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.

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.

The use of high energy moisture characteristic to assess soil stability

Soil Research ◽  
1984 ◽  
Vol 22 (3) ◽  
pp. 349 ◽  
Author(s):  
N Collis-George ◽  
BS Figueroa
Keyword(s):  
Aggregate Stability ◽  
High Energy ◽  
Laboratory Method ◽  
Soil Stability ◽  
Structural Index ◽  
Quick Method ◽  
Stability Ratio ◽  
Moisture Characteristic ◽  
The Stability ◽  
Structural Indices

The laboratory method of determining aggregate stability introduced by Childs in 1940 is reconsidered. A convenient and quick method of interpreting the experimental results is presented and provides the structural index for a given soil treatment. The ratio of the structural indices for two soil treatments provides the stability ratio, which is of relevance to erosion and pedogenetic studies of structure. Illustrative results show that pretreatments such as air drying, grinding and sieving affect the structural index and stability ratio.

scholarly journals Fast immersion to test the stability of aggregates in water: consequences for interpreting results from tropical soil classes

2019 ◽  
Vol 42 ◽  
pp. e42453
Author(s):  
Rodrigo Fonseca da Silva ◽  
Patriciani Estela Cipriano ◽  
Matias Siueia Junior ◽  
Geslin Mars ◽  
Moacir de Souza Dias Junior
Keyword(s):  
Soil Aggregates ◽  
Geometric Mean ◽  
Weighted Average ◽  
Aggregate Stability ◽  
Stability Index ◽  
Average Diameter ◽  
Tropical Soils ◽  
Organic Carbon Content ◽  
Pre Treatment ◽  
High Organic Carbon Content

Aggregates are the primary structural components of soil and have been used as an indicator of soil quality in conservation systems. The objective of this study was to analyse the effect of slow pre-wetting on the results of the aggregate stability test for different classes of tropical soils. Data were arranged in a 2 x 4 factorial design with three replications, in which the first factor comprised the two methods of pre-treatment on soil aggregates: without pre-wetting (WOPW), which considered the moisture of the aggregates in the field, and with pre-wetting (WPW), which considered the slow wetting of aggregates through capillarity on wet filter paper for 24h. The second factor consisted of four soil classes: Typic Dystrustept (Cambissolo Aplico distrófico in Embrapa), Typic Hapludult (Argissolo Amarelo distrófico), Rhodic Kandiudult (Nitossolo Vermelho distrófico), and Anionic Acrudox (Latossolo Vermelho distróferrico) and considered horizons A and B. The pre-wetting significantly increased the values of the weighted average diameter, geometric mean diameter and aggregate stability index. In soils with high organic carbon content, the practice of pre-moistening did not provide variation in aggregation.

An examination of the wet aggregate analysis, the moisture characteristic, and infiltration-percolation methods of determining the stability of soil aggregates

Soil Research ◽  
1972 ◽  
Vol 10 (1) ◽  
pp. 15 ◽  
Author(s):  
N Collis-George ◽  
KB Laryea
Keyword(s):  
Structural Stability ◽  
Soil Aggregates ◽  
High Energy ◽  
Characteristic Method ◽  
Analysis Method ◽  
Flood Irrigation ◽  
Aggregate Analysis ◽  
Moisture Characteristic ◽  
The Stability

Four methods of assessing structural stability of aggregates which employ different disruptive forces have been examined. Sorptivity (Philip 1957) has been demonstrated to be a useful method of assessing structural stability of soils during infiltration. The results obtained are consistent with those using either the high energy moisture characteristic method of Childs (1940, 1942), the wet aggregate analysis method of Quirk (1950), and the qualitative slaking-dispersion classification of aggregates proposed by Emerson (1967). Using these four methods, one soil was classified as stable, and two unstable to flood irrigation, whereas conventional chemical definitions did not distinguish unequivocally between them.

scholarly journals Aggregate stability in soils cultivated with eucalyptus

2011 ◽  
Vol 46 (1) ◽  
pp. 89-96 ◽  
Author(s):  
Junior Cesar Avanzi ◽  
Lloyd Darrell Norton ◽  
Marx Leandro Naves Silva ◽  
Nilton Curi ◽  
Anna Hoffmann Oliveira ◽  
...  
Keyword(s):  
Organic Matter ◽  
Soil Organic Matter ◽  
Management Practices ◽  
Aggregate Stability ◽  
Stability Index ◽  
Tropical Soils ◽  
High Energy ◽  
Native Vegetation ◽  
Stability Ratio ◽  
Eucalyptus Plantation

The objective of this work was to evaluate the aggregate stability of tropical soils under eucalyptus plantation and native vegetation, and assess the relationships between aggregate stability and some soil chemical and physical properties. Argisols, Cambisol, Latosols and Plinthosol within three eucalyptus-cultivated regions, in the states of Espírito Santo, Rio Grande do Sul and Minas Gerais, Brazil, were studied. For each region, soils under native vegetation were compared to those under minimum tillage with eucalyptus cultivation. The aggregate stability was measured using the high-energy moisture characteristic (HEMC) technique, i.e., the moisture release curve at very low suctions. This method compares the resistance of aggregates to slaking on a relative scale from zero to one. Thus, the aggregate stability from different soils and management practices can be directly compared. The aggregate stability ratio was greater than 50% for all soils, which shows that the aggregate stability index is high, both in eucalyptus and native vegetation areas. This suggests that soil management adopted for eucalyptus cultivation does not substantially modify this property. In these soils, the aggregate stability ratio does not show a good relationship with clay or soil organic matter contents. However, soil organic matter shows a positive relationship with clay content and cation exchange capacity.

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 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 The stability of soil aggregates in tilled fallow areas in Hyderabad district, Pakistan

2015 ◽  
Vol 27 (1) ◽  
pp. 51-60
Author(s):  
Ahmed Tagar ◽  
Jan Adamowski
Keyword(s):  
Soil Erosion ◽  
Size Distribution ◽  
Soil Aggregates ◽  
Aggregate Stability ◽  
Aggregate Size ◽  
Indus River ◽  
Aggregate Size Distribution ◽  
Sieve Size ◽  
The Stability ◽  
The Village

Abstract Arid areas are particularly susceptible to soil erosion due to long dry periods and sudden heavy downpours. This study investigates the aggregate size distribution and aggregate stability of twelve tilled fallow areas of Hyderabad district, Sindh, Pakistan. This study determined aggregate size distribution by dry sieving to evaluate the seedbed condition and aggregate stability using wet sieving to assess the susceptibility of tilled fallow areas to soil erosion. The aggregate size distribution of the soils of the selected areas was highly variable. Gulistan-e-Sarmast had the largest number of clods (51.0%) followed by Kohsar (49.0%), Latifabad # 10 (41.10%) and Daman-e-Kohsar (39.0%). Fazal Sun City, the left side of the Indus River, the Village Nooral Detha and the left side of the Abdullah Sports city had a greater number of large (>8.0 mm) and small aggregates (<0.5 mm). The optimum aggregate size distribution was found in the left side of the channel, which had the largest number of aggregates (50.50%) in the 0.5–8.0 mm sieve size range. Maximum aggregate stability (AS) was found in Gulistan-e-Sarmast (46%), Kohsar (42%) and Latifabad # 10 (34%), while all other soils had minimum aggregate stability (<14%). The minimum aggregate stabilities demonstrate that the tilled fallow areas of Hyderabad district are highly susceptible to erosion. Therefore, the present study suggests investigating potential ways to enhance the aggregate stabilities of soils.

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