scholarly journals Abiotic and Biotic Factors Influencing the Effect of Microplastic on Soil Aggregation

Soil Systems ◽  
2019 ◽  
Vol 3 (1) ◽  
pp. 21 ◽  
Author(s):  
Anika Lehmann ◽  
Katharina Fitschen ◽  
Matthias Rillig
Keyword(s):  
Soil Structure ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Soil Aggregation ◽  
Soil Biota ◽  
Aggregate Formation ◽  
Sterile Soil ◽  
Soil Aggregate Stability ◽  
Abiotic And Biotic Factors ◽  
Positive Effect

Plastic is an anthropogenic, ubiquitous and persistent contaminant accumulating in our environment. The consequences of the presence of plastics for soils, including soil biota and the processes they drive, are largely unknown. This is particularly true for microplastic. There is only little data available on the effect of microplastics on key soil processes, including soil aggregation. Here, we investigated the consequences of polyester microfiber contamination on soil aggregation of a sandy soil under laboratory conditions. We aimed to test if the microfiber effects on soil aggregation were predominantly physical or biological. We found that soil biota addition (compared to sterile soil) had a significant positive effect on both the formation and stabilization of soil aggregates, as expected, while wet-dry cycles solely affected aggregate formation. Polyester microfiber contamination did not affect the formation and stability of aggregates. But in the presence of soil biota, microfibers reduced soil aggregate stability. Our results show that polyester microfibers have the potential to alter soil structure, and that these effects are at least partially mediated by soil biota.

scholarly journals Dynamics of Soil Organic Carbon and Labile Carbon Fractions in Soil Aggregates Affected by Different Tillage Managements

2021 ◽  
Vol 13 (3) ◽  
pp. 1541
Author(s):  
Xiaolin Shen ◽  
Lili Wang ◽  
Qichen Yang ◽  
Weiming Xiu ◽  
Gang Li ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
No Tillage ◽  
Labile Carbon ◽  
Carbon Fractions ◽  
Soil Aggregate Stability ◽  
Positive Effects

Our study aimed to provide a scientific basis for an appropriate tillage management of wheat-maize rotation system, which is beneficial to the sustainable development of agriculture in the fluvo-aquic soil areas in China. Four tillage treatments were investigated after maize harvest, including rotary tillage with straw returning (RT), deep ploughing with straw returning (DP), subsoiling with straw returning (SS), and no tillage with straw mulching (NT). We evaluated soil organic carbon (SOC), dissolved organic carbon (DOC), permanganate oxidizable carbon (POXC), microbial biomass carbon (MBC), and particulate organic carbon (POC) in bulk soil and soil aggregates with five particle sizes (>5 mm, 5–2 mm, 2–1 mm, 1–0.25 mm, and <0.25 mm) under different tillage managements. Results showed that compared with RT treatment, NT treatment not only increased soil aggregate stability, but also enhanced SOC, DOC, and POC contents, especially those in large size macroaggregates. DP treatment also showed positive effects on soil aggregate stability and labile carbon fractions (DOC and POXC). Consequently, we suggest that no tillage or deep ploughing, rather than rotary tillage, could be better tillage management considering carbon storage. Meanwhile, we implied that mass fractal dimension (Dm) and POXC could be effective indicators of soil quality, as affected by tillage managements.

scholarly journals Sludge amendment accelerating reclamation process of reconstructed mining substrates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dan Li ◽  
Ningning Yin ◽  
Ruiwei Xu ◽  
Liping Wang ◽  
Zhen Zhang ◽  
...  
Keyword(s):  
Soil Structure ◽  
Aggregate Stability ◽  
Soil Aggregate ◽  
Soil Reclamation ◽  
Soil Restoration ◽  
Total Biomass ◽  
Soil Aggregate Stability ◽  
Mining Soil ◽  
Positive Correlations ◽  
Reclamation Process

AbstractWe constructed a mining soil restoration system combining plant, complex substrate and microbe. Sludge was added to reconstructed mine substrates (RMS) to accelerate the reclamation process. The effect of sludge on plant growth, microbial activity, soil aggregate stability, and aggregation-associated soil characteristics was monitored during 10 years of reclamation. Results show that the height and total biomass of ryegrass increases with reclamation time. Sludge amendment increases the aggregate binding agent content and soil aggregate stability. Soil organic carbon (SOC) and light-fraction SOC (LFOC) in the RMS increase by 151% and 247% compared with those of the control, respectively. A similar trend was observed for the glomalin-related soil protein (GRSP). Stable soil aggregate indexes increase until the seventh year. In short, the variables of RMS determined after 3–7 years insignificantly differ from those of the untreated sample in the tenth-year. Furthermore, significant positive correlations between the GRSP and SOC and GRSP and soil structure-related variables were observed in RMS. Biological stimulation of the SOC and GRSP accelerates the recovery of the soil structure and ecosystem function. Consequently, the plant–complex substrate–microbe ecological restoration system can be used as an effective tool in early mining soil reclamation.

Vegetation dynamics drive the evolution of soil aggregate stability during the first 14,000 years of soil development in the Swiss alps

2021 ◽  
Author(s):  
Konrad Greinwald ◽  
Tobias Gebauer ◽  
Ludwig Treuter ◽  
Victoria Kolodziej ◽  
Alessandra Musso ◽  
...  
Keyword(s):  
Vegetation Dynamics ◽  
Plant Cover ◽  
Aggregate Stability ◽  
Root Traits ◽  
Soil Aggregate ◽  
Swiss Alps ◽  
Soil Aggregate Stability ◽  
Alpine Regions ◽  
The Stability ◽  
Positive Effect

&lt;p&gt;&lt;strong&gt;Aims:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;The stability of hillslopes is an essential ecosystem service, especially in alpine regions with soils prone to erosion. One key variable controlling hillslope stability is soil aggregate stability. However, there is comparatively little knowledge about how vegetation dynamics affect soil aggregate stability during landscape evolution.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Methods:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;We quantified soil aggregate stability by determining the Aggregate Stability Coefficient (ASC), which was developed for stone-rich soils. To reveal how hillslope aging and corresponding changes in vegetation affect the evolution of ASC, we measured plant cover, diversity, and root traits along two chronosequences in the Swiss Alps.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Results:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;We found a significant positive effect of vegetation cover and diversity on ASC that was mediated via root traits. These relationships, however, developed in a time-depended manner: At young terrain ages, above- and belowground vegetation characteristics had a stronger effect on aggregate stability than species diversity, whereas these relationships were weaker at older stages.&lt;/p&gt;&lt;p&gt;&lt;strong&gt;Conclusions:&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;Our findings highlight the importance of vegetation dynamics for the evolution of aggregate stability and enhance our understanding of processes linked to hillslope stabilization, which is a key priority to avoid further soil degradation and connected risks to human safety in alpine areas.&lt;/p&gt;

scholarly journals Do different arbuscular mycorrhizal fungi affect the formation and stability of soil aggregates?

2019 ◽  
Vol 43 ◽  
Author(s):  
Marisângela Viana Barbosa ◽  
Daniela de Fátima Pedroso ◽  
Nilton Curi ◽  
Marco Aurélio Carbone Carneiro
Keyword(s):  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Stability Index ◽  
Arbuscular Mycorrhizal ◽  
Soil Aggregate ◽  
Porous Space ◽  
Soil Aggregate Stability ◽  
The Mean

ABSTRACT Soil structure, which is defined by the arrangement of the particles and the porous space forming aggregates, is one of the most important properties of the soil. Among the biological factors that influence the formation and stabilization of soil aggregates, arbuscular mycorrhizal fungi (AMF) are distinguished due to extrarradicular hyphae and glomalin production. In this context, the objective of this study was to evaluate different AMF (Acaulospora colombiana, Acaulospora longula, Acaulospora morrowiae, Paraglomus occultum and Gigaspora margarita) associated with Urochloa brizantha (A. Rich.) Stapf on soil aggregate stability. The study was conducted in a completely randomized design, using an Oxisol and autoclaved sand 2:1 (v/v), with seven treatments: five AMF; and treatments with plants without inoculation and with only the soil, with 5 replicates. The experiment was conducted during 180 days and the following variables were evaluated: mycelium total length (TML); production of easily extractable glomalin-related soil protein (GRSP) in the soil and aggregate classes; stability of the dry and immersed in water aggregates through the mean geometric diameter (MGD) and the mean weighted diameter (MWD) of aggregates; and the soil aggregate stability index (ASI). It was observed that the inoculation favored soil aggregation, with a high incidence of A. colombiana, which presented the highest MGD, TML and GRSP production in the aggregates with Ø>2.0mm and for A. colombiana and A. morrowiae in the aggregates with Ø<0.105 mm, when compared to the treatment without inoculation. These results show that there is a distinction between the effects of different AMF on the formation and stability of soil aggregates.

Stabilization of Soil Aggregates in Relation to Soil Redistribution by Intensive Tillage on a Steep Hillslope

2014 ◽  
Vol 955-959 ◽  
pp. 3566-3571 ◽  
Author(s):  
Yong Wang ◽  
Zhuang Xiong ◽  
Wu Xian Yan ◽  
Yue Qun Qiu
Keyword(s):  
Soil Aggregates ◽  
Geometric Mean ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Soil Aggregate ◽  
Soil Aggregate Stability ◽  
Mean Weight Diameter ◽  
Tillage Operation ◽  
Sloping Land ◽  
The Impact

The objective of this study was to investigate soil aggregate stability within landscape on hillslopes by intensive tillage. Traditional tillage by consecutive hoeing was performed 5 and 20 times on steeply sloping land of the Sichuan Basin, China, by using the methods of simulated tillage to analyze the impact of long-term tillage on soil aggregates at different slope positions. The dry-sieved method was used to determine distribution of aggregate size in the different landscape positions, and mean weight diameter (MWD) and geometric mean diameter (GMD) as indices of soil aggregate stability. The different times of tillage resulted in different soil aggregate distributions. The results showed that the MWD and GMD values of aggregates were significantly decreased (p< 0.05) after 20-tillage operation, compared with pre-tillage operation. The differences in distributions of MWD and GMD demonstrate that the choice of the tillage times can be an important factor in changing soil aggregate stability and productivity in steeply sloping fields.

Comparison of aggregate stability within six soil profiles under conventional tillage using various laboratory tests

Biologia ◽  
2009 ◽  
Vol 64 (3) ◽  
Author(s):  
Radka Kodešová ◽  
Marcela Rohošková ◽  
Anna Žigová
Keyword(s):  
Organic Matter ◽  
Soil Aggregates ◽  
Organic Matter Content ◽  
Aggregate Stability ◽  
Clay Content ◽  
Soil Aggregate ◽  
Matter Content ◽  
The Other ◽  
Structure Stability ◽  
Soil Aggregate Stability

AbstractSoil structure stability was studied in every diagnostic horizons of six soil types (Haplic Chernozem, Greyic Phaeozem, two Haplic Luvisols, Haplic Cambisol, Dystric Cambisol) using different techniques investigating various destruction mechanisms of soil aggregates. Soil aggregate stability, assessed by the index of water stable aggregates (WSA), varied depending on the organic matter content, clay content and pHKCl. The presence of clay and organic matter coatings and fillings, and presence of iron oxides in some soils increased stability of soil aggregates. On the other hand periodical tillage apparently decreased aggregate stability in the Ap horizons. Coefficients of aggregate vulnerability resulting from fast wetting (KV 1) and slow wetting (KV 2) tests showed similar trends of the soil aggregate stability as the WSA index, when studied for soils developed on the similar parent material. There was found close correlation between the WSA index and the KV 1 value, which depended also on the organic matter content, clay content and pHKCl. Less significant correlation was obtained between the WSA index and the KV 2 value, which depended on the organic matter content and clay content. Coefficients of vulnerability resulting from the shaking after pre-wetting test (KV 3) showed considerably different trends in comparison to the other tests due to the different factors affecting aggregate stability against the mechanical destruction. The KV 3 value depended mostly on cation exchange capacity, pHKCl and organic matter content.

scholarly journals Can cocoa agroforestry restore degraded soil structure following conversion from forest to agricultural use?

2020 ◽  
Vol 94 (6) ◽  
pp. 2261-2276
Author(s):  
Danny Dwi Saputra ◽  
Rika Ratna Sari ◽  
Kurniatun Hairiah ◽  
James M. Roshetko ◽  
Didik Suprayogo ◽  
...  
Keyword(s):  
Root Length ◽  
Soil Structure ◽  
Fine Root ◽  
Aggregate Stability ◽  
Agricultural Systems ◽  
Degraded Soil ◽  
Soil Layers ◽  
Soil Aggregate Stability ◽  
Fine Root Length ◽  
Cocoa Agroforestry

AbstractAlternating degradation and restoration phases of soil quality, as is common in crop-fallow systems, can be avoided if the restorative elements of trees and forests can be integrated into productive agroforestry systems. However, evidence for the hypothesis of ‘internal restoration’ in agroforestry is patchy and the effectiveness may depend on local context. We investigated to what extent cocoa (Theobroma cacao, L.) agroforestry can recover soil structure and infiltration in comparison to monoculture systems across the Konaweha Watershed, Southeast Sulawesi. We compared soil organic carbon, fine root length and weight, soil aggregate stability, macroporosity and infiltration from three soil layers at five land use systems: i.e. degraded forests, 9–14 years old of complex-cocoa agroforestry, simple-cocoa agroforestry, monoculture cocoa and 1–4 years old annual food crops, all with three replications. In general, roots were concentrated in the upper 40 cm of soil depth, contained of 70% and 86% of total fine root length and weight. Compared to simple agroforestry and cocoa monoculture, complex agroforestry had greater root length and weight in the topsoil, even though it attained only half the values found in degraded forests. Higher root density was positively correlated to soil organic carbon. In upper soil layers, complex agroforestry had slightly higher soil aggregate stability compared to other agricultural systems. However, no significant difference was found in deeper layers. Complex agroforestry had higher soil macroporosity than other agricultural systems, but not sufficient to mimic forests. Degraded forests had two times faster steady-state soil infiltration than agricultural systems tested (13.2 cm h−1 and 6 cm h−1, respectively), relevant during peak rainfall events. Compared to other agricultural systems, complex agroforestry improves soil structure of degraded soil resulting from forest conversion. However, a considerable gap remains with forest soil conditions.

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

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

<p class="teksabst"><strong>Abstrak.</strong><em> </em>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 <em>Cyperus pilosus</em> 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. <em>Klebsiella </em>sp. LW-13 yang dikombinasi dengan 1% bahan organik dan <em>Bukholderia anthina </em>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 <em>Bukholderia anthina </em>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.</p><p><em><strong>Abstract</strong></em>. 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.</p><p> </p>

Determination of soil aggregate disintegration dynamics using laser diffraction

Clay Minerals ◽  
2010 ◽  
Vol 45 (1) ◽  
pp. 23-34 ◽  
Author(s):  
A. Bieganowski ◽  
M. Ryżak ◽  
B. Witkowska-Walczak
Keyword(s):  
Soil Aggregates ◽  
Aggregate Stability ◽  
Diffraction Method ◽  
Soil Aggregate ◽  
Laser Diffraction ◽  
Measuring System ◽  
Equivalent Diameter ◽  
Soil Aggregate Stability ◽  
Aggregate Fractions

AbstractA new practical and precise method for determining soil aggregate stability is described. Four air-dry aggregate fractions (<0.25, 0.25–0.5, 0.5–1.0 and 1.0–2.0 mm) were added to thoroughly stirred water in a Mastersizer 2000 laser diffractometer. The suspension obtained was passed directly through the measuring system. The dynamics of median (equivalent diameter d50) particle-size distribution decrease (interpolated with a logarithmic function) was assumed to be the measure of soil aggregate stability. In order to show the applicability of the new method, the results obtained (for selected and diverse soils) were compared with those from the wet sieving standard method. The main conclusion is that the proposed method is convenient and can be successfully used for the estimation of soil aggregate stability. Moreover, it has wider application because standard sieving methods are restricted to aggregates >0.25 mm whereas, with the use of the laser diffraction method, smaller aggregates can be measured. The energy delivered to the aggregates in the process of aggregate disintegration is more reproducible in the method described here. The method also provides an opportunity to verify that the soil aggregates are completely destroyed (lack of the changes of the median value shows the end of soil aggregate disintegration).

scholarly journals Bacterial and fungal predator – prey interactions modulate soil aggregation

2020 ◽  
Author(s):  
Amandine Erktan ◽  
Matthias C. Rillig ◽  
Andrea Carminati ◽  
Alexandre Jousset ◽  
Stefan Scheu
Keyword(s):  
Soil Aggregates ◽  
Food Resource ◽  
Soil Microbial Communities ◽  
Acanthamoeba Castellanii ◽  
Soil Aggregate ◽  
Soil Aggregation ◽  
Aggregate Formation ◽  
Negative Consequences ◽  
Saprotrophic Fungi ◽  
Predator Prey

Abstract. The formation and stabilisation of soil macro-aggregates protects soils from erosion, a major worldwide threat on soils. While the role of bacteria and fungi in soil aggregation is well established, how predators feeding on microbes modify soil aggregation has hardly been tested. Here, we studied how predators modulate the effect of microbial prey on soil aggregation. We focused on two predator – prey interactions: bacterial-based interactions comprising amoebae (Acanthamoeba castellanii) grazing on free-living bacteria (Pseudomonas fluorescens), and fungal-based interactions comprising collembolans (Heteromurus nitidus) grazing on saprotrophic fungi (Chaetomium globosum). We conducted a microcosm experiment lasting six weeks and assessed changes in soil aggregate formation and stabilisation, together with modifications in soil microbial communities (PLFAs). We further traced the food resource consumed by microbes using δ13C isotopic tracing. The protist A. castellanii increased the formation of soil aggregates but decreased their stability, without affecting bacterial abundance and community composition, suggesting that the changes were due to amoebae-mediated changes in the production of bacterial mucilage. Saprotrophic fungi showed the highest positive effect on soil aggregate formation and stabilisation, associated with a more efficient use of particulate organic carbon (chopped litter) added to the microcosms. Adding collembolans decreased the abundance of fungi and their ability to capture carbon of litter origin, with negative consequences on soil aggregation. Our work here has demonstrated that trophic interactions are important for achieving a mechanistic understanding of biological contributions to soil aggregation.

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