Land or garden management involves improving plant growth capacity, sometimes with the use of fertilizers. It also includes removing pests. A pest is any plant or animal that compromises the health of humans, plants, animals or the environment. Pesticide is a generic term that describes any agent that kills pest. While the former would appear to benefit water bodies, both fertilizers and pesticides can compromise the health of the aquatic community andm in some cases, impact humans.

Significance
A fertilizer can be natural or synthetic. It may contain nitrogen, phosphorus or potassium to enhance plant growth. While that may sound good, it can be deadly for water environments. These elements occur naturally in the environment, but the balance of these elements is finely tuned. For example, phosphorus may be inert in soils and rocks. However, an increase in phosphorus through erosion or runoff can encourage the growth of invasive and non-native plant species. Weedy species can crowd out native ones, removing important food sources for aquatic life. As the plants die, decomposition removes oxygen from the water, increasing the likelihood of fish kill.

Identification
Pesticides pose additional impacts. Pesticides are toxic; that is their purpose. They can act as selective or non-selective agents. A selective pesticide will have little impact on related organisms, whereas a non-selective pesticide can harm anything living. The risk comes from non-targeted organisms being affected. Runoff or spilled pesticides into waterways can cause fish kill and plant die off. As with fertilizers, the loss of oxygen through decomposition can jeopardize the long term health of the aquatic ecosystem.

Misconceptions
The potential for harmful effects on the water bodies is sobering when compared to their use and aftermath. However, the U.S. EPA estimates that 300 million pounds of pesticides are used each year. Their use has been deadly. The American Society for the Prevention of Cruelty to Animals reports over 30,000 pet poisonings each year. Humans also are at risk. Of the 27 most commonly used pesticides, 15 are classified as carcinogens.

Warning
Long-term effects of fertilizers and pesticides on the environment are not widely known. Certainly, wildlife is at risk. Chemicals can concentrate in predators and scavengers feeding on treated fish, compounding their effects. Likewise, children are at greater risk because they eat more in proportion to their body size than adults. With chemicals that don't degrade over time, the chance that concentrations will reach deadly levels increases.

Prevention/Solution
While pests cost land managers, pesticide application is not a long term solution. Alternative strategies are available. Organic farming and integrated pest management (IPM) are two alternatives. IPM looks for natural solutions to pest problems such as using predators and parasites of pests. Sustainable agriculture seeks a solution by preventing damage from practices like excessive tillage that would make crops susceptible to pest infestations. It combines a holistic approach of protecting the land while still being profitable.

Best practices in land management can negate the need for fertilizers and pesticides which unnaturally alter the landscape. A long-term solution is the best approach for sustainable land and water management.

From Network Resources