Soil Physics

2003 ◽  
Author(s):  
Anthony S. R. Juo ◽  
Kathrin Franzluebbers
Keyword(s):  
Plant Growth ◽  
Soil Texture ◽  
Nutrient Content ◽  
Fine Sand ◽  
Coarse Sand ◽  
Adsorptive Capacity ◽  
Soil Physics ◽  
Clay Particles ◽  
Soil Particles ◽  
Sand Particles

Soil physics deals with physical properties of soils such as soil texture, porosity, soil water, soil aeration, soil temperature, soil structure, and the influence of these properties on plant growth. Soil texture refers to the particle-size distribution of soils. The primary soil particles are arbitrarily divided into different size classes. The International Society of Soil Science defines soil particles larger than 0.02 mm and smaller than 2 mm as sand, those larger than 0.002 mm but smaller than 0.02 mm as silt, and those smaller than 0.002 mm as clay. Soil particles larger than 2 mm, such as gravel and stones, are called coarse fragments and are not part of the soil itself, to which the term soil texture applies, but can have considerable influence on soil properties and plant growth. Sand particles (0.02-2 mm) can be further divided into fine sand (0.02-0.2 mm) and coarse sand (0.2-2 mm). Sand particles can be rounded or angular, and are noncohesive. They usually consist of a single mineral, usually quartz (SiO2) or other primary silicate, and may appear brown, yellow, or red as a result of Fe-oxide coatings. Due to its mineral composition, sand has a smaller plant-nutrient content than finer soil particles. Sand particles have large voids between them which promote drainage of water and entry of air into the soil. Due to their low specific surface area, sand particles can hold little water, therefore rain needs to be received at short intervals to enable plant growth on sandy soils. Silt particles (0.002-0.02 mm) do not feel gritty when rubbed between fingers and are not visible to the unaided eye as sand particles are. Quartz is generally the dominant mineral. However, when silt is composed of weatherable minerals, the release of plant nutrients can be significant. The pores between silt particles are smaller and more numerous than those in sand, and silt therefore retains more water than sand, which helps to sustain plant growth. Silt itself does not exhibit much stickiness or plasticity and is therefore easily washed away by water. If silt fractions have some cohesion and adsorptive capacity, it is due to a film of adhering clay particles.

Observations on soil protozoa

1919 ◽  
Vol 9 (4) ◽  
pp. 430-444 ◽  
Author(s):  
D. Ward Cutler
Keyword(s):  
Fine Sand ◽  
Coarse Sand ◽  
Dilution Method ◽  
Counting Method ◽  
Liquid Media ◽  
Sand Soil ◽  
Soil Particles ◽  
Soil Protozoa ◽  
Direct Counting ◽  
Direct Counting Method

1. It has been shown that the direct counting method for soil protozoa devised by Kopeloff and Coleman for use in liquid media gives results entirely comparable with those obtained by a dilution method.2. The factors governing the relation between the protozoa and the soil particles are those of surface action, and the capacity of various substances, sand, soil and clay, for retaining these organisms is specific and constant.3. Coarse sand is capable of withdrawing per gram approximately 145,000 amoebae and flagellates per c.c. from a suspension of any strength. Fine sand withdraws approximately 980,000 per c.c: soil and partially sterilised soil 1,650,000, ignited soil 1,500,000 and clay 2,450,000.4. These figures are constant for given material and organisms and are independent of the concentration of the suspension, the time of action, or whether the suspension contains cysts or active forms of the amoebae and flagellates investigated. Also the action is the same when the experiment is performed with a suspension of living or dead organisms.5. Experiments with the ciliate—Colpoda cucullus—show that coarse sand per gram retains 27,000 per c.c.; fine sand per gram 185,000 per c.c; soil and partially sterilised soil 280,000 per c.c; ignited soil 270,000 per c.c. and clay 450,000 per c.c.

scholarly journals Effect of Bovine Manure on Fecal Coliform Attachment to Soil and Soil Particles of Different Sizes

2007 ◽  
Vol 73 (10) ◽  
pp. 3363-3370 ◽  
Author(s):  
Andrey K. Guber ◽  
Yakov A. Pachepsky ◽  
Daniel R. Shelton ◽  
Olivia Yu
Keyword(s):  
Clay Fraction ◽  
Free Cell ◽  
Organic Coating ◽  
Bacterial Attachment ◽  
Fecal Coliforms ◽  
Clay Particles ◽  
Soil Particles ◽  
Soil Fractions ◽  
Sand Particles ◽  
Coated Sand

ABSTRACT Manure-borne bacteria can be transported in runoff as free cells, cells attached to soil particles, and cells attached to manure particles. The objectives of this work were to compare the attachment of fecal coliforms (FC) to different soils and soil fractions and to assess the effect of bovine manure on FC attachment to soil and soil fractions. Three sand fractions of different sizes, the silt fraction, and the clay fraction of loam and sandy clay loam soils were separated and used along with soil samples in batch attachment experiments with water-FC suspensions and water-manure-FC suspensions. In the absence of manure colloids, bacterial attachment to soil, silt, and clay particles was much higher than the attachment to sand particles having no organic coating. The attachment to the coated sand particles was similar to the attachment to silt and clay. Manure colloids in suspensions decreased bacterial attachment to soils, clay and silt fractions, and coated sand fractions, but did not decrease the attachment to sand fractions without the coating. The low attachment of bacteria to silt and clay particles in the presence of manure colloids may cause predominantly free-cell transport of manure-borne FC in runoff.

The Characteristic of Petroleum Contaminant Adsorption Materials and the Estimation of Adsorption Attenuation

2011 ◽  
Vol 179-180 ◽  
pp. 197-202
Author(s):  
Yu Bo Xia ◽  
Yue Suo Yang ◽  
Xin Qiang Du
Keyword(s):  
Fine Sand ◽  
Coarse Sand ◽  
Adsorptive Capacity ◽  
Medium Sand ◽  
Freundlich Model ◽  
Adsorption Reaction ◽  
Pollution Levels ◽  
Main Action

Based on the experiment in lab and the investigation in study site, we have studied the adsorption of fine sand, medium sand and coarse sand which composes the aquifer. The different type's soil is different to the petroleum adsorption, the adsorptive capacity of fine sand is strongest, the coarse sand adsorption is worst. The adsorptive capacity of Sandy in 33.8% to 46.1%, adsorptive capacity of gravel is 9.2%. Freundlich model is more accurate to explain the sorption of the sands. The adsorption reaction of sand is very rapid, and it often only needs less than a day to reach adsorption reaction balance. The pollution levels are underestimated, and has been underestimated approximately 37.1% to 41.4%, and adsorption attenuation is a main action in study site.

scholarly journals Effect of different levels of humic acids on the nutrient content, plant growth, and soil properties under conditions of salinity

2011 ◽  
Vol 6 (No. 1) ◽  
pp. 21-29 ◽  
Author(s):  
H. Khaled ◽  
H.A. Fawy
Keyword(s):  
Plant Growth ◽  
Humic Substances ◽  
Humic Acids ◽  
Foliar Application ◽  
N Uptake ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Nutrient Content ◽  
Nutrient Elements ◽  
A Minor

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil fertility and textures with their complex and heterogenous structures although they occupy a minor percentage of the soil weight. Humic acids are an important soil component that can improve nutrient availability and impact on other important chemical, biological, and physical properties of soils. The effects of foliar and soil applications of humic substances on the plant growth and some nutrient elements uptake of Corn (Hagein, Fardy10) grown at various salt concentrations were examined. Sodium chloride was added to the soil to obtain 20 and 60mM saline conditions. Solid humus was applied to the soil one month before planting and liquid humic acids were sprayed on the leaves twice on 20<sup>th</sup> and 40<sup>th</sup> day after seedling emergence. The application doses of solid humus were 0, 2 and 4 g/kg and those of liquid humic acids were 0, 0.1 and 0.2%. Salinity negatively affected the growth of corn; it also decreased the dry weight and the uptake of nutrient elements except for Na and Mn. Soil application of humus increased the N uptake of corn while foliar application of humic acids increased the uptake of P, K, Mg,Na,Cu and Zn. Although the effect of interaction between salt and soil humus application was found statistically significant, the interaction effect between salt and foliar humic acids treatment was not found significant. Under salt stress, the first doses of both soil and foliar application of humic substances increased the uptake of nutrients.

Improved CFD modeling and validation of erosion damage due to fine sand particles

Wear ◽  
2015 ◽  
Vol 338-339 ◽  
pp. 339-350 ◽  
Author(s):  
Amir Mansouri ◽  
Hadi Arabnejad ◽  
Soroor Karimi ◽  
Siamack A. Shirazi ◽  
Brenton S. McLaury
Keyword(s):  
Fine Sand ◽  
Cfd Modeling ◽  
Erosion Damage ◽  
Sand Particles

scholarly journals Marine substrate response from the analysis of seismic attributes in CHIRP sub-bottom profiles

2017 ◽  
Vol 65 (3) ◽  
pp. 332-345 ◽  
Author(s):  
Larissa Felicidade Werkhauser Demarco ◽  
Antonio Henrique da Fontoura Klein ◽  
Jorge Antonio Guimarães de Souza
Keyword(s):  
Grain Size ◽  
Seismic Reflection ◽  
Ground Truth ◽  
Fine Sand ◽  
Seismic Attributes ◽  
Coarse Sand ◽  
Unconsolidated Sediments ◽  
Shallow Gas ◽  
Size Classes ◽  
Seismic Reflection Profiles

Abstract This paper presents an evaluation of the response of seismic reflection attributes in different types of marine substrate (rock, shallow gas, sediments) using seafloor samples for ground-truth statistical comparisons. The data analyzed include seismic reflection profiles collected using two CHIRP subbottom profilers (Edgetech Model 3100 SB-216S), with frequency ranging between 2 and 16 kHz, and a number (38) of sediment samples collected from the seafloor. The statistical method used to discriminate between different substratum responses was the non-parametric Kruskal-Wallis analysis, carried out in two steps: 1) comparison of Seismic Attributes between different marine substrates (unconsolidated sediments, rock and shallow gas); 2) comparison of Seismic Attributes between different sediment classes in seafloors characterized by unconsolidated sediments (subdivided according to sorting). These analyses suggest that amplitude-related attributes were effective in discriminating between sediment and gassy/rocky substratum, but did not differentiate between rocks and shallow gas. On the other hand, the Instantaneous Frequency attribute was effective in differentiating sediments, rocks and shallow gas, with sediment showing higher frequency range, rock an intermediate range, and shallow gas the lowest response. Regarding grain-size classes and sorting, statistical analysis discriminated between two distinct groups of samples, the SVFS (silt and very fine sand) and the SFMC (fine, medium and coarse sand) groups. Using a Spearman coefficient, it was found that the Instantaneous Amplitude was more efficient in distinguishing between the two groups. None of the attributes was able to distinguish between the closest grain size classes such as those of silt and very fine sand.

The late Wisconsinan olistostrome of the lower Coppermine River valley, Northwest Territories

1986 ◽  
Vol 23 (11) ◽  
pp. 1700-1708 ◽  
Author(s):  
Denis A. St-Onge ◽  
Jean Lajoie
Keyword(s):  
Debris Flows ◽  
Late Quaternary ◽  
Fine Sand ◽  
Coarse Sand ◽  
Coarse Fraction ◽  
River Valley ◽  
Glacial Lake ◽  
The North ◽  
Geologic Record ◽  
Coppermine River

The late Quaternary olistostrome exposed in the lower Coppermine River valley fills a paleovalley that ranges in apparent width from 150 to 400 m and was cut into Precambrian bedrock before the last glaciation. The olistostrome is here named the Sleigh Creek Formation. The coarse fraction of the formation is matrix supported; beds are massive or reversely graded and have sharp, nonerosive contacts. These characteristics suggest deposition of the coarse fraction by debris flows. The olistostrome sequence is bracketed by, and wedged into, a marine rhythmite sequence, which indicates that deposition occurred in a marine environment.About 10 500 years BP glacier ice in the Coronation Gulf lowland dammed the valley to the south, which was occupied by glacial Lake Coppermine. Sediments accumulated in this lake in a 30 m thick, coarsening upward sequence ranging from glaciolacustrine rhythmites of silt and fine sand at the base to coarse sand alluvium, and deltaic gravels at the top. As the Coronation Gulf lowlands became ice free, the Coppermine River reoccupied its former drainage course to the north. The steep south to north gradient and rapid downcutting by the river through the glacial lake sediments produced unstable slope conditions. The resulting debris flows filled a bedrock valley network below the postglacial sea level, forming the diamicton sequence.The interpretation of the Sleigh Creek Formation raises questions concerning silimar diamicton deposits usually defined as "flowtills." More generally, the results of this study indicate that care must be used when attempting paleogeographic reconstructions of "glaciogenic" deposits in marine sequences in any part of the geologic record.

scholarly journals The effects of arbuscular mycorrhizal fungi inoculation on Euterpe oleracea mart. (açaí) seedlings

1999 ◽  
Vol 34 (6) ◽  
pp. 1018-1024 ◽  
Author(s):  
Elizabeth Ying Chu
Keyword(s):  
Plant Growth ◽  
Arbuscular Mycorrhizal Fungi ◽  
Mycorrhizal Fungi ◽  
Arbuscular Mycorrhizal ◽  
Nutrient Content ◽  
Euterpe Oleracea ◽  
Plastic Bags ◽  
Matter Production ◽  
Infected Root ◽  
Black Plastic

With the objective of verifying the response of Euterpe oleracea seedlings to seven arbuscular mycorrhizal fungi species, an experimental trial was carried out under greenhouse conditions. Seeds of E. oleracea were sown in carbonized rice husk. Germinating seeds were initially transferred to plastic cups, containing fumigated Reddish Yellow Quartz Sand and inoculated with arbuscular mycorrhizal fungi. Two months later, seedlings were transferred to 2 kg black plastic bags, containing the same soil without fumigation. Plant growth and mineral nutrients were evaluated nine months after mycorrhizal inoculation. Differential effects were observed among the species tested, with Scutellispora gilmorei being the most effective ones in promoting growth and nutrient content of E. oleracea seedlings. The increment resulted from inoculation with S. gilmorei were 92% in total plant height, 116% in stem diameter, 361% in dry matter production, 191% in N, 664% in P, 46% in K, 562% in Ca, 363% in Mg and 350% in Zn contents, comparing to uninoculated controls. Infected root length was positively correlated to nutrient content and plant growth. It was concluded that growth and nutrient uptake of E. oleracea seedlings could be significantly improved by inoculation of effective arbuscular mycorrhizal fungi.

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