Soil Particle Size and Porosity
Question:
A comparison between two methods of investigating:
What is the effect of changing particle size (i.e. the texture of
soil) on the porosity of the soil?
This is basically investigating in two different ways, "What is the
effect of changing particle size (i.e. the texture of the soil) on the
porosity of the soil?" The two different methods can then be compared.
Predictions
Porosity is the amount of air space in a soil. There are two types of
porosity which are called Total Porosity and Water Holding Porosity.
In my investigation there are two different methods of calculating
porosity. The first experiment enables you to calculate Water Holding
Porosity and the second experiment enables you to calculate the Total
Porosity of a soil.
I would expect Clay soils (very small particles) to have the largest
Water Holding Porosity and therefore also the highest Total Porosity.
I would expect Sands and Sandy soils (large particles) to have the
lowest Water Holding Porosity and therefore the lowest Total Porosity.
Silty Soils should have a Water Holding Porosity and a Total Porosity,
that are greater than Sand but less than Clay. I am basically
predicting that the smaller the particle size of the soil, the greater
the Porosity.
In my experiment these soils will be used :
1. Newport (Silt Loam)
2. Hamble (Silt Clay Loam)
3. Wallasea (Clay)
4. Sand
For Total Porosity and Water Holding Porosity, I would expect the
soils to come in this order (with the largest at the top) :
* Wallasea (Clay)
* Hamble (Silt Clay Loam)
* Newport (Silt Loam)
* Sand
Equipment
Measuring Cylinders
Gooch Crucibles (to hold the soil)
Balance (to weigh the soil)
Beakers (to pour the water)
Chemicals
H2O (Water) Newport Soil Wallasea Soil Hamble Soil Sand
• For the spacing, a consideration should be done for the depth of compressible layer, permeability of soil and location of ground water table. As well as that when compacting for deeper layers a wider spacing should be used compared to upper layers.
Conductivity: Thermal conductivity of the growing media which is related to the wet or dry environment (W/(m-K).
Grain size refers to a diameter of an individual particle and grain shape refers to the roundness or how close the shape is to a sphere. Navajo’s grain size averages at 0.2 millimeters in diameter and grain shape is well rounded and well sorted. Pottsville grain size averages at 3.81 centimeters in diameter and it is also well rounded, but it is not well sorted. Porosity is a measure (using meters) of how much empty space is in a rock and permeability is the measure (using Darcy) of ease in which liquid can move through a rock. Navajo’s porosity varies from 1.2% to 15% and the permeability ranges from 0.06md to 54md. Pottsville’s porosity varies from 11% to 15% and the permeability
Dense to very dense natural and compacted foundation soils had settled a maximum of 4inches or four-tenths of a percent of the wall height. By the comparison of the
Each type of soil has its characteristics in terms of water holding capacity. The first type is sand. Sand has the largest particles, with huge spaces between them, this is why sand doesn’t have the ability to hold water. Clay has the smallest particles compared to the other type, so it has good water storage qualities. It’s sticky to the touch when wet, but smooth when dry. () Clay has many fine pores, which gives it a higher capacity to hold water, than other types of soil. Eventually, it holds a higher amount of water than sand does.
...n be derived from empirical relationships with other measurements such as porosity, NMR and sonic logging.
The largest of the primary types of soil particles is sand, which ranges between 0.05 and 2 millimeters in diameter. Silt particles are smaller than sand particles, ranging between 0.002 and 0.05 millimeters in diameter. Clay particles are the smallest of all, at less than 0.002 millimeters in diameter. Soils that are more than 50 percent sand particles are considered to be "sandy soils."Soils made up of more than 80 percent sand are simply referred to as "sand." Sandy soils tend to be easier to work than clay soils, and sandy soils are well-aerated, which helps to keep plants' roots
Vertisols are mainly soils that have a high content of expending clay and that have at some time of the year deep wide cracks. They shrink when drying and swell when they become wetter. Vertisols are mineral soils that have a exist in a well-balanced supply of moisture or warmer soil temperatu...
What is soil? “Soil is a complex mixture of eroded rock, mineral nutrients, decaying organic matter, water, air, and billions of living organisms, most of them microscopic decomposers.” (Miller and Spoolman, 211). As stated, soil is made when a mixture of items such as eroded rock and mineral nutrients come together. Soil is used in a plethora of ways. Soil is where many of the nutrients plants need to grow comes from, soil purifies water, and even absorbs carbon dioxide from the atmosphere to be stored as carbon compounds (Miller and Spoolman, 211). Scientists study soil to develop a better understanding how this crucial factor in human’s survival functions and how to make sure humans don’t waste this precious resource (Miller and Spoolman, 211).
There are two important properties that determine the hydraulic conductivity: the geometry of the pore system and the intrinsic properties.
Figure 3.10 shows the free body diagram of Archimedes principle. The density of materials is defined as a ratio of mass per unit volume. The unit of density is kilogram per cubic meter (kgm-3). Density of the solids could be determined by the technique as referred as the apparent porosity and apparent density. The density is difference for different materials. The lighter products have lower value of density compare to the heavier product which have higher value of density. The formula for density is:
pores is related to the rate at which water is lost from the leaves. A
The Water Content of Soil The water content of soil is a major factor that will determine what sort of plants are able to grow, and when considering a system of sand dunes will have considerable effects on the zonation and succession of that environment. In order to investigate this, trial experiments were initially carried out in order to determine the most effective method of assessing a section of the dunes and obtaining results. Once these results had been obtained, adjustments to the original method were made, and the process of gaining results took place. After tabulating the results, and drawing appropriate graphs, I concluded that within a system of sand dunes, zonation and succession of plant species is present, and as the distance from the strand line increases, so too does the water content of the soil. I also concluded that the water content of the soil is affected by the aspect of its position as well, which relates directly to its exposure.
Salinity is simply the amount of salts contained in the soil which is estimated by measuring the electrical conductivity of a removed soil solution. An electrical device can easily measure the amount of salt contained in the soil. In millimhos/cm or micromhos/cm, a salt concentration of a gram per litre is about 1.5 millimhos/cm).
Some soils have exceptionally good properties which is useful for plant growth and some soils are hard to cultivate. One of the major causes of tillage addiction is soil compaction also known as tillage pan.The intensity of tillage depends on the level of soil compaction. The huge mechanical stress applied to soil by powerful machinery is also an outcome of compaction. These forces lead to the loss of soil aggregates and pore spaces.