Chemical pesticides and fertilizers can be purchased at almost any garden supply store and provide easy-to-use and effective solutions to common gardening problems, from weeds and bugs to lackluster growth. However, chemical pesticides and fertilizers also have disadvantages, often leading gardeners toward biological and organic solutions.
Chemical Pesticide Uses
Although pesticides tend to be associated with controlling harmful insects, they include any substance that controls a living organism defined as a pest--a broad term referring to harmful, unwanted organisms. In addition to insecticides, pesticides include fungicides, rodent poisons and weed control chemicals. Pesticides may act by preventing, destroying or repelling a harmful organism.
Chemical Pesticide Function
Most chemical pesticides act by disrupting the nervous systems of the organisms that they target. For example, commonly used pesticides interfere with the transmission of acetylcholine, a neurotransmitter responsible for communicating directions from the brain to the muscles of the body.
Chemical Fertilizer Uses
Application of chemical fertilizer provides nutrients in the soil that plants need to grow. As plants grow, they deplete soil nutrients and, in some instances where a concentrated number of a single plant species is being grown, such as in agriculture, nutrients are not restored to the soil by natural means, thus requiring fertilizers.
Chemical Fertilizer Function
Plants require three basic nutrients to grow: nitrogen, phosphorus and potassium. Chemical fertilizers contain these three substances in varying proportions, in addition to micronutrients, such as iron or zinc, that further enhance plant growth. Fertilizers provide direct nourishment to the roots of plants.
The use of pesticides allows us to control highly destructive organisms, such as insects that destroy crops or animals that carry deadly diseases. Chemical pesticides have contributed to making crops more productive and affordable, allowing food producers to expend less labor and use less land to grow the same amount of food. Likewise, chemical fertilizers have increased the productivity of food crops. Chemical fertilizers have the advantage of allowing the grower to more tightly control which nutrients are added to the soil, ensuring that plant needs are met.
According to the U.S. Environmental Protection Agency, "By their very nature, most pesticides create some risk of harm." Because it is rarely possible to target pesticides to only a particular pest, chemical pesticides also tend to cause collateral harm to other organisms in the environment. Chemical pesticides may be toxic to people, pests and other harmless or beneficial organisms, such as honeybees. Chemical pesticides may be damaging to the environment, and some pests develop resistance to the chemical methods used to control them. Chemical fertilizers may also be harmful. Chemical fertilizers leach into groundwater, causing toxic effects in humans and polluting bodies of water. Chemical fertilizers encourage the growth of harmful aquatic organisms, such as algae, that disrupt aquatic ecosystems.