Farmers' Role In Reducing Water Pollution

Water pollution is a pressing issue, and the agriculture sector is a significant contributor. While there is no guaranteed method to reduce the problem, farmers can implement several best practices to mitigate agricultural runoff and, in turn, water contamination. This includes using cover crops to prevent soil erosion, carefully managing fertilisers and pesticides, implementing nutrient management techniques, and controlling livestock access to waterways.

Use cover crops to prevent soil erosion

Cover crops are plants that are intentionally sown in farmland between regular crop cycles, often during the off-season. They are a great tool for farmers to minimise soil movement off fields and prevent soil erosion. Cover crops protect and strengthen the soil, holding it in place with their roots and providing cover from wind and rain.

Soil erosion is a major problem on farmland, and it can contribute to water pollution. Erosion occurs when the top layer of soil is washed away by water or wind, and this can happen if the ground is left bare or if there is insufficient vegetation to hold the soil in place. Erosion can also occur during farming operations such as tilling or ploughing. Cover crops can reduce this risk by slowing down wind speeds at ground level and decreasing the velocity of water in runoff.

The active roots of cover crops hold the soil in place, preventing water erosion, while their above-ground growth shields the soil from wind erosion. Covering the soil also protects it from rainfall splatter. When it rains, water hits the soil with great impact, causing soil displacement. Cover crops reduce the impact of raindrops by up to 60%, thereby reducing soil erosion, compaction, and nutrient runoff.

Cover crops can also increase nutrient efficiency through reduced soil erosion. They scavenge residual nitrogen, converting it to proteins such as enzymes, hormones, and amino acids. This helps to improve the fertility and water retention of the soil, leading to healthier crops and higher yields for farmers.

While there may be initial costs for farmers to plant and maintain cover crops, the long-term benefits for their farmland make it a valuable investment. Cover crops improve soil health, increase crop yields, and reduce machinery costs. They also help to suppress pests, host beneficial organisms, attract pollinators, scavenge nutrients, and supply forage.

Improve fertiliser and pesticide management

Farmers can play a crucial role in reducing water pollution by improving their fertiliser and pesticide management practices. Here are some detailed and direct instructions for farmers to help mitigate water pollution:

Precision in Application:

Farmers should ensure that fertilisers and pesticides are applied in the correct amounts, at the right time of year, and using the appropriate method. Overapplication of fertilisers can cause root saturation, leading to products moving to less-saturated areas and potentially contaminating water sources. Applying fertilisers to frozen or partially thawed ground can also interfere with adequate soil penetration, increasing the risk of runoff. Precision in application can help prevent excess nutrients from reaching water bodies.

Use of Slow-Release Fertilisers:

By using slow-release fertilisers, farmers can reduce the risk of nutrients washing off fields and into nearby water sources. Slow-release fertilisers release nutrients more slowly, making them less likely to run off into lakes, rivers, or streams.

Adherence to Instructions and Safety Distance:

Farmers should carefully follow the instructions on fertiliser and pesticide labels. Maintaining a safe distance from water sources is crucial. For example, keeping a distance of 10 metres from ditches and 50 metres from drinking water supplies when handling or applying these chemicals is recommended. This helps prevent direct contamination of water sources.

Use of Buffer Strips:

Planting trees, shrubs, or grasses along the edges of fields, especially those bordering water bodies, can create conservation buffers that absorb or filter nutrients before they reach the water. Implementing buffer strips can significantly reduce nutrient runoff and improve water quality.

Cover Crops:

Planting cover crops between regular crop cycles can help prevent soil erosion and reduce water pollution. Cover crops protect the soil with their roots, holding it in place, and providing cover from wind and rain. They also improve soil fertility and water retention, leading to healthier crops and higher yields.

Water Management with Sensors:

Excessive irrigation is a significant cause of water pollution in agriculture. Farmers can use smart sensors to understand when and how much to water their crops, preventing over-watering and reducing the risk of pollution.

By implementing these measures, farmers can significantly improve their fertiliser and pesticide management, reducing the impact of agricultural activities on water sources and helping to protect the environment and public health.

Implement a wastewater management system

Implementing a wastewater management system is crucial to reducing water pollution on farmland. Here are some detailed steps and strategies for farmers to consider when implementing such a system:

Understand the Sources of Wastewater Pollution

Before implementing a wastewater management system, it is essential to identify the sources of pollution on your farm. Common sources of wastewater pollution in agriculture include:

• Animal waste: Improper disposal or storage of manure can lead to water pollution.
• Chemical handling: Agricultural chemicals, such as fertilisers, pesticides, and veterinary medicines, can contaminate water sources if not stored, handled, or applied properly.
• Irrigation: Over-irrigation or improper irrigation practices can lead to runoff, carrying fertilisers and pesticides into nearby water bodies.
• Soil erosion: When soil is washed away by water or wind, it can end up in water bodies, contributing to water pollution.
• Nonpoint source pollution: This includes sediment runoff, nutrient runoff, and pesticides from fields during rain storms.
• Point source pollution: This includes animal wastes, silage liquor, milking parlour wastes, slaughtering waste, and vegetable washing water.

Adopt Good Agricultural Practices

Farmers can implement several practices to reduce the impact of these pollution sources:

• Use cover crops: Plant cover crops between regular crop cycles to prevent soil erosion and improve soil health.
• Careful fertiliser and pesticide use: Follow instructions on labels, avoid application near waterways, and consider using slow-release fertilisers.
• Proper chemical storage and handling: Store chemicals in tightly sealed containers, dispose of excess chemicals according to regulations, and avoid application near water sources.
• Manure management: Regularly test and treat waste, use manure as fertiliser in fields, and properly store waste to prevent runoff.
• Implement erosion control measures: Use techniques like contour ploughing, crop mulching, crop rotation, and installing riparian buffers to reduce runoff and retain soil.

Treat and Reuse Wastewater

Treating and reusing wastewater can help reduce pollution and conserve water resources:

• Primary treatment: This involves mechanical treatment to remove solid substances and preliminary treatments to address physical and mechanical aspects.
• Secondary treatment: This step includes chemical and biological processes to further treat the water. Water at this stage can be used for irrigating crops.
• Tertiary treatment: Advanced physical and chemical processes are applied to make the water suitable for indirect drinking and recharging surface and groundwater bodies.
• Constructed wetlands: These natural systems can be used to treat animal wastes and facilitate their breakdown.
• Anaerobic lagoons: Animal slurries are often treated in these lagoons before disposal or application to grassland.

Minimise Waste and Recycle Water

Minimising waste and recycling treated wastewater can help reduce pollution and conserve resources:

• Waste minimisation: Implement practices to reduce the amount of waste generated on the farm, such as proper storage and handling of chemicals and efficient use of water.
• Wastewater reuse: Treated wastewater can be used for irrigation, reducing the demand for freshwater resources and helping to fertilise agricultural lands.
• Effluent reuse: Treated effluent can be used for cleaning and other non-potable purposes, reducing the overall water consumption on the farm.

Monitor and Maintain the System

Regular monitoring and maintenance are crucial to ensure the effectiveness of the wastewater management system:

• Regular water testing: Conduct periodic tests to determine the presence and levels of pollutants in water sources and treated wastewater.
• System maintenance: Inspect and maintain the wastewater treatment system to ensure it is functioning optimally and address any issues promptly.
• Record-keeping: Keep detailed records of wastewater treatment processes, test results, and maintenance activities for reference and compliance with regulations.

Control livestock access to waterways

Livestock access to waterways can have a detrimental impact on water quality, leading to increased levels of sediment, nutrients, and pathogens. This can also result in the erosion of riparian margins and banks, potentially altering the hydrology and drainage pathways of the site.

To reduce the negative impact of livestock on waterways, farmers can implement several measures:

Fencing and Alternative Water Sources

Fencing can be used to limit or exclude livestock from watercourses, improving water quality. The ideal fencing location is along the outer edge of a grassy strip or a vegetated buffer, allowing for filtration and reducing the risk of flooding or ice damage. Alternative water sources, such as nose pumps or solar/wind pumping systems, can also be provided to reduce the need for livestock to access waterways.

Limited Access Ramps

Limited access ramps allow cattle partial access to watercourses, reducing harm to the habitat while preserving their drinking source. These ramps should be designed with firm footing to prevent bank erosion and fenced to restrict livestock movement.

Stream Crossings

Stream crossings provide livestock with controlled access to pastures on the other side of a stream, minimising the impact on water quality. Well-managed crossings can also help maintain or improve water quality and provide solid footing for livestock.

Filter and Buffer Strips

Filter and buffer strips are densely vegetated land between the surface water and the pasture. They help protect water quality by reducing the runoff of nutrients, bacteria, sediment, and other contaminants. Filter strips, in particular, aid in reducing manure runoff and soil erosion.

Create conservation buffers to catch runoff

Conservation buffers are an effective and cost-efficient management practice that can be used to improve water quality. They are areas or strips of permanent vegetation that can be placed along field borders, and they work to minimise soil erosion by reducing surface runoff.

There are several types of buffer strips, including contour grass strips and wind trap strips, which feature rows of different perennial vegetation. These strips can reduce wind damage to young plants, conserve soil moisture, and minimise soil erosion. Buffer strips can also be used for water control and quality improvement, such as filter strips, grassed waterways, riparian buffer zones, and wetlands. All these practices have the common goal of preventing further degradation of soil and water quality by reducing soil erosion and nutrient loading into surface and groundwater, moderating water temperatures, and preventing water contamination.

Well-designed buffer strips can effectively minimise the movement of soil sediment, nutrients, pesticides, and pathogens through the soil profile and from fields as runoff, thereby improving water quality. They can also improve wildlife habitats and air quality by reducing chemical emissions. To maintain their effectiveness in trapping pollutants, intensive management of conservation buffers is required. For example, sediment trapped by buffers can change the land shape and cause runoff to flow parallel to the buffers, so it is important to periodically remove sediments and re-establish vegetation.

One of the functions of conservation buffers is to trap nutrients such as nitrogen and phosphorus. By periodically harvesting the buffer vegetation, farmers can remove trapped nutrients from the system, preventing their eventual release into the soil and potential movement into water sources. Conservation buffers have been shown to be very effective in facilitating pesticide degradation and reducing pesticide concentrations in subsurface water flow.

Frequently asked questions