Factors of Soil Aggregation
There are many features that characterize a soil. One such feature is aggregates. There are many different types of aggregates, such as platy, prismatic, granule, blocky, angular, and more. There are several different factors which influence the formation of these aggregates. Hans Jenny, in his book Factors of Soil Formation (1941), recognizes five factors which influence soil formation: climate, biota, topography, parent material, and time. This paper will explore each of these factors in order to gain a better understanding as to what influences aggregate formation and strength.
Before exploring aggregate formation and strength, the word "aggregate" must be clearly defined. Singer and Munns (1996) define aggregate as a word synonymous to "ped" which refers to "a group of primary particles held together by various soil-stabilizing agents" (pg. 28) and "are described according to their shape, size, stability, and east with which we can see them in the soil" (pg. 28). There are six main types of aggregate shape: granular, subangular blocky, angular blocky, prismatic, columnar, and platy (Singer and Munns, 1996). Aggregates of different shapes form under different conditions, however, the basic elements that cause aggregate formation remain the same.
Now that "aggregate" has been defined, the discussion of formational factors may begin. The formation of aggregates begins at the smallest level, with tiny particles of less than five micrometers called colloids (Singer and Munns, 1996). At this size, electrostatic bonding and hydrogen bonding hold particles together (Black, 1968). This causes several effects. First, the amount of clay present becomes important, since most electrostatic and inter...
... middle of paper ...
...arides that are effective binding compounds. Fungal
hyphae on cast surfaces can physically enmesh and stabilize casts, but stabilization is most strongly promoted by drying, which brings the organic and mineral compounds into close association, promoting clay-polyvalent cation-organic matter linkages" (pg. 1743).
The factors which influence soil formation, and consequently aggregates, are complexly linked. Each factor interacts, influences, and in turn is dependent upon each other factor. Through this amazingly intricate relationship, several factors are recognized as more influential in aggregate formation. To fully list all possible elements which work to form a single aggregate would take many years, and many volumes of books to complete. This paper has hopefully provided insight into several of the most important factors that influence aggregate formation.
Mississippi has a variety of different soils .The three general soils are 1) the river flood plain, known as the Delta, 2) a loess region, or bands of soils formed in windblown material that adjoins the Delta, and 3) Coastal Plain. The Mississippi Delta is better for growing row crop, while the loess and Coastal Plain region are better for animal production and forestry. The loess and Coastal Plain regions are divided based on similar soils, geology, climate, water resources, and land use called Major Land Resource Areas. The Mississippi Delta’s soil comes from sediments left by flooding various rivers in the region, rather than being a typical Delta formed by the mouth of a river. In the Delta most of the land is farmed, with three-fourths of the cropland to the north. Controlling surface water and drainage are major soil management issues. In the Delta soils are naturally diverse because of their alluvial origin. Particle sizes within the sediment decrease as distance from the originating stream increase. Another factor in Delta soil formation us surface water movement over time, because soils that formed under standing water have different properties than soils formed under moving water. Soils with large amounts of clay particles have unique features. When the soil is dry, small round aggregates form at the surface that look like shotgun buckshot, which is where the popular name for Delta clay soils “buckshot” came from. Soils with large clay content have very slow water filtration rates; this has led to significant aquaculture and rice production in the region. When floodwaters receded in the Delta, strong winds blew some of the dry sediment left by flooded river to the adjacent uplands to form the loess areas. Because of eas...
plants and animals piled up into thick layers. This stuff is called organic material (it was
Ordinary fluid flow is different from granular flow so study of every particle’s behavior is necessary. Different physical phenomena, like interaction between particles and
(Ant)arctic (high-latitude) and alpine (mountain) areas are affected by relatively similar climates, as latitude and altitude produce similar meteorologic effects. In these geographic regions where temperature is at such a pronounced extreme, climate would seem to be the leading factor of soil development. It is my goal in this research paper to answer the following question: How do the soils of arctic and alpine areas differ? This idea, taken largely from an abstract by Birkeland (1975), will be explored through the comparison of the soils of these two geographic regions, and an analysis of the soil development factors in those environments.
Through the information and policies that have been presented, the New Israeli Shekel is surely a strong and trusted currency. The Bank of Israel has shown that it has the ability to maintain its currency and its growing economy. The partnership with the United States assures the rest of the world that there is a world power behind Israel. And the strong economic presence that Israel has allows Israel to continue to grow and thrive. The Israeli Shekel and the US Dollar are both floating currencies that are influenced by national and world politics. While each has the ability to move on its own, there are many factors that show the strength and the relationship that they have to each other. As Israel continue to develop, we will surely continue to see the strength and the support that the Shekel carries in the international community.
It was a day meant to be at Disneyland. My cousins came down all the way from South Africa to visit us, and seeing as theyʼve never been to the Happiest Place on Earth before, we decided to take them.
...2013). Pimps Down: A Prosecutorial Perspective on Domestic Sex Trafficking. University Of Memphis Law Review, 43(4), 1013-1045.
It happens when particles make effective collisions with sufficient energy. The sand is Apparatus = == == =
There are two types of aggregate piers: Rammed Aggregate Piers and Vibrated Aggregate Piers (vibro stone columns).
Tuberculosis in the 1980s were evident through the several years of rising case accounts to its highest point in 1992 this is alarmingly high because the disease travels through the air. As a result, it affects more people, worsening the impact of this disease. It also the impact the lack of education; corrupt living conditions, famine, deprived usage of health care, shortage vaccination charges and poor treatments all contribute to high tuberculosis cases consequence affecting thousand deaths.
Tuberculosis is an infectious disease which causes millions of death in humans. In India approximately 500,000 deaths occurs now and then. TB is an air borne disease which is caused by Mycobacterium tuberculosis. Apart from M. tuberculosis, there are many strains of Mycobacterial species like M. bovis , M .africanum , M. microti, M. caprae , M. pinnipedi i, M. canetti and M. mungi. Together these species are known to be M. tuberculosis complex. The main target of tuberculosis is the lungs (i.e. pulmonary tuberculosis) as well as other parts of the body (i.e. systemic tuberculosis). Most tuberculosis does not cause infection which is known as latent tuberculosis (i.e. they remain in inactive form). The spread of infection is due to active TB infection cough, sneeze, and fluid transmission or by aerosol in the air, and not by surface contact.
Tuberculosis, a sometimes crippling and deadly disease, is on the rise and is revisiting both the developed and developing world. The global epidemic is growing and becoming more dangerous. The breakdown in health services, the spread of HIV/AIDS and the emergence of multi drug-resistant TB are contributing to the worsening impact of this disease. Overall, one-third of the world's population is currently infected with the TB bacillus.
In fact, the lack of sufficient attention to this kind of social issue has resulted in no reliable estimation of the actual number of victims or a way to prevent such underground business from continuing in our society. In the article, “Domestic Minor Sex Trafficking in United States,” the author pointed out that some of the major commercial sex markets to include the United States, Jamaica, Japan, and the Netherlands maintain a sense of a “culture of tolerance.” By just focusing on the United States, the article stated that the “United States [is] shaped by a culture that glamorizes pimping and prostitution.” One can carefully notice that song lyrics, online or video games, clothing, and many media platforms are all promoting such a “culture of tolerance” that glamorizes pimps to be embodied in our daily lives. From my personal experience, I remember last year when my father accidentally bought a video game called GTA without checking the rating for my little brother to play. I went online to conduct some research on this video game in order to ensure it was appropriate for my little brother to play. I thought it was a car racing game, but surprisingly, there are certain scenes which include pimps and commercial sexual exploitation. As such, I do think that growing youth are lured into the commercial sex trade business, and the pimp culture is being normalized. The commercial sex trade
Ch, David L., ler, and MIT News Office. “Flexible, Light Solar Cells Could Provide New Opportunities - MIT News Office.” MIT’s News Office. Accessed November 24, 2013. http://web.mit.edu/newsoffice/2012/hybrid-flexible-light-solar-cells-1221.html.
Worldwide Tuberculosis is caused by M.bovis and M.africanum, in addition to M.tuberculosis. This is likely due to closer interactions between people and livestock, another host for the organisms. Transmissions to humans from susceptible animal species and their products like milk is also possible. It affects lungs and respiratory tract. With the advent of the AIDS epidemic, there has been a steady yearly increase in the number of global TB cases. In the United States, this disease mostly occurs among homeless, elderly and malnourished, or among alcoholic males, minorities and immigrants. The majority of active cases result from reactivation of old, dormant infections.