Fertilizers enhance soil quality by adding nutrients that may be lacking or present in inadequate amounts. As plants grow, they deplete the soil of nutrients needed for the next generation of plants. Fertilizers replace these losses to ensure continued production. According to the International Fertilizer Industry Association, a fertilizer must contain at least a 5 percent combination of nitrogen, phosphorus or potassium. You may think that organic fertilizers are safe. However, these products still carry environmental risks.
Less Effective
Organic fertilizers depend upon microorganisms in the soil to release their nutrients. Their behavior is in turn influenced by soil temperatures. When soil temperatures are low, activity slows, impairing the effectiveness of organic fertilizers. The risk then exists that over-application of fertilizers may occur, compounding any other negative effects.
Pet Risks
As the name implies, organic fertilizers contain natural ingredients such as bone meal and blood meal which may attract pets. Ingesting large quantities of bone meal can cause bowel obstructions in your pet. While operable, surgery and aftercare costs can be expensive. Blood meal can cause gastrointestinal distress and vomiting. Smaller dogs and senior pets are at a greater risk of complications such as dehydration. The iron content of blood meal can cause other more serious effects. Drs. Foster and Smith warn that excessive iron can lead to bowel perforation and cell damage.
Low Oxygen Levels
Agricultural runoff often contains organic and inorganic fertilizers used on crops to replenish soils. This particular form of pollution is the leading cause of water pollution in the United States, reports the U.S. Environmental Protection Agency (EPA).
The effect of fertilizer runoff has created what the EPA refers to as an ecological dead zone at the mouth of the Mississippi River at the Gulf of Mexico. The fertilizers create an explosion of algal growth, which causes bacteria to proliferate to decompose the dying algae, depleting the dissolved oxygen in the water. This effect makes the water inhabitable for any life.
Escalating Risks
The International Plant Nutrition Institute estimates that need for the ecological intensification of crops will grow with the rising population levels. Ecological intensification is the process of increasing land yield; one approach is through the nutritional support of fertilizers. Organic fertilizer use continues to grow worldwide. According to the Research Institute of Organic Agriculture, land in organic farms grew 9 percent from 2007 to 2008.
Organic farming embraces the use of organic fertilizers. The environmental risks will grow with increasing use of these products. While organic fertilizers may be preferable to inorganic options, they still pose risks from the manipulation of nutrients. As long as fertilizers are used, issues such as the dead zone in the Gulf of Mexico will persist, with the threat of more widespread effects.
References
- International Fertilizer Industry Association: What Are Fertilizers?
- "Ecology and Field Biology"; Robert Leo Smith; 1990
- Drs. Foster and Smith: Iron Toxicity in Dogs and Cats
- U.S. Environmental Protection Agency: Protecting Water Quality from Agricultural Runoff
- U.S. Environmental Protection Agency: Gulf Hypoxia Action Plan 2008
