Many experts and marketers tout the benefits of chemical fertilizers (also know as synthetic) – they are effective for plant growth, they are cheap and readily available, they are simple to use… all of this is true. However, there is a downside.
Chemical fertilizers are primarily produced from non-renewable energy resources (oil & natural gas) and manufacturing processes are extremely energy intensive (high carbon footprint). Most experts agree that runoff from chemical fertilizer application is the primary cause of fresh water algae blooms.
Many chemical fertilizers are quick-release, meaning that nutrients are immediately available for plant uptake. Plants do not bank nutrients for later use so, the excess either burns the plant, washes away in the next rain or both. Slow-release fertilizers often use a chemical polymer coating to control the release of nutrients.
While these fertilizers are effective for plant growth they can be harmful to soil biology by depositing excess salts, they do not provide micro nutrients and trace minerals required for healthy soil, and they do not add organic matter to the soil. Without a healthy soil, plants become more dependent on chemical inputs.
Chemical fertilizers are often credited with the tremendous boost in agricultural efficiency we have enjoyed during the past century. This has come at the cost of depleted topsoil, fresh water pollution and an ever increasing dependency on an unsustainable resource.
Additionally, the use of chemical fertilizers often goes hand-in-hand with the use of chemical pesticides which we’ll discuss in another post.