Water quality has always been a priority for agriculture but in recent years those concerns have escalated because of problems in the Western Lake Erie Basin and the Saginaw Bay. Many have pointed at farming as the primary cause. We in agriculture need to be aware that farming practices do have an impact on water quality, both positive and negative. Nutrient movement off fields is an area where farmers need to take the initiative. There are three key areas where this can be done.
Management practices of concern are those that directly involve nutrient applications. Nutrient rates need to be adjusted to ensure that they are being used by the crop and not running off or leaching through the soil. Timing of application should coincide with the plant needs. Nutrients, especially phosphorus, should be incorporated when spread in the fall unless it is spread on an established cover crop. Nutrients, specifically nitrogen, applied to ensure cover crop growth should be only spread at the rate for crop removal. Steps should be taken to ensure that nutrient loss by volatilization, leaching, and run-off is minimized.
Land Use Practices
Some farms can make changes in land use such as using cover crops or conservation tillage to protect water quality. Incorporating perennial crops, such as energy crops, can protect water quality by ensuring that land close to surface water is not disturbed. These lands are actively farmed but soil disturbance of soil is minimal. Livestock farms can extend their pasture land base or even extend their rotation. Farms may also consider taking land that has a high risk for run-off or those near surface water out of their rotation completely.
Edge of Field
Farmers need to take an accurate inventory of their field margins and look at what is running off. Many fields are tiled and growers need to consider drainage water management and other engineering options that can minimize when and how much water leaves the field. Other practices such as constructed wetlands, buffers, and filter strips along the edge of fields trap nutrient movement. These must be properly installed and maintained. Bioreactors are also being used to remove nutrients from drainage systems.
For more information on these topics please browse the Michigan State University Extension Agriculture site and continue checking the MSU News site as we continue to discuss ways agriculture can have a positive impact on water quality.