, air and soil), (3) toxicological implications of microplastics on human beings, (4) scenario of microplastics disposal during COVID-19 pandemic and (5) major challenges and future directions to curtail them. We suggest that addressing these knowledge gaps will lay the groundwork to counteract such environmental issues which are important to prevent them from exacerbating. Combating microplastic contamination can be achieved through an intensive and combined effort of all, including the stakeholders, researchers, educators, media and policymakers. We can join the effort to manage plastic in the environment by refusing, reducing, reusing and recycling the plastic products, to prolong every item’s life cycle as far as possible. A start would be a focus on limiting the use of single-use plastic products, especially if alternatives are readily available.
... Concerns have been raised with respect to the techniques used in the agricultural sector that may cause MnP pollution in agricultural soils (Kumar et al. 2020;Tian et al. 2022). Common agricultural practices such as the use of plastic films for insulation and mulching, plastic water pipes for irrigation and plastic greenhouse covers, or the application of sewage sludge as fertilizer, are some of the potential sources of MnP contamination (Steinmetz et al. 2016;Brodhagen et al. 2017) in agricultural areas. Unsurprisingly, agricultural soils are therefore estimated to receive a major portion (up to 14%) of the total released plastic to the environment (Alimi et al. 2018;Horton et al. 2017) and are thought to be a major sink for MnP pollution, with the number of MnPs released onto land estimated to be 4-23 times more than to the ocean (Horton et al. 2017). ...
Article
Full-text available
An overview of the current state of knowledge on the pollution of agricultural soils with microplastic and nanoplastic (MnP) particles is provided and the main MnP sources are discussed. MnP transport mechanisms from soil to groundwater, as well as the potential impact of MnPs on soil structure are considered, and the relevance of co-contaminants such as agrochemicals is further highlighted. We elaborate on why MnPs in soil and groundwater are understudied and how analytical capabilities are critical for furthering this crucial research area. We point out that plastic fragmentation in soils can generate secondary MnPs, and that these smaller particles potentially migrate into aquifers. The transport of MnP in soils and groundwater and their migration and fate are still poorly understood. Higher MnP concentrations in agricultural soils can influence the sorption behavior of agrochemicals onto soil grains while attachment/detachment of MnPs onto soil grains and MnP-agrochemical interactions can potentially lead to enhanced transport of both MnP particles and agrochemicals towards underlying groundwater systems.
... These concerns are supported by estimates that the accumulation of MPs in terrestrial ecosystems is far greater than that in the ocean (Luca et al., 2016;Horton et al., 2017;Alimi et al., 2018). In agroecosystems, compost, sludge, irrigation, and agro-plastics are the main pathways of MP input to farmland (Nizzetto et al., 2016;Steinmetz et al., 2016;Weithmann et al., 2018;Okoffo et al., 2021). For instance, plastic films are widely used on the soil surface of agricultural crops to improve productivity, with studies detecting a 2-fold increase in plastic fragments in soils with plastic mulching compared to soils without it . ...
Article
Microplastics provide a new ecological niche for microorganisms, and the accumulation levels of microplastics (MPs) in terrestrial ecosystems are higher than those in marine ecosystems. Here, we applied the zymography to investigate how MPs — polyethylene [PE], and polyvinyl chloride [PVC]) at two levels (0.01% and 1% soil weight) impacted the spatial distribution of soil hydrolases, nutrient availability, and rice growth in paddy soil. MPs increased the above-ground biomass by 13.0%–15.5% and decreased the below-ground biomass by 8.0%–15.1%. Addition of 0.01% and 1% MPs reduced soil NH4+ content by 18.3%–63.2% and 52.2%–80.2%, respectively. The average activities of N- and P-hydrolases increased by 0.8%–4.8% and 1.9%–6.3% with addition of MPs, respectively. The nutrient uptake by rice plants and the enzyme activities in hotspots increased with MP content in soil. The accumulation of MPs in paddy soil could provide an ecological niche that facilitates microbial survival, alters the spatial distribution of soil hydrolases, and decreases nutrient availability.
... The use of plastic in agriculture and the accumulation of microplastic in agricultural soil has been highlighted (United Nations Environment Programme, 2021). Vegetable crop production, including in organic farming, is a major user of plastic, particularly as mulch and tunnels for several purposes (e.g. earlier production, higher yield, weed control, cleaner vegetables) (Lamont, 2017(Lamont, , 2005, which is a threat to long-term soil quality (Steinmetz et al., 2016). Microplastics may have detrimental effects on plant growth (Liu et al., 2021), on soil properties (Zhang et al., n.d.), on the fitness of soil bacteria and earthworms (Jiang et al., 2020), and may be found in fruit and vegetables at worrying concentrations (Oliveri Conti et al., 2020). ...
... When water flows through mangroves, MPs can be attached to different parts of mangrove plants based on the characteristics of MPs (Soler et al., 2020;Van Melkebeke et al., 2020;Duan et al., 2021;Li et al., 2019). These MPs have a trend of becoming submicroplastics and have even further degraded to NPs in 30 years (Fig. 3a) (Steinmetz et al., 2016;Davranche et al., 2019). Additionally, some MPs may enter mangrove plants by being degraded into smaller sizes after they have been absorbed and remain on their surface for a period of time . ...
... As a result, residual plastic films move and build up in agricultural soils, which can reduce soil productivity by obstructing water infiltration, hindering soil gas exchange, restricting root growth, and changing the microbial community structures in the soil (Jian et al. 2020). Plastic films contribute to soil degradation and are potential soil pollutants (Steinmetz et al. 2016). Also, plastic mulch installation is time-and labor-intensive, and requires the use of expensive and specialized machinery like drip tape layer and bed presses (Kader et al. 2017). ...
Article
Soil degradation and water scarcity are key constraints underlying low crop productivity in arid and semiarid regions. Therefore, adoption of improved technologies and effective management practices for optimizing soil water conservation and improving soil fertility is crucial for sustainable food production in dryland areas. A meta-analysis using the preferred reporting items for systematic reviews and meta-analyses guideline was performed to synthesize studies investigating the impact of plastic film and wheat straw mulching on maize water use efficiency (WUE), evapotranspiration, and grain yield in northern China. Articles published from 2001 to 2021 were examined to investigate the influence of mulching and ridge-furrow rainwater harvesting systems on maize grain yield. The meta-analysis demonstrated that the plastic mulched ridge with straw mulch furrow increased maize grain yield and water use efficiency in low rainfall areas. Compared to traditional flat planting (TFP) with no mulching, plastic film mulch with straw mulched furrow (PMR + SMF) treatment significantly (p = 0.0008) increased WUE of maize by 69.51% in areas where air temperature was < 10 °C but had no significant effect on evapotranspiration. Maize grain yield in Shaanxi and Gansu areas increased significantly (by 52.52%, p < 0.00001) with the integration of PMR + SMF system compared to the TFP with the no mulching. However, the plastic film mulch and wheat straw mulch acting solely or in combination did not significantly affect maize evapotranspiration under the different climate and soil types investigated. The integration of RFRHs with plastic film with wheat straw mulching can improve crop productivity and WUE. Findings from the meta-analysis lay a platform for the adoption of climate-smart integrated soil water management practice in semiarid areas to strengthen climate-resilient crop production.
... However, the improper recycling of aged plastic films is an emerging source of MPs in farmland . The use of plastic mulch in intensive cultivation systems accelerates the accumulation of MPs in soil (Steinmetz et al., 2016). ...
Article
Microplastic (MP) pollution has become a global concern due to the generation of extensive plastic waste and products (370 million metric tons in 2020) that are difficult to biodegrade. Therefore, MPs have attracted a great deal of research attention, and many new findings regarding MPs (over 9000 papers published in the last 3 years) have been reported. MPs generally exert adverse effects on plants. As MPs accumulate in agricultural ecosystems, many studies have sought to understand the sources and fates of MPs and their effects on various plants. However, there have been few reviews of the properties of MPs, their effects on plants, and their interactions with other factors (e.g., drought, heat, ultraviolet light, plant hormones, heavy metals, and other pollutants) remain poorly understood. In this review, we performed scientometrics analyses of research papers (January 1, 2019, to September 30, 2022) in this field. We focused on the recent progress in the classification of MPs and their sources, circulation, and deposition in agricultural ecosystems. We review MP uptake and transport in plants, as well as factors (size, type, and environmental factors) that affect MP uptake, the positive and negative effects of MPs on plants, and the mechanisms of MP impacts on plants. We discuss current issues and future perspectives concerning research into plant interactions with MPs, along with some promising methods to manage the MP issue.
... However, little is known about the plastic mulching effects in Brazil regarding microplastics. Recent studies reinforce the need for truly biodegradable plastic mulching [163,164]. ...
Chapter
In the last 50 years, Brazil changed its position of food importer to become one of the main global players in food, fiber, and renewable energy productions. This shift was only possible because of the country’s favorable climate condition, soil types, relief, and environmental diversity, together with agricultural technological advances such as the use of no-till, level terraces, development of adapted seeds, intensification of mechanized agriculture, and currently smart agriculture. However, the country still faces problems with agricultural land degradation, such as soil erosion (water and wind), slash-and-burn agriculture, soil compaction and overgrazing, salinity, the abusive use of agrochemicals, and microplastics. In this chapter, we discuss some of these issues on the agricultural land degradation in Brazil, showing the main challenges, advances, and perspectives on this topic.KeywordsFood securityNo-tillRotational grazing systemsSoil erosionSoybeans
... Biosolids contain concentrated microplastics removed during wastewater treatment (Lusher et al. 2019). In addition to biosolids, plasticulture such as plastic mulching materials, contributes to microplastics in agricultural fields (Steinmetz et al. 2016). Recently, concerns about agriculture-derived microplastics were cited as a top priority in the state of California (California Ocean Science Trust 2021). ...
Article
Although many studies have focused on the importance of littering and (or) illegal dumping as a source of plastic pollution to freshwater, other relevant pathways should be considered, including wastewater, stormwater runoff, industrial effluent/runoff, and agricultural runoff. Here, we conducted a meta-analysis focused on these four pathways. We quantified the number of studies, amount and characteristics of microplastics reported, and the methods used to sample and measure microplastics from each pathway. Overall, we found 121 studies relevant to our criteria, published from 2014 to 2020. Of these, 54 (45%) quantified and characterized microplastics in discharge pathways. Although most focused on wastewater treatment plant effluent (85%), microplastic concentrations were highest in stormwater runoff (0.009 to 3862 particles/L). Morphologies of particles varied among pathways and sampling methods. For example, stormwater runoff was the only pathway with rubbery particles. When assessing methods, our analysis suggested that water filtered through a finer (<200 um) mesh and of a smaller volume (e.g., 6 L) captured more particles, and with a slightly greater morphological diversity. Overall, our meta-analysis suggested that all four pathways bring microplastics into freshwater ecosystems, and further research is necessary to inform the best methods for monitoring and to better understand hydrologic patterns that can inform local mitigation.
... The use of biodegradable plastics in intensive agrosystems has multiplied in recent years (Satti and Shah, 2020;Fan et al., 2021). Therefore, more attention is urgently needed to further elucidate the impacts produced by biodegradable MPs on the environmental fates of amide herbicides (Steinmetz et al., 2016). These studies would help to provide comprehensive theoretical support for the risk assessment and management of the coexistence of MPs and amide herbicides in intensive agrosystems. ...
Article
Coexisting of microplastics (MPs) and residual herbicides has received substantial attention due to concerns about the pollutant vector effect. Here, the widely used amide herbicides were examined for their sorption behaviors on the priority biodegradable and nondegradable MPs identified in intensive agriculture. The fitting results indicated that the interactions between napropamide (Nap)/acetochlor (Ace) and the MPs, i.e., poly (butyleneadipate-co-terephthalate) microplastic (PBATM), polyethylene microplastic (PEM), and polypropylene microplastic (PPM), may be dominated by hydrophobic absorptive partitioning on the heterogeneous surfaces. Additionally, chemisorption cannot be ignored for the sorption of Nap/Ace on the biodegradable MPs. The sorption capacities of Nap/Ace on the MPs followed the order of PBATM > PEM > PPM. The differences in sorption capacity which varied by the MP colors were not significant. The hydrophobicity of the herbicides and the MPs, the rubber regions, surface O-functional groups, benzene ring structures and large specific surface area of the biodegradable MPs played key roles in the better performance in sorbing amide herbicides. Moreover, MPs, especially biodegradable MPs, might lead to a higher vector effect for residual amide herbicides than some other common environmental media. This study may provide baseline insights into the great potential of biodegradable MPs to serve as carriers of residual amide herbicides in intensive agrosystems.
... The distribution of microplastics in soils in the horizontal space is often not uniform but heterogeneous (Rillig et al., 2017;Sun et al., 2022), i.e., microplastics are present in one soil microsite (patch) but absent in its horizontally adjacent soil microsites or microplastics are present in adjacent microsites with different concentrations. For instance, long-term plastic film shedding and random disposal of plastics may create soil patches with microplastics (Steinmetz et al., 2016;Blasing and Amelung, 2018;Zhang and Liu, 2018). Sewage sludge application, wastewater irrigation, human tillage, soil biota activity, atmospheric deposition and wind-or water-mediated movement may redistribute microplastics in soils and create horizontal soil patches with different concentrations of microplastics (Barnes et al., 2009;Nizzetto et al., 2016;Cai et al., 2017;Lwanga et al., 2017;Rillig et al., 2017). ...
Article
Full-text available
Contamination of soils by microplastics can have profound ecological impacts on terrestrial ecosystems and has received increasing attention. However, few studies have considered the impacts of soil microplastics on plant communities and none has tested the impacts of spatial heterogeneity in the horizontal distribution of microplastics in the soil on plant communities. We grew experimental plant communities in soils with either a homogeneous or a heterogeneous distribution of each of six common microplastics, i.e., polystyrene foam (EPS), polyethylene fiber (PET), polyethylene bead (HDPE), polypropylene fiber (PP), polylactic bead (PLA) and polyamide bead (PA6). The heterogeneous treatment consisted of two soil patches without microplastics and two with a higher (0.2%) concentration of microplastics, and the homogeneous treatment consisted of four patches all with a lower (0.1%) concentration of microplastics. Thus, the total amounts of microplastics in the soils were exactly the same in the two treatments. Total and root biomass of the plant communities were significantly higher in the homogeneous than in the heterogeneous treatment when the microplastic was PET and PP, smaller when it was PLA, but not different when it was EPS, HDPE or PA6. In the heterogeneous treatment, total and root biomass were significantly smaller in the patches with than without microplastics when the microplastic was EPS, but greater when the microplastic was PET or PP. Additionally, in the heterogeneous treatment, root biomass was significantly smaller in the patches with than without microplastics when the microplastic was HDPE, and shoot biomass was also significantly smaller when the microplastic was EPS or PET. The heterogeneous distribution of EPS in the soil significantly decreased community evenness, but the heterogeneous distribution of PET increased it. We conclude that soil heterogeneity in the horizontal distribution of microplastics can influence productivity and species composition of plant communities, but such an effect varies depending on microplastic chemical composition (types) and morphology (shapes).
... In China, a four-fold increase of plastic mulch use, from 319 to 1245 megatons, has been noted between 1991 and 2011, and much of this is difficult to recycle. In Spain and many eastern and south-eastern countries, more than 50% of plastic waste is estimated to be landfilled (Steinmetz et al., 2016). Slight differences in the composition of MPs with different land use patterns in different regions have also been reported (Wang et al., 2021a), but on the whole, the proportion of PE and PP MPs in farmland in each region exceeded that of other MP types. ...
Article
Microplastics (MPs) accumulation in farmland has attracted global concern. Smallholder farming is the dominant type in China's agriculture. Compared with large-scale farming, smallholder farming is not constrained by restrictive environmental policies and public awareness about pollution. Consequently, the degree to which smallholder farming is associated with MP pollution in soils is largely unknown. Here, we collected soil samples from both smallholder and large-scale vegetable production systems to determine the distribution and characteristics of MPs. MP abundance in vegetable soils was 147.2–2040.4 MP kg⁻¹ (averaged with 500.8 MP kg⁻¹). Soil MP abundance under smallholder cultivation (730.9 MP kg⁻¹) was twice that found under large-scale cultivation (370.7 MP kg⁻¹). MP particle sizes in smallholder and large-scale farming were similar, and were mainly <1 mm. There were also differences in MP characteristics between the two types of vegetable soils: fragments (60%) and fibers (34%) were dominant under smallholder cultivation, while fragments (42%), fibers (42%), and films (11%) were dominant under large-scale cultivation. We observed a significant difference in the abundance of fragments and films under smallholder versus large-scale cultivation; the main components of MPs under smallholder cultivation were PP (34%), PE (28%), and PE-PP (10%), while these were PE (29%), PP (16%), PET (16%), and PE-PP (13%) under large-scale cultivation. By identifying the shape and composition of microplastics, it can be inferred that agricultural films were not the main MP pollution source in vegetable soil. We show that smallholder farming produces more microplastics pollution than large-scale farming in vegetable soil.
... It should be noted that variation in water availability alters soil physical [15], chemical [16] and microbiological properties [17]. The latter is relevant because, according to several authors, some soil bacterial communities can alter the functional characteristics of plants [18] and allow greater resistance to pathogen invasion [19]. ...
Article
Full-text available
Calafate fruits have a high content of phenolic compounds and an antioxidant activity up to four times higher than that of blueberries. The establishment of a calafate orchard and irrigation responses on fruit and soil characteristics have been scarcely studied. Therefore, the objective of this study was to evaluate the effect of water replenishment rate: 0%, 50%, 100% and 150% of reference evapotranspiration (ET0), on soil microbiological activity, plant physiological response, fruit yield and chemical composition in a calafate orchard. The results showed that irrigation at 50% ET0 presented significant increases in soil urease, dehydrogenase and acid phosphatase activity. Likewise, irrigation at 50% ET0 significantly increased stomatal conductance and plant chlorophyll index, which led to a significant increase in fruit yield being 60% higher compared to the other treatments. Despite the higher fruit yield, 50% ET0 irrigation had a similar level of total anthocyanins and ORAC antioxidant capacity as the 100% ET0 treatment. In contrast, 0% and 150% ET0 treatments showed a higher degree of stress and got higher values for total anthocyanins and fruit antioxidant capacity. Irrigation rates 50% ET0 increases fruit yield while maintaining fruit quality and optimizing water resources in commercial orchards of calafate.
... Hence, this system can be perceived as not being fully beneficial from the point of view of agro-technics and the broadly understood concept of biodiversity. Serious problems related to the use of synthetic mulches are the need for the expensive disposal of these materials after the end of the cultivation cycle and the potential for serious environmental contamination [23]. The use of biodegradable materials that decompose naturally may be a solution, but due to their fast rate of degradation, they are currently used primarily for vegetable growth [24]. ...
Article
Full-text available
In order to achieve sustainable food production, non-chemical weed management practices need to be developed for fruit growing. Tailor-made floor management systems enable efficient weed regulation, but they also affect the soil quality in an orchard. In this article, the effects of various floor management systems in a ‘Red Jonaprince’ apple (Malus × domestica Borkh.) orchard on the soil properties and the trees’ nutritional status and initial development during the first two years after the orchard’s establishment were assessed. The experiment was set up in the spring of 2017 in the Experimental Orchard of WULS. ‘Red Jonaprince’ cv. trees grafted on M.9 rootstock were planted with 3.5 × 1 m spacing between them. Different floor management systems were applied to the rows, including the selected organic mulches: Miscanthus × giganteus straw (MG1 and MG2), spent mushroom substrates (SMS1 and SMS2), herbicide strip (HS), clear mechanical soil cultivation (MC), and synthetic black mulch (BC). The organic mulches affected the soil properties significantly. Spent mushroom substrates (SMS1, SMS2) increased the P and K contents in the soil, increased the salinity 10-fold, and retarded the growth in terms of the trunk cross-section area (TCSA) and its increment compared with other systems. Miscanthus × giganteus straw mulch (MG1, MG2) was associated with a more vigorous shoot growth compared with other combinations in the first year of the study as it provided a better tree nitrogen nutritional status. The floor management system affected the generative development of the trees. Mulching with a spent mushroom substrate boosted the flower bud formation intensity, but it did not affect the yielding quantity. Moreover, due to the poor fruit set, the trees mulched with a spent mushroom substrate (SMS2) gave a low initial bearing. High crop loads were noted for the trees treated with black synthetic mulch (BC) and the trees mulched with Miscanthus × giganteus straw (MG1). This was an effect of the tree size rather than the blooming intensity, while there were no differences in the cropping efficiency index (CEI) parameter.
... Drylands occupy approximately 45 % of the Earth's land surface, and dryland agriculture plays a pivotal role in the global food supply, production of which is largely constrained by low water availability (Prăvălie, 2016). Plastic film mulching (PM) can effectively improve soil water and heat conditions, can dramatically increase crop yields, and is widely used in dryland agriculture around the world (Kasirajan and Ngouajio, 2012;Li et al., 2004;Liu et al., 2009;Steinmetz et al., 2016). Soil microbial communities are susceptible to agricultural management practices applied for maintaining soil quality and crop productivity Trivedi et al., 2016). ...
Article
Soil fungi are closely associated with crop growth in agricultural ecosystems through processes such as nutrient uptake and pathogenesis. Plastic film mulching (PM) plays a dominant role in increasing crop yields in dryland agriculture worldwide. The functional guilds of soil fungi under PM and their effects on crops remain unclear. In this study, we explored the absolute abundance, diversity, community composition, and functional guilds of soil fungi after short-term (2 years) and long-term (10 years) mulching experiments. Short-term mulching caused a 37 %–51 % decrease in absolute fungal abundance owing to abrupt changes in the microenvironment. The response of the fungal community to PM varied with sites, with the effect being more pronounced under poor hydrothermal conditions (314 mm). The abundance of potential fungal pathogens decreased under PM; for example, Gibberella (maize ear rot) abundance was 45 % and 72 % lower under short- and long-term mulching, respectively, when compared with that in a non-mulching control group. In contrast, the abundance of plant biocontrol fungi increased under PM; for instance, Glomeromycota abundance increased twofold under long-term mulching. Although PM did not alter the complexity and stability of fungal co-occurrence network, competition among fungi increased in the absence of sufficient carbon (C) sources. Long-term mulching reduced phytopathogen guilds by 12 %–77 % and increased arbuscular mycorrhizal fungi (AMF) guilds by 89 %–94 %. Structural equation modeling suggested that PM altered fungal functional guilds mainly by shaping the structure of the fungal community, and fungal pathogens decreased with increased AMF functional guilds, inducing higher maize yields. These results showed for the first time, from a microbial perspective, that pathogens reduction owing to PM could explain 4.4 % of maize yield variation, providing theoretical guidance to accomplish sustainability of continuous maize mulching.
... Plastic mulching is a globally applied agricultural technique because of its instant economic benefits such as higher yields and increased WUE (Gao et al., 2019). However, plastic mulching promoted soil degradation and soil water repellency, and increased the release of greenhouse gases; plastic residues were likely to fragment into microplastics and accumulate in the soil where they can successively sorb agrochemicals (Steinmetz et al., 2016). In this field experiment, plastic film was covered with 2-3 cm of soil, which complicated the subsequent recycling of the film at harvest. ...
Article
Drought stress is the main limiting factor to spring maize production in the North China Plain (NCP). However, amounts of soil water and precipitation evaporate unproductively during the long fallow season before sowing spring maize. Therefore, sub-surface plastic mulching (PM) and straw mulching (SM) were conducted to reduce evaporation following the harvest of the previous season's crop in this three-year study. PM resulted in less water evaporation during the fallow season compared with SM and the control without mulching (CK). Thus, more water was stored in the soil under PM. Similarly, evapotranspiration from sowing to the sixth-leaf stage (V6) in CK and SM was increased by 18.5-43.1% compared with PM. Conversely, evapotranspiration of PM was higher than that of CK and SM during the V6-silking period. During the grain filling stage, there was no significant difference in evapotranspiration among treatments owing to abundant rainfall. Correlation analysis indicated that excessive soil water used during the fallow season and seedling stage exacerbated the yield reduction. However, more water employed from V6 to silking increased yield. PM increased soil temperature during the seedling stage, thus accelerating spring maize growth, but without significantly affecting grain yield. PM could increase leaf area index, thus improving the biomass accumulation. Finally, the kernel setting rate was elevated under PM compared to CK and SM. Grain yield, water use efficiency (WUE), and annual WUE of PM were increased by 9.3-15.2%, 8.7-15.6%, and 16.7-25.8% relative to CK and SM, respectively. In conclusion, sub-surface plastic mulching stored water for spring maize growth and development, and enhanced water availability during the critical stage of water demand, thus increasing grain yield and WUE and reducing annual evapotranspiration.
... Mulching has been studied extensively on tomato, wheat, corn, and other crops (Table 1). It has also been stated that using plastic mulch to preserve soil moisture effectively increases growth and yield (Bajguz & Hayat, 2009) and increases water-use quality (Steinmetz et al., 2016). ...
Chapter
Drought, salinity, temperature extremes, and heavy metals are the major environmental factors that limit sustainable crop production worldwide and consequently restrict crop yield. There is a dire need for environment-friendly agricultural practices to achieve long-term food production for the growing population. Mulching has become a common method in modern agricultural practices because of its numerous benefits, such as moisture conservation, augmentation temperature of the soil, reduction of insect pests, weed management, escalation of crop yield, and the effective use of nutrients present in the soil, as well as decreased soil salinity. Mulching also enhances plants’ resistance to pests and diseases and various stress factors like heat, salinity, drought, metals, and high or low temperatures. In addition to this, mulches could also provide economic, aesthetic, and other ecological benefits to agriculture. Mulching markedly increased the growth, yield, nutrient use, and water use efficiency in crop plants under stressed and non-stressed conditions. As a result, future research could also focus on economic, environment friendly, and, more importantly, biodegradable materials on plant growth, balanced nutrition, yield, and quality under various abiotic stress conditions. This chapter focuses on the many essential aspects of mulches on the productivity and establishment of multiple crops under stressful environments.
... Mulching is a soil conservation method that minimizes evaporation, adjusts soil temperature, and thus impacts crop yields positively Scale: x ≤ 0.5 = strongly disagree; 0.5 < x ≤ 1.0 = disagree; 1.0 < x ≤ 1.5 = uncertain; 1.5 < x ≤ 2.0 = agree; x > 2.0 = strongly agree. (Steinmetz et al., 2016;Acheampong et al., 2019). This practice has become critical to cocoa production due to the recognition that global cocoa yields are restricted by nutrient and water availability. ...
Article
Full-text available
Climate change can have huge consequences for cocoa farming and the livelihoods of communities in tropical Africa, although evidence of such effects is scanty. This study evaluated the perceptions of smallholder cocoa farmers on climate change manifestations and adaptations in the Adansi South District, Ghana. The study involved a survey of 150 households and three focus group discussions from three communities in the district. The Mann-Kendall trend test was used to evaluate the rainfall and temperature trends for the period 1981–2019. The weighted average index (WAI) was used to determine the farmers' perception of climate change, its physical manifestation on their cocoa farms, and adaptation practices. While the district's temperature varied considerably from 1981 to 2019, only a marginal increase in annual rainfall was observed. The farmers correctly perceived the changes in climate (WAI = 2.07), evidenced by changes in rainfall patterns (1.76), frequent bushfires (1.68), and increasing intensity of the sun (1.65). Physical manifestations of these changes included increased dieback of cocoa trees (1.77), diseases and pest infestation (1.75), decreased yields (1.69), and stunted growth (1.65). Adaptation measures included early planting of cocoa seeds (1.87), intercropping (1.70), mulching (1.65), planting of drought-resistant varieties (1.64), and crop diversification (1.63). The adaptation measures were influenced by gender, age, education, and farming experience, among other socioeconomic factors. The findings suggest the need for relevant policies to educate cocoa farmers on the effects of climate change, highlighting the risks and benefits, and prioritizing key adaptation options for sustainable cocoa production in Ghana.
... While the adverse effects of mulching on soil carbon stock include enhancing microbial decomposition activities and a significant increase in GHG emissions (Chen et al., 2019;Ma et al., 2018). Some studies suggest that enhanced GHG emission by mulching sometimes offsets its SOC related mitigation capability (Steinmetz et al., 2016;Xia et al., 2018). Therefore, it is crucial to calculate net GWP to estimate the overall effect of surface mulching. ...
Chapter
Net global warming potential and greenhouse gas index express the actual environmental cost of an agricultural system and assist in solving the global challenges of increasing food production and identifying the primary targets for mitigation in different cropping systems and regions. This chapter reviews the effects of different soil surface mulching approaches on GWP, NGWP, and GHGI of different agricultural cultivation systems. We broadly discussed the prospects of mulching techniques used in isolation or combination with other conservation management approaches. In addition, the chapter also sheds light on methods of quantifying climate-related indexes and highlights the pros and cons of different protocols. The literature suggested that residue-based soil mulching may increase yield-scaled GWP due to its triggering effect on GHG emissions with and without improving crop yield. In contrast plastic film as mulch could reduce GWP by enhancing nutrient use efficiency and unique interaction with rainfall events that correlate with large pulses of GHGs emissions. Moreover CO2 equivalent C inputs in the soil were also reported to be higher in plastic film mulch systems than in crop residues suggesting relatively low NGWP and GHGI for the former mulching approach. However, changes in agronomic inputs and farm machinery requirements between plastic and residue mulching approaches were ignored entirely by the published reports and thus did not truly represent the potential of mulching to reduce or induce NGWP in different cropping systems. Residue mulching can decrease indirect GHGs emissions associated with agronomic inputs and farm operations.KeywordsGlobal warming potentialNutrient use efficiencyYield
Article
Plastics, especially microplastics in soils, are considered a severe environmental issue worldwide. However, globally, the main research focus is on microplastic pollution in the marine environment, the microplastic pollution on soils and sediments remains on the sideline so far. But the fact is that microplastics are omnipresent in terrestrial systems in the form of microbeads in industrial systems and in sewage sludge. Their presence in agricultural soils and sediments is enormously increased due to plastic mulching, plastic greenhouses and compost and extensive use of controlled release fertilizers. Therefore, this review outlines the global scenario regarding plastics and microplastics production, consumption, and possible pathways of penetration into the soil environment. Various mechanisms to restrict and manage the pathways of plastics and microplastics into the soil environment are also discussed. This review also focuses on the challenges and limitations on the use of plastic alternates such as bioplastics and oxo plastics. Also, the knowledge gaps on the source of microplastics in the environment and their deleterious effects on properties of soil, soil health and focused light on their soil trophic transfer in food chains via plants. This review provides a detailed insight on the management and possible control measures to alleviate the potential risk caused by microplastics pollution in the soil environment and the overall ecosystem's health. In spite of the occurrence and fate of microplastics on terrestrial environment, knowledge gaps and challenges for tackling this contamination are also explored which facilitates the policy makers to develop regulatory measures towards the containment of microplastics in living ecosystem.
Preprint
Full-text available
The use of poly (butylene adipate-co-terephthalate) (PBAT) has increased widely but PBAT-degrading bacteria have rarely been studied. During this study, we used farm soil (Shaanxi ( yuan Jia cun )) to isolate and identify PBAT-degrading bacteria (Bacillus strains). We then accessed the effect of growth factors on PBAT degradation as well as the lipase activity of PBAT-degrading bacteria. The serial dilution method was used to isolate the PBAT-degrading microbes from the farm soil of Xinjiang. Microbial colonies were spread and streaked many times to get pure colonies. Xin-A and Xin-B were gram-positive bacteria. Lipase production of these strains was studied using para nitrophenyl palmitate as a substrate which showed that both bacteria were lipase producing and the lipase production of Xin-B (14 U/mL) was superior to Xin-A (11.7 U/mL) degrading almost 13.7% PBAT in 14 days. These results provide technical support for the highly efficient degradation of PBAT in the environment.
Article
Full-text available
The toxicity of MPs on aquatic creatures has been extensively studied, but little attention was paid to terrestrial organisms. To fill this gab, we conducted a series of experiments using Drosophila as a model organism to understand whether exposure to different concentrations (0.005, 0.05, 0.5 µg/ml) of polystyrene microplastics (PS-MPs) beads (2 µm in size) can impact flies feeding activity, digestion and excretion. The ability of flies to distinguish between normal and PS-MPs treated food media was tested first, and then we evaluated the effects of a 7-day short-term exposure to PS-MPs on food intake, mortality, starvation resistance, fecal pellet count, and the cellular structure of mid gut cells. The results revealed that flies can really differentiate and ignore MPs-treated food. We discovered sex-specific effects, with male flies being more sensitive to PS-MPs, with all males dying after 14 days when exposed to 0.5 µg/ml of PS-MPs, whereas female flies survived more. All male flies exposed to PS-MPs died after 24 h of starvation. Midgut cells showed concentration-dependent necrosis and apoptosis in response to PS-MPs. Our findings provide new insights into MPs toxicity on terrestrial organisms and giving a warning that management measures against MPs emission must be taken.
Article
The Huangshui catchment on the northeastern Qinghai-Tibet Plateau (QTP) was selected as the study area to investigate the abundance, distribution characteristics, and influencing factors of microplastics (MPs) in surface agricultural soils (0-20 cm). The MP levels ranged from 6 to 444 items/kg, with an average of 86 items/kg. The relative abundance of small-sized MPs (<2 mm) was higher than that of large-sized MPs (2-5 mm). Polyethylene was the most common, and residual mulching film in farmland was the main source of MPs. The spatial distribution characteristics of MPs were analyzed through inverse distance weight interpolation, and MP abundance in agricultural soils in neighboring urban areas was significantly higher than that in other areas. Further analysis found that population density was significantly positively correlated with MP abundance (R2 = 0.9090, p < 0.01), indicating that human activities play a key role in MP pollution even in remote areas. In addition, the effects of irrigation, land use type, and soil physicochemical properties on the abundance of MPs were analyzed. Atmospheric transport and irrigation with surface water contribute to soil MP pollution. The direct effects of soil properties on MP abundance are still largely unclear, requiring further studies.
Article
The widespread distribution of phthalates (PAEs) in agricultural soils is increasing drastically; however, the environmental occurrence and potential risk of PAEs in agricultural systems remain largely unreviewed. In this study, the occurrence, sources, ecotoxicity, exposure risks, and control measures of PAEs contaminants in agricultural soils are summarized, and it is concluded that PAEs have been widely detected and persist in the soil at concentrations ranging from a few μg/kg to tens of mg/kg, with spatial and vertical variations in China. Agrochemicals and atmospheric deposition have largely contributed to the elevated contamination status of PAEs in soils. In addition, PAEs cause multi-level hazards to soil organisms (survival, oxidative damage, genetic and molecular levels, etc.) and further disrupt the normal ecological functions of soil. The health hazards of PAEs to humans are mainly generated through dietary and non-dietary pathways, and children may be at a higher risk of exposure than adults. Improving the soil microenvironment and promoting biochemical reactions and metabolic processes of PAEs are the main mechanisms for mitigating contamination. Based on these reviews, this study provides a valuable framework for determining future study objectives to reveal environmental risks and reduce the resistance control of PAEs in agricultural soils.
Article
Plastic is considered one of the most indispensable commodities in our daily life. At the end of life, the huge ever-growing pile of plastic waste (PW) causes serious concerns for our environment, including agricultural farmlands, groundwater quality, marine and land ecosystems, food toxicity and human health hazards. Lack of proper infrastructure, financial backup, and technological advancement turn this hazardous waste plastic management into a serious threat to developing countries, especially for Bangladesh. A comprehensive review of PW generation and its consequences on environment in both global and Bangladesh contexts is presented. The dispersion routes of PW from different sources in different forms (microplastic, macroplastic, nanoplastic) and its adverse effect on agriculture, marine life and terrestrial ecosystems are illustrated in this work. The key challenges to mitigate PW pollution and tackle down the climate change issue is discussed in this work. Moreover, way forward toward the design and implementation of proper PW management strategies are highlighted in this study.
Article
Film mulching (FM) is an agronomic measure worldwide, yet its effect on cadmium (Cd) accumulation in plants is unknown. This study investigated the potential for phytoremediation with FM treatment of Cyperus esculentus L. (chufa) and Sedum alfredii Hance (S. alfredii)-oil crop rotation system. The FM increased the biomass and Cd content of the chufa, resulting in an increase of 65.0-193.5% in the Cd accumulation. S. alfredii also was planted using non-film mulching and film mulching (FMSA), followed by rotation oil plants using non-film mulching. Soil pH and dissolved organic carbon content were significantly reduced, and the Cd grain size fraction of macro-aggregates was significantly increased by FMSA, which increased the uptake of available Cd by S. alfredii. This phenomenon further promoted the accumulation of Cd in S. alfredii and reduced the Cd content of aboveground tissues and seeds in subsequent oil crops. Vegetable oils were safely produced in all treatments due to their low Cd content. Compared with non-film mulching, FM increased the Cd accumulation of rotation systems by 66.8-96.4%, and the Cd remediation efficiency reached 11.8-12.9%. Collectively, the FM treatment effectively improved the remediation efficiency of Cd in the rotation system and ensured the safe production of vegetable oil.
Article
Full-text available
Tarımda plastik malç kullanımı, küresel boyutta tarımsal üretimi büyük ölçüde artıran, ancak çevresel olarak ciddi miktarda plastik kirliliği yaratan bir uygulamadır. Bu çalışmada, 2008 ve 2017 yıllarından bu yana çilek üretiminde plastik malç uygulanan Konya ili Hüyük İlçesi tarım topraklarındaki plastik miktar ve türleri araştırılmıştır. Toprak örneklerinde plastikleri ekstrakte edebilmek için NaCl (1.2 g cm-3) çözeltisi kullanılmıştır. 14 yıl boyunca plastik malç uygulaması yapılan tarlada 377.33 adet kg kuru toprak-1 plastik bulunurken, 5 yıl boyunca plastik malç uygulaması yapılan tarlada ise 75.53 adet kg kuru toprak-1 plastik belirlenmiştir. Ekstrakte edilen tüm plastiklerin ortalama boyutu 2.04 ± 0.12 mm olarak hesaplanmıştır. H1 tarlasına ait toprak örneğinde plastiklerin boyutu 1.98 ± 0.14 mm iken, H5 tarlasında ise 2.30 ± 0.32 mm olarak bulunmuştur. H1 toprak örneğinde % 92.76 mikroplastik ve % 7.24 mezoplastik tespit edilmişken, H5 örneğinde % 82.35 mikroplastik ve % 17.65 mezoplastik tespit edilmiştir. Fourier dönüşümü kızılötesi analizleri (ATR-FTIR) sonucu tespit edilen plastiklerin bileşiminin uygulanan malç materyali ile eşleştiği ve tespit edilen polimer türünün polietilen (PE) olduğu, bu durumun da plastik parçacıkların malç materyalinden kaynaklandığını ortaya koymuştur. Elde edilen bu bulgular, tarımda plastik malç materyali kullanımının karasal ortamlarda önemli mikroplastik kirliliği oluşturduğunu doğrulamaktadır. Bu plastiklerin de uzun vadede toprakta birikmesi ve daha da küçük parçalara ayrılması sonucu toprak kirliliğinin her geçen gün artacağı kaçınılmazdır.
Article
Microplastic (MP) pollution has become a major concern in recent years. In agricultural production, MPs can not only affect the growth of crops but also affect yield. Compared with micron-sized MPs, nanoplastics (NPs) may be more harmful to plants. However, the effects of NPs on plant growth and development have attracted relatively little attention. As such, research has currently plateaued at the level of morphology and physiology, and the molecular mechanisms are still unclear. In this study, soybeans (Glycine max L.) were treated with polystyrene nanoplastics (PS-NPs) to observe phenotypic changes and measure the effects of PS-NPs on diverse aspects of soybeans. Compared to the control group, the soybean stem and root lengths were inhibited by 11.78% and 12.58%, respectively. The reactive oxygen species content and the antioxidant enzyme activities changed significantly (p < 0.05). The accumulation of manganese (Mn) and magnesium (Mg) in the roots revealed that root transmembrane transport was affected by PS-NPs stress. The content of salicylic acid 2-O-β-glucoside was inhibited whereas the accumulation of l-tryptophan, the precursor of auxin synthesis, was significantly increased (p < 0.05) in leaves. Transcriptomic analysis showed that PS-NPs could affect soybean DNA repair, membrane protein transport, and hormone synthesis and response. This study revealed the toxicity of NPs to soybeans and that NPs affected a variety of biological processes through transcriptome and hormone metabolome analysis, which provides a theoretical basis to further study the molecular mechanism of the effects on plants.
Article
The persistence of microplastics (MPs) in agricultural lands using plastic mulch will be an issue of major environmental concern in meeting the sustainable development goals (SGDs) of the near future. This research work aims at identifying and removal of MPs from rainfall runoff water (RRW) from MP-contaminated agricultural lands using the novel electrochemical coagulation (ECC) treatment technology. The MPs were extracted from the soil samples before identification. The pH, moisture content, MP abundance in soil, and particle size were determined. The RRW from the agricultural land loaded with MPs was treated using stainless steel (SS) electrodes in an electrochemical reactor. The removal efficiency of MPs, COD, chloride, and TDS at 45 min electrolyzing time was 98%, 46%, and 48%, respectively. Higher percentages of MP removal were achieved for increased MP concentrations in RRW. The difference in dry sludge generated during ECC for raw RRW and MP-loaded RRW was 2.42–4.09 kg/m3 of RRW treated. SEM, EDS, and ATR-FTIR spectroscopy analysis revealed the disintegration pattern of MPs into nano-sized particles. EDS of agricultural soil showed 8.2% carbon and 48.1% oxygen, whereas MP particles showed 62–64% carbon and 20–22% oxygen, respectively. The ATR-FTIR spectra for both spiked and extracted MP particle from the contaminated soil showed C–H stretch, CH2 bends, etc.; the MP particle was identified as LDPE-type plastic mulch. The EDS of ECC sludge showed loads of MPs with 47% C, 35% O, 1.6–2.3% Al, 2–2.6% Si and 10.3–12.9% Fe. The ECC process showed its effectiveness in 98% MP removal from the RRW in a short hydraulic retention time (HRT) of < 45 min.
Chapter
We present an updated state of the art about the land degradation in the Italian agriculture. After preliminary outlines about the main characteristics of the Italian climate and soils, we analyse the risks of desertification, erosion, salinization, sealing/compaction, contamination and organic matter reduction of soils. Minor factors of soil degradation (overgrazing, forest fires, pollution due to microplastics and agrochemicals) are also discussed. This review shows that, in the Italian agricultural soils, the rates of sealing, compaction and organic matter decline are close to the values recorded in several European countries. Soil erosion and landslides are the major degradation factors in steeper agricultural areas of the mid mountains and hills, and particularly in the internal areas of Southern Italy. High erosion rates are the main reason of reductions in soil organic matter, which worsens soil fertility and induces biodiversity loss. Unsuitable soil management and unsustainable agricultural exploitation aggravate these land degradation factors. In contrast, natural areas have been subjected to severe environmental regulations (e.g. the national and regional parks) for many years, and these environments are not particularly vulnerable. The final considerations provide insight regarding the possible countermeasures to limit the land degradation rates in the affected areas and ensure soil conservation in the other zones.KeywordsContaminationDesertificationErosionSalinizationSealing/compactionSoil health
Article
Full-text available
Contamination of soils in agroecosystems with microplastics (MPs) is of increasing concern. The contamination of the environment/farmland soils with MPs (1 µm to 5 mm sized particles) and nanoplastics (NPs; <1 µm sized particles) is causing numerous effects on ecological soil functions and human health. MPs enter the soil via several sources, either from intentional plastic use (e.g., plastic mulch, plastic greenhouses, plastic‐coated products) or indirectly from the input of sewage sludge, compost, or irrigation water that is contaminated with plastic. Once in the soil, plastic debris can have various impacts such as changes in soil functions and physicochemical properties and it affects soil organisms due to its toxic behavior. This review paper describes the different effects of plastic waste to understand the consequences for agricultural productivity. Furthermore, we identify knowledge gaps and highlight the required approaches, indicating future research directions on sources, transport, and fate of MPs in soils to improve our understanding of various unspecified abiotic and biotic impacts of MP pollution in agroecosystems. Microplastic impacts on agroecosystem soil.
Article
Plastic pollution has been recognized as a serious environmental problem, and microbial degradation of plastics is a potential, environmentally friendly solution to this. Here, we analyzed and compared microbial communities on waste plastic films (WPFs) buried for long periods at four landfill sites with those in nearby soils to identify microbes with the potential to degrade plastics. Fourier-transform infrared spectroscopy spectra of these WPFs showed that most were polyethylene and had signs of oxidation, such as carbon-carbon double bonds, carbon-oxygen single bonds, or hydrogen-oxygen single bonds, but the presence of carbonyl groups was rare. The species richness and diversity of the bacterial and fungal communities on the films were generally lower than those in nearby soils. Principal coordinate analysis of the bacterial and fungal communities showed that their overall structures were determined by their geographical locations; however, the microbial communities on the films were generally different from those in the soils. For the pulled data from the four landfill sites, the relative abundances of Bradyrhizobiaceae, Pseudarthrobacter, Myxococcales, Sphingomonas, and Spartobacteria were higher on films than in soils at the bacterial genus level. At the species level, operational taxonomic units classified as Bradyrhizobiaceae and Pseudarthrobacter in bacteria and Mortierella in fungi were enriched on the films. PICRUSt analysis showed that the predicted functions related to amino acid and carbohydrate metabolism and xenobiotic degradation were more abundant on films than in soils. These results suggest that specific microbial groups were enriched on the WPFs and may be involved in plastic degradation.
Article
The prevalence of microplastics in soil has recently attracted substantial interest as they pose a major threat to the agricultural ecosystem. Microplastics (MPs), though widely found in marine habitats and explored in detail, their presence in agricultural soil remains relatively unexplored. Microplastics are entering the environment either directly through manufactured particles or those originating from the breakdown of larger macroplastics. In soil, microplastics can be transported both horizontally and vertically through the soil fauna. Hence, in order to understand the possible threats posed by microplastics in soil to the environment, this review aims in conducting a meta – analysis to integrate the recent studies in sources, fate and migration of microplastics into agriculture, impacts on soil health, trophic transfers to food chains and the associated adverse impact on soil biota. Results reveals that major sources of microplastics in soil includes sludge followed by wastewater and mulch film. Its effect on soil properties depends on the soil type, size, concentration and type of polymer. Though the occurrence of microplastics in soil has been reported in various countries, its presence in various other countries is still unexplored. Furthermore, several studies validates the effect of microplastics on soil biota at various trophic stages and even endanger human health by food chains. MPs exert both ecotoxicity and genotoxicity in plants. It delays germination by affecting both the vegetative and reproductive growth of plants. It also affects the ecosystem through the sorption of organic and inorganic pollutants. Nevertheless, detailed insights on the effect of microplastics on soil beneficial organisms and the trophic transfer onto humans requires further studies.
Chapter
Global efforts are being made to reduce the world's high reliance on synthetic herbicides for weed control to protect human health and the environment and avoid the outbreak of weeds in various crops. Concerning the adverse effects on humans and the environment of the use of herbicides, a fair and cautious approach to restricting or even stopping the use of agrochemical products must be envisaged. Several methods provide information on agroecological activities in this context, such as mulching, which can contribute to the sustainable management of weeds in various field crops worldwide. In organic farming, mulching, by providing a barrier to sun, heat, or moisture exchange, is helpful as one strategy for integrated weed control. Evaporation is minimized, moisture is retained, and structure and temperature are controlled. On the other hand, the Mulching practice has many benefits, such as improving soil structure and texture by increasing infiltration and water retention and providing many insects and earthworms with a refuge. In addition, it promotes root penetration and growth and thus can also minimize erosion through nutrient uptake from deeper soil layers. Mulches control weeds by keeping the surface of the soil from receiving sunlight as light is needed for some weeds to germinate, and even necessary for all green plants to grow. Therefore, Mulches can be the best choice to control weeds in the field and reduce dependence on synthetic herbicides for weed control to prevent weeds’ germination in various agronomic crops.KeywordsCropsMulchesWeedsManagement
Article
Full-text available
Film mulching is an important agricultural practices used to improve crop productivity. Field experiments were conducted using maize (Zea mays L.) to determine the effect of film mulching on soil physical properties and maize yield in 2006 and 2007 cropping seasons. The experiment was a randomized complete black design (RCBD) with four film treatments viz. Black film (BM), white film (WM), Black / white film (BWM) and no-treatment (NM). Seedling from three mulching treatments emerged 2days earlier than those from non-mulched treatments. Film mulching significantly (P <-0.05) increased soil temperature (taken at different times) and water retention relative to the un-mulched treatments. Results of the study show bulk density decrease of 9% (BWM), 4% (WM) and 17% (BM) at 45 DAP in the first season and 4% (BM), 1% (BWM) and 6% (WM) at 90 DAP in the second season compared to the un-mulched treatment. Yield increase of 55-78% (first season) and 108-142% (second season) were observed in film mulch treatment relative to the control. Film mulch can be used to increase crop production to meet the food need of the increasing human population.
Article
Full-text available
The world consumption of plastics in agriculture amounts yearly to 6.5 million tons. In addition to conventional polymers used in agriculture for greenhouses and mulches such as PE, PVC, EVA, photo-selective and luminescent polymers have been used, in order to improve the quality of crops. For the same reason plastic nets are used mainly in countries with tropical and Mediterranean climates. For an environmentally friendly agricultural activity, an alternative strategy can be represented by bio-based agricultural raw materials. For low environmental impact applications, biodegradable materials for agricultural films are nowadays produced. An overview of the main methods for the disposal and recycling of plastic materials are presented with the results of mechanical and radiometric tests on recycled plastics. The strategies to reduce the burden of plastics in agriculture are: a correct procedure for the collection, disposal and recycling of post-consumption plastics; the increase of lifetime duration and performance; and the introduction and promotion of bio-based materials.
Article
Full-text available
Due to the widespread use and durability of synthetic polymers, plastic debris occurs in the environment worldwide. In the present work, information on sources and fate of microplastic particles in the aquatic and terrestrial environment, and on their uptake and effects, mainly in aquatic organisms, is reviewed. Microplastics in the environment originate from a variety of sources. Quantitative information on the relevance of these sources is generally lacking, but first estimates indicate that abrasion and fragmentation of larger plastic items and materials containing synthetic polymers are likely to be most relevant. Microplastics are ingested and, mostly, excreted rapidly by numerous aquatic organisms. So far, there is no clear evidence of bioaccumulation or biomagnification. In laboratory studies, the ingestion of large amounts of microplastics mainly led to a lower food uptake and, consequently, reduced energy reserves and effects on other physiological functions. Based on the evaluated data, the lowest microplastic concentrations affecting marine organisms exposed via water are much higher than levels measured in marine water. In lugworms exposed via sediment, effects were observed at microplastic levels that were higher than those in subtidal sediments but in the same range as maximum levels in beach sediments. Hydrophobic contaminants are enriched on microplastics, but the available experimental results and modelling approaches indicate that the transfer of sorbed pollutants by microplastics is not likely to contribute significantly to bioaccumulation of these pollutants. Prior to being able to comprehensively assess possible environmental risks caused by microplastics a number of knowledge gaps need to be filled. However, in view of the persistence of microplastics in the environment, the high concentrations measured at some environmental sites and the prospective of strongly increasing concentrations, the release of plastics into the environment should be reduced in a broad and global effort regardless of a proof of an environmental risk. Electronic supplementary material The online version of this article (doi:10.1186/s12302-015-0069-y) contains supplementary material, which is available to authorised users.
Article
Full-text available
Mulches provide aesthetic, economic and environmental benefits to urban landscapes. Mulching is especially useful in the establishment of trees in landscapes that receive minimal care, such as restoration sites. In general, mulches improve soil health, creating healthy populations of plants and associated animals. These biodiverse, stable landscapes are more resistant to stress, are more aesthetically pleasing, require fewer applications of pesticides and fertilizers, and are ultimately more sustainable than those without mulch cover. All mulches are not created equally, however, and this review compares the costs and benefits of landscape mulches as reported in the scientific literature. It also presents real and perceived problems associated with various landscape mulches.
Article
Full-text available
The Niagara wine region of Ontario is at the northern fringe of adaptability for Vitis vinifera. In some growing seasons many V. vinifera cultivars do not reach full maturity before the impending winter forces harvest. It has been demonstrated in many studies that sunlight is critical to quality grape production through its effect on photosynthesis and on the expression of genes involved in production of secondary metabolites important to grape quality. Reflective mulch has the potential to improve berry quality through its effect on the microclimate within the canopy and in particular light penetration into the fruiting zone. A multi-varietal trial was established in a commercial vineyard in 2003 to determine the effect of reflective mulch on berry, must and wine quality of Ontario grown V. vinifera grapes. It was hypothesised that increased light resulting from the reflective mulch would improve berry quality, which would in turn produce deeply colored wines with pleasantly, complex sensory characteristics. Results reported in this paper are limited to the cultivar 'Cabernet Franc' portion of this study, which includes an assessment of microclimate within the canopy, berry quality over development from cluster closure to harvest and an experiment to determine the effect of reflective mulch on insect populations within the canopy. The reflective mulch product used in this study deteriorated significantly over the season becoming oxidized, dirty and in some cases losing it reflective coating. While this deterioration undoubtedly impacted the results of this study, mulch enhanced the quantity and quality of light into the fruiting zone, advanced veraison and in general increased oBrix, total phenolics, flavonols and anthocyanins of 'Cabernet Franc' berries at harvest. Mulch also reduced the number of insects trapped in the canopy especially aphids and leafhoppers. These results indicate there is potential for reflective mulch to improve berry quality in Niagara grown grapes, particularly in a late, cool or short growing season.
Article
Full-text available
Background and Aims Although maize roots have been extensively studied, there is limited information on the effect of root exudates on the hydraulic properties of maize rhizosphere. Recent experiments suggested that the mucilaginous fraction of root exudates may cause water repellency of the rhizosphere. Our objectives were: 1) to investigate whether maize rhizosphere turns hydrophobic after drying and subsequent rewetting; 2) to test whether maize mucilage is hydrophobic; and 3) to find a quantitative relation between rhizosphere rewetting, particle size, soil matric potential and mucilage concentration. Methods Maize plants were grown in aluminum containers filled with a sandy soil. When the plants were 3-weeks-old, the soil was let dry and then it was irrigated. The soil water content during irrigation was imaged using neutron radiography. In a parallel experiment, ten maize plants were grown in sandy soil for 5 weeks. Mucilage was collected from young brace roots growing above the soil. Mucilage was placed on glass slides and let dry. The contact angle was measured with the sessile drop method for varying mucilage concentration. Additionally, capillary rise experiments were performed in soils of varying particle size mixed with maize mucilage. We then used a pore-network model in which mucilage was randomly distributed in a cubic lattice. The general idea was that rewetting of a pore is impeded when the concentration of mucilage on the pore surface (g cm−2) is higher than a given threshold value. The threshold value depended on soil matric potential, pore radius and contract angle. Then, we randomly distributed mucilage in the pore network and we calculated the percolation of water across a cubic lattice for varying soil particle size, mucilage concentration and matric potential. Results Our results showed that: 1) the rhizosphere of maize stayed temporarily dry after irrigation; 2) mucilage became water repellent after drying. Mucilage contact angle increased with mucilage surface concentration (gram of dry mucilage per surface area); 3) Water could easily cross the rhizosphere when the mucilage concentration was below a given threshold. In contrast, above a critical mucilage concentration water could not flow through the rhizosphere. The critical mucilage concentration decreased with increasing particle size and decreasing matric potential. Conclusions These results show the importance of mucilage exudation for the water fluxes across the root-soil interface. Our percolation model predicts at what mucilage concentration the rhizosphere turns hydrophobic depending on soil texture and matric potential. Further studies are needed to extend these results to varying soil conditions and to upscale them to the entire root system.
Article
Full-text available
Global crop yields are limited by water and nutrient availability. Soil mulching (with plastic or straw) reduces evaporation, modifies soil temperature and thereby affects crop yields. Reported effects of mulching are sometimes contradictory, likely due to differences in climatic conditions, soil characteristics, crop species, and also water and nitrogen (N) input levels. Here we report on a meta-analysis of the effects of mulching on wheat and maize, using 1310 yield observations from 74 studies conducted in 19 countries. Our results indicate that mulching significantly increased yields, WUE (yield per unit water) and NUE (yield per unit N) by up to 60%, compared with no-mulching. Effects were larger for maize than wheat, and larger for plastic mulching than straw mulching. Interestingly, plastic mulching performed better at relatively low temperature while straw mulching showed the opposite trend. Effects of mulching also tended to decrease with increasing water input. Mulching effects were not related to soil organic matter content. In conclusion, soil mulching can significantly increase maize and wheat yields, WUE and NUE, and thereby may contribute to closing the yield gap between attainable and actual yields, especially in dryland and low nutrient input agriculture. The management of soil mulching requires site-specific knowledge.
Article
Full-text available
Synthetic polymers, commonly named plastics, are among the most widespread anthropogenic pollutants of marine, limnic and terrestrial ecosystems. Disruptive effects of plastics are known to threaten wildlife and exert effects on natural food webs, but signs for and knowledge on plastic biodegradation are limited. Microorganisms are the most promising candidates for an eventual bioremediation of environmental plastics. Laboratory studies have reported various effects of microorganisms on many types of polymers, usually by enzymatic hydrolysis or oxidation. However, most common plastics have proved to be highly recalcitrant even under conditions known to favour microbial degradation. Knowledge on environmental degradation is yet scarcer.With this review, we provide a comprehensive overview of the current knowledge on microbiological degradation of several of the most common plastic types. Furthermore, we illustrate the analytical challenges concerning the evaluation of plastic biodegradation as well as constraints likely standing against the evolution of effective biodegradation pathways.
Article
Full-text available
Controlling competing vegetation during early growth is one of the most important practices for the successful establishment of poplar plantations. Today, most poplar plantations in temperate regions are established on abandoned marginal agricultural land where competing vegetation is usually present during the first years after planting. Thus, the objective of this study was to examine how the growth of two kinds of poplar planting materials, un-rooted cuttings and bare-rooted seedlings was influenced by different vegetation control and soil preparation practices. Across treatments, un-rooted cuttings grew more rapidly than the bare-rooted seedlings. Our results also show that mulching with a degradable carpet or permanent polyethylene plastic increased seedling growth to a similar extent and more strongly in the cases of no treatment (in control plots). In addition, the results suggest that soil preparation in the mulched area favored seedling growth, but this effect was restricted to the first year after planting. These findings indicate that optimal practices for establishing poplar plantations on former agricultural land include planting un-rooted cuttings in prepared soil and mulching.
Article
Full-text available
Significance Deforestation for tree cash crop plantations such as oil palm, rubber, and cacao agroforest in the tropics results in strong decreases in soil organic carbon (SOC) stocks, with much of this carbon lost through carbon dioxide (CO 2 ) emissions and leaching. We found that SOC stock losses in oil palm, rubber, and cacao agroforestry plantations in Indonesia, Cameroon, and Peru could be predicted by the amount of SOC in the original forests: the more SOC present initially, the more SOC lost after conversion. When natural forests were replaced by tree cash crop plantations, SOC losses of up to 50% were found. We recommend that these SOC losses be incorporated in the Intergovernmental Panel on Climate Change tier 1 method for carbon accounting.
Article
Full-text available
The phase out of methyl bromide has forced strawberry (Fragaria xananassa Duchesne) growers to consider the use of cultural methods such as colored mulches to enhance weed control. Black plastic mulch controls most weeds; however, black mulch often does not warm the soil as well as clear mulch. Soil warming with clear mulch is desirable for early season markets, but clear mulch does not control weeds. Neither black nor clear mulches combine the ideal weed control and soil warming characteristics required. Seven colored mulches, as well as clear, black and no mulch were evaluated in California organic and conventional strawberries to identify mulch factors associated with weed control and soil warming. Laboratory and greenhouse experiments were also conducted to isolate the effects of light transmittance through mulch on weed germination and growth. The effect of mulch color on transmittance of photosynthetically active light (400 to 700 nm) through mulches was the key weed control factor, and was more important than the effect of mulch color effect on weed germination. Satisfactory weed control was provided by all mulches except clear, blue and red-brown laminated. Clear and black mulches provided the greatest soil warming in sunny and cloudy climatic conditions, respectively, although plants in clear mulched conventional production system plots produced the highest yield of marketable berries. Green and brown plastic mulches provided the best combinations of soil warming and weed control benefits at all trial locations.
Article
Full-text available
Container production has increased rapidly in many parts of the U.S. over the past 15 years. Container production has been the fastest growing sector in the nursery industry and the growth is expected to continue. Weed growth in container-grown nursery stock is a particularly serious problem, because the nutrients, air, and water available are limited to the volume of the container. The extent of damage caused by weeds is often underestimated and effective control is essential. Various researchers have found that as little as one weed in a small (1 gal) pot affects the growth of a crop. However, even if weeds did not reduce growth, a container plant with weeds is a less marketable product than a weed-free product. Managing weeds in a container nursery involves eliminating weeds and preventing their spread in the nursery, and this usually requires chemical controls. However, chemical controls should never be the only management tools implemented. Maximizing cultural and mechanical controls through proper sanitation and hand weeding are two important means to prevent the spread and regeneration of troublesome weeds. Cultural controls include mulching, irrigation methods (subirrigation), and mix type. Nursery growers estimate that they spend $500 to $4000/acre of containers for manual removal of weeds, depending on weed species being removed. Economic losses due to weed infestations have been estimated at approximately $7000/acre. Reduction of this expense with improved weed control methodologies and understanding weed control would have a significant impact on the industry. Problems associated with herbicide use in container production include proper calibration, herbicide runoff concerns from plastic or gravel (especially when chemicals fall between containers) and the need for multiple applications. As with other crops, off-site movement of pesticides through herbicide leaching, runoff, spray drift, and non-uniformity of application are concerns facing nursery growers. This article reviews some current weed control methods, problems associated with these methods, and possible strategies that could be useful for container nursery growers.
Article
Full-text available
Plastic mulch is commonly used with micro-irrigation in developed countries; however, Chinese farmers use plastic mulch on a vast scale independent of micro-irrigation. For the past three decades, China's land area in plastic mulch has exceeded the world's total land area in micro-irrigation. We report results from the water-scarce region of Minqin County, where 87% of Chinese farmers interviewed responded that they use plastic mulch to conserve water and 53% to increase yields. Survey results indicated the desire to conserve water through the use of plastic mulch to be statistically equivalent to the desire to increase yields. Responses to interviews and surveys indicate that farmers perceive water savings of 24–26% when plastic mulch is used. Interview and survey responses suggest farming families are shifting to purchasing wheat from outside the region; a potential import of “virtual water” into this water-scarce region.
Article
Full-text available
The experiment was carried out in the vegetation seasons of 2010 and 2011. The main purpose of the study was to determine the effects of mulch practices (a control-unmulched treatment, a plastic mulch treatment, and a straw mulch treatment) on fresh ear yield and some yield-related traits of sweet corn according to 3 sowing dates: 1 April, 15 April, and 1 May, respectively. The main effects of sowing dates were significant for the harvest period, the emerging rate from soil, the fresh ear yield per hectare, and the yield components of the sweet corn. The emergence rate of sweet corn was decreased on 1 April and 15 April due to the low soil temperature on these sowing dates. Of the mulch practices, the plastic mulch practice resulted in the highest emergence rate, the highest ear length, the highest ear diameter, the highest ear weight, the highest number of kernels per ear, the highest fresh ear yield, and the highest fresh ear number in both 2010 and 2011. The fresh ear yield and yield components were decreased by the straw mulch practice in both 2010 and 2011. The effects of the sowing date x mulch practice interactions on emergence rate, fresh ear yield, and some yield-related traits of sweet corn were statistically (P < 0.05 and P < 0.01) significant in both years. Of the interactions between the sowing dates and the mulch practices, the highest emergence rate (91.2% in 2010 and 93.7% in 2011), highest ear length (18.4 cm in 2010 and 18.5 cm in 2011), highest ear diameter (45.2 mm in 2010 and 46.5 mm in 2011), highest ear weight (229.1 g in 2010 and 227.1 g in 2011), highest number of kernels per ear (562.1 grains in 2010 and 552.3 grains in 2011), highest fresh ear yield (14,952.6 kg ha(-1) in 2010 and 14,805.2 kg ha(-1) in 2011), and highest fresh ear numbers (65,781.8 cobs ha(-1) in 2010 and 65,789.6 cobs ha(-1) in 2011) were determined from the plastic mulch practices on 1 May, the latest sowing date. The lowest emergence rate, the lowest fresh ear yield, and the lowest yield components were obtained from the straw mulch practice on 1 April, the earliest sowing date, in both 2010 and 2011.
Article
Full-text available
Three cultivars ‘Zefyr’, ‘Honoeoye’ and ‘Polka’ were grown on beds mulched with black plastic or without it, as well as in low tunnels covered by transparent polyethylene film or Agronet (Pegas agro, 17 g·m-2), or without covering. The quality of fruits determined by content of ascorbic acid, titratable acidity, soluble solids, total content of phenolics and anthocyanins, antiradical activity, and radical scavenging activity (RSA) was evaluated during two seasons. Significant differences in phytochemical contents within strawberry cultivars, production seasons and cultivation methods were stated. Cultivar had the greatest influence on the content of ascorbic acid, total phenolics and RSA among all the studied factors. The amount of anthocyanins was mainly influenced by plant covering, while the annual climatic conditions had the greatest impact on the amount of titratable acidity and soluble solids. Soil mulching had the lowest influence on the chemical content of fruits.
Article
Full-text available
The world consumption of plastics in agriculture amounts yearly to 6.5 million tons. In addition to conventional polymers used in agriculture for greenhouses and mulches such as PE, PVC, EVA, photo-selective and luminescent polymers have been used, in order to improve the quality of crops. For the same reason plastic nets are used mainly in countries with tropical and Mediterranean climates. For an environmentally friendly agricultural activity, an alternative strategy can be represented by bio-based agricultural raw materials. For low environmental impact applications, biodegradable materials for agricultural films are nowadays produced. An overview of the main methods for the disposal and recycling of plastic materials are presented with the results of mechanical and radiometric tests on recycled plastics. The strategies to reduce the burden of plastics in agriculture are: a correct procedure for the collection, disposal and recycling of post-consumption plastics; the increase of lifetime duration and performance; and the introduction and promotion of bio-based materials.
Article
Full-text available
This study investigated the combined effects of drip irrigation and mulches on yield, water-use efficiency and economic return of tomato. The treatments of the study comprised different combinations of three drip irrigation levels (100, 75 and 50% of crop water requirement, ETc) and two mulches (black polyethylene sheet and paddy straw). The yield and yield-contributing characters in the mulched treatments for all levels of irrigation were significantly higher compared to those in the unmulched treatments. The yield of tomato increased with the increasing amount of irrigation water in unmulched treatment. The trend was reversed when drip irrigation was coupled with mulches. The highest yield for each mulch (81.12 t/ha for polyethylene and 79.49 t/ha for straw) was obtained when 50% of water requirement was applied. With 100% water application, polyethylene-mulched treatment produced lower yield than the straw-mulched treatment. The highest water use efficiency of 592 kg/ha/mm was obtained with 50% water application under polyethylene mulch. The highest net return (US$ 7098/ha), incremental net return (US$ 1556/ha), and incremental benefit-cost ratio (7.03) were found for 50% water application with straw mulch. The study thus reveals that drip irrigation with mulch has an explicit role in increasing the land and water productivity of tomato.
Article
Recent olive cultivation in Mediterranean Countries is characterised by the strong diffusion of high-density cropping systems and by the most environmentally conscious management regarding all the agronomic practices and the waste disposal as well. This research has investigated the possibility of the use of De-Oiled Pomace (DOP) as an eco-friendly tool for weed control in a high-density olive orchard providing an environmental comparison with other soil management techniques. Five methods of weed control have been compared in a two-year experimental orchard at the Bari University (Southern Italy): mulching with de-oiled olive pomace (DOP), nonwoven tissue (TNT) and polyethylene film (PEN), chemical (CHI) and mechanical (MEC) weeding, on the three most adapted to high-density orchards olive cultivars (Arbequina, Arbosana and Koroneiki). The data collected during the experimental test are submitted to an LCA (Life Cycle Assessment) analysis and five scenarios have been drafted based on DOP use and destinations. The results showed that the chemical wedding produced the greatest environmental burdens, and the higher environmental performances of DOP mulching scenarios for all environmental indexes, with burdens reductions and/or environmental credits. The presence in the following years of some biomarkers sensitive to macro and micro pollutants and heavy metals, in experimental plots mulched with DOP, confirmed the high environmental sustainability of this technique, excluding any kind of soil pollution in the medium-term period in the high-density olive orchard.
Chapter
The development of polyethylene as a plastic film in 1938 and its subsequent introduction as a clear and black plastic mulch in the early 1950s revolutionized the commercial production of selected vegetable crops. Throughout the succeeding years and to the present day, research, extension and industry personnel, together with growers, have documented the advantages of using different plastic mulches as one component of a complete “intensive” vegetable production system. Although a variety of vegetables can be grown successfully using plastic mulches, muskmelons, honeydews, watermelons, squash, cucumbers, tomatoes, peppers, eggplant, okra, sweet corn, and Cole crops have shown significant increases in earliness, total yield, and improved quality. Research since the 1950s continued on field evaluation of new formulations of degradable, first photo and now bio, wavelength-selective, and a wide array of various colored plastic mulches and on cropping systems to best utilize these specific improvements. The use the plastic mulches for the production of vegetable crops continues to increase throughout the United States and the world.
Article
Soil solarization is an environment-friendly soil pasteurization technique which uses the solar energy to increase the soil temperature to diminish soil-related pests and pathogens. The efficiency of this technique is closely related with a number of factors such as soil water and organic matter contents and feature of cover material; therefore, the effect of solarization was studied under applications of CO2, basaltic tuff (BT), organic matter (OM) and a different color plastic cover (PE2) on soil temperature and microbial activity as dehydrogenase enzyme activity (DHA) and soil respiration (CO2). The trial was carried out in a greenhouse for 32 days. Organic matter, salt and lime contents, pH and texture class of greenhouse soil were 1.7%, 0.055%, 38.5%, 7.7 and clay, respectively. According to the results, while the lowest CO2 value was determined as 12.9 mg/100 g ds. 24 h in the A6 (PE2) application, the highest CO2 value was determined as 16.3 mg/100 g ds. 24 h in the A4 (+OM 1.5 kg/m(2)) application. The dehydrogenase enzyme activities (DHA) yielded similar results with the applications, however, the highest value (291.2 mu g TPF/10 g ds.) was in A7 (control). Soil (0-5 cm) temperatures varied between 28.1 and 60.1 degrees C with applications and the lowest soil temperature was determined in the control plot. The effect of the applications to soil temperature led to significant differences statistically (p<0.05). The results documented that the organic matter (OM) and CO2 amendments (OM or +OM+CO2) had a role in protecting soil microbial activity (dehydrogenase-DHA) and soil respiration (CO2) from the detrimental effects of the heating of solarization.
Article
Five organic mulches (pine bark, hardwood bark, cedar chips, longleaf pine needles, shortleaf pine needles), used alone or in combination with two inorganic mulches (black polyethylene, woven polypropylene), were evaluated over two years for weed control, durability, aesthetic value, and influence upon soil temperature. Organic mulches reduced total weed counts by 50% compared to control plots. and underlaying organic mulches with polyethylene resulted in complete control. Polypropylene, used in combination with organic mulch, was ineffective in controlling perennial weed species. Pine bark was the most durable organic mulch, requiring the least replenishment (70% initial volume) after 630 days. Durability of organic mulches increased when underlaid with polyethylene. Longleaf pine needles were rated most attractive, and underlying organic materials with either polyethylene or polypropylene enhanced appearance. Organic mulches reduced maximum daily temperatures at the soil surface by 2.2–3.3°C (4–6°F) and increased minimum daily temperatures by 1.1–2.2°C (2–4°F). However, the type of organic mulch did not affect temperatures at the soil surface.
Article
Agricultural plastics area significant contributor to solid waste disposal problems, particularly in areas with heavy use of plastic-covered greenhouses or mulch films. Field-burning and landfilling are no longer viable options for disposal in many areas. Reuse and reduced weight of films are two methods to reduce the amount of material requiring disposal. Recycling, incineration, and on-site degradation appear to be the most-promising technologies for disposal. Each technology has its drawbacks. These include dirt and pesticide residues on mulch films, the presence of stabilizers and photoactivators, possible limitations to recycling mixtures of types of plastics, and high costs for recycling and incineration facilities. This is an active area of research for many members of the American Society for Plasticulture.
Article
The use of mulches is gaining worldwide attention in a number of different crops, including vineyards. However, the effects of mulches on arthropod assemblages are not well documented. We therefore conducted an initial investigation into the effects of three different types of mulch on arthropod assemblages in vineyards. Sampling took place from March to June 2010 on four wine grape farms in the Stellenbosch/ Paarl region using pitfall traps. All arthropods were identified to family level and classified into functional feeding groups. A total of forty different families of springtail (Collembola) and insect (Insecta) were recorded. Cluster analysis indicated a high degree of similarity between the mulch sites and also between the control sites, based on soil-dweffing arthropod diversity. Springtails and ants were most abundant and could be used as reference organisms for future, larger-scale studies on mulches.
Article
Plastic mulches have various beneficial effects on crop production, including an increase in soil temperature, conservation of soil moisture, texture and fertility; and the control of weeds, pests and diseases. This technology is not only helping to alleviate the issue of climate change but also helping farmers to increase yield, thereby high economic returns for the better quality produce. Challenges faced for commercialization of plastic mulches were lack of mechanization and intensive labour requirement. Tractor mounted mulch laying machine acquired reasonable acceptance in the developed world while its adaptation was limited in developing world particularly South East Asia. Benefit cost analysis of adapting mulch laying machine for viable use was done. Three options such as manual, partially mechanized, and mechanized process of mulch laying were analyzed. The analysis revealed that total operational cost of the machine is INR Rs. 2129 / ($ 36) per hectare with saving of 31.78 % with partially mechanized (Bed planter + Manual Mulch + Manual Drip Laying) and 68.8 % with completely manual operation. Plastic mulching machine also saves 81.43 % and 95.20 % labour over partially mechanized operation and completely manual operation respectively.
Article
Access to water has been identified as one of the most limiting factors in economic growth of Australia's horticultural sector. Water reclaimed from wastewater (sewage) is being increasingly recognized as an important resource and agricultural sector is currently the largest consumer of this resource. An overview of the Australian experience of using reclaimed wastewater to grow horticultural crops is presented in this paper: from regulations governing it and treatment processes, to management and risk-minimization practices that ensure this resource is used in a sustainable manner, not impacting adversely human health or environment. A case study covering socio-economic and environmental implications of recycled-water irrigation is also presented.