scholarly journals Aggregation of subtropical soil under liming: a study using laser diffraction

2010 ◽  
Vol 34 (3) ◽  
pp. 725-734 ◽  
Author(s):  
Edson Campanhola Bortoluzzi ◽  
Cristiano Poleto ◽  
Álvaro José Baginski ◽  
Vanderlei Rodrigues da Silva
Keyword(s):  
Traditional Method ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Soil Surface ◽  
Stability Index ◽  
Laser Diffraction ◽  
Soil Aggregation ◽  
Subtropical Soil ◽  
Dispersion Agent ◽  
The Stability

Laser diffraction (LD) provides detailed analysis of particle size distribution. Its application to testing the stability of soil aggregates can assist studies on the aggregation of soils with contrasting electrochemical properties. The objectives of the present work were: (a) to propose a protocol for using LD to study soil aggregation, (b) to study the aggregation of an Acrisol under the influence of different doses and forms of lime. Samples were collected in 2005 from a Brazilian Acrisol that in 1994 had received 0.0; 2.0; 8.5 and 17.0 Mg ha-1 of lime, left on the soil surface or incorporated. Aggregates from 4.76 to 8.00 mm diameters were studied using the traditional method proposed by Kemper & Chepil (1965), with wet sieving, while aggregates from 1.00 to 2.00 mm were studied using a CILAS® laser diffractometer that distinguishes particles ranging from 0.04 to 2,500.00 μm. LD readings were made after six consecutive pre-treatments, using agitation times, a chemical dispersion agent and ultrasound. Mean Weighted Diameter (MWD) and the Aggregate Stability Index (ASI) calculated, using the traditional method does not discriminate the treatments. However, LD is able to produce detailed data on soil aggregation, resulting in indexes of stability of aggregates that are linearly related to the doses of lime applied (MWD: R² = 0.986 and ASI: R² = 0.876). It may be concluded that electrochemical changes in the Brazilian Acrisol resulting from incorporated lime affect the stability of aggregates, increasing stability with increased doses of lime.

scholarly journals Aggregate stability by the "high energy moisture characteristic" method in an oxisol under differentiated management

2014 ◽  
Vol 38 (5) ◽  
pp. 1633-1642 ◽  
Author(s):  
Érika Andressa da Silva ◽  
Geraldo César de Oliveira ◽  
Bruno Montoani Silva ◽  
Carla Eloize Carducci ◽  
Junior Cesar Avanzi ◽  
...  
Keyword(s):  
Soil Aggregates ◽  
Aggregate Stability ◽  
Soil Surface ◽  
Stability Index ◽  
Tropical Soils ◽  
High Energy ◽  
Stability Parameters ◽  
Aggregation State ◽  
Moisture Characteristic ◽  
The Stability

Studies testing the High Energy Moisture Characteristic (HEMC) technique in tropical soils are still incipient. By this method, the effects of different management systems can be evaluated. This study investigated the aggregation state of an Oxisol under coffee with Brachiaria between crop rows and surface-applied gypsum rates using HEMC. Soil in an experimental area in the Upper São Francisco region, Minas Gerais, was studied at depths of 0.05 and 0.20 m in coffee rows. The treatments consisted of 0, 7, and 28 Mg ha-1 of agricultural gypsum rates distributed on the soil surface of the coffee rows, between which Brachiaria was grown and periodically cut, and compared with a treatment without Brachiaria between coffee rows and no gypsum application. To determine the aggregation state using the HEMC method, soil aggregates were placed in a Büchner funnel (500 mL) and wetted using a peristaltic pump with a volumetric syringe. The wetting was applied increasingly at two pre-set speeds: slow (2 mm h-1) and fast (100 mm h-1). Once saturated, the aggregates were exposed to a gradually increasing tension by the displacement of a water column (varying from 0 to 30 cm) to obtain the moisture retention curve [M = f (Ψ) ], underlying the calculation of the stability parameters: modal suction, volume of drainable pores (VDP), stability index (slow and fast), VDP ratio, and stability ratio. The HEMC method conferred sensitivity in quantifying the aggregate stability parameters, and independent of whether gypsum was used, the soil managed with Brachiaria between the coffee rows, with regular cuts discharged in the crop row direction, exhibited a decreased susceptibility to disaggregation.

Determination of aggregate stability using laser diffraction method in soil with varied texture and carbon content

2020 ◽  
Author(s):  
Agnieszka Józefowska ◽  
Magdalena Ryżak ◽  
Justyna Sokołowska ◽  
Karolina Woźnica ◽  
Tomasz Zaleski ◽  
...  
Keyword(s):  
Organic Matter ◽  
Organic Carbon ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Diffraction Method ◽  
Laser Diffraction ◽  
Organic Additives ◽  
Organic Mineral ◽  
Active Bacteria ◽  
The Stability

<p>Keywords: soil texture, aggregate stability, organic additives, earthworms, microbial activity,</p><p>Lubbers et al. (2017) emphasised that earthworm by creating macroaggregates increase the amount of organic carbon in the soil. Such macroaggregates contain particulate organic matter, fungal hyphae, or roots, and afterwards, during the decomposition of macroaggregates, the organic matter becomes more resistant to microbial attack (Pulleman et al. 2005). Earthworms, through feeding and burrowing, are important elements in C cycling (Curry and Schmidt 2007). However, the type of introduced organic matter (Huang et al. 2018) and abiotic factors (Six et al. 2004) are equally important in creating stable organic-mineral components as well as the presence of earthworms.</p><p>A six-month experiment was carried out to test how the soil structure (the stability of soil aggregates) behave under the influence of various organic additives. For each soil, except the reference samples, one of the listed additives was introduced, i.e. straw, straw with fulvic acid, peat (garden soil), compost, compost with active bacteria cultures and straw with fulvic acids, humus and active bacteria cultures. The research was carried out on soils with four types of texture, i.e. sandy, loamy, silty and clayey soil. In the project, three different species of earthworms commonly occurred in Polish soils were a structure-forming factor (<em>Apporectodea rosea, Apporectodea calliginosa</em> and<em> Dendrobena rubillus</em>). After the experiment, the amount of organic carbon in the soil, dissolved organic carbon, humus forms and microbiological activity of the soil were evaluated. The stability of the soil aggregates was determined using two methods: the sieve method (Kemper and Rosenau 1986) and laser diffraction method (Bieganowski et al. 2018),</p><p>Based on this research it was noted that the aggregate stability is correlated mainly with soil texture. The applied additives had the most significant influence on the transformation of organic carbon in the soil. Soil organic carbon, which may be incorporated into the soil in the form of the organic-mineral colloids, is an essential element in the balance of the carbon in nature. Among the tested additives, organic carbon from compost, peat and compost with active bacteria cultures was in the highest amount associated with fine earth particles (about 36-48%). For comparison, only less than 8.5% of the organic carbon from the straw was incorporated into the mineral part of the soil.</p><p>Two methods to measures aggregate stability are not comparable for sandy soils. In the wet-sieving method the sand fraction higher than 0.25 mm pretend to be stable aggregates.</p><p> </p><p>The study was financed by The National Science Centre, Poland, grant No. 2017/01/X/ST10/00777, statistical analysis was made based the knowledge and skills <span><span>achieved during the training: organized as part of the project: Integrated Program of the University of Agriculture in Kraków, which is co-financed by the European Union (POWR.03.05.00-00-z222/17)</span></span></p>

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.

scholarly journals Soil aggregation under different management systems

2012 ◽  
Vol 36 (6) ◽  
pp. 1868-1877 ◽  
Author(s):  
Cibele Mascioli Rebello Portella ◽  
Maria de Fátima Guimarães ◽  
Christian Feller ◽  
Inês Cristina de Batista Fonseca ◽  
João Tavares Filho
Keyword(s):  
Chemical Properties ◽  
Aggregate Stability ◽  
Stability Index ◽  
Conventional Tillage ◽  
Soil Aggregation ◽  
Natural State ◽  
Native Forest ◽  
Water Dispersible ◽  
Soil Preparation ◽  
And Chemical Properties

Considering that the soil aggregation reflects the interaction of chemical, physical and biological soil factors, the aim of this study was evaluate alterations in aggregation, in an Oxisol under no-tillage (NT) and conventional tillage (CT), since over 20 years, using as reference a native forest soil in natural state. After analysis of the soil profile (cultural profile) in areas under forest management, samples were collected from the layers 0-5, 5-10, 10-20 and 20-40 cm, with six repetitions. These samples were analyzed for the aggregate stability index (ASI), mean weighted diameter (MWD), mean geometric diameter (MGD) in the classes > 8, 8-4, 4-2, 2-1, 1-0.5, 0.5-0.25, and < 0.25 mm, and for physical properties (soil texture, water dispersible clay (WDC), flocculation index (FI) and bulk density (Bd)) and chemical properties (total organic carbon - COT, total nitrogen - N, exchangeable calcium - Ca2+, and pH). The results indicated that more intense soil preparation (M < NT < PC) resulted in a decrease in soil stability, confirmed by all stability indicators analyzed: MWD, MGD, ASI, aggregate class distribution, WDC and FI, indicating the validity of these indicators in aggregation analyses of the studied soil.

scholarly journals Role of Gliricidia sepium in Improving Aggregate Stability of Ultisol Limau Manis Padang: A LABoratory study

Jurnal Solum ◽  
2012 ◽  
Vol 9 (1) ◽  
pp. 44
Author(s):  
Yulnafatmawita Yulnafatmawita ◽  
Asmar Asmar ◽  
Vitria Purnamasari
Keyword(s):  
Organic Matter Content ◽  
Aggregate Stability ◽  
Stability Index ◽  
Gliricidia Sepium ◽  
Soil Aggregate ◽  
Matter Content ◽  
Soil Aggregate Stability ◽  
Top Soil ◽  
The Stability

There is no much public concern about soil aggregate stability improvement of a soil.  This is due to the fact that it does not directly affect crop yield for a short term, but it determines sustainable agriculture and development for a long term.  This research was aimed to investigate soil physical properties especially soil aggregate stability of Ultisols after fresh OM application, then to determine the exact OM dosage to improve the stability.  Ultisols used was from Limau Manis (± 367 m asl), an area in lower footslope of Mount Gadut, having wet tropical rainforest. Due to land use change, farming activities in that sloping area could enhance erosion process in the environment.  Therefore, efforts to anticipate the erosion must be found.  Fresh OM applied was Gliricidia sepium which was found plenty in the area.  Five levels of fresh Gliricidia sepium, were 0, 5, 10, 15, and 20 t/ha.  Top soil (0-20 cm depth) was mixed with OM, then incubated for 3 months in glasshouse.  The results after a 3-month incubation showed that SOM content did not statistically increase, but it improved based on the criteria, from very low to low level as OM was applied for ≥ 10 t/ha. It seemed that 10 t/ha Gliricidia sepium was the best dosage at this condition. There was a positive correlation between SOM content and aggregate stability index of Ultisols after fresh Gliricidia sepium addition.Keywords: Ultisols, soil aggregate stability, soil organic matter content

scholarly journals A Mathematical Approach to Evaluating the Influence of Various Factors on the Stability of Aggregates in Vertisols

1969 ◽  
Vol 53 (1) ◽  
pp. 57-60
Author(s):  
M. A. Lugo López ◽  
Raúl Pérez Escolar
Keyword(s):  
Organic Matter ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Correlation Coefficients ◽  
Clay Content ◽  
Mathematical Approach ◽  
Single Factor ◽  
Additional Increase ◽  
Independent Variable ◽  
The Stability

A mathematical approach is presented in this paper to evaluate the influence of such factors as clay content, silt content, organic matter, Ca + Mg, and soluble sodium upon the stability of soil aggregates in a group of Vertisols from the Lajas Valley, P.R. The relationships between aggregate stability and silt and clay were not significant. When the percentage of organic matter was considered as the independent variable, a highly significant correlation coefficient of 0.66 was obtained. Therefore, almost 43 percent of the variability in aggregate stability could be explained on the basis of this single factor. Attempts to increase the percentage of the variability which could be explained in terms of the content of Ca + Mg, and also of soluble sodium, yielded correlation coefficients of 0.70 and 0.74, respectively. Thus, only a slight, but significant, additional increase could be explained when these variables were included.

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.

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>

scholarly journals Skier triggering, snow temperatures and the stability index for dry-slab avalanche initiation

1999 ◽  
Vol 45 (150) ◽  
pp. 190-200 ◽  
Author(s):  
D. M. McClung ◽  
Jürg Schweizer
Keyword(s):  
Shear Stress ◽  
Size Effects ◽  
Traditional Method ◽  
Quantitative Method ◽  
Strong Influence ◽  
Load Ratio ◽  
Stability Index ◽  
Field Observations ◽  
Strength Failure ◽  
The Stability

AbstractFor more than 30 years the quantitative method of evaluating stability (e.g. Roch, 1966; Föhn, 1987; Jamieson, 1995; Jamieson and Johnston, 1998a) has been focused on calculation of a strength-to-load ratio (or stability index): when the shear stress applied to the weak layer reaches the shear strength, failure is imminent. However, field observations combined with experience and measurements indicate that snow-slab temperatures and slab hardness can have a strong influence on dry-snow slab stability. In this paper, we present a simple static analysis of the stability index, and discuss the importance of slab temperatures and hardness and macroscopic size effects (factors not contained in the stability index) on snow-slab stability. Our conclusion is that the traditional method lacks some elements which are very important in snow-slab stability, particularly when skier triggering is involved.

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