Influence of biomineralization on a profile of a tropical soil affected by erosive processes

Most of the soils of tropical countries, especially those in South America and Africa, are affected by erosion processes. As a result, researchers in the field of geotechnical engineering, specifically in the context of "biotechnology" or "bioengineering", have been investigating the use of microorganisms to improve the geotechnical properties and stability of soils. Using this approach, this work was developed to analyze the effects of the implementation of a calcium carbonate precipitating nutrient in native microbiota on the mitigation of erosion processes in a tropical soil profile. The methodology used in this research consisted of collecting undisturbed samples in a soil profile located in an area affected by erosion processes. In such samples, the native bacteria were identified, and it was determined that the nutrient B4 induced the precipitation of calcium carbonate. Subsequently, soil samples were characterized physically, chemically, mineralogically and mechanically in their natural state and after the addition of the nutrient. The tests were performed at least fifteen days after treatment with the nutrient. It was concluded that the use of the nutrient B4 enabled the native bacteria present in the soil to precipitate calcium carbonate, resulting in improvements in the physical, chemical, mineralogical and mechanical properties of the soil, which allowed for the mitigation of erosion processes that characterize the soil profile studied. The conclusions derived from the study apply not only to other tropical soil profiles subjected to erosion but also to improvements of the geotechnical behavior of soils in general.

Download Full-text

Comparison of shrink-swell indices of some Saskatchewan soils and their relationships to standard soil characteristics

Canadian Journal of Soil Science ◽

10.4141/cjss92-036 ◽

1992 ◽

Vol 72 (4) ◽

pp. 429-439 ◽

Cited By ~ 10

Author(s):

E. De Jong ◽

L. M. Kozak ◽

H. B. Storehouse

Keyword(s):

Surface Area ◽

Linear Extension ◽

Clay Content ◽

Soil Characteristics ◽

Soil Samples ◽

Plasticity Index ◽

Soil Profiles ◽

Undisturbed Samples ◽

Standard Soil ◽

Highly Correlated

Shrink-swell indices for 27 soil samples (representing the major horizons of eight soil profiles) were determined and related to soil texture, organic and inorganic C content, and specific surface area. The coefficient of linear extension was measured from saturation and from 33 kPa matric suction to oven-dryness on undisturbed clods (COLEclod) and on remolded samples of the less than 2-mm fraction (COLErod); the Atterberg limits were determined on the less than 0.4-mm fraction. COLEclod, COLErod and the plasticity index were highly correlated with each other and with clay content and surface area, but not with organic or inorganic C. The extent of the shrinkage was significantly (P > 0.01) related to the water content at the start of the shrinkage test; this relationship was clearer for the remolded than the undisturbed samples, possibly due to the structure of the clods. Key words: Coefficient of linear extension, plasticity index, clods vs. remolded, texture, organic carbon

Download Full-text

Assessment of Soil Physical Characteristics of Luvisols Under Monoculture of Vines

Acta Horticulturae et Regiotecturae ◽

10.1515/ahr-2016-0006 ◽

2016 ◽

Vol 19 (1) ◽

pp. 21-27

Author(s):

Vladimír Šimanský ◽

Marek Kolenčík

Keyword(s):

Soil Profile ◽

Soil Structure ◽

Aggregate Stability ◽

Stability Index ◽

Total Porosity ◽

Soil Samples ◽

Soil Profiles ◽

Average Content ◽

Average Value ◽

Soil Physical Characteristics

Abstract The physical properties of Luvisols under vineyards of the Nitra wine-growing area (Slovakia) were evaluated in the paper. Soil samples were taken from two selected localities (Nitra - Dražovce, Vráble). The obtained results showed that in the soil profile of Dražovce, the average contents of non-capillary pores, capillary pores and semi-capillary pores to the total porosity were equal to 26.1, 64.4 and 9.4%, respectively, and in the soil profile of Vráble - 22.3, 75.6 and 2.1%, respectively. In the Dražovce locality, the average content of aggregate stability index (Sw) decreased in the following order: abandoned vineyard > grassy strip between the vineyard rows > intensively cultivated rows of vineyard. In contrast, in the Vráble locality, higher average contents of Sw were determined in intensively cultivated rows of vineyard in comparison to grassy strip between the vineyard rows. The lowest average value of vulnerability coefficient (Kv) was observed in abandoned vineyard (Dražovce locality) and in both localities in grassy strip between the vineyard rows. Intensive cultivation of the vineyard rows resulted in higher vulnerability of soil structure. The values of maximum capillary capacity were almost the same in both soil profiles of Luvisols. A higher content of soil moisture was observed in the soil profile in the Vráble locality (33.6±2.50) in comparison to the Dražovce locality (30.6±5.44). Higher content of storage moisture was determined in the Vráble locality (2,684 l m-2) in comparison to the Dražovce locality (2,450 l m-2).

Download Full-text

KARAKTERISTIK TANAH DAN PERBANDINGAN PRODUKSI KELAPA SAWIT (Elaeis guineensis Jacq.) DENGAN METODE TANAM LUBANG BESAR DAN PARIT DRAINASE 2:1 PADA LAHAN SPODOSOL DI KABUPATEN BARITO TIMUR PROPINSI KALIMANTAN TENGAH - INDONESIA

Jurnal Pertanian Tropik ◽

10.32734/jpt.v2i2.2897 ◽

2015 ◽

Vol 2 (2) ◽

pp. 148-158

Author(s):

Surianto

Keyword(s):

Soil Texture ◽

Oil Palm ◽

Soil Profile ◽

Chemical Properties ◽

Exchangeable Cations ◽

Soil Horizon ◽

Soil Profiles ◽

Negative Effect ◽

Hole Profile ◽

And Chemical Properties

Spodosol soil of Typic Placorthod sub-group of East Barito District is one of the problem soils with the presence of hardpan layer, low fertility, low water holding capacity, acid reaction and it is not suitable for oil palm cultivation without any properly specific management of land preparation and implemented best agronomic practices. A study was carried out to evaluate the soil characteristic of a big hole (A profile) and no big hole (B profile) system and comparative oil palm productivity among two planting systems. This study was conducted in Spodosol soil at oil palm plantation (coordinate X = 0281843 and Y = 9764116), East Barito District, Central Kalimantan Province on February 2014, by surveying of placic and ortstein depth and observing soil texture and chemical properties of 2 (two) oil palm's soil profiles that have been planted in five years. Big hole system of commercial oil palm field planting on the Spodosol soil area was designed for the specific purpose of minimizing the potential of a negative effect of shallow effective planting depth for oil palms growing due to the hardpan layer (placic and ortstein) presence as deep as 0.25 - 0.50 m. The big hole system is a planting hole type which was vertical-sided with 2.00 m x 1.50 m on top and bottom side and 3.00 m depth meanwhile the 2:1 drain was vertical-sided also with 1.50 m depth and 300 m length. Oil palm production was recorded from the year 2012 up to 2014. Results indicated that the fractions both big hole profile (A profile) and no big hole profile (B profile) were dominated by sands ranged from 60% to 92% and the highest sands content of non-big hole soil profile were found in A and E horizons (92%). Better distribution of sand and clay fractions content in between layers of big hole soil profiles of A profile sample is more uniform compared to the B profile sample. The mechanical holing and material mixing of soil materials of A soil profile among the upper and lower horizons i.e. A, E, B and C horizons before planting that resulted a better distribution of both soil texture (sands and clay) and chemical properties such as acidity value (pH), C-organic, N, C/N ratio, CEC, P-available and Exchangeable Bases. Investigation showed that exchangeable cations (Ca, Mg, K), were very low in soil layers (A profile) and horizons (B profile) investigated. The low exchangeable cations due to highly leached of bases to the lower layers and horizons. Besides, the palm which was planted on the big hole system showed good adaptation and response positively by growing well of tertiary and quaternary roots that the roots were penetrable into deeper rooting zone as much as >1.00 m depth. The roots can grow well and penetrate much deeper in A profile compared to the undisturbed hardpan layer (B profile). The FFB (fresh fruit bunches) production of the non-big hole block was higher than the big hole block for the first three years of production. This might be due to the high variation of monthly rainfall in-between years of observation from 2009 to 2014. Therefore, the hardness of placic and ortstein as unpenetrable agents by roots and water to prevent water loss and retain the water in the rhizosphere especially in the drier weather. In the high rainfall condition, the 2:1 drain to prevent water saturation in the oil palm rhizosphere by moving some water into the drain. Meanwhile, the disturbed soil horizon (big hole area) was drier than un disturbance immediately due to water removal to deeper layers. We concluded that both big hole and 2:1 drain are a suitable technology for Spodosol soil land especially in preparing palms planting to minimize the negative effect of the hardpan layer for oil palm growth.

Download Full-text

Screening and antimicrobial activity of actinomycetes isolated from the rhizosphere of Clitoria ternatea

Journal of Nature and Natural Sciences ◽

10.26859/jnnsci.v1i01.9591 ◽

2016 ◽

Vol 1 (01) ◽

Author(s):

Vemavarapu Bhaskara Rao ◽

Kandlagunta Guru Prasad ◽

Krishna Naragani ◽

Vijayalakshmi Muvva

Keyword(s):

Escherichia Coli ◽

Staphylococcus Aureus ◽

Antimicrobial Activity ◽

Candida Albicans ◽

Calcium Carbonate ◽

Rhizosphere Soil ◽

Soil Samples ◽

Antimicrobial Spectrum ◽

Clitoria Ternatea ◽

Primary Screening

The air dried rhizosphere soil samples pretreated with calcium carbonate was employed for the isolation of actinomycete strains. Serial dilution plate technique was used for the isolation of actinomycetes. A total of 20 actinomycete strains designated as BS1-BS20 were isolated from the rhizosphere of medicinal plant Clitoria ternatea. All the 20 strains were subjected to primary screening for antimicrobial activity. Among the 20 strains screened, 10 strains exhibited high antimicrobial spectrum against Staphylococcus aureus, Escherichia coli and Candida albicans.

Download Full-text

Variation in Salinity through the Soil Profile in South Coastal Region of Bangladesh

Journal of Bangladesh Academy of Sciences ◽

10.3329/jbas.v42i1.37829 ◽

2018 ◽

Vol 42 (1) ◽

pp. 11-23

Author(s):

Mohammad Asadul Haque

Keyword(s):

Electrical Conductivity ◽

Salt Stress ◽

Soil Profile ◽

Ph Value ◽

Soil Depth ◽

Coastal Region ◽

Soil Samples ◽

Salt Accumulation ◽

Top Soil ◽

Academy Of Sciences

The spatial variability of salt accumulation through the soil profile was studied at Latachapali union of Kalapara upazila, Patuakhali district, Bangladesh. The soil samples were collected from 30 locations covering six villages of the union: Kuakata, Malapara, Fashipara, Khajura, Mothaopara and Tajepara. Five locations were randomly selected from each village. From each location soil samples were collected from three soil depths at 0-2 cm, 2.1-4 cm and 4.1-6 cm. Electrical conductivity of top 0-2 cm soil depth was 20.49 dS/m, in 2.1-4 cm soil depth was 7.14 dS/m and in 4.1-6 cm soil depth 4.15 dS/m. The study soils were strongly acidic having pH value 4.73, 4.99 and 5.20 in 0-2, 2.1-4 and 4.1-6 cm soil depth, respectively. The highest of 8.8 Na:K ratio was found in 0-2 cm soil depth. The Na:K ratio gradually decreased with the increase of soil depth, having 6.59 in 2.1-4 cm and 5.42. in 4.1-6 cm soil depth. The results clearly reveal that the top soil is very much sensitive to salt stress. Based on the electrical conductivity and Na:K ratio the Fashipara, Kuakata and Tajepara village were found seriously affected by salinity.Journal of Bangladesh Academy of Sciences, Vol. 42, No. 1, 11-23, 2018

Download Full-text

Vertical differentiation of pedogenic iron forms – a key of hydromorphic soil profile development

Hungarian Geographical Bulletin ◽

10.15201/hungeobull.70.4.6 ◽

2021 ◽

Vol 70 (4) ◽

pp. 369-380

Author(s):

Marianna Ringer ◽

◽

Gergely Jakab ◽

Péter Sipos ◽

Máté Szabó ◽

...

Keyword(s):

Soil Profile ◽

Water Saturation ◽

Vertical Position ◽

Soil Profiles ◽

Spatial And Temporal Patterns ◽

Hydromorphic Soil ◽

Annual Variations ◽

Wide Range ◽

The Vertical Distribution ◽

Iron Forms

This paper focuses on the vertical distribution and characterisation of pedogenic iron forms in a Gleysol- Histosol transect developed in a marshy area in the Danube-Tisza Interfluve, Hungary. Four soil profiles were investigated along a series of increasing waterlogging and spatial and temporal patterns of hydromorphic pedofeatures (characteristics of pedogenic iron forms) were recorded. Frequent and wide-range redox potential (Eh) changes caused the emergence of many types of redoximorphic iron features, including mottles, plaques and nodules. The forms of these features depended on the micro-environments determined by the vertical position in the soil profile and the presence of plant roots. The greatest iron enrichment occurred in the zone of most intensive and widest-range redox fluctuations. Increasing water saturation resulted the extension of gleyic pattern due to the existence of permanent reduction. Most of the features also showed annual variations during the varying periods of water saturation and aeration.

Download Full-text

CHARACTERIZING A TROPICAL SOIL VIA SEISMIC IN SITU TESTS

Brazilian Journal of Geophysics ◽

10.22564/rbgf.v37i3.2006 ◽

2019 ◽

Vol 37 (3) ◽

pp. 263

Author(s):

Breno Padovezi Rocha ◽

Heraldo Luiz Giacheti

Keyword(s):

Shear Modulus ◽

Shear Wave ◽

Wave Velocity ◽

Shear Wave Velocity ◽

Soil Profile ◽

Site Investigation ◽

Tropical Soil ◽

Engineering Properties ◽

Foundation Engineering

ABSTRACT. The shear wave velocity (Vs) is an important geotechnical parameter to be used in dynamic problems (e.g. earthquakes and vibration problems) as well as in static deformation analysis such as excavations and foundation engineering design. There are several in situ seismic tests to determine Vs such as the crosshole and the downhole techniques, as well as hybrid tests (e.g. seismic dilatometer – SDMT). This paper presents crosshole, downhole and SDMT tests carried out in a typical tropical soil profile from Brazil. Advantages and limitations regarding the test procedures and interpretation are briefly presented and differences observed among Vs determined by these techniques are discussed. Shear wave velocities (Vs) estimated from the crosshole, downhole and SDMT tests ranging from 194 to 370 m/s. The shear wave velocity suggests that the experimental site could be divided into two strata, which are in agreement with soil profile description. The maximum shear modulus (G0) calculated from the Vs by theory of elasticity can be used to show the investigated tropical soil is a typical unusual geomaterial. This article also emphasizes that the SDMT is a useful test for site investigation since it allows a great means for profiling geostratigraphy and soil engineering properties during routine site investigation as well as for dynamics problems. Keywords: shear wave velocity, maximum shear modulus, crosshole, downhole, SDMT.RESUMO. A velocidade de onda cisalhante (Vs) é um parâmetro geotécnico empregado em análises dinâmicas (terremotos e problemas de vibração), bem como em análises estáticas (escavações e projeto de fundações). Existem vários ensaios sísmicos de campo para a determinação de Vs, entre eles as técnicas crosshole e downhole, e os ensaios híbridos (por exemplo, dilatômetro sísmico – SDMT). Este artigo apresenta os ensaios crosshole, downhole e SDMT realizados em um perfil típico de solo tropical do Brasil, as vantagens e limitações dos procedimentos de ensaio e de interpretação são brevemente apresentadas, e as diferenças observadas entre os valores de Vs determinados pelas diferentes técnicas são discutidas. Os perfis de Vs determinados pelas diferentes técnicas variaram de 194 a 370 m/s. A velocidade da onda cisalhante sugere que o campo experimental investigado pode ser dividido em dois horizontes, os quais estão de acordo com a descrição do perfil do solo estudado. O módulo de cisalhamento máximo (G0), calculado a partir de Vs pela teoria da elasticidade, pode ser utilizado para demonstrar o comportamento não convencional do solo investigado. Este artigo também enfatiza que o SDMT é um ensaio geotécnico útil para a investigação geotécnica do subsolo, uma vez que permite a definição do perfil estratigráfico e a estimativa de parâmetros estáticos e dinâmicos de um projeto.Palavras-chave: velocidade de onda cisalhante, módulo de cisalhamento máximo, crosshole, downhole, SDMT.

Download Full-text

Effects of soil pH and texture on soil carbon and nitrogen in soil profiles under different land uses in Mun River Basin, Northeast Thailand

PeerJ ◽

10.7717/peerj.7880 ◽

2019 ◽

Vol 7 ◽

pp. e7880 ◽

Cited By ~ 9

Author(s):

Wenxiang Zhou ◽

Guilin Han ◽

Man Liu ◽

Xiaoqiang Li

Keyword(s):

Soil Carbon ◽

River Basin ◽

Soil Ph ◽

Soil Samples ◽

Soil Profiles ◽

Land Uses ◽

Agricultural Lands ◽

Carbon And Nitrogen ◽

Soil Carbon And Nitrogen ◽

Forest Lands

Soil carbon and nitrogen are essential factors for agricultural production and climate changes. A total of 106 soil samples from three agricultural lands (including two rice fields and one sugarcane field) and four non-agricultural lands (including two forest lands, one wasteland and one built-up land) in the Mun River Basin were collected to determine soil carbon, nitrogen, soil pH, soil particle sizes and explore the influence of pH and soil texture on soil C and N. The results show that total organic carbon (TOC) and nitrogen (TON) contents in topsoil (TOC: 2.78 ~ 18.83 g kg−1; TON: 0.48 ~ 2.05 g kg−1) are much higher than those in deep soil (TOC: 0.35 ~ 6.08 g kg−1; TON: <0.99 g kg−1). In topsoil, their contents of forest lands and croplands (TOC: average 15.37 g kg−1; TON: average 1.29 g kg−1) are higher than those of other land uses (TOC: average 5.28 g kg−1; TON: average 0.38 g kg−1). The pH values range from 4.2 to 6.1 in topsoil, and with increase in soil depth, they tend to increase and then decrease. Soil carbon, nitrogen and the C/N (TC/TN ratio) are negatively correlated with soil pH, demonstrating that relatively low pH benefits the accumulation of organic matter. Most soil samples are considered as sandy loam and silt loam from the percentages of clay, silt and sand. For soil profiles below 50 cm, the TOC and TON average contents of soil samples which contain more clay and silt are higher than those of other soil samples.

Download Full-text

Biological activity of soils cultivated with yacón (Smallanthus sonchifolius Poep. & Endl) H. Robinson, inoculated with Azospirillum brasilense and native mycorrhizal fungi

Revista de Ciencias Agrícolas ◽

10.22267/rcia.213801.148 ◽

2021 ◽

Vol 38 (1) ◽

pp. 125-133

Author(s):

María Gabriela Di Barbaro ◽

Horacio Enrique Andrada ◽

Eleodoro Eduardo Del Valle ◽

Celia Inés Brandán

Keyword(s):

Biological Activity ◽

Mycorrhizal Fungi ◽

Azospirillum Brasilense ◽

Microbial Consortium ◽

Soil Samples ◽

Biological Processes ◽

Smallanthus Sonchifolius ◽

Physical Chemical ◽

Promote Plant Growth ◽

Time Of Harvest

The soil is influenced by the roots of plants because the exudate radicals affect its physical, chemical, and biological processes. The aim of this research was to evaluate the microbial activity of soils cultivated with yacón (Smallanthus sonchifolius Poep. & Endl) H. Robinson and inoculated with microorganisms which promote plant growth. The experimental design used was randomized blocks with three repetitions per treatment. Each repetition corresponded to a 3m x 3m plot with 25 plants, in 5 cultivation lines with a distance of 70 cm apart. Four treatments were applied at the time of plantation. These consisted of yacón propagules inoculated with Azospirillum brasilense (T1) and native mycorrhizal fungi (T2) inoculated with the microbial consortium (T3). In the control treatments, the propagules were not inoculated with these microorganisms (T0). Soil samples were collected in lots cultivated with yacón located in the Province of Catamarca, in the northwest of Argentina. The samples were collected at the time of implantation and harvest during three agricultural cycles. The total Biological Activity (TBA) of the collected samples was determined by Fluorescein Diacetate Hydrolysis. The TBA of the soil was affected by the different crop treatments, which rose in the analyzed soils and was statistically different from the control treatments. Significant differences were also observed between the TBA of the soils at the beginning of the crops in comparison with the recorded values of the crop at the time of harvest. The inoculation of yacón propagules with A. brasilense and native mycorrhizal fungi affects the TBA of the cultivated soils marking a significant increase.

Download Full-text