Effects of Microplastic Fibers on Soil Aggregation and Enzyme Activities Are Organic Matter Dependent

Microplastic as an anthropogenic pollutant accumulates in terrestrial ecosystems over time, threatening soil quality and health, for example by decreasing aggregate stability. Organic matter addition is an efficient approach to promote aggregate stability, yet little is known about whether microplastic can reduce the beneficial effect of organic matter on aggregate stability. We investigated the impacts of microplastic fibers in the presence or absence of different organic materials by carrying out a soil incubation experiment. This experiment was set up as a fully factorial design containing all combinations of microplastic fibers (no microplastic fiber addition, two different types of polyester fibers, and polyacrylic) and organic matter (no organic matter addition, Medicago lupulina leaves, Plantago lanceolata leaves, wheat straw, and hemp stems). We evaluated the percentage of water-stable aggregates (WSA) and activities of four soil enzymes (β-glucosidase, β-D-celluliosidase, N-acetyl-b-glucosaminidase, phosphatase). Organic matter addition increased WSA and enzyme activities, as expected. In particular, Plantago or wheat straw addition increased WSA and enzyme activities by 224.77 or 281.65% and 298.51 or 55.45%, respectively. Microplastic fibers had no effect on WSA and enzyme activities in the soil without organic matter addition, but decreased WSA and enzyme activities by 26.20 or 37.57% and 23.85 or 26.11%, respectively, in the presence of Plantago or wheat straw. Our study shows that the effects of microplastic fibers on soil aggregation and enzyme activities are organic matter dependent. A possible reason is that Plantago and wheat straw addition stimulated soil aggregation to a greater degree, resulting in more newly formed aggregates containing microplastic, the incorporated microplastic fibers led to less stable aggregates, and decrease in enzyme activities This highlights an important aspect of the context dependency of microplastic effects in soil and on soil health. Our results also suggest risks for soil stability associated with organic matter additions, such as is common in agroecosystems, when microplastics are present.

Download Full-text

Perbaikan Stabilitas Agregat Tanah Pasir Berlempung Menggunakan Bakteri Pemantap Agregat dan Bahan Organik

Jurnal Tanah dan Iklim ◽

10.21082/jti.v42n2.2018.161-167 ◽

2020 ◽

Vol 42 (2) ◽

pp. 161

Author(s):

Diana Utama ◽

Nuni Gofar ◽

Adipati Napoleon

Keyword(s):

Organic Matter ◽

Incubation Period ◽

Soil Aggregates ◽

Aggregate Stability ◽

Soil Aggregation ◽

Cattle Manure ◽

Loamy Sand ◽

Sand Soil ◽

Loamy Sand Soil ◽

Observation Period

Abstrak. Penelitian ini bertujuan untuk menganalisis stabilitas agregat tanah dengan perlakuan berbagai isolat bakteri pemantap agregat (BPA) dan bahan organik berupa kompos yang terbuat dari campuran 90% rumput Cyperus pilosus Vahl dan 10% kotoran sapi, dengan masa inkubasi yang berbeda. Taraf perlakuan terdiri dari kontrol, kombinasi isolat I, II, dan III masing – masing dikombinasikan dengan komposisi bahan organik 0%, 0.5%, dan 1%. Hasil penelitian ini menunjukkan aplikasi isolat BPA pada tanah pasir berlempung disertai pemberian bahan organik menyebabkan populasi yang lebih tinggi dibandingkan tanpa aplikasi keduanya. Klebsiella sp. LW-13 yang dikombinasi dengan 1% bahan organik dan Bukholderia anthina MYSP113 yang dikombinasi dengan berbagai taraf bahan organik (0 hingga 1%) menyebabkan agregat menjadi sangat mantap sekali pada pengamatan 60 hari setelah aplikasi. Eksopolisakarida yang dihasilkan bakteri akan mengikat partikel tanah dan membentuk agregasi. Penggunaan bakteri Bukholderia anthina MYSP113 dinilai lebih efisien dalam pemanfaatannya untuk memantapkan agregat tanah karena memiliki kemampuan terbaik untuk memantapkan agregat tanah hingga sangat mantap sekali dengan atau tanpa penambahan bahan organik pada periode 60 hari pengamatan.Abstract. This study aimed to analyze the aggregate stability of soil with sdifferent treatments of aggregate-stabilizing bacteria and organic matter (compost made of mixture of 90% Cyperus pilosus Vahl grass biomass and 10% cattle manure) at different incubation period. Treatments consisted of control, combination of three different isolate with three different composition of organic matter (0%, 0.5%, and 1%). The results showed that the application of aggregate-stabilyzing bacteria to loamy sand soil and organic matter causes a higher bacteria population than without both applications. Klebsiella sp. LW-13 combined with 1% organic matter and Bukholderia anthina MYSP113 which was combined with various levels of organic matter (0 to 1%) showed high aggregation at observation of 60 days after application. The exopolysaccharide produced by bacteria binds soil particles and forms soil aggregation. The use of Bukholderia anthina MYSP113 bacteria is considered to be efficient in its utilization to stabilize soil aggregates because it has the best ability to stabilize soil aggregates to be highly stable with or without the addition of organic matter in the 60-day observation period.

Download Full-text

Assessing of soil aggregate stability: the sand-correction and its relevance

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/35/2807 ◽

2009 ◽

pp. 29-47

Author(s):

Andrea Huisz

Keyword(s):

Wheat Straw ◽

Soil Structure ◽

Sandy Loam ◽

Aggregate Stability ◽

Index Formula ◽

Soil Aggregate Stability ◽

Mean Weight Diameter ◽

Loam Soil ◽

The Mean ◽

Organic Matter Addition

Soil structure and changes in its quality caused by Maize stem (1), Wheat straw (2) and Maize stem & wheat straw (3) addition were assessed by three aggregate-stability indices. We observed that the NSI index formula proposed by Six et al. (2000) was nonsensitive to the changes in soil structure caused by the investigated organic matter addition. Furthermore it overestimates the aggregate-stability of the investigated silty sandy loam soil. Therefore we proposed a new modified NSI formula which is sensitive to the questionable treatments and that resulted in a morerealistic NSI data. The most sensitive index to differences of the investigated treatments were the Mean weight diameter (MWD) proposed by van Bavel (1953, in Kemper és Rosneau, 1986).

Download Full-text

Crop residues amendments quality and effect on greenhouse gas emissions and aggregate stability

10.5194/egusphere-egu2020-5973 ◽

2020 ◽

Author(s):

Gheorghe Stegarescu ◽

Jordi Escuer ◽

Karin Kauer ◽

Endla Reintam

Keyword(s):

Organic Matter ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Wheat Straw ◽

Oilseed Rape ◽

Biochemical Composition ◽

Crop Residues ◽

Aggregate Stability ◽

Total Carbon ◽

Gas Emissions

The organic residues amendments have been widely studied for their essential role of enriching the soil with organic matter. Although the pathways of the fresh organic matter additions are very complex, so is the effect. Thus, the quality of the crop residues incorporated into the soil is a valuable attribute when deciding to switch to conservation agriculture. The different C/N ratio and biochemical composition of the crop residues will affect in various ways soil CO2, N2O and CH4 emissions and soil structural stability. The study explores the effect of different crop residues incorporated in the soil on greenhouse gas emissions and aggregate stability. The incubation experiment consisted of five treatments: control (just soil), sand (as reference), soil mixed with wheat straw, soil mixed with green fresh rye residues and soil mixed with green fresh oilseed rape residues. The residues were applied into the soil at a rate of 6 g C kg-1 of soil. The pots of all the treatments were placed for incubation for 105 days at approximately 23 oC and covered with dark plastic bags. The wetting procedure was done five times at 0-11-26-46-75 days to bring the soil to field capacity for water. The sampling for the gas emissions and aggregate stability was done before wetting and after wetting. The gas emissions were sampled using the chamber method and analysed in a Gas Chromatographer. The water-stable aggregates were analysed using the wet sieving method. The plant material was chemically analysed for total carbon and nitrogen and the biochemical composition on Fourier Transform Infrared Spectroscopy. The results revealed that the cumulative CO2 emissions in oilseed rape were 8% higher than in rye treatment. Also, it was 76% higher than in wheat straw treatment and 95 % higher than in control treatment. The highest cumulative N2O emissions were registered in rye treatment 18.79 (&#177;0.48) mg m-2 h-1. Oilseed rape treatment had 19% lower cumulative emissions compared to rye and 98 % higher compared to control and wheat straw treatments. Both rye and oilseed rape had a low C/N ratio 12 and 10, respectively whereas wheat straw had 98 C/N ratio. From a biochemical point of view, the wheat straw was richer in stable compounds such as lignin, cellulose and hemicellulose followed by rye and oilseed rape which had a higher content of labile compounds such as sugars and easily decomposable proteins. In general mean aggregate stability increased significantly only in the wheat straw treatment being 34.69% &#177;1.35.&#160;In conclusion, this study showed that crop residues with low C/N ratio have a negative effect on greenhouse emissions. But do not have a long term effect on the increase of aggregate stability. On the contrary, the wheat straw has a positive impact on greenhouse gases, and it increased aggregate stability.&#160;

Download Full-text

Effect of crop residues on soil aggregate stability

Acta Agraria Debreceniensis ◽

10.34101/actaagrar/30/2986 ◽

2008 ◽

pp. 23-32

Author(s):

Andrea Huisz ◽

Tibor Tóth ◽

Tamás Németh

Keyword(s):

Organic Matter ◽

Wheat Straw ◽

Soil Structure ◽

Crop Residues ◽

Aggregate Stability ◽

Soil Aggregate ◽

Organic Matters ◽

Soil Aggregate Stability

Soil structure may be improved by adding readily decomposable organic matter. The extent of amelioration depends on the chemical build-up and decomposability of the crop residues. Three different kinds of organic matters were investigated: (1) maize stem, (2) wheat straw, and (3) maize stem& wheat straw. Comparing the aggregate stabilizing effects of the differently decomposable organic matters to each other, the expected maize stem & wheat straw (mw) > maize stem (m) > wheat straw (w) order was proved.

Download Full-text

Impact of soil use on aggregate stability and its relationship with soil organic carbon at two different altitudes in the Colombian Andes

Agronomía Colombiana ◽

10.15446/agron.colomb.v37n3.77601 ◽

2019 ◽

Vol 37 (3) ◽

pp. 263-273

Author(s):

Efraín Francisco Visconti-Moreno ◽

Ibonne Geaneth Valenzuela-Balcázar

Keyword(s):

Organic Matter ◽

Organic Carbon ◽

Soil Organic Carbon ◽

Aggregate Stability ◽

Tropical Climate ◽

Mineral Particle ◽

Organic Carbon Content ◽

Rice Soils ◽

Organic Matter Pool ◽

Different Altitudes

The stability of soil aggregates depends on the organic matter, and the soil use and management can affect the soil organicmatter (SOM) content. Therefore, it is necessary to know therelationship between aggregate stability and the content of SOMin different types of soil use at two different altitudes of theColombian Andes. This study examined the conditions of soilaggregate stability expressed as a distribution of the size classes of stable aggregates (SA) and of the mean weighted diameter of the stable aggregates (MWD). To correlate these characteristics with the soil organic carbon (OC), we measured the particulate organic matter pool (POC), the OC associated with the mineral organic matter pool (HOC), the total organic carbon content (TOC), and the humification rate (HR). Soils were sampled at two altitudes: 1) Humic Dystrudepts in a cold tropical climate (CC) with three plots: tropical mountain rainforest, pastures, and crops; 2) Fluvaquentic Dystrudepts in a warm tropical climate (WC) with three plots: tropical rainforest, an association of oil palm and pastures, and irrigated rice. Soils were sampled at three depths: 0-5, 5-10 and 10-20 cm. The physical properties, mineral particle size distribution, and bulk density were measured. The content of SA with size>2.36 mm was higher in the CC soil (51.48%) than in the WC soil (9.23%). The SA with size 1.18-2.36 mm was also higher in the CC soil (7.78%) than in the WC soil (0.62%). The SA with size 0.60-1.18 mm resulted indifferent. The SA with size between 0.30 and 0.60 mm were higher in the WC soil (13.95%) than in the CC soil (4.67%). The SA<0.30 mm was higher in the WC soil (72.56%) than in the CC soil (32.15%). It was observed that MWD and the SA>2.36 mm increased linearly with a higher POC, but decreased linearly with a higher HR. For the SA<0.30 mm, a linear decrease was observed at a higher POC, while it increased at a higher HR.

Download Full-text

Intake and digestion of lucerne hay and wheat straw by cattle 14 to 56 weeks of age

Australian Journal of Agricultural Research ◽

10.1071/ar9910621 ◽

1991 ◽

Vol 42 (4) ◽

pp. 621 ◽

Cited By ~ 2

Author(s):

J Leibholz

Keyword(s):

Organic Matter ◽

Wheat Straw ◽

Dry Matter ◽

Total Organic Matter ◽

Wet Sieving

Eight Friesian calves, 8 weeks of age, were prepared with rumen and abomasal cannulae. Four calves were given lucerne and four calves were given wheat straw sprayed with urea and minerals. The diets were changed over between the calves every 6 weeks until the calves were 56 weeks of age. The particles in the rumen that passed through a 1 mm screen during wet sieving were 66 to 73% of the total particles in the rumen of calves given lucerne and 77 to 84% of the particles in the rumen of the calves given wheat straw. The digestion of organic matter in the stomach was 71 to 79% of the total organic matter digested in the calves given lucerne. In the calves given wheat straw, between 82 and 95% of the total organic matter digestion occurred in the stomach. The apparent digestion of dry matter in the calves given lucerne was 61-6856 and did not change with age of the calves. The apparent digestion of dry matter when the calves were given wheat straw was 42% at 14 weeks of age, and it increased to 53% at 56 weeks of age. The digestion of nitrogen in the intestine in the heifers given wheat straw increased to 26 weeks of age while that of heifers given lucerne hay decreased.

Download Full-text

Nitrogen addition stimulates soil aggregation and enhances carbon storage in terrestrial ecosystems of China: A meta‐analysis

Global Change Biology ◽

10.1111/gcb.15604 ◽

2021 ◽

Author(s):

Xiaofei Lu ◽

Enqing Hou ◽

Jieyun Guo ◽

Frank S. Gilliam ◽

Jianlong Li ◽

...

Keyword(s):

Carbon Storage ◽

Meta Analysis ◽

Terrestrial Ecosystems ◽

Nitrogen Addition ◽

Soil Aggregation

Download Full-text

Linking Genes to Traits in Fungi

Microbial Ecology ◽

10.1007/s00248-021-01687-x ◽

2021 ◽

Author(s):

A. L. Romero-Olivares ◽

E. W. Morrison ◽

A. Pringle ◽

S. D. Frey

Keyword(s):

Organic Matter ◽

Nitrogen Uptake ◽

Brown Rot ◽

Terrestrial Ecosystems ◽

Organic Matter Decomposition ◽

Gene Frequencies ◽

Ecological Processes ◽

Linked Gene ◽

Carbon Cycles ◽

Brown Rot Fungi

AbstractFungi are mediators of the nitrogen and carbon cycles in terrestrial ecosystems. Examining how nitrogen uptake and organic matter decomposition potential differs in fungi can provide insight into the underlying mechanisms driving fungal ecological processes and ecosystem functioning. In this study, we assessed the frequency of genes encoding for specific enzymes that facilitate nitrogen uptake and organic matter decomposition in 879 fungal genomes with fungal taxa grouped into trait-based categories. Our linked gene-trait data approach revealed that gene frequencies vary across and within trait-based groups and that trait-based categories differ in trait space. We present two examples of how this linked gene-trait approach can be used to address ecological questions. First, we show that this type of approach can help us better understand, and potentially predict, how fungi will respond to environmental stress. Specifically, we found that trait-based categories with high nitrogen uptake gene frequency increased in relative abundance when exposed to high soil nitrogen enrichment. Second, by comparing frequencies of nitrogen uptake and organic matter decomposition genes, we found that most ectomycorrhizal fungi in our dataset have similar gene frequencies to brown rot fungi. This demonstrates that gene-trait data approaches can shed light on potential evolutionary trajectories of life history traits in fungi. We present a framework for exploring nitrogen uptake and organic matter decomposition gene frequencies in fungal trait-based groups and provide two concise examples on how to use our framework to address ecological questions from a mechanistic perspective.

Download Full-text