Factors influencing contaminant losses to water
Soil type influences nutrient loss from farms and, as part of this year’s National Ploughing Championships, the Teagasc Agricultural Sustainability Support and Advisory Programme (ASSAP) is demonstrating a rainfall simulator to show how rainwater moves through various soil types.
The loss of contaminants such as nutrients, sediment and pesticides to water from agricultural sources is increasingly under the spotlight. Recent EPA reports have highlighted the role farming plays as a source of contaminants impacting water quality. Soil type, weather conditions and land management all influence the type of contaminant lost and the pathway through which it enters the nearby stream or groundwater.
When assessing farms under ASSAP, Teagasc and dairy co-op advisors discuss the diffuse loss of nutrients (phosphorus and nitrate), sediment and pesticides to water with farmers to help improve the understanding of how contaminants leave a field and enter the drainage network.
This year at the National Ploughing Championships the ASSAP display at the Teagasc stand will simulate field, management and weather conditions to show how water interacts with different soils and moves through different pathways to enter water.
Noel Meehan, Teagasc ASSAP Programme Manager tells us more about the rainfall simulator in the short clip below.
The five soil trays are filled with different soil types and when combined with a rainfall simulator provides a visual representation of real time losses of phosphorus, sediment and nitrate.
The five soils are:
- Poorly draining grassland soil
- Freely draining tillage soil
- Poorly draining tillage soil
- Freely draining grassland soil
- High organic matter peat soil
Soils 1, 3 and 5 will show that these soils become saturated quickly and water then moves via the over land flow pathway bringing with it phosphorus and sediment. There is a greater potential for sediment loss on tillage fields where no cover/catch crop is present.
Soils 2 and 4 will show that these soils allow water to move downwards through the soil profile with nitrate lost via the sub surface pathway to groundwater. There is a greater potential for nitrate losses from tillage fields in autumn where no cover/catch crop is present.
For more information on ASSAP, click here
Teagasc at the Ploughing
Over the course of the National Ploughing Championships, some of the key highlights have been featured on Teagasc Daily. Check these out below: