how is cotton harmful to the soil? what was done to keep the earth usable?
459475
It uses up all of the "nutrients" or whatever in the soil.  Crop rotation and planting things like legumes were done to allow the land to recharge between planting cycles.
440983
http://en.wikipedia.org/wiki/Soil_life
405069
Honestly, the effects are endless. I'm currently working on this topic for my Master's (that what I should be doing right now) and when you really start to delve into the study of it, it's really quite disgusting because it affects everything we rely on to live.  But to sum it up, when the land is polluted, it really leads to pollution, destruction, and loss of everything else. The pollution makes it way into our water sources, kills plants, and  consequently, that is one cause that leads to the loss of animal species.  Polluted land is often treated with chemicals to "clean it up" that ends up in the soil and poisons our food sources.  The issue really is complex, but I encourage you to study it further.  You won't look at this world the same.
124552
Soil absorbs moisture. It has small openings and the water gets in the small holes. The cohesion and adhesion of the water constitute a force that keeps the water in the soil, to a certain extent.
642291
http://natres.psu.ac.th/Link/SoilCongress/bdd/symp9/1375-t.pdf
955876
I would suggest homemade non-toxic solutions such as the ones I use on tomato plants. I mix in a blender a head of garlic, some hot peppers, a litre of water and some natural (ivory) soap that has been dissolved by shaving it into water.  I mix all of this and use a spray bottle to apply it to roses and veggies... it kills aphids, cotton bugs and is safe for the plants and soil. The soap helps the garlic and hot peppers to adhere to the plant and they are a great repellent for sucking insects.
874165
cotton, tobacco, opium, just to name a few. But do some of your own research! :-)
934319
Erosion is caused mainly by inadequate handling of the ground (but it is a natural process). It depends on the composition of the soil (more sands, more erosion; more clay, less erosion).\n\nTo prevent it, ' the main one is to keep the ground covered '.\n\nThe covering protects against the impact of rain, as an umbrella, preventing the torrent formation. It is important to reduce the speed of the draining of the water and its impact in the ground.\n\nIf the covering of the ground well will be made, with more than 30% of the covered surface, the risks of the erosion diminishes more than in 60%. The direct plantation is a good technique to be used too.
345553
On Earth, soil is generally considered to be weathered material capable of supporting plant life.[2] Soil forms through a variety of soil formation processes, and includes weathered rock "parent material" combined with dead and living organic matter and air. Soils are vital to all life on Earth because they support the growth of plants, which supply food and oxygen and absorb carbon dioxide and nitrogen.\n\nIntroduction\nBecause of it's position in the landscape and its dynamic physical, chemical, and biologic functions, soil is among our most important natural resources. Indeed, engineers, agronomists, chemists, geologists, geographers, biologists, microbiologists, sylviculturists, sanitarians, archaeologists, and specialists in regional planning, all depend on, and contribute to, knowledge of soils. While the general concept of soil is well established, the definition of soil varies, hinging on the perspective of the discipline or occupation employing it as a resource.\n\nSoil occupies the pedosphere, one of Earth's spheres that the geosciences use to conceptually organise the Earth. This is the conceptual perspective of pedology and edaphology, the two main branches of soil science. Both branches apply a combination of soil physics, soil chemistry, and soil biology. Due to the numerous interactions between the biosphere, atmosphere, and hydrosphere that are hosted within the pedosphere, more integrated, less soil-centric concepts are also valuable. Many concepts essential to understanding soil come from individuals not identifiable strictly as soil scientists. This highlights the interdisciplinary nature of soil concepts.\n\nThe understanding of soil is incomplete. Despite the duration of mankind's dependence on and curiosity about soil, exploring the diversity and dynamic of this opaque resource continues to reward. New and refreshing avenues of soil research are compelled by our need to understand soil in the context of climate change [3], greenhouse gases [4] [5], and carbon sequestration. [6]\n\nVasily V. Dokuchaev, a Russian geographer, is credited with identifying soil as a resource whose distinctness and complexity deserved to be separated conceptually from geology and crop production and treated as a whole.\n\nPreviously, soil had been considered a product of physicochemical transformations of rocks, a dead substrate from which plants derive nutritious mineral elements. Soil and bedrock were in fact equated. Dokuchaev considers the soil as a natural body having its own genesis and its own history of development, a body with complex and multiform processes taking place within it. The soil is considered as different from bedrock. The latter becomes soil under the influence of a series of soil-formation factors (climate, vegetation, country, relief and age). According to him, soil should be called the "daily" or outward horizons of rocks regardless of the type; they are changed naturally by the common effect of water, air and various kinds of living and dead organisms. [7] \n\nWhat is soil?\nSoil classification\nMain article: soil classification \nSoil classification is a contentious subject, from the structure of the classification system itself, to the definitions of classes and types, and finally in the application in the field. Every classification system starts with its own individual definition of soil. The essential problem is that soils do not reproduce or have DNA like living organisms, so no "objective" criteria can be used to choose among classifications. The most qualified specialists in the world can and do spend hours during a field trip at each soil profile, arguing about the classification. Yet, in a well-constructed system, the different names refer to similar concepts, so that interpretations do not vary widely.\n\nThe Unified Soil Classification System (or USCS) is used in engineering, geology and soil science disciplines to describe the texture, grain size,
991866
(1) It is very important to identify the soil texture when doing a commercial framing because to maximize the profit.\n\n(2) Soil Management is  the basis of all scientific agriculture, which involves six essential practices. They are mentioned here for your convenience.\na) Proper tillage; \nb) Maintenance of a proper supply of organic matter in the soil \nc) Maintenance of a proper nutrient supply; \nd) Control of soil pollution;\ne) Maintenance of the correct soil acidity; \n f) Control of erosion\n\n(3) When doing a soil test, we can realize nature of soil which we use and we can take necessary steps to develop the soil if it is in poor condition.It is the clear reason that soil tests are done before  the cultivation..
334577
Well, if you're considering burning fossil fuels like coal and oil, then it wouldn't pose much danger because they only release carbon dioxide and water vapours into the atmosphere and this release of CO2 apparently helps to maintain the CO2 cycle.\nHowever, there are organic compounds (some used as fuels), including polymers like 'polytetrafluoroethene' that are non-biodegradable and so cause a litter problem in landfill sites. And if we burn them, they release toxic gases like carbon monoxide which can cause cancer and hence damage the environment.
720397
Wind and water erosion both erode top layes of the soil which is fertile.\nBoth can be controlled by planting trees over loose soil so that the roots can prevent soil erosion.\n\nBut water erosin is much more harmful since it can cut up land and make it unfit for cultivation, and water erosion can only take plaec where there is a slope.
1071619
Good question.... one that I had never thought about.. I am supposing it is because it came from US and that makes it more of a repulsion. We use animal feces to spread on the ground as fertilizer and that is acceptable... in Korea and some other areas, they use human feces to spread on the ground(do not know why as it has no fertilizers value whatsoever) but that is though of by Western standards as disgraceful
76491
Depends on the soil and what chemical process was used, but mostly plant nutrients. Very helpful website below.
794
When I was an undergraduate I did an experiment with some classmates in a blant biology lab class related to this question.  We collected soil from two areas: one area that received drainage from a local copper mine, and one close area that didn't receive the drainage.  We put the soil in water to extract the contents and used the water to water some wheatgrass seeds.  The grass watered with the extract of the drainage soil was different in color, shorter, and had fewer root hairs, as I recall.  In other words, it was less healthy.  In our experiment, then, the type of water definitely had an effect on the growth of the grass.
92969
It's just an organic mineral like coal. It is created with enormous amounts of heat and pressure over millions of years from fossils. It really doesn't have a purpose it's just under the surface of the earth.
527085
water is a natural resource and we use it foe almost everything, soil is anouther natural resource and u should know wat we use it for, things like that r natural resources