Soil pollution is defined as the presence of toxic chemicals (pollutants or contaminants) in soil, in high enough concentrations to pose a risk to human health and/or the ecosystem. The main reason why the soil becomes contaminated is due to the presence of man made waste. The waste produced from nature itself such as dead plants, carcasses of animals and rotten fruits and vegetables only adds to the fertility of the soil. However, our waste products are full of chemicals that are not originally found in nature and lead to soil pollution.
- Industrial Activity
- Agricultural Activities
- Waste Disposal
- Accidental Oil Spills
- Acid Rain
Effects of Soil Pollution
- Effect on Health of Humans:
Considering how soil is the reason we are able to sustain ourselves, the contamination of it has major consequences on our health. Crops and plants grown on polluted soil absorb much of the pollution and then pass these on to us. This could explain the sudden surge in small and terminal illnesses. Long term exposure to such soil can affect the genetic make-up of the body, causing congenital illnesses and chronic health problems that cannot be cured easily. In fact, it can sicken the livestock to a considerable extent and cause food poisoning over a long period of time. The soil pollution can even lead to widespread famines if the plants are unable to grow in it.
- Effect on Growth of Plants:
The ecological balance of any system gets affected due to the widespread contamination of the soil. Most plants are unable to adapt when the chemistry of the soil changes so radically in a short period of time. Fungi and bacteria found in the soil that bind it together begin to decline, which creates an additional problem of soil erosion. The fertility slowly diminishes, making land unsuitable for agriculture and any local vegetation to survive. The soil pollution causes large tracts of land to become hazardous to health. Unlike deserts, which are suitable for its native vegetation, such land cannot support most forms of life.
- Decreased Soil Fertility:
The toxic chemicals present in the soil can decrease soil fertility and therefore decrease in the soil yield. The contaminated soil is then used to produce fruits and vegetables which lacks quality nutrients and may contain some poisonous substance to cause serious health problems in people consuming them.
- Toxic Dust:
The emission of toxic and foul gases from landfills pollutes the environment and causes serious effects on health of some people. The unpleasant smell causes inconvenience to other people.
- Changes in Soil Structure:
The death of many soil organisms (e.g. earthworms) in the soil can lead to alteration in soil structure. Apart from that, it could also force other predators to move to other places in search of food.
A re-engineering process that attempts to restore an area of land back to its natural state after it has been damaged as a result of some sort of disruption. The process involves such things as removing all man-made structures, toxins and other dangerous substances, improving the soil conditions and adding new flora.
Although land rehabilitation is most often used to rectify problems caused by man-made processes such as mining, oil drilling and other petrol-chemical related processes, it is also used to “clean up” natural processes. For example, natural disasters such as earthquakes and flooding can also cause damage to the natural environment. Land rehabilitation techniques can be used to speed up the amount of time necessary to restore the location to back to its original state.
Indiscriminate Use of Fertilizers
People often don’t follow the directions for fertilizers and pesticides. Most people don’t measure, or they think using a stronger solution will relieve the problem sooner. Once again there is no away. The stuff we sprinkle on the lawns and spray on weeds doesn’t stay there, much of it is washed off our yards and down the storm drains which lead to our creeks which feed our rivers, which fill our reservoirs. The same reservoirs that are our source of drinking water. We are polluting our only fresh water source.
Organic gardening can save you money and create healthier lawns which need less maintenance. Why do we fertilize lawns to make them grow faster so we have to mow more often? It makes no sense to me
Pollution by Indiscriminate use of Urea
Urea, being most common N fertilizer, is indiscriminately used irrespective of scientific prescriptions. Excessive use of urea leads to several adverse implications on soil, crop quality and overall ecosystem. Some major disadvantages of excessive/indiscriminate use of urea are listed as under:
- It enhances mining of soil nutrients that are not applied or applied inadequately, thus leading to deterioration of soil fertility. Such soils may require more fertilizers over time to produce optimum yields.
- Nitrogen applied in excess of crop demand is lost through volatilization, denitrification and leaching.
- Excessive use of N (urea) encourages climate change (when lost through denitrification) and groundwater pollution (when lost through leaching). Increase in nitrate content of groundwater in some intensively-cropped areas has been reported, which is obviously due to leaching of nitrates beyond crop root zone. Increase in nitrate content of groundwater is potentially harmful, as it is used for drinking purposes in most of the rural areas.
- Fertilizer N (urea) application beyond recommended rates enhances crop succulence, thus making the plants prone to disease and pest infestation, and to lodging.
Pollution by indiscriminate use of Phosphorus
Heavy amounts of fertilizer chemicals like potassium, nitrogen and phosphorus in natural water systems can actually cause “dead zones” where wild life cannot survive because of lower oxygen levels and chemical poisoning. Beneficial insects and organisms like honeybees and soil microbes can be killed alongside the pests, eliminating some of the ecosystem beneficial to crop health and sustainability.
Indiscriminate use of Potassium
- Potassium Iodide should be taken only when there is a clear public health recommendation to do so. Indiscriminate use of the product can cause side-effects such as inflammation of the salivary glands, nausea, rashes, intestinal upset and possible severe allergic reactions.
- Potassium iodide can also interact with other medications, especially certain types of cardio-vascular medications such as ACE inhibitors, angiotensin II receptor blockers and potassium-sparing diuretics.
- Potassium iodide pills are not “radiation antidotes”. They do not protect against external radiation, or against any other radioactive substances.
The term vermicomposting means the use of earthworms (Plate 9) for composting organic residues. Earthworms can consume practically all kinds of organic matter and they can eat their own body weight per day, e.g. 1 kg of worms can consume 1 kg of residues every day. The excreta (castings) of the worms are rich in nitrate, available forms of P, K, Ca and Mg. The passage of soil through earthworms promotes the growth of bacteria and actinomycetes. Actinomycetes thrive in the presence of worms and their content in worm casts is more than six times that in the original soil.
Benefits of Vermicomposting:
- Improves soil aeration
- Enriches soil with micro-organisms
- Microbial activity in worm castings is 10 to 20 times higher than in the soil and organic matter that the worm ingests
- Attracts deep-burrowing earthworms already present in the soil
- Improves water holding capacity
- The castings are rich in humic acids, which condition the soil and help balance pH
- Improves nutrient recycling
- Plant growth
- Enhances germination, plant growth, and crop yield
- Improves root growth and structure
- Enriches soil with micro-organisms
- Finished vermicompost can be mixed directly into the soil as a soil amendment, as plant medium or used to make compost tea.
- Provides plants with essential nutrients and aids in the suppression of plant diseases.
- Worm castings contain five times more nitrogen, seven times more phosphorus, and 11 times more potassium than ordinary soil, the main minerals needed for plant growth.
Economic Benefits of Vermicompost:
- Vermicomposting has a low capital investment and is a sustainable process. Once worm composting is started the worms will reproduce, never needing replacement. In fact, a successful vermicomposter may produce enough worms to supply others. “
- Much of our daily existence is spent in surroundings designed to conceal the processes that sustain life and which contribute, possibly more than any other factor, to the acute sensory impoverishment of our living environment” (Hough, 2004). Vermicomposting brings nature into the home, allowing occupants to observe the natural process and become more aware of the amount of waste their home generates.
- Vermicomposting is a simple, cost effective practice that has great potential for many environmental benefits. This method is especially effective for Manitobans as it is harder to use conventional outdoor composters in the winter time. Vermicomposting allows for yearlong composting, and Red Wriggler Haven supplies both worms and bins to start the process.
Disadvantages / Issues of Vermicompost
- Not as effective on a smaller-scale. In order for thermophilic temperatures to be reached and sustained, a ‘critical mass’ of material is needed (1 m3 or more). High temperatures can result in more nitrogen (and water) loss. Also, because large quantities of waste are generally required, it can be more labor-intensive.
- One of the major downfalls of vermicomposting is the fact that it won’t eliminate weed seeds and there is not yet enough evidence to indicate that pathogens will be destroyed (only really a concern when original waste materials contain large quantities of pathogens). Worm composting can also be challenging when it comes to dealing with large quantities of waste accumulated in a short period of time. Unlike regular composting, worm composting needs to stay at relatively low temperatures so waste materials need to be applied in thin layers.