Authors :
Rukaiya Rifhat; Pin Gao
Volume/Issue :
Volume 9 - 2024, Issue 3 - March
Google Scholar :
https://tinyurl.com/23ck3wzn
Scribd :
https://tinyurl.com/yev8w8su
DOI :
https://doi.org/10.38124/ijisrt/IJISRT24MAR2137
Abstract :
Microplastic (MP) pollution poses a huge
threat to rice fields, but the distribution characteristics of
MPs in farmlands of different types of areas are still
uncertain. In this work, 24 samples from 12 rice fields of
four different land-use types (Factory, highway,
greenhouse/mulching and normal fields) were collected
from Songjiang, Shanghai. From our selected sites, it was
found that MP abundances were in the range of 233.33-
173.33 particles/kg in rhizosphere and bulk soil. MP
distribution results showed that over 40% of particles
were less than 1 mm and MP sizes ranging between 1 and
5 mm represented the greatest proportion. According to
our study, MP in rhizosphere soil has the highest
abundance (233.33 ± 57.73 particles/kg) than bulk soil.
The particle shape classified as fragment (with edges
and angular) was the most frequent shape found near
factory areas, with an abundance of approximately
37.10%. Copolymers of polypropylene- polyethylene
(PP/PE) at 24.30% were the most abundant polymers in
rice lands in both bulk and rhizosphere soils; following is
polystyrene (PS) at 21.40%, respectively. Most of the
particles found in soils were white. Statistical analyses
showed that fields near factories and fields where plastic
mulching (mulch film and greenhouse crops) was used
had a significantly higher particle abundance for bulk
and rhizosphere soils, hence identifying plastic mulching
as a major contributor to MP pollution in paddy soils. In
industrial areas, MP can also be generated by released
waste or by air. Microbial studies in rice roots,
rhizosphere soil, and bulk soil show variation in the
abundance of different species and genera. The dominant
bacterial phyla in rice roots are Proteobacteria,
Actinobacteriota, Firmicutes, and Bacteroidota. These
microbes have been observed and can be impacted by the
presence of MPs. Rhizosphere soil and bulk soil have an
abundance of Chloroflexi, Actinobacteriota,
Proteobacteria, Firmicutes, and Acidobacteriota. The
specific effects on the microbial community structure
depend on factors like MP type, concentration, and
exposure duration. As our study was field-based, the
significant effect of a specific type or concentration of MP
was difficult to identify.
Variation analyses of MP characteristics revealed
that paddy lands were more likely to contain fragment
shapes and large MP particles (1-5 mm). Also,
rhizosphere soils were likely to contain fragment shapes
and pony-size MPs (0.02-0.2 mm). Differences among rice
fields may depend on various reasons, such as using slow-
release fertilizers, mulching plastic application, irrigation,
atmospheric fallout, etc. This study provides some proper
evidence about the characteristics of MP pollution in rice
fields of Songjiang and explores some probable conditions
and predominant MP sources in rice fields.
Keywords :
Microplastics, Songjiang City, Soil, Paddy Field, Microplastic Classification.
Microplastic (MP) pollution poses a huge
threat to rice fields, but the distribution characteristics of
MPs in farmlands of different types of areas are still
uncertain. In this work, 24 samples from 12 rice fields of
four different land-use types (Factory, highway,
greenhouse/mulching and normal fields) were collected
from Songjiang, Shanghai. From our selected sites, it was
found that MP abundances were in the range of 233.33-
173.33 particles/kg in rhizosphere and bulk soil. MP
distribution results showed that over 40% of particles
were less than 1 mm and MP sizes ranging between 1 and
5 mm represented the greatest proportion. According to
our study, MP in rhizosphere soil has the highest
abundance (233.33 ± 57.73 particles/kg) than bulk soil.
The particle shape classified as fragment (with edges
and angular) was the most frequent shape found near
factory areas, with an abundance of approximately
37.10%. Copolymers of polypropylene- polyethylene
(PP/PE) at 24.30% were the most abundant polymers in
rice lands in both bulk and rhizosphere soils; following is
polystyrene (PS) at 21.40%, respectively. Most of the
particles found in soils were white. Statistical analyses
showed that fields near factories and fields where plastic
mulching (mulch film and greenhouse crops) was used
had a significantly higher particle abundance for bulk
and rhizosphere soils, hence identifying plastic mulching
as a major contributor to MP pollution in paddy soils. In
industrial areas, MP can also be generated by released
waste or by air. Microbial studies in rice roots,
rhizosphere soil, and bulk soil show variation in the
abundance of different species and genera. The dominant
bacterial phyla in rice roots are Proteobacteria,
Actinobacteriota, Firmicutes, and Bacteroidota. These
microbes have been observed and can be impacted by the
presence of MPs. Rhizosphere soil and bulk soil have an
abundance of Chloroflexi, Actinobacteriota,
Proteobacteria, Firmicutes, and Acidobacteriota. The
specific effects on the microbial community structure
depend on factors like MP type, concentration, and
exposure duration. As our study was field-based, the
significant effect of a specific type or concentration of MP
was difficult to identify.
Variation analyses of MP characteristics revealed
that paddy lands were more likely to contain fragment
shapes and large MP particles (1-5 mm). Also,
rhizosphere soils were likely to contain fragment shapes
and pony-size MPs (0.02-0.2 mm). Differences among rice
fields may depend on various reasons, such as using slow-
release fertilizers, mulching plastic application, irrigation,
atmospheric fallout, etc. This study provides some proper
evidence about the characteristics of MP pollution in rice
fields of Songjiang and explores some probable conditions
and predominant MP sources in rice fields.
Keywords :
Microplastics, Songjiang City, Soil, Paddy Field, Microplastic Classification.
