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| | Soil structure - Wikipedia, the free encyclopedia |
 | | A major focus of study in the area of soil conservation, from at least the Dust Bowl era in the United States, is the effect of agricultural tillage methods on soil structure. | | | Some of the known determining factors affecting soil structure in nature are moisture, clay content, and organic matter (such as microscopic organisms, fungi, small roots, etc.). | | | Although the issue has implications for all farmers, those espousing and practicing organic farming techniques are often especially sensitive to preserving soil structure. |
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http://en.wikipedia.org/wiki/Soil_structure
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| | Soil - Wikipedia, the free encyclopedia |
| | Soil is vital to all life on earth because it supports the growth of plants, which supply food and oxygen and absorb carbon dioxide and nitrogen. | | | Human actions also can degrade soil through the depletion of nutrients, pollution, contamination, and compaction, and by increasing the rate of erosion, which is the relocation of soil through the movement of water or wind. | | | The rock and mineral content of soil is categorized according to particle size as sand (coarsest), silt or clay (finest); the ratio of these particles to a great degree determines the soil classification and characteristics. |
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http://en.wikipedia.org/wiki/Soil
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| | ICS's water management solutions for arid and semi-arid regions |
| | Soil structure and soil texture also have an impact on water infiltration rate and thus on water management efficiency: water losses from evaporation or runoff are either reduced or increased when soil structure is modified. | | | Among the different environmental characteristics, soil structure is often neglected, although it has a strong impact on water and nutrient access and uptake by the crop. | | | The volume of studied soil is separated in units, each unit having a unique history in terms of management practices (agricultural equipment used). |
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http://www.ics-agri.com/soil-structure.htm
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| | Soil structure |
| | Good soil structure is critical for maintaining the long-term capacity of agricultural land to produce crops. | | | Adequate soil cover is important for protecting the soil against the direct impact of raindrops and full sunlight. | | | Soil exposure = ratio of the number of months of low soil cover the length of the LUS |
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http://www.asb.cgiar.org/data/dataset/IDAUBSCE.htm
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| | Deterioration of soil structure - subsoils |
| | Soil compaction is a dynamic soil process referring to an increase in the density of a soil. | | | Natural aggregates are called peds, therefore a soil may be pedal or apedal depending on the presence or absence of peds. | | | Soil structure or pedality, refers to the arrangements of soil particles and the spaces (pores) between them. |
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http://www.netc.net.au/enviro/fguide/detosub.html
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| | ingham.html |
| | Immobilization of nutrients in soil, i.e., retention of carbon, nitrogen, phosphorus, and many micronutrients in the horizons of soil from which plants obtain their nutrients, is a process performed by bacteria and fungi. | | | For agricultural soils, fungal biomass is around 1 to 50 meters per gram soil, while for forest soils, fungal biomass is between 1000 meters to 60 km per gram of soil. | | | Effects of streptomycin, cycloheximide, fungizone, captan, carbofuran, cygon, and PCNB on soil microbe populations and nutrient cycling. |
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http://www.rain.org/~sals/ingham.html
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| | 6.2 Soil Structure and Friability |
| | Soil structure describes how the basic soil materials (sand and clay) are arranged into soil aggregates and the pore spaces between them (see Figure 1). | | | A well structured soil resists the erosive forces of water and wind, does not crust, allows seedlings to emerge unimpeded and can be worked over a wide range of moisture contents with minimal damage. | | | Structural quality of a particular soil type can be assessed by measuring soil strength, the size and stability of aggregates and by looking at pore density and root growth. |
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http://www.bettersoils.com.au/module6/6_2.htm
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| | 10(t) Introduction to Soils |
| | Soils of the humid tropics are generally red or yellow because of the oxidation of iron or aluminum, respectively. | | | Maximum soil fertility occurs in the range 6.0 to 7.2. | | | Soil fertility is directly influenced by pH through the solubility of many nutrients. |
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http://www.physicalgeography.net/fundamentals/10t.html
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| | NO-TILL AND SOIL STRUCTURE |
| | Use a soil probe or dig a hole to determine the moisture content and exact depth of the compacted layer. | | | Earthworms, soil inhabiting insects, other burrowing animals, and channels left by decayed plant roots also can be important agents in improving water movement into and through the soil. | | | Soil compaction reduces water infiltration and drainage, limits aeration, restricts root growth, and reduces water and nutrient uptake. |
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http://southcenters.osu.edu/soil/compact.htm
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| | Improving Clay Soils |
| | Clay soils are relatively fertile because of this capacity to adsorb these important plant nutrients. | | | I understood that in southeastern soils, it would be very difficult to increase the percentage of organic matter in the soil very quickly. | | | In clay soils, clay particles are typically arranged along a horizontal plane in a platelike structure. |
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http://www.taunton.com/finegardening/pages/g00012.asp
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| | SOIL PHYSICAL PROPERTIES |
| | Assumption: The particle density of this soil is 2.65 g/cm³. | | | The soils often hinder roots from penetrating the soil in search of water and nutrients. | | | These soils allow roots to easily penetrate the soil in search of water and nutrients. |
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http://www.cst.cmich.edu/users/Franc1m/esc334/lectures/physical.htm
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| | Soil Pit Structure |
| | Soil structure is the arrangement of smaller soil particles to form larger pieces, such as these blocks. | | | That is because this soil has been plowed, and the structure of the soil has been destroyed. | | | A lot of soil erosion happened in the 1930’s—so much soil was blowing around in the air that it became known as the Dust Bowl. |
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http://www.oznet.ksu.edu/fieldday/kids/soil_pit/soil_structure.htm
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| | John and Bob's Improves Soil Structure |
| | Most soil amendments either add soluble calcium to the soil, or they create calcium within the soil by some kind of reaction with soil lime (calcium carbonate) such as soil sulfur or sulfuric acid. | | | Soil Optimizer will add nutrient holding capacity to the soil, improve nutrient uptake for nitrogen, phosphorus and all the micro-nutrients including zinc and iron. | | | As a result, soil scientists have discovered how important the role of the active ingredient in JandB's Soil Optimizer (the soluble part of soil humus) is, in promoting better soil structure. |
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http://www.johnandbobs.com/article3.htm
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| | ARS Project: BIOGEOCHEMICAL PROCESSES INFLUENCING SOIL STRUCTURE AND ORGANIC CARBON SEQUESTRATION (404154) Annual Report |
| | The soil organic matter is very important because it acts as a glue to help stabilize soil structure and is a major reservoir of both plant nutrients and plant available water. | | | However, accumulation of C in the heavy sub-fraction of POM, a biologically-active form of SOC, was greatest in native prairie remnant soils, intermediate in the oldest reconstructed prairie soils, and least in cultivated agricultural soil. | | | Logsdon, NSTL, evaluated various methods for measuring changes in soil structure and demonstrated that existing methods are unable to quantify the effects of cropping system on the rate water moves through the soil, the density of the soil, the volume of large pores, or distance between large pores. |
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http://www.ars.usda.gov/research/projects/projects.htm?ACCN_NO=404154&fy=2003
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| | Corn and the Environment- Corn, Soil Structure and Erosion |
| | Good soil structure is important in allowing crop plants to yield well, and in helping resist erosion caused by the action of rainfall, melting snow in early spring, and wind. | | | The control of soil erosion and the use of soil tests which ensure that excessive phosphate fertilizer is not applied are means of reducing water contamination by phosphates. | | | While this helps to improve the structure of deeper soil layers, it is less effective in stabilizing surface soil than are the fine, shallow roots of crops such as perennial grass species and winter cereals. |
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http://www.ontariocorn.org/envt/enverosion.htm
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| | soil: Components and Structure |
| | Influence of soil structure on the shrinkage behaviour of a soil irrigated with saline-sodic water. | | | The structure of agriculture: implications for soil and water conservation. | | | Coarser soils have lower capacity to retain organic plant nutrients, gases, and water, which are essential for plants. |
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http://www.infoplease.com/ce6/sci/A0861165.html
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| | Building Healthy Soil |
| | As the structure of a soil is made more granular and crumbly by decomposing organic matter, the soil absorbs moisture that would otherwise run off, causing erosion and a loss of nutrients in the process. | | | For soil that is primarily clay or sand, or that has a hard surface crust (water runs off), or is compacted, incorporate 2 to 3 inches of organic matter in the top few inches of soil and mulch liberally for several years. | | | The first step to improving your soil is to have your soil tested for pH and nutrient levels. |
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http://www.ext.vt.edu/pubs/envirohort/426-711/426-711.html
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| | Help4diy.com®>Improving Soil Structure |
| | Fertile soil will make gardening a pleasure, plants will flourish and be more resistant to pest and disease attack, worms and natural soil organisms will help to make the soil easier to work and improve drainage naturally. | | | Dry areas of soil are usually found under large trees which draw the moisture out of the ground. | | | Adjusting soil pH or 'acid' levels of the soil. |
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http://www.btinternet.com/~kappacel/improvin.htm
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| | Quantification of soil structure |
| | Structure, the arrangement of particles in a soil or other porous medium, is a major influence on the hydraulic properties of the medium. | | | A related problem is the artificial modification of soil structure, as happens when soil is disturbed for purposes of farming, waste disposal, mining, construction, or other activities. | | | Often it is the most important known factor, because the arrangement of particles plays the biggest role in determining the size and shape of the pores that conduct water. |
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http://wwwrcamnl.wr.usgs.gov/uzf/theory.struc.html
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| | Soil Structure |
| | Aggregates can be as small as a grain of sand or as large as a pea. | | | A well-structured soil is made up of aggregates of varying sizes that allow maximum space for air and water (ideally about 20% to 25% for each by volume). | | | Unnecessary digging or rototilling may break down aggregates into a fine powder, reducing pore space. |
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http://www.hcs.ohio-state.edu:16080/mgonline/soils/soi04/05soi04.htm
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| | Soil structure and its quantitative parameter |
| | The traditional soil mechanics approach has developed from explaining the different mechanics laws of soil with different soil structure to suggesting some quantitative parameters of soil structure for some special soil. | | | But it is still difficult to find the prospect to get a general quantitative parameter of soil structure due to its limitation in describing both the geometric and the mechanics features of soil particles and due to also its complication in measuring the micro-morphology soil properties. | | | This kind of soil structure potential can be measured by releasing it through disturbance, loading and watering of soil and taken as the foundation of the quantitative soil structure parameter determination. |
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http://www.ins.itu.edu.tr/2001/abstract/1129.htm
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| | CHAPTER ONE: SOIL TEXTURE, STRUCTURE AND COLOR |
| | Name five soil constituents and the soil color you would expect them to be associated with. | | | When manipulating a moist soil sample, you observe noticeable grittiness yet you are able to form a ribbon of 4 inches consistently. | | | The presence of mottles at a particular depth in the soil profile indicates the soil is saturated at and below this depth for some time each year. |
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http://soils.ag.uidaho.edu/Soils206/Manual/one.htm
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| | Soil Structure, |
| | Soil and crop scientists/researchers, environmental soil quality scientists, soil conservationists and managers, ground water professionals and scientists. | | | Topics covered in Soil Structure include soil structure determination, soil fabric genesis and functions, strength and stress distribution, fabric changes in plastic clays, the effects of organic matter and earthworms, air slaking, and hydraulic conductivity changes. | | | Improved procedures for measuring and calculating the unsaturated hydraulic conductivity of structured soils are also given. |
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http://www.floridaplants.com/CR/soilstruct.htm
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| | Step-by-step guide: Structure |
| | Single Grained: Soil is broken into individual particles that do not stick together. | | | Massive: Soil has no visible structure, is hard to break apart and appears in very large clods. | | | Columnar: Vertical columns of soil that have a salt "cap" at the top. |
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http://ltpwww.gsfc.nasa.gov/globe/pvg/prop1.htm
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| | Dirt Radar |
| | The use of radar to measure soil's fractal dimension is a nice extension of the classical idea of measuring a jagged shoreline by using yardsticks of many different sizes, observes Dwight Jaggard of the University of Pennsylvania in Philadelphia. | | | The fractal dimension is a good indicator of a soil's density, water content, and porosity. | | | What's more, the technique can be performed without removing the soil from its environment. |
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http://focus.aps.org/story/v10/st17
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| | Soil Structure affected by tree drying |
| | In general, flood irrigation is considered the most destructive while soils that are wetted by capillary rise retain the initial soil structure for a greater length of time. | | | Of course these cracks would close if the soil was at all a swelling type of clay, and so the drying of the soil would not be exacerbated by the cracks, at least initially anyway. | | | If we take, for example, a soil that has been tilled to produce a loose collection of aggregates conducive to rapid root growth, the rate decline in soil physical fertility from this state will depend, partly, on the application rate of water. |
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http://www.metla.fi/archive/forest/1996/07/msg00049.html
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| | Soil Structure Interaction |
| | The spring stiffness must be selected approximately three orders-of-magnitude greater than the stiffness of the structure at the connecting nodes. | | | The spring stiffness should be large enough so the fundamental periods of the system are not changed, and small enough not to cause numerical problems. | | | It is apparent that the stiffness terms in Equation (16.15b) represent the stiffness of the contact springs only. |
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http://www.csiberkeley.com/Tech_Info/soilStructInter.htm
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| | Modifying soil structure using plant roots |
| | The main objectives of this thesis was to test the possibility of using plant roots to modify soil structure and to use laboratory screening methods to find plant species suitable for penetrating strong soil. | | | Löfkvist, J. and Arvidsson, J. A method for screening the ability of different crops to penetrate compacted soil and increase hydraulic conductivity. | | | The second method used natural soil compacted by different vertical stresses. |
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http://diss-epsilon.slu.se/archive/00000838
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| | DPIWE - Improving Soil Structure |
| | There are many soil management practices which can improve soil structure of krasnozems. | | | Incorporate crop residues in the soil rather than harvesting or burning. | | | Lupins, oats or short rotation ryegrass increase soil organic matter in the soil and the roots act as "biological rippers" improving infiltration rates. |
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http://www.dpiwe.tas.gov.au/inter.nsf/WebPages/EGIL-53CV66?open
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| | Publications - Dr. A.J.M. Smucker |
| | Tillage effects on soil nitrogen and plant biomass in a corn-alfalfa rotation. | | | Soil compaction and crop residue management effects on root diseases of annual food legumes. | | | Root exudation, soil wetting and drying modifications of soil aggregate stability. |
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http://www.msu.edu/~smucker/publications.htm
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| | Soil Structure and Fabric |
| | An assessment of soil fabric is required for a proper evaluation of soil structure. | | | The physical constitution of a soil material as expressed by the spatial arrangement of the solid particles and associated voids. | | | As one reads the micromorphology literature, one finds that there may not be a consistent use or interpretaiton of the terms "soil structure" and "soil fabric". |
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http://www.ces.ncsu.edu/plymouth/programs/fabric.html
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| | Scientific American: Radar Can Probe Soil's Structure |
| | Klaudia Oleschko of the National Autonomous University of Mexico and her colleagues determined that although soil structure is extremely heterogeneous, on the scale of one centimeter to one meter it is also a fractal. | | | Determining whether or not a swath of soil will lend itself to agricultural use usually requires extensive testing, which may disrupt the soil and can be time-consuming. | | | The authors conclude that ground-penetrating radar is "a prominent tool for nondestructive soil studies." |
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http://www.sciam.com/print_version.cfm?articleID=000085A7-6C09-1DAC-815A809EC5880000
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| | Compost Improves Soil Structure and Garden Fertility |
| | For sandy soils, compost will increase the water-holding capacity and retain more nutrients. | | | Compost also adds some nutrients to the soil. | | | Taking the time to improve your soil before planting can help you reap sweet success from your garden. |
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http://www.cahe.nmsu.edu/news/1997/032497_compost_1997.html
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| | soil structure lecture notes |
| | A granular or crumb structure is best for agricultural crop production - what 3 key factors are important in its formation ? | | | Structure - grouping or arrangement of soil particles | | | - Causes soil crusting in poorly structured soils |
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http://sanangelo.tamu.edu/agronomy/txla/soilnote.htm
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| | tables |
| | Table 1 - Prominent minerals in soil clay fraction by relative degree of soil development from least developed (1) to most developed (13) (adapted from Jackson and Sherman 1953). | | | Increases the cation exchange capacity (CEC) of the soil; 20 to 70 percent of the CEC of many soils is caused by organic matter | | | Typical dark color of many soils is caused by organic matter |
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http://www.cr.nps.gov/seac/soilsmanual/tables.htm
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| | How does soil structure influence plant growth? |
| | Tamping the soil or shaking the soil up in water will do this. | | | If you have, then you probably know how important the structure of soil is to healthy plants. | | | When soil structure breaks down plants and animals (including humans) suffer. |
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http://www.eddept.wa.edu.au/deo/MIDLANDS/Landcare/Activities/soil8.htm
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| | Soil Structure (HS6) |
| | Why do farmers need to know the types of soil combinations in a field if they are going to plant crops? | | | Collect soil samples from your yard or other accessible area. | | | Loosely pour three inches of soil sample into the tube. |
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http://www.florence.ars.usda.gov/kidsonly/high/hs6.htm
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| | ARS Publication request: Effects of Soil Structure on Water Retention |
| | Technical Abstract: Procedures for predicting soil water retention have been developed to use various levels of soil information; however, soil survey qualitative structure class which is reliably estimated in the field and part of every soils description has never been incorporated into the procedures. | | | The overall order of importance of structure classes are shape, grade, and size; however, for water retention less than -33 kPa, size and grade are most important; while for water retention greater than -33 kPa, shape and grade are the most important. | | | Using a national soil database, we investigated the usefulness of incorporating the eeffect of soil structure (grade, size, and shape) on the prediction of water retained at -6 kPa, -10 kPa, -33 kPa, and -1500 kPa matric potential. |
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http://www.ars.usda.gov/research/publications/publications.htm?SEQ_NO_115=105111
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| | Quantification of soil structure |
| | In the study by Nimmo and Akstin (1988), described under Quantification of soil structure, we demonstrated the usefulness of the relation of water retention to unsaturated hydraulic conductivity through capillary constructs. | | | This model has also found application in representing water relations in frozen soils. | | | The result is a substantial improvement in accuracy for dry-range modeling because it turns the extrapolation problem (predicting water retention points in a range drier than any measurements) into an interpolation problem (predicting water retention points in a range between the measurements and the known oven-dry point). |
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http://wwwrcamnl.wr.usgs.gov/uzf/theory.lowwc.html
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| | Soil Structure revisited |
| | of a soil when you only know what’s in the soil survey? | | | Look it up for a similar soil | | | What we’ve seen of soil structure so far has involved structure of the solid phase. |
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http://www.agron.iastate.edu/soilphysics/a577struct2.html
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| | Soil Structure |
| | The arrangement of soil particles into groups or aggregates determines the "structure." A single mass or cluster of soil consisting of many soil particles held together in a particular way imparts particular physical characteristics to the soil, such as a clod, prism, crumb or granule. | | | Soil structure is often more important than the texture to the farmer. | | | Examples of various types of soil structure are shown in Figure 3.3. |
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http://www.agcentral.com/imcdemo/03Soil/03-06.htm
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| | Erosion - Terrain -- Erosion and Hydrology |
| | Information on erosion control, and soil management techniques. | | | Areas most susceptible to wind erosion on agricultural land include much of North Africa | | | To get realistic rivers, you have two choices: calculate the erosion and water flow Erosion is typically calculated for each cell in a heightfield. |
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http://erosion.surferspace.com
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| | structure grades, soil |
| | strong (structure forte) durable peds that are quite evident in undisturbed soil, adhere weakly to one another, withstand displacement, and become separated when the soil is disturbed. | | | Three grades of structure designated from 1 to 3 are: | | | moderate (structure modèrèe) well-formed distinct peds, moderately durable and evident, but not distinct, in undisturbed soil. |
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http://sis.agr.gc.ca/cansis/glossary/structure_grades,_soil.html
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| | Laboratory Impulse Tests for Soil-Underground Structure Interactions |
| | ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA, 19428-2959 USA | | | This paper describes four large-scale impulse tests on a 1-m-high prototype subsection of an underground structure subjected to controlled impulsive lateral loadings propagating through a 0.75-m-thick backfill soil. | | | The shock exerted on an underground structure caused by an underground explosion will vary with the detonation depth, the intensity of detonation force, and distance of detonation source from the underground structure. |
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http://www.astm.org/JOURNALS/TESTEVAL/PAGES/742.htm
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| | Identification of the Hualien soil-structure interaction system (ResearchIndex) |
| | The parameters identified are the shear moduli of several near-field soil regions as well as Young's moduli of the shell sections of the structure. | | | Joints Damage Assessment of Framed Structures Using Neural.. | | | 1 Identification of structural and soil properties from forced.. |
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http://citeseer.ist.psu.edu/404558.html
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| | Step-by-step guide: Table of Contents |
| | Soil Particle Density: Introduction and comparision between bulk density and particle density | | | Taking Bulk Density Samples Using the Soil Pit or Other Exposed Soil Profile, part 2 | | | If You Are Not Taking Bulk Density Samples and Using the Soil Pit or Other Exposed Road Cut Profile |
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http://ltpwww.gsfc.nasa.gov/globe/pvg/chartoc.htm
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| | Soil and Structure Consulting, Inc. |
| | Many other structural consulting firms will tell you their job is just to find problems. | | | Thank you for your interest in Soil and Structure Consulting. | | | If you have any other questions, use our more information form or call us at (703) 391-8911. |
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http://www.soilandstructure.com
(166 words)
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| | Soil & Structure Dynamics Ltd Dynamic |
| | The result of all these tools is a solution which enables accurate assessment of soil structure interaction problems with the minimum billable time. | | | However, unlike many other SSI programs on the market Win-SSI offers a graphical user interface to guide you through the production of your SSI analyses, selecting from your personal library of soil profiles and time history sets. | | | Win-SSI is a windows program to analyse soil structure interaction (SSI) problems using the CLASSI methodology. |
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http://www.soilstructure.co.uk
(188 words)
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| | The Field Museum Underground Adventure |
| | There's more to soil than meets the eye. | | | The world of soil is a rich habitat for many amazing creatures. | | | What do you think life would be like if you lived underground? |
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http://www.fieldmuseum.org/undergroundadventure
(96 words)
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