Excessive nitrate or sediment levels can affect local fish populations and increase the cost to treat drinking water. The pollutants also find their way into water bodies downstream like a reservoir or the ocean and create algal blooms or hypoxic or ‘dead zones.’ According to the researchers, the dead zone in the northern Gulf of Mexico is directly correlated with nitrate that comes from the Mississippi River Basin.
They compared different approaches to improving water quality, such as cutting runoff from farms and adding wetlands, then gauged the economic costs of each.
Because most methods rely on voluntary participation by individual farms and are implemented by a patchwork of different agencies, the researchers found that they tend to be less effective.
“Currently, there’s individual management or conservation practices, and those include cover crop, high-precision fertiliser application, reduced tillage, constructed wetlands and ravine tip management...