Runoff: What Is It, What Are the Causes and How Can We Avoid It? - Fitleaf

Runoff: What Is It, What Are the Causes and How Can We Avoid It?

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Agriculture, Hydroponics, Sustainability

When it comes to responsible land stewardship and environmental protection, runoff from fertilizer and agricultural chemicals can be a serious issue. Caused by excess fertilizer being washed off of a field during a rainstorm or flooding, it washes into waterways, where it can have devastating effects on the local wildlife. But what exactly is it, what causes it and how can it be avoided in modern food production? Here’s a look at the issue to help you gain a better understanding.

Photo by Patrick Brinksma on Unsplash

What Is Runoff?

Runoff, in its simplest form, is fertilizer, pesticides or other agricultural inputs that has been displaced due to excessive irrigation, rainwater or flooding. When these compounds end up in the water, they flow with the water to the lowest possible point, typically waterways such as ponds, streams, rivers, lakes and oceans. Once there, it can wreak terrible havoc on the environment. Though agriculture can be a strong source of runoff, it also comes from overzealous lawncare and golf courses, which require fine turf to play, requiring extensive fertilizer use.

Photo by Daniel Watson on Unsplash

Why Is Runoff a Problem?

When runoff flows into a waterway, it can cause a wide range of issues. Pesticides can kill insects and smaller fish. As part of the waterway’s life cycle, larger fish and other wildlife then eat these insects and fish, the pesticides can concentrate in the larger fish’s tissues. Eventually, these larger fish and aquatic animals can be caught or hunted for food, which when eaten can be damaging to human health. Similar cycles in the ocean with heavy metals are part of the reason why the government recommends limiting the consumption of seafood and fish due to heavy metals.

Photo by Mihály Köles on Unsplash

Fertilizer is another issue altogether, primarily nitrogen (which is the one element which is often used in an excessive manner). When it runs into a waterway, it fertilizes aquatic plants, such as algae, which go into a strong growth cycle. As the algae go into a bloom stage, they block sunlight, which kills the plants in the waterway. Without food and oxygen produced by the plants, insect, fish and other aquatic life dies off, leaving a sterile waterway.

How Is Runoff Caused?

Consider the last time you got a really great deal on some produce. If the farmer was growing so much produce that they were able to sell at a low price, there’s a decent chance they’re maximizing the amount of fertilizer they’re putting on their land in order to maximize their yields. This is especially true at supermarkets or larger vendors that have contracts with their farms to produce a specific amount of produce per week. This excess fertilizer can then runoff in the water when there’s a heavy rain, especially after a drought, or over-irrigation of fields, this translates to an irresponsible use of fertilizers.

Image from Pixabay

The same holds true of chemical pesticides. Farmers run a business, and that business has to keep operating to stay in operation. If a pest, whether a weed, insect or disease, infests the crop, they stand a good chance of losing productivity, whether through outright loss or through reduced yields due to damage to the plants. Genetically modified organisms, such as Roundup Ready corn, are commonly sprayed with excessive herbicides to remove weeds in the crop without harming the crop itself, which can lead to herbicide runoff, killing aquatic plants and leaving fish and wildlife to starve.

How Can We Avoid Runoff?

The easiest way to avoid runoff is to avoid overfertilizing and overusing chemical treatments on plants. However, this is often not a practical approach in commercial agriculture, where acres upon acres of fields must be tended using heavy machinery. When you garden in a small plot, you’re able to keep up with your plants readily. But commercial farming often has to have limited manpower to get the job done at a cost-effective point, so farmers use chemical controls and fertilizers to make the best possible yields.

The best way to avoid runoff is by preventing it in the first place. Only using the amount of fertilizer or chemical pesticides (preferably organic for one’s health) that are needed helps limit the amount that is free to run off in rainwater. Many homeowners make a big mistake by overfertilizing their lawns, thinking that a little more won’t hurt anything – it does! Avoiding excessive irrigation, which causes water to run off into the waterways, can also help limit runoff issues. Using gardening methods that limit or eliminate runoff, such as hydroponics, also does a wonderful job to fix the problem.

What Is Hydroponics?

The best way to avoid runoff is to avoid having the opportunity for nutrients to leave the plant growth system in the first place. One option to consider in this concept is growing a hydroponics garden. Because hydroponics is a self-contained system, with no irrigation involved, there is virtually no chance of runoff happening in the environment. But what exactly is it?

Photo by Fitleaf

Hydroponics uses a range of options to grow plants in a water-based solution that has had nutrients added to it. The systems range from very simple to very complex. Because the nutrients in the solution are monitored, there is a minimal amount of fertilizer left in the system even if the water is discharged. However, most systems simply recirculate the same water over and over again until it’s used by the plants, maximizing the use of the nutrients and minimizing the possibility of runoff to the environment while giving water a better use. 

But what about chemical use? Though there is virtually no possibility of runoff from a hydroponics system in the first place, you don’t need to worry about chemicals regardless. For the most part, especially when you are starting your own plants from seeds and minimizing the risk of diseases and insects brought in from outside plants, there are very few pests to worry about in a hydroponics system. This is because the system is separate from the soil. If you choose to set up your system outdoors, you may have some pests wander in, but the number will be much lower than you would find in a soil-based system.

Runoff can be a serious problem, killing wildlife and sterilizing waterways. Fortunately, responsible use of fertilizer and agricultural chemicals, including the use of hydroponics to avoid any runoff issues whatsoever, can be a great way to grow your own food while avoiding this risk. Hydroponics allow you to produce food year-round in very little space, while avoiding chemicals due to reduced issues with weeds, insects and disease. Fitleaf is your gardening partner. To learn more about gardening, check out some of our other pages and references.

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