The world’s food production relies heavily on the use of fertilizers. This paper presents the benefits and risks of fertilizers’ application to food and the environment. Fertilizer use is crucial in ensuring maintenance of the world’s food security. However, they have an impact on plant, air, soil, water, and human health. Fertilizer use, altogether with other human activities, affects the environment adversely or beneficially. The advantage or adversity of the activity depends on a person’s point of view. Policy makers, manufacturers and farmers, should have adequate knowledge on fertilizers. Farmers need communication on correct techniques of their use. Improving the efficiency of fertilizers poses a significant challenge. Inefficient use of fertilizers wastes natural resources and result in substantial economic loss. Additionally, it also affects the environment negatively.
Fertilizer is any natural or synthetic, inorganic or organic material that supplies plants with essential nutrients for the plants growth. Use of fertilizer results to abundant produce. Organic fertilizers come from a variety of substances including plant matter, household wastes, manure, and sewage water. Organic fertilizers have small percentages of nutrients, therefore; large quantities must be used to supply sufficient nutrients. Inorganic fertilizers come from the processing of mineral deposits such as potash, phosphate rock, or lime. Some fertilizers such as urea can be industrially manufactured through chemical processes (Addiscott, 2005). Inorganic fertilizers contain three main components; phosphorous, potassium, and nitrogen. Organic fertilizers depend on locally available resources such as woodland filter, legume, cattle manure, cereal, household wastes among others.
Huge quantities of organic fertilizers must be used to supply enough nutrients to improve food production. As a result of this limitation, farmers rarely use organic fertilizers. Inorganic fertilizers contain a high percentage of nutrients. They have to be applied at least twice during a growing season. Farmers prefer inorganic fertilizers over organic fertilizers because they result in high yields, and require little labor. Application of fertilizers affects the food and also the environment. The impacts can be positive or negative. However, inorganic fertilizers pose many threats to the environment.
Advantages of Fertilizers
The main purpose to use fertilizers is to increase food productivity. Fertilizers increase the amount of nutrients required for the growth of food crops. They also improve the harvest produced. As a result of increase in the world population and urbanization, pressure on the food production has increased. Most of the world’s food grows in the rural areas. Industrialization has developed. This has reduced the land available for food production. Both organic and inorganic fertilizers assist in growing the produce of the small available chunks of land under agriculture. In addition, fertilizers can be used in the growth of fodder, for animal use. The animals also serve in increasing the availability of food. Additionally, excess perishable food produced can be used as food for the animals. Organic fertilizers improve long-term soil productivity and biodiversity. They provide micronutrients and organic matter for organisms that the plants are absorbing.
Run-off of excess fertilizer into the surface water and underground infiltration has a positive side, as well. It enhances growth of planktons, which provide a source of food for the fish, by increasing food availability. Application of phosphorous favors plants protection against diseases. This happens through the correction of soil phosphorous deficiency, or speeding up the plant’s maturation process, hence disfavoring pathogens that affect young tissues. Potassium in the fertilizer stimulates a plant’s healing process through its interaction with scar parasites. It increases cold resistance and delays maturation and senescence of fruits. Calcium makes the plants’ cell walls resistant to pathogens. Calcium deficiency increases the crop’s susceptibility to fungi.
Adverse Effect of Fertilizer on Food
Over fertilization is a term used to refer to excess use of fertilizer. Similar to under fertilization, it can have detrimental effects on crops. Excessive use of a vital nutrient may cause “fertilizer burn” causing the drying up of leaves and in some cases the death of the plant. Drying up food crops would reduce the produce resulting in inadequate food supply. Majority of the inorganic fertilizers contain poisonous nitrates. If consumed without thorough cleaning, they may have a detrimental impact on human health. When consumed, nitrates reduce to nitrites in the body. The nitrite oxidizes blood hemoglobin, lowering the ability of red blood cells to transport and deliver oxygen (Hatfield, 2008).
Marine life is another source of food in the world. When ground water becomes contaminated with nitrogen, marine “dead zones” form. They result from the nitrates’ effect increasing plant life. As a result, the marine plants deplete the oxygen. Fish and crustaceans starve, resulting in a food production decrease around the world. Many parts of the world use raw sewer sludge as fertilizer. It contains a high percentage of plants nutrients. However, the sludge contains hazardous chemicals (Leigh, 2004). The sewer systems used in most developing countries are open for public dumping. They also serve as a dumping site for most industries in these countries. They contain chemicals from pesticides, medicine, and repellents among others. These chemicals may end up in human bodies if the plants absorb them. If not properly composted, organic fertilizers may contain disease causing organisms as well as pathogens. Some fertilizers contain toxic persistent organic pollutants such as polychlorinated dibenzofurans. Excess use of nitrogen fertilizers may increase the pest’s longevity, birthrate, and overall fitness.
Benefits of Fertilizers to the Environment
When analyzing the impact of fertilizers on the environment, most people overlook their benefits. Although inorganic fertilizers cause more damage than good to the environment, organic fertilizers have several benefits. One far-fetched benefit is the preservation of the flora and fauna. Over-cultivation of land depletes its nutrients (Isherwood, 1998). Fertilizers replenish the nutrients, enabling farmers to cultivate the same piece of land for many years. This has eliminated the need to clear additional land for cultivation. Previously, farmers used to grow crops on one piece of land for about three seasons before moving to a new piece of land exposing it to soil erosion. This affects the biosphere, since it avails food, nutrient supplies, habitat, migration routes, and breeding areas.
Adverse Impacts of Fertilizers on Environment
Although fertilizers increase productivity of the soil, in the long-run, excessive use of fertilizers deplete soil quality. Excess fertilizer use increases soil acidity levels. A recommendation exists to have a test on the soil every three years to check whether the amount of fertilizer applied is right. Excessive use of fertilizer may lead to eutrophication. The nitrates and phosphates in the fertilizers become toxic to aquatic life. This leads to increased algae growth in the water bodies, decreasing oxygen levels in the water. The toxic environment results in the death of aquatic flora and fauna. This alters the food chain since some birds and animals depend on aquatic animals, such as fish, as their main source of food. Drinking of the contaminated water may result in several health problems. A general effect of the contaminated water consumption is the blue baby syndrome. It occurs in infants with the skin appearing as bluish or purple. In addition, studies have shown that lawn fertilizer may cause health risks such as chronic diseases and cancer in human beings, especially children.
Fertilizers have caused changes in the climate across the globe. Ammonia, nitrogen, carbon dioxide, and methane are some of the chemicals contained in fertilizers. Their emission contributes to the increase of greenhouse gases in the environment. Carbon dioxide, methane, and nitrous oxide, a byproduct of nitrogen, are the three most significant greenhouse gases. They absorb solar radiation rather than allowing the radiation of the excess heat. The greenhouse gases lead to the changes in the weather pattern and increase global warming. Nitrate loss by leaching, nitrous oxide loss, and ammonia volatilization are the forms in which nitrogen escapes the agricultural system into the environment (Erisman, 2009).
This loss and subsequent deposition lead to eutrophication of natural habitats, marine waters, and acidification of lakes and soils. Additionally, ammonia may react with sulphur oxides in the air forming ammonium sulphate, which raises soil acidification when it precipitates. Phosphate fertilizers contain some elements, such as cadmium that occur naturally in phosphate rock. They go through the manufacturing process to the final product. Phosphate fertilizers often contain uranium, a radioactive element. It may accumulate and build up in vegetables, posing a health risk to human beings. Excessive contamination of the air by fertilizers may result in cardiac diseases, cancer, respiratory ailments, as well as increased production of allergenic pollen.
In conclusion, use of fertilizers affects the amount of food produced as well as the environment. Organic and inorganic fertilizers have various impacts. The farmers should be aware of the repercussions of using fertilizers to the environment. Policy makers should set up legislation across the world on the use of fertilizers. These laws should also be enforced effectively.