The Story of Organic Matter Decay in Soils
To most people, humus is a garlic-y chickpea spread for sandwiches or pita bread. However, to soil scientists, its something entirely different. Soil humus is a mixture of dark, colloidal organic compounds relatively resistant to decomposition. These compounds result from the decay of organic litter and accumulate in the O and A horizons of soils. Soil humus helps glue mineral particals into aggregates, giving structure to the soil and affecting soil stability.
There are three main classifications of humus: fulvic acid, humic acid and humin. Humin is insoluble but fulvic and humic acids are soluble in dillute NaOH solution. Humic acids precipitate in acidic solution, but fulvic acids remain soluble. Humic molecules are incredibly varied in composition, but generally are characterized by:
1) many active chemical functional groups exposed to the surrounding solution for reaction with other substances in the solution.
2) a very large cross-linked and "folded" molecule with molecular weights in the hundreds of thousands of grams per molecule" (Miller and Donahue, 1990, p. 185).
Humus has a large surface area per unit of mass and is highly charged (similar to clay), and individual humus molecules are dynamic and constantly changing form (but may remain humus for several thousand years). Humus includes sugar amines, nucleic acids, phospholipids, vitamins, sulfolipis, polysaccharides and many other unclassified compounds (Miller and Donahue, 1990). Figure 1 shows a hypothetical structure of a humic acid with many of the characteristic functional groups. Fulvic acid and humin have similar structures. The COOH and phenolic OH groups are weakly acidic, which give humus its pH b...
... middle of paper ...
...II, the environmental conditions alone may determine the rate. (Melillo et al., 1989) Aber et al. supported this conclusion, but measured major differences in the nitrogen content during Phase II, indicating that only the carbon was uniform during this stage (Aber et al, 1990). Other researchers had also separated two stages of decomposition: early decay, when "free" cellulose decomposes quickly, and later decay, when cellulose is shielded by lignin and can be decayed only with the coprocessing of the lignin (Aber et al., 1990).
In summary, through a series of complex reactions, microbes mediate the conversion of organic material such as leaves and twigs to the dark humus which colors and glues our soils. Without these processes, the soils would be loose, non-cemented dusts and no life would be able to grow on them, and the world would be a very different place.
The Atlantic slave trade that took place over an expanse of 350 years affected the people involved on both sides of that time. The slave owners in t...
With the new sources of labor presented in the Atlantic Slave Trade, America was another region that gained many developments in its economy, and society. Slavery played an integral part in ...
This paper will give an analysis of the Trans-Atlantic Slave Trade explaining the challenges and painful afflictions African peoples had to endure. Revealing the constant struggles of the African during the trade and how it correlates with people in present day society. Additionally, the system also established the World economy by utilizing Africans for stock and exchange.
As one evaluates the article, “Children Need to Play, Not Compete,” Jessica Statsky explains the dangers of children being involved in competitive sports at a young age. She worries that sports “entice children into physical actions that are bad for growing bodies” (para. 3). She also states that coaches and parents may push their child athletes farther than they want to be pushed. Statsky explains how life lessons may be learned and friendships may be gained through sports, and that winning should not be the most important part of playing. With possible risks of life long injuries, one should support Statsky in her claim that children should learn to play the game, not so much compete.
Are youth sports too intense? Studies shows that some youth sports are too violent for some kids. Every day kids are being pushed beyond their limits by their coach,parents and fans.sports have some kids eat different to make them lose weight or gain weight. There are many examples of how people have gotten out of hand during youth sports games, more so parents than kids in most cases. Parents need to become more educated before becoming too involved with their children’s youth sports, otherwise they will be bringing more of a lack sportsmanship to their children’s youth sports than their already is.
Some people may argue that Competitive sports give children many chances to work with a team, and get in shape(Lisa Bigelow). But this is not always true, some coaches and parents push their kid to the edge and can harm them. Over working a child is not good at young ages, because they can only take so much and their body is not fully developed. Teamwork skills aren’t always provided if a coach is making a player the star of the team, some of kids may feel left out and possibly want to quit. Kids that aren’t as athletic as some kids might not be able to physically do what more athletic kids can do, this can make them feel like they aren’t good enough. With coaches pushing kids too hard can get kids to go against each other, potentially causing them to harm one another. Getting kids to going against each other is not good teamwork. Working kids over the limit of what
The transatlantic slave trade was economically valuable because it raised production for cash crops in America. It was popular among people because it created a successful economy as slaves were not viewed as people. The demand for free labor rose and therefore so did the outurn of captured slaves. This paper shows what drove the slave trade to be so successful and why it wasn't stopped earlier. If people looked into slaves differently or if prices for them were a little higher than the slave trade may not have been so successful and therefore may have been stopped earlier but at the cost of a poor economy for America. Although America’s economy would have certainly been affected, so would the lives of millions of Africans. These people may have been able to thrive and grow in peace, if the slave trade had been stopped
Autism, or autism spectrum disorder, refers to a range of conditions characterized by challenges with social skills, repetitive behaviors, speech and nonverbal communication, as well as by unique strengths and differences (autism speaks 2012). Often known as the childhood disease, is anything but that. It is a disease, a neuro-development disorder that is highly costly through one’s life. There are different levels of autism, different spectrums. Such as Asperger’s to high-functioning Autism. The earliest signs of Autism date back to the 12th century, when physicians and scientist thought it was part of the schizorphic disorder. Although there are many medications that can be given to kids and adults with autism as well as therapies there is
Kids who are pushed into playing multiple sports over multiple sports seasons have a much higher chance of getting injured, as a result of overuse of their bodies. Kids should only be pushed in a sport if they want to play not because their parents want to. In many cases parents determine whether to push the children or not. Kids who train too much are much more susceptible to serious injuries such as torn ACLs which require long periods of rehabilitation (Chronicle). In the article “Sports Should be Fun not Forced” the author states that there is a 30% increase in boys and a 56% increase in girls with fractured forearms as a direct result of overuse. Sports specialization can also result in injuries, In the article “Is it Wise to Specialize?” ,Dr Neeru Jayanthi watched 1200 athletes who “specialized” in a sport and discovered that kids who specialize in sports have a 70% to 93% more likely chance of getting hurt of a child who plays multiple sports (Sagas) . Injuries are inevitable in sports, however, by parents having their kids overwork they are enhancing their children’s chances of getting hurt. Sports injuries are never good and they can deter kids away from sports. Parents need to realize this fact and alleviate a child’s opportunity to get an injury. In our current society athletes are becoming bigger, faster and stronger, and that athletes seem to need to
In autism the child development processes get delayed and hence children started to show many deficiencies in learning, talking and communication as compared to normal kids of their age. The intensity and symptoms of the autism varies from child to child, hence make it difficult to diagnose in the very earliest years of the disease development.
In the United States the relationship between cost and quality of care is difficult to comprehend, the US has the highest per capita spending for health care in the world, but ranks only 26th in quality of care when comparing with other developed countries. The United States leads the world in excessive cost specialty and intensive medical treatment, but falls behind other developed countries in relation to low cost medical interventions like primary care visits and vaccinations which can improve the quality of life and longevity. In the United States, higher cost of healthcare does not always equate to higher quality, for instance in the US there is no policy stating that a new drug or device should be less expensive and more effective than an existing product. The result is that the new drugs or devices
Microbial decomposition releases nutrients into the environment that are needed by other organisms. Microbes are also involved in the cycling of many other important compounds in — and between — ecosystems, including oxygen, carbon and nitrogen. Many microbes use the energy of sunlight to convert carbon dioxide to oxygen, which we need to breathe. As they do this, they create new organic material — themselves — which are then eaten by other organisms. In this way, the cycling of nutrients and energy
Although professional sports are very popular, did you know that less than 1% of high school athletes ever make it to the pros? (Smith). Such a small percent, yet so many high schoolers play sports because sports are the cool and popular thing to do. Most children played sports since they were in preschool. Travel sports start around first grade and most parents tell their kids to go out and play so they get involved in these sports. A lot of time and money is spent to train the young athletes. Many have questioned whether competing in these sports is good for teens and if the desire to win for some has taken over the “fun” aspect. However, the number of young people involved in competitive sports keeps increasing. Young athletes, should not focus so heavily on competitive sports because they put too much pressure on their minds and bodies, the stress they face ruins the enjoyment of sports in this time of their lives, and distracts them from focusing on getting a good education.
Compost is an easy solution to eliminating the waste that our environment brings, while at the same time, providing many benefits to us, and the environment. By using compost, it improves our plant growth by enriching the soil that it drinks its nutrients from. It helps us avoid buying soil amendments such as peat, bark mulch and bagged manure. Compost also loosens the heavy clay that is in our soil, while improving the capacity to hold water and adding essential nutrients.
Soil is the most important non-renewable resource on any farm. Healthy soil is key to a good