Microplastics in the agroecosystem: effects of plastic mulch film residues on the soil-plant system

In the last decades, the use of plastic mulch film in (semi-) arid agricultural regions has strongly increased. Plastic residues from mulching remain and accumulate in soil that can lead to serious environment problems. Biodegradable plastic mulch films were produced as environmentally friendly alternative for solving plastic pollution in agricultural land. However, the effects of polyethylene and biodegradable mulch film residues on soil-plant system are largely unknown.In this PhD project, we performed a series of experiments to assess the effects of low density polyethylene (LDPE) and biodegradable plastic (Bio, made of polyethylene terephthalate, polybutylene terephthalate, pullulan) with macro- (5 mm2, Ma) and micro- (50 &#181;m-1 mm, Mi) sizes on wheat growth, rhizosphere microbiome, soil physicochemical and hydrological properties and soil suppressiveness. The results showed that plastic residues presented negative effects on both above- and below-ground &#160;parts for both vegetative and reproductive development of wheat. We also identified significant effects of Bio and LDPE plastic residues on the rhizosphere bacterial communities and on the blend of volatiles emitted in the rhizosphere. Tested with a gradient in concentration of plastic residues (0, 0.5%, 1% and 2% w/w), soil physicochemical and hydrological properties nonmonotonically responded to residual amount of plastic debris in the soil. Lastly, although we did not observe effects of plastic residues on disease infection in our experiment, we anticipated that soil suppressiveness and other soil functions would be affected with the presence of plastics in soil.Overall, our study provides evidence for impacts of plastic residues on the soil-plant system, suggesting urgent need for more research examining their environmental impacts on agroecosystems.

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Effects of plastic mulch film residues on soil-microbe-plant systems under different soil pH conditions

Chemosphere ◽

10.1016/j.chemosphere.2020.128901 ◽

2020 ◽

pp. 128901

Author(s):

Yin Liu ◽

Qing Huang ◽

Wen Hu ◽

Jiemin Qin ◽

Yingrui Zheng ◽

...

Keyword(s):

Soil Ph ◽

Plastic Mulch ◽

Soil Microbe ◽

Mulch Film ◽

Ph Conditions

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Insulative effect of plastic mulch systems and comparison between the effects of different plant types

Open Agriculture ◽

10.1515/opag-2020-0028 ◽

2020 ◽

Vol 5 (1) ◽

pp. 317-324

Author(s):

Kayla Snyder ◽

Christopher Murray ◽

Bryon Wolff

Keyword(s):

Soil Moisture ◽

Root Zone ◽

Plastic Mulch ◽

Root Zone Temperature ◽

Tomato Plants ◽

Black Film ◽

Black And White ◽

Mulch Film ◽

Mulch Films ◽

Zone Temperature

AbstractTo address agricultural needs of the future, a better understanding of plastic mulch film effects on soil temperature and moisture is required. The effects of different plant type and mulch combinations were studied over a 3.5-month period to better grasp the consequence of mulch on root zone temperature (RZT) and moisture. Measurements of (RZT) and soil moisture for tomato (Solanum lycopersicum), pepper (Capsicum annuum) and carrot (Daucus carota) grown using polyolefin mulch films (black and white-on-black) were conducted in Ontario using a plot without mulch as a control. Black mulch films used in combination with pepper and carrot plants caused similar RZTs relative to uncovered soil, but black mulch film in combination with tomato plants caused a reduction in RZT relative to soil without mulch that increased as plants grew and provided more shade. White-on-black mulch film used in combination with tomatoes, peppers or carrots led to a reduction in RZT relative to soil without mulch that became greater than the temperature of soil without mulch. This insulative capability was similarly observed for black mulch films used with tomato plants. Apart from white-on-black film used in combination with tomatoes, all mulch film and plant combinations demonstrated an ability to stabilize soil moisture relative to soil without mulch. RZT and soil moisture were generally stabilized with mulch film, but some differences were seen among different plant types.

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Impact of plastic mulch film debris on soil physicochemical and hydrological properties

Environmental Pollution ◽

10.1016/j.envpol.2020.115097 ◽

2020 ◽

Vol 266 ◽

pp. 115097 ◽

Cited By ~ 3

Author(s):

Yueling Qi ◽

Nicolas Beriot ◽

Gerrit Gort ◽

Esperanza Huerta Lwanga ◽

Harm Gooren ◽

...

Keyword(s):

Plastic Mulch ◽

Mulch Film

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Study on the Biodegradation of Plastic Mulch Film Residue of Farmland by Galleria mellonella

Hans Journal of Agricultural Sciences ◽

10.12677/hjas.2020.105039 ◽

2020 ◽

Vol 10 (05) ◽

pp. 255-262

Author(s):

彩霞吕

Keyword(s):

Galleria Mellonella ◽

Plastic Mulch ◽

Mulch Film

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The effects of biodegradable mulch film on the growth, yield, and water use efficiency of cotton and maize in an arid region

10.1101/703264 ◽

2019 ◽

Author(s):

Lu Deng ◽

Ruide Yu ◽

Qian Wang

Keyword(s):

Soil Temperature ◽

Water Use ◽

Arid Region ◽

Growth Yield ◽

Bare Soil ◽

Plastic Film ◽

Plastic Mulch ◽

Mulch Film ◽

Biodegradable Mulch ◽

Use Efficiency

AbstractPlastic residual film pollution in China is serious, and the use of degradable mulch film instead of plastic mulch can effectively alleviate this situation. The substitution of common polyethylene plastic mulch film with biodegradable mulch film in the agricultural production of cotton and maize in an arid region was investigated in the present study. Using bare soil as the control, we compared the effects of common polyethylene plastic film and biodegradable mulch film on crop growth, yield, and water use efficiency (WUE) in maize and cotton. The results indicated that: (1) the biodegradable mulch film in this region remained intact for 60 days after being laid down, significantly degrading after 120 days, and was associated with increased soil temperature, moisture conservation, and degradability in comparison to a bare soil control. (2) Both the biodegradable mulch film and the polyethylene plastic film significantly increased various physiological parameters, such as crop height, stalk diameter, and leaf area. (3) The biodegradable mulch film significantly increased maize and cotton crop yield by 69.4–76.2% and 65.2–71.9%, respectively, compared to the bare soil control. (4) Compared to the bare soil control, the biodegradable mulch film effectively increased WUE in the crops by 64.5–73.1%. In summary, biodegradable mulch film had comparable results to the common polyethylene plastic film in increasing soil temperature, moisture conservation, crop growth, yield, and WUE. As the biodegradable mulch film causes no residual pollution, it is thus preferable to common plastic mulch film for agricultural applications in arid regions and supports the sustainable development of agroecosystems.

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