Editor's note: The following information was provided by Todd County Soil and Water Conservation District.
Google the word “phosphorus.” What comes up? Fertilizer. Phosphorous only reaches surface waters due to farming and fertilizer, right? No. Let’s dig up the dirt on phosphorous.
Phosphorous is a naturally occurring element in our soils (from phosphate rock). Todd County soils, particularly in the northeast and southeast parts of the county are naturally very high in natural phosphorus — in the forests, in places where no man has disturbed, and where land disturbance has occurred. Phosphorus is found in nearly every organic thing and is a necessary component to life.
What does this mean for water quality?
Generally, phosphorus attaches itself to organic particles. In areas where disturbance takes place either man-made or natural, phosphorus can travel with organic particles by wind or water. The faster water moves across a surface, the more likely phosphorous will reach surface waters such as lakes and streams. Impervious surfaces such a well-manicured lawns, roofs, roads and even vertical surfaces can increase phosphorus run-off.
Phosphorus is transported via urban areas, street drains and in residential and lakeshore cabins at the greatest rates. Farm fields and adding additional fertilizers to fields, lawns, and gardens can contribute.
And then there are the geese — geese scat are total phosphorus bombs. Lakes turn green; wildlife is altered; organics sink; the fill process begins.
Natural processes add phosphorus to water bodies — it’s called eutrophication in which, over thousands of years, lakes fill to transition to bogs, then forests. But let not our actions increase the rate of eutrophication.
What to do? Allow ditch grasses to reach a height of 6-8 inches minimum to trap soil particulates before reaching the water body.
Raise the height of your lawn mower; a nice trim lawn isn’t required to be one inch tall. Vegetation absorbs nutrients and slows runoff.
Change definitions of well landscaped yards. Plant wide natural buffers and shrubs along shores.
Plant rye or oats as a cover after harvest or leave organics/corn stover on the field to prevent soil blow. Grumble but acknowledge the buffer law.
Construct buildings, parking lots, and roads back from lakes, rivers, and streams, vegetate and widen road shoulders. Take soil tests to match fertilizer to the needs of your yard, garden or farm soils. Appreciate wetlands as absorption sponges. Let nature run its course without expedition.