Preventing Runoff Pollution: Protecting External Fertilization

Fertilizers are essential for agriculture, providing plants with the nutrients they need to grow and flourish. However, when not properly managed, they can have detrimental effects on the environment, particularly on water bodies. This is known as fertilizer runoff, and it occurs when excess fertilizers are washed away from fields and farms, contaminating groundwater and surrounding land. This can happen due to over-fertilization, application on frozen or partially thawed ground, excessive irrigation, and improper yard waste disposal. To prevent fertilizer runoff, farmers can adopt nutrient management techniques, such as applying the right amount of fertilizer at the right time of year and with the correct method. Implementing conservation practices, such as conservation tillage, cover crops, and field buffers, can also help reduce nutrient losses and prevent periods of bare ground that are susceptible to erosion and nutrient runoff. Additionally, proper management of livestock access to streams and collaboration with stakeholders across watersheds are crucial in minimizing the impact of fertilizer runoff on external fertilization and the environment.

Proper fertiliser application

• Apply the right amount of fertiliser at the right time of year and with the right method: Farmers should use only the required amount of fertiliser for their crops and avoid over-application, which can lead to runoff. They should also time their fertiliser application with the crop's needs and avoid applying it when the ground is frozen or partially thawed, as this increases the risk of runoff.
• Adopt nutrient management techniques: Farmers can improve nutrient management by applying nutrients (fertiliser and manure) in the correct amounts, at the right time of year, with suitable methods, and in the right location.
• Use conservation tillage practices: Reducing the frequency and intensity of tilling can improve soil health, reduce erosion, and decrease the chances of nutrients reaching waterways through runoff.
• Ensure year-round ground cover: Planting cover crops or perennial species can prevent soil erosion and loss of nutrients into waterways, especially during periods when the ground is bare and more susceptible to runoff.
• Implement controlled-release fertiliser: Using controlled-release fertiliser ensures a slow and constant release of nutrients during the growing season, matching the needs of the crop and reducing the risk of excess fertiliser washing away.
• Optimise fertiliser timing and application rate: Farmers should adjust fertiliser application based on seasonal variations and rainfall patterns to minimise nutrient loss.
• Use water-saving irrigation techniques: Techniques like alternate wetting and drying (AWD) irrigation can reduce water inputs and enhance water use efficiency, thereby lowering the volume of surface runoff.
• Explore ecological ditches: Ecological ditches, engineered based on traditional agricultural ditches, can effectively remove nutrients, sediments, and pollutants from agricultural runoff before it reaches receiving waters.
• Construct wetlands: Constructed wetlands, acting as a transitional zone between farmland and receiving waters, can absorb, adsorb, and physically settle nutrients, particles, and organic matter, providing an additional treatment barrier before runoff reaches water bodies.

By following these guidelines, farmers can significantly reduce fertiliser runoff, protect water quality, and minimise the impact of external fertilization.

Use slow-release fertiliser

Using slow-release fertiliser is a great way to prevent runoff pollutants from affecting external fertilisation. Slow-release fertilisers are designed to release a controlled amount of nutrients over an extended period, typically the entire growing season. This is in contrast to traditional fertilisers, which release a large amount of nutrients all at once. By using a slow-release fertiliser, you can ensure that the grass or plants have time to absorb the nutrients fully, reducing the risk of excess fertiliser running off into nearby water sources or the groundwater.

Slow-release fertilisers are particularly effective at preventing fertiliser runoff because they only release nutrients when the grass or plants are actively growing. This means that the nutrients are more likely to be absorbed and used by the plants, rather than sitting on the surface and washing away. Additionally, slow-release fertilisers can help to reduce the amount of fertiliser that is needed overall, as it is released gradually and continuously, rather than all at once. This not only helps to prevent runoff but can also save money and reduce the environmental impact of fertiliser use.

Another benefit of slow-release fertilisers is that they can be applied less frequently than traditional fertilisers. This not only saves time and effort but also reduces the risk of over-application, which is a common cause of fertiliser runoff. With slow-release fertilisers, you can simply apply the fertiliser at the beginning of the growing season and trust that it will continue to release nutrients at a steady rate throughout the season. This can be especially useful for farmers or gardeners who may not have the time or resources to apply fertiliser multiple times throughout the year.

It is important to note that even with slow-release fertilisers, it is still crucial to follow best practices for fertiliser application. This includes applying the correct amount of fertiliser for the specific type of grass or plants being grown, as well as avoiding application on frozen or partially thawed ground, where the fertiliser is more likely to run off into water sources. Additionally, keeping fertiliser away from water sources, such as streams or lakes, can further reduce the risk of nutrient pollution.

By using slow-release fertilisers and following these best practices, individuals and farmers can help to prevent runoff pollutants from affecting external fertilisation, protecting both the environment and their own investments.

Avoid fertilising frozen or partially frozen ground

Fertilisers are essential for plant growth, providing them with the necessary nutrients to flourish. However, applying fertilisers to frozen or partially frozen ground can lead to runoff, causing environmental and ecological issues. Here are some reasons why you should avoid fertilising frozen or partially frozen ground:

Impact on Water Bodies

When fertilisers are applied to frozen ground, they cannot easily penetrate the soil. Instead, they are more likely to run off into nearby water bodies, such as streams, lakes, or warmer soil. This can lead to an excess of nutrients in these water bodies, causing eutrophication. Eutrophication is the over-enrichment of nutrients, particularly nitrogen and phosphorus, which can lead to the growth of microscopic organisms that deplete oxygen levels in the water, a condition known as hypoxia. This can have fatal consequences for fish and other aquatic life.

Inability of Plants to Absorb Nutrients

During winter, many plants go dormant and are unable to absorb fertilisers effectively. Applying fertilisers to frozen or partially frozen ground can result in the nutrients being washed away by rain or snowmelt, leading to waste and potential contamination of water sources.

Increased Risk of Runoff

Frozen or partially frozen ground acts as a barrier, preventing fertilisers from being absorbed into the soil. In the event of heavy rainfall or snowmelt, the water will flow downhill, carrying the fertilisers with it. This increases the risk of fertilisers reaching water bodies and causing pollution.

Negative Impact on Soil Health

Excessive fertiliser application on frozen or partially frozen ground can lead to a build-up of salts in the soil, causing a condition known as fertiliser burn. This can result in yellow or brown grass and require significant time and water to restore the health of the lawn.

Best Practices

To prevent these issues, it is recommended to wait until spring, when the frost is out of the fields and the soil is dry, before applying fertilisers. This allows the fertilisers to be effectively absorbed by the soil and utilised by plants, reducing the risk of runoff and environmental contamination.

Avoid over-watering

Over-watering your lawn or garden can lead to fertiliser runoff, as it can cause fertiliser to wash away more easily. Here are some tips to avoid over-watering:

• Leave lawn clippings on the lawn as nourishment. They will return nutrients to the soil, reducing the need for fertiliser. They also help absorb water to prevent runoff.
• Use slow-release fertiliser to control the release of nutrients, keeping it low and constant during the growing season. This will prevent fertiliser runoff as it will only release nutrients when the grass is actively growing and can absorb them.
• Set your mower blades high to help reduce runoff. Taller grass will absorb more water, leading to a stronger root system that keeps water in place and prevents runoff. A stronger root system will also help your lawn or garden withstand droughts, reducing the need for watering.
• Keep fertiliser away from water sources such as streams or lakes to reduce the risk of nutrient pollution. When applying fertiliser in your garden, use mulch to hold in soil moisture and keep fertiliser in place during heavy rainfall.
• Use the right amount of fertiliser for your lawn or garden. A good rule of thumb is to apply half a pound to a pound of nitrogen for every 1,000 square feet.

Proper yard waste disposal

Yard waste can contain harmful chemicals such as fertilisers, pesticides, and herbicides, which can contaminate water sources if not disposed of properly. Grass clippings and leaves, for example, should not be swept into storm drains or streets as they can block water flow and cause flooding. They can also introduce excess nutrients into water sources, causing algae blooms and eutrophication, which can be harmful to aquatic life and reduce water oxygen levels, potentially causing fish kills.

To prevent this, grass clippings can be left on the ground to decompose and nourish the lawn, or they can be collected and composted. Leaves can be bagged and left for trash pickup. In some places, yard waste can be left for curbside pickup, and some municipalities have programs in place to monitor and control the quality of runoff water.

It is important to be mindful of the proper methods for yard waste disposal to prevent water contamination and maintain a healthy ecosystem.

Frequently asked questions